JP4718943B2 - Distribution system load distribution estimation method, apparatus and program, and voltage estimation method, apparatus and program - Google Patents

Description

  The present invention relates to a load distribution estimation method, apparatus, and program for a distribution system, and a voltage estimation method, apparatus, and program. More specifically, the present invention relates to a load distribution estimation method and the like, a voltage estimation method, and the like of a distribution system in which consumers and distributed power sources are interconnected.

  The voltage calculation method in the conventional distribution system uses the information such as substation transmission voltage, transmission current, contracted power of high and low voltage consumers and power consumption obtained from the system for voltage calculation of distribution lines. The voltage over the entire distribution line is calculated by calculation specialized for descent (Non-Patent Document 1).

  This method is based on the assumption that current flows only in the forward power flow direction from the substation toward the load side at the end of the distribution line.The voltage drop amount is calculated for each section divided by the pole switch. Thus, the voltage at each point is calculated by the accumulation.

  In addition, the load distribution information for each section is required to calculate the voltage drop in each section, but since the instantaneous load of high and low voltage consumers is not measured, it is roughly calculated from the contract power and power consumption. Load distribution calculation is performed, and a load distribution table is created in advance and used for voltage calculation.

Taiji Sekine: Power Distribution Technology General Manual, Ohmsha, 1991.

  However, in the voltage calculation method of Non-Patent Document 1, since the voltage of the entire distribution system is estimated based on the measurement information at one end of the distribution system installed at the substation transmission, it goes to the end of the distribution line. The accuracy of estimation is low. Furthermore, the conventional method based on load apportionment based on contract power and power consumption is based on the assumption that the load distribution is always constant, and does not take into account the time change or seasonal change of the load distribution. In systems with large fluctuations in load distribution, the accuracy of voltage estimation is low.

  Further, in recent years, there is a concern about the influence on the operation control of the power distribution system while the connection of the distributed power source to the power distribution system is rapidly progressing. With regard to voltage management in particular, operation control has become difficult even at present due to the influence of customer's phase adjusting equipment and the thickening of distribution lines, and the development of a new voltage management technique is required.

  On the other hand, with the advancement of technologies such as semiconductors and sensing, the distribution system facilities have become more sophisticated, and the introduction of switches with sensors has been promoted for the purpose of determining the fault section of the distribution system and managing the state. Has been.

  In addition, a shift to a new power supply system (hereinafter referred to as a demand area system) for controlling a distribution system in which a large number of distributed power sources are connected is expected. As for voltage management of demand area systems, in addition to being able to perform highly accurate voltage management, due to capital investment problems, etc. It is also necessary to respond to the situation peculiar to the demand point system where the voltage management accuracy is gradually increased by gradually introducing the power supply based on the power supply introduction situation.

  Here, the problem of voltage deviation from the upper limit is regarded as the most important problem when the distributed power supply system is expanded to the distribution lines. There is a possibility of deviating from the voltage management range with a slight interconnection amount with respect to the capacity. Even when a deviation of the voltage management width occurs, it is difficult to specify the cause and the deviation section from the measurement data of the substation. In the voltage calculation method of Non-Patent Document 1, the distributed power supply is connected. The deviation of voltage due to the system cannot be known. Furthermore, the conventional voltage calculation method is based on the premise that current flows only in the forward power flow direction from the substation toward the terminal side of the distribution line, and does not consider the reverse power flow from the distributed power source. Therefore, it is necessary to deal with the distribution system voltage calculation when determining whether or not the interconnection of the distributed power supply is possible, and it becomes necessary to deal with the calculation separately from the conventional voltage calculation, and the correspondence becomes difficult as the number of interconnections increases. It is assumed that

  Because of these problems, it is necessary to improve the accuracy of distribution line voltage management, to effectively use facilities and equipment that have been introduced, and to investigate voltage management methods that take into account reverse power flow from distributed power sources.

  Therefore, the present invention effectively estimates the load distribution and voltage of the distribution system by effectively utilizing the equipment and equipment that are being introduced, and also accurately estimates the load distribution and voltage even when the distributed power source is connected. An object is to provide a load distribution estimation method and a voltage estimation method of a possible distribution system.

In order to achieve such an object, a load distribution estimation method for a distribution system according to claim 1 is a virtual centralized load on a plurality of nodes in a distribution system section. A step (S1) for creating a power flow calculating circuit, a step (S2) for creating a distribution pattern of a plurality of virtual concentrated loads having different receiving end voltages in the distribution system section, and a power flow represented by Equation 1 and Equation 2 For the transmission end active power Ps and the transmission end reactive power Qs in the calculation circuit, Ploss and Qloss are set to zero as initial conditions, and the total PL (load) and total load load (reactive power) QL are calculated (S3 -1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The total load PL (active power) and the total load QL (reactive power) in the distribution system section are distributed to the virtual centralized load in the plurality of nodes according to the distribution pattern of the virtual centralized load to calculate the load for each of the plurality of nodes ( S3-2)
Tidal current calculation is performed using the load of each node, and line loss (active power) Ploss and line loss (reactive power) Qloss of distribution lines in the distribution system section are calculated (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged (S3). With -5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
The new load total PL 'and the load sum QL (disabled power)' electrical distribution for each distribution pattern of virtual centralized load by performing the process anew from S3-2 to S3-4 using the (active power) A step (S3) of calculating a calculated power receiving end voltage of the system section and a step of selecting a distribution pattern of the virtual concentrated load having the smallest difference between the actually measured power receiving end voltage and the calculated power receiving end voltage are provided.

According to another aspect of the present invention, there is provided a distribution distribution load estimation apparatus for a distribution system, wherein a distribution system load distributed and distributed in a distribution system section is represented by a virtual concentrated load at a plurality of nodes in the distribution system section. , Means for creating a distribution pattern of a plurality of virtual concentrated loads having different receiving end voltages in the distribution system section, and the transmitting end active power Ps and the transmitting end in the power flow calculation circuit expressed by Equation 1 and Equation 2 With respect to reactive power Qs, Ploss and Qloss are set to zero as initial conditions, and total PL of load (active power) and total QL of load (reactive power) are calculated (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The total load PL (active power) and the total load QL (reactive power) in the distribution system section are distributed to the virtual centralized load in the plurality of nodes according to the distribution pattern of the virtual centralized load to calculate the load for each of the plurality of nodes ( S3-2)
Tidal current calculation is performed using the load of each node, and line loss (active power) Ploss and line loss (reactive power) Qloss of distribution lines in the distribution system section are calculated (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged (S3). With -5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
The new load total PL 'and the load sum QL (disabled power)' electrical distribution for each distribution pattern of virtual centralized load by performing the process anew from S3-2 to S3-4 using the (active power) Means for calculating the calculated power receiving end voltage of the system section and means for selecting the distribution pattern of the virtual concentrated load having the smallest difference between the actually measured power receiving end voltage and the calculated power receiving end voltage are provided.

Furthermore, the distribution distribution load estimation program according to claim 9 is a virtual centralized load on a plurality of nodes in the distribution system section, wherein the computer distributes the distribution system load distributed at least in the distribution system section. Means for generating a power flow calculating circuit, means for generating a distribution pattern of a plurality of virtual concentrated loads having different power receiving end voltages in the distribution system section, and power transmitting end active power Ps in the power flow calculating circuit expressed by Formula 1 and Formula 2. And the total PL of the load (active power) and the total QL of the load (reactive power) are calculated with Ploss and Qloss set to zero as initial conditions for the transmission end reactive power Qs (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The total load PL (active power) and the total load QL (reactive power) in the distribution system section are distributed to the virtual centralized load in the plurality of nodes according to the distribution pattern of the virtual centralized load to calculate the load for each of the plurality of nodes ( S3-2)
Tidal current calculation is performed using the load of each node, and line loss (active power) Ploss and line loss (reactive power) Qloss of distribution lines in the distribution system section are calculated (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged (S3). With -5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
The new total load PL 'and the load sum QL (disabled power)' electrical distribution for each distribution pattern of virtual centralized load by performing the process anew from S3-2 to S3-4 using the (active power) It is made to function as means for calculating the calculated power receiving end voltage of the system section and means for selecting the distribution pattern of the virtual concentrated load having the smallest difference between the actually measured power receiving end voltage and the calculated power receiving end voltage.

  Therefore, according to the load distribution estimation method, apparatus and program of this distribution system, the load distribution of the distribution system is estimated based not only on the actual measurement value at the transmission end but also the actual measurement value at the reception end. The load distribution of the distribution system reflecting the voltages at the transmission end and the reception end is estimated. In addition, the distribution distribution load is estimated by performing a power flow calculation by collecting the distribution system loads that are actually distributed and distributed in the distribution system section within a certain range and virtually expressing them as multiple concentrated loads. Is done. Further, a plurality of virtual concentrated load distribution patterns are created so that the receiving end voltages in the distribution system section are different, and the calculated receiving end voltage closest to the actually measured receiving end voltage is selected from the plurality of virtual concentrated load distribution patterns. Since the distribution pattern is selected, the load distribution of the distribution system that is close to the actual distribution of the load of the distribution system is estimated, and even if the distribution of the load of the distribution system changes, it is adjusted to the change The load distribution is estimated.

According to a second aspect of the present invention, there is provided a load distribution estimating method for a distribution system, wherein a distribution system load distributed and distributed in a distribution system section is represented by a virtual concentrated load at a plurality of nodes in the distribution system section. (S1) , a step (S2) of creating a distribution pattern of a plurality of virtual concentrated loads having different receiving end voltages in the distribution system section, and a power transmission end in the power flow calculation circuit expressed by Equation 1 and Equation 2 With regard to the active power Ps and the transmission end reactive power Qs, Ploss and Qloss are set to zero as initial conditions, and a total PL of loads (active power) and a total QL of loads (reactive power) are calculated (S3-1).
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The total load PL (active power) and the total load QL (reactive power) in the distribution system section are distributed to the virtual centralized load in the plurality of nodes according to the distribution pattern of the virtual centralized load to calculate the load for each of the plurality of nodes ( S3-2)
Tidal current calculation is performed using the load of each node, and line loss (active power) Ploss and line loss (reactive power) Qloss of distribution lines in the distribution system section are calculated (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged (S3). With -5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
The new load total PL 'and the load sum QL (disabled power)' electrical distribution for each distribution pattern of virtual centralized load by performing the process anew from S3-2 to S3-4 using the (active power) A step (S3) of calculating the calculated power receiving end voltage of the system section, and the measured power receiving end voltage and the calculated power receiving end voltage for each distribution pattern of the virtual concentrated load are arranged in descending order of the value, and calculation before and after the actual power receiving end voltage. A step of selecting a distribution pattern of the virtual concentrated load of the receiving end voltage, and a step of estimating the load distribution in the distribution system section by linearly interpolating the load distribution of the two selected distribution patterns of the virtual concentrated load. ing.

The distribution distribution load estimation device according to claim 6 creates a power flow calculation circuit by expressing distribution distribution loads distributed and distributed in the distribution system section as virtual concentrated loads at a plurality of nodes in the distribution system section. Means for generating a distribution pattern of a plurality of virtual concentrated loads having different receiving end voltages in the distribution system section, and transmitting end active power Ps and transmitting end reactive power in the power flow calculation circuit expressed by Equation 1 and Equation 2. With respect to Qs, Ploss and Qloss are set to zero as an initial condition, and the total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section are calculated (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The total load PL (active power) and the total load QL (reactive power) in the distribution system section are distributed to the virtual centralized load in the plurality of nodes according to the distribution pattern of the virtual centralized load to calculate the load for each of the plurality of nodes ( S3-2)
Tidal current calculation is performed using the load of each node, and line loss (active power) Ploss and line loss (reactive power) Qloss of distribution lines in the distribution system section are calculated (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged (S3). With -5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
The new load total PL 'and the load sum QL (disabled power)' electrical distribution for each distribution pattern of virtual centralized load by performing the process anew from S3-2 to S3-4 using the (active power) The means for calculating the calculated receiving end voltage of the system section, the measured receiving end voltage and the calculated receiving end voltage for each distribution pattern of the virtual concentrated load are arranged in descending order of the value, and the calculated receiving end voltage before and after the actually measured receiving end voltage. And a means for linearly interpolating the load distributions of the two selected virtual concentrated load distribution patterns to estimate the load distribution in the distribution system section.

The distribution system load distribution estimation program according to claim 10, wherein the computer represents at least a distribution system load distributed and distributed in the distribution system section as a virtual concentrated load in a plurality of nodes in the distribution system section. Means for creating a power flow calculation circuit, means for creating a distribution pattern of a plurality of virtual concentrated loads having different receiving end voltages in the distribution system section, power transmission end active power Ps and power transmission in the power flow calculation circuit expressed by Formulas 1 and 2 With respect to the end reactive power Qs, Ploss and Qloss are set to zero as the initial condition, and the total PL of the load (active power) in the distribution system section and the total QL of the load (reactive power) are calculated (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The total load PL (active power) and the total load QL (reactive power) in the distribution system section are distributed to the virtual centralized load in the plurality of nodes according to the distribution pattern of the virtual centralized load to calculate the load for each of the plurality of nodes ( S3-2)
Tidal current calculation is performed using the load of each node, and line loss (active power) Ploss and line loss (reactive power) Qloss of distribution lines in the distribution system section are calculated (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged (S3). With -5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
The new load total PL 'and the load sum QL (disabled power)' electrical distribution for each distribution pattern of virtual centralized load by performing the process anew from S3-2 to S3-4 using the (active power) The means for calculating the calculated receiving end voltage of the system section, the measured receiving end voltage and the calculated receiving end voltage for each virtual concentrated load distribution pattern are arranged in order of increasing or decreasing value, and the calculated receiving end voltage before and after the actual receiving end voltage A function for selecting a distribution pattern of virtual concentrated loads and a function for estimating a load distribution in a distribution system section by linearly interpolating the load distributions of the two selected distribution patterns of virtual concentrated loads are used.

  Therefore, according to the load distribution estimation method, apparatus and program of this distribution system, the load distribution of the distribution system is estimated based not only on the actual measurement value at the transmission end but also the actual measurement value at the reception end. The load distribution of the distribution system reflecting the voltages at the transmission end and the reception end is estimated. In addition, the distribution distribution load is estimated by performing a power flow calculation by collecting the distribution system loads that are actually distributed and distributed in the distribution system section within a certain range and virtually expressing them as multiple concentrated loads. Is done. Further, a plurality of virtual concentrated load distribution patterns are created so that the receiving end voltages in the distribution system section are different, and a calculation receiving end voltage close to the actually measured receiving end voltage is selected from the plurality of virtual concentrated load distribution patterns. Since the distribution distribution of the distribution system is estimated by selecting the distribution pattern of the two virtual concentrated loads and performing linear interpolation, the load distribution of the distribution system closer to the actual distribution status of the distribution system is estimated. At the same time, when the load distribution of the power distribution system changes, the load distribution according to the change is estimated.

According to a third aspect of the present invention, there is provided a voltage estimation method for a distribution system, wherein a distribution current distributed in a distribution system section is represented by a virtual concentrated load at a plurality of nodes in the distribution system section, and a power flow calculation circuit is provided. Step (S1) for creating, step (S2) for creating a distribution pattern of a plurality of virtual concentrated loads with different receiving end voltages in the distribution system section, and the power transmission end effective in the power flow calculation circuit expressed by Equation 1 and Equation 2 With respect to power Ps and transmission end reactive power Qs, Ploss and Qloss are set to zero as initial conditions to calculate total PL (load power) and total load load (reactive power) QL in the distribution system section (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The total load PL (active power) and the total load QL (reactive power) in the distribution system section are distributed to the virtual centralized load in the plurality of nodes according to the distribution pattern of the virtual centralized load to calculate the load for each of the plurality of nodes ( S3-2)
Tidal current calculation is performed using the load of each node, and line loss (active power) Ploss and line loss (reactive power) Qloss of distribution lines in the distribution system section are calculated (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged (S3). With -5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
The new load total PL 'and the load sum QL (disabled power)' electrical distribution for each distribution pattern of virtual centralized load by performing the process anew from S3-2 to S3-4 using the (active power) A step (S3) of calculating the calculated power receiving end voltage of the system section, a step of selecting a distribution pattern of the virtual concentrated load having the smallest difference between the measured power receiving end voltage and the calculated power receiving end voltage, and the distribution of the selected virtual concentrated load And a step of estimating a voltage at each point in the distribution system section by performing a tidal current calculation using a pattern.

The voltage estimation device for a distribution system according to claim 7 creates a power flow calculation circuit by expressing the distribution system load distributed and distributed in the distribution system section as virtual concentrated loads at a plurality of nodes in the distribution system section. Means, means for creating a distribution pattern of a plurality of virtual concentrated loads having different receiving end voltages in the distribution system section, and transmitting end active power Ps and transmitting end reactive power Qs in the power flow calculation circuit expressed by Equation 1 and Equation 2. Assuming that Ploss and Qloss are zero as the initial condition, the total PL of the load (active power) in the distribution system section and the total QL of the load (reactive power) are calculated (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The total load PL (active power) and the total load QL (reactive power) in the distribution system section are distributed to the virtual centralized load in the plurality of nodes according to the distribution pattern of the virtual centralized load to calculate the load for each of the plurality of nodes ( S3-2)
Tidal current calculation is performed using the load of each node, and line loss (active power) Ploss and line loss (reactive power) Qloss of distribution lines in the distribution system section are calculated (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged (S3). With -5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
The new load total PL 'and the load sum QL (disabled power)' electrical distribution for each distribution pattern of virtual centralized load by performing the process anew from S3-2 to S3-4 using the (active power) Using the means for calculating the calculated receiving end voltage of the system section, the means for selecting the distribution pattern of the virtual concentrated load with the smallest difference between the measured receiving end voltage and the calculated receiving end voltage, and the selected virtual concentrated load distribution pattern And a means for estimating the voltage at each point in the distribution system section by performing the power flow calculation.

12. The distribution system voltage estimation program according to claim 11, wherein the computer represents at least a distribution system load distributed and distributed in the distribution system section as virtual concentrated loads in a plurality of nodes in the distribution system section. Means for creating a calculation circuit, means for creating a distribution pattern of a plurality of virtual concentrated loads having different receiving end voltages in the distribution system section, and transmitting end active power Ps and transmitting end in the power flow calculating circuit expressed by Equations 1 and 2 For reactive power Qs, Ploss and Qloss are set to zero as initial conditions, and the total PL of loads (active power) and the total QL of loads (reactive power) are calculated (S3-1).
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The total load PL (active power) and the total load QL (reactive power) in the distribution system section are distributed to the virtual centralized load in the plurality of nodes according to the distribution pattern of the virtual centralized load to calculate the load for each of the plurality of nodes ( S3-2)
Tidal current calculation is performed using the load of each node, and line loss (active power) Ploss and line loss (reactive power) Qloss of distribution lines in the distribution system section are calculated (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged (S3). With -5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
The new load total PL 'and the load sum QL (disabled power)' electrical distribution for each distribution pattern of virtual centralized load by performing the process anew from S3-2 to S3-4 using the (active power) Means for calculating the calculated receiving end voltage of the system section, means for selecting the distribution pattern of the virtual concentrated load having the smallest difference between the measured receiving end voltage and the calculated receiving end voltage, and the tidal current using the selected virtual concentrated load distribution pattern It is made to function as a means to estimate the voltage in each point in a distribution system section by calculating.

  Therefore, according to the voltage estimation method, apparatus, and program of this distribution system, the load distribution of the distribution system is estimated based on not only the actual measurement value at the transmission end but also the actual measurement value at the reception end, and then at each point in the distribution system section. Since the voltage is estimated, the voltage at each point in the distribution system section reflecting the voltages at the transmission end and the reception end of the distribution system is estimated. In addition, the distribution distribution system load distribution is estimated by performing a power flow calculation by collecting a large number of distribution system loads that are actually distributed and distributed in a certain range and virtually expressing them as multiple concentrated loads. After that, the voltage at each point in the distribution system section is estimated. Further, a plurality of virtual concentrated load distribution patterns are created so that the receiving end voltages in the distribution system section are different, and the calculated receiving end voltage closest to the actually measured receiving end voltage is selected from the plurality of virtual concentrated load distribution patterns. Since the distribution pattern is selected and the load distribution of the distribution system is estimated, the voltage at each point in the distribution system section is estimated, so the distribution system section reflects the actual load distribution in the distribution system section. In addition, the voltage at each point in the distribution system section is estimated after estimating the load distribution according to the change even when the distribution state of the distribution system load changes.

Further, the voltage estimation method for the distribution system according to claim 4 is a power flow calculation circuit in which the distribution system load distributed and distributed in the distribution system section is represented by virtual concentrated loads at a plurality of nodes in the distribution system section. Step (S1) for creating, step (S2) for creating a distribution pattern of a plurality of virtual concentrated loads having different receiving end voltages in the distribution system section, and the power transmission end effective in the power flow calculation circuit expressed by Equation 1 and Equation 2 With respect to power Ps and transmission end reactive power Qs, Ploss and Qloss are set to zero as initial conditions, and total PL (load power) and total QL of load (reactive power) in the distribution system section are calculated (S3-1).
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The total load PL (active power) and the total load QL (reactive power) in the distribution system section are distributed to the virtual centralized load in the plurality of nodes according to the distribution pattern of the virtual centralized load to calculate the load for each of the plurality of nodes ( S3-2)
Tidal current calculation is performed using the load of each node, and line loss (active power) Ploss and line loss (reactive power) Qloss of distribution lines in the distribution system section are calculated (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged (S3). With -5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
The new load total PL 'and the load sum QL (disabled power)' electrical distribution for each distribution pattern of virtual centralized load by performing the process anew from S3-2 to S3-4 using the (active power) A step (S3) of calculating the calculated power receiving end voltage of the system section, and the measured power receiving end voltage and the calculated power receiving end voltage for each distribution pattern of the virtual concentrated load are arranged in descending order of the value, and calculation before and after the actual power receiving end voltage. The process of selecting the distribution pattern of the virtual concentrated load of the receiving end voltage, the process of estimating the load distribution in the distribution system section by linearly interpolating the load distribution of the distribution pattern of the two selected virtual concentrated loads, and the linear interpolation A step of estimating a voltage at each point in the distribution system section by performing a power flow calculation using the load distribution obtained in the above.

The voltage estimation device for a distribution system according to claim 8 creates a power flow calculation circuit by representing distribution system loads distributed and distributed in the distribution system section as virtual concentrated loads at a plurality of nodes in the distribution system section. Means for generating a distribution pattern of a plurality of virtual concentrated loads having different receiving end voltages in the distribution system section, and transmitting end active power Ps and transmitting end reactive power Qs in the power flow calculation circuit expressed by Equation 1 and Equation 2. Assuming that Ploss and Qloss are zero as the initial condition, the total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section are calculated (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The total load PL (active power) and the total load QL (reactive power) in the distribution system section are distributed to the virtual centralized load in the plurality of nodes according to the distribution pattern of the virtual centralized load to calculate the load for each of the plurality of nodes ( S3-2)
Tidal current calculation is performed using the load of each node, and line loss (active power) Ploss and line loss (reactive power) Qloss of distribution lines in the distribution system section are calculated (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged (S3). With -5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
The new load total PL 'and the load sum QL (disabled power)' electrical distribution for each distribution pattern of virtual centralized load by performing the process anew from S3-2 to S3-4 using the (active power) The means for calculating the calculated receiving end voltage of the system section, the measured receiving end voltage and the calculated receiving end voltage for each distribution pattern of the virtual concentrated load are arranged in order of increasing or decreasing value, and the calculated receiving end voltage before and after the actual receiving end voltage. The means for selecting the distribution pattern of the virtual concentrated load of the two, the means for estimating the load distribution in the distribution system section by linearly interpolating the load distribution of the distribution pattern of the two selected virtual concentrated loads, and obtained by linear interpolation Means for estimating the voltage at each point in the distribution system section by performing tidal current calculation using the load distribution.

13. The distribution system voltage estimation program according to claim 12, wherein the computer represents at least a distribution system load distributed and distributed in the distribution system section as a virtual concentrated load at a plurality of nodes in the distribution system section. Means for creating a calculation circuit, means for creating a distribution pattern of a plurality of virtual concentrated loads having different receiving end voltages in a distribution system section, and power transmission end active power Ps and power transmission end in the power flow calculation circuit expressed by Equation 1 and Equation 2 With respect to reactive power Qs, Ploss and Qloss are set to zero as initial conditions, and total PL of load (active power) and total QL of load (reactive power) are calculated (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The total load PL (active power) and the total load QL (reactive power) in the distribution system section are distributed to the virtual centralized load in the plurality of nodes according to the distribution pattern of the virtual centralized load to calculate the load for each of the plurality of nodes ( S3-2)
Tidal current calculation is performed using the load of each node, and line loss (active power) Ploss and line loss (reactive power) Qloss of distribution lines in the distribution system section are calculated (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged (S3). With -5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
The new load total PL 'and the load sum QL (disabled power)' electrical distribution for each distribution pattern of virtual centralized load by performing the process anew from S3-2 to S3-4 using the (active power) The means for calculating the calculated receiving end voltage of the system section, the measured receiving end voltage and the calculated receiving end voltage for each virtual concentrated load distribution pattern are arranged in order of increasing or decreasing value, and the calculated receiving end voltage before and after the actual receiving end voltage Means to select distribution pattern of virtual concentrated load, means to estimate load distribution in distribution system section by linear interpolation of load distribution of two selected virtual concentrated load distribution patterns, load distribution obtained by linear interpolation It is made to function as a means to estimate the voltage in each point in a distribution system section by performing tidal current calculation using it.

  Therefore, according to the voltage estimation method, apparatus, and program of this distribution system, the load distribution of the distribution system is estimated based on not only the actual measurement value at the transmission end but also the actual measurement value at the reception end, and then at each point in the distribution system section. Since the voltage is estimated, the voltage at each point in the distribution system section reflecting the voltages at the transmission end and the reception end of the distribution system is estimated. In addition, the distribution distribution system load distribution is estimated by performing a power flow calculation by collecting a large number of distribution system loads that are actually distributed and distributed in a certain range and virtually expressing them as multiple concentrated loads. After that, the voltage at each point in the distribution system section is estimated. Further, a plurality of virtual concentrated load distribution patterns are created so that the receiving end voltages in the distribution system section are different, and a calculation receiving end voltage close to the actually measured receiving end voltage is selected from the plurality of virtual concentrated load distribution patterns. Since the distribution distribution of one virtual concentrated load is selected and linear interpolation is performed to estimate the distribution of the distribution system, the voltage at each point in the distribution system section is estimated, so the actual load of the distribution system The voltage at each point in the distribution system section that better reflects the distribution status of the distribution system is estimated, and even if the distribution status of the load on the distribution system changes, the load distribution according to the change is estimated and the distribution system section The voltage at each point is estimated.

  As described above, according to the load distribution estimation method, apparatus and program of the distribution system of the present invention, the load distribution of the distribution system reflecting the voltages at the transmission end and the reception end of the distribution system is estimated. It is possible to improve the estimation accuracy of the load distribution. In addition, distribution system loads distributed in large numbers are virtually represented by a plurality of concentrated loads to estimate distribution distribution load distribution, so it is possible to easily estimate distribution distribution load distribution. . Furthermore, by selecting a distribution pattern from a plurality of virtual concentrated load distribution patterns or linearly interpolating the two distribution patterns, the distribution distribution load distribution that is close to the actual distribution distribution distribution distribution distribution is estimated. Since the load distribution is estimated in accordance with the change of the actual load distribution status of the distribution system, it is possible to improve the estimation accuracy of the load distribution of the distribution system.

  Further, according to the voltage estimation method, apparatus and program of the distribution system of the present invention, the voltage at each point in the distribution system section reflecting the voltage at the transmission end and the reception end of the distribution system is estimated. It is possible to improve the estimation accuracy of the voltage at each point. In addition, the distribution system load distributed in large numbers is virtually represented by multiple concentrated loads, and the load distribution of the distribution system is estimated, and then the voltage at each point in the distribution system section is estimated. It is possible to easily estimate the voltage at each point in the system section. In addition, the voltage at each point in the distribution system section reflects the actual load distribution status of the distribution system by selecting a distribution pattern from the distribution patterns of multiple virtual concentrated loads or linearly interpolating the two distribution patterns. Therefore, it is possible to improve voltage estimation accuracy at each point in the distribution system section. Furthermore, since the voltage at each point in the distribution system section is estimated according to the change in the actual load distribution status of the distribution system, for example, the load distribution status changes during the day, or the customer and the distribution It is possible to estimate the voltage at each point in the distribution system section with high accuracy even when the interconnection state of the type power source changes.

  Hereinafter, the configuration of the present invention will be described in detail based on the best mode shown in the drawings.

  1 to 5 show an example of an embodiment of a load distribution and voltage estimation method and apparatus of a distribution system according to the present invention. In addition, in this embodiment, as shown in FIG. 2, as a power distribution system, measuring devices 5A, 5B, 5C, and 5D (hereinafter referred to as measuring devices 5A to 5D) are placed on a distribution line 4 connected to the transformer 3. Is taken as an example.

  Measuring instrument 5A-5D is a division switch with a sensor, for example. The sensor-equipped sorting switch is a sorting switch capable of measuring data such as voltage, active power, and reactive power of the distribution line 4 in addition to the role as a normal sorting switch. In addition, measuring instrument 5A-5D is not restricted to this, The voltage, active power, and reactive power of the distribution line 4 can be measured and those measured data can be displayed or provided to an external device. Any device may be used.

  Further, in the present embodiment, a case where the load distribution and the voltage are estimated for the distribution system section 2 surrounded by the measuring instruments 5B and 5C in FIG. 2 will be described as an example. In addition, although the section length of the distribution system section 2 which is an installation space | interval of the measuring instruments 5B and 5C can consider about 5 km, for example, it is not restricted to this, It may be longer or shorter than this.

  The distribution distribution load and voltage estimation device according to the present invention includes a circuit setting means for creating a power flow calculation circuit by representing a distribution system load distributed and distributed in a distribution system section as a plurality of virtual concentrated loads, Distribution section of the distribution system by calculating the power flow for each virtual concentrated load distribution pattern using the virtual power distribution pattern setting means that creates a distribution pattern of multiple virtual power loads with different receiving end voltages in the power system section and the power flow calculation circuit A virtual concentrated load calculating means for calculating the calculated receiving end voltage, a selecting means for selecting a distribution pattern of the virtual concentrated load having the smallest difference between the measured receiving end voltage and the calculated receiving end voltage, and the estimated load distribution. It is composed of voltage estimation means for estimating the voltage at each point in the distribution system section by performing power flow calculation. Here, the selection unit arranges the calculated power receiving end voltage and the calculated power receiving end voltage for each virtual concentrated load distribution pattern in order of increasing or decreasing value, and the distribution of the virtual concentrated load of the calculated power receiving end voltage before and after the measured power receiving end voltage. A pattern may be selected. In this case, the load distribution and voltage estimation device of the distribution system further linearly interpolates the load distribution of the distribution patterns of the two selected virtual concentrated loads in the distribution system section. Load distribution calculating means for estimating the load distribution.

  The load distribution and voltage estimation method of the power distribution system according to the present invention is distributed in the power distribution system section 2 surrounded by the power transmission end measuring instrument 5B and the power receiving end measuring instrument 5C, as shown in the flowchart of FIG. The power distribution calculation load 6 is generated by expressing the distributed distribution system load as a plurality of virtual concentrated loads (S1), and a distribution pattern of a plurality of virtual concentrated loads having different receiving end voltages in the distribution system section 2 is generated. (S2) The power flow calculation circuit 6 is used to calculate the power flow for each virtual concentrated load distribution pattern to calculate the calculated power receiving end voltage of the distribution system section 2 (S3), and the measured power receiving end voltage Vr and the virtual concentrated load Arrange the calculated receiving end voltage for each distribution pattern in order of increasing or decreasing value and select the distribution pattern of the virtual concentrated load of the calculated receiving end voltage before and after the actually measured receiving end voltage Vr (S4), and select the two selected virtual concentrated loads Distribution of The load distribution in the distribution system section 2 is estimated by linearly interpolating the load distribution in the distribution system (S5), and the power flow is calculated using the load distribution obtained by the linear interpolation, so that the various locations in the distribution system section 2 are calculated. The voltage at the point is estimated (S6).

  The load distribution estimation method and voltage estimation method of the present invention will be described below with reference to the flowchart shown in FIG.

(1) Creation of tidal current calculation circuit for virtual concentrated load distribution estimation (S1)

  In applying the estimation method of the present invention, first, as shown in FIG. 3, a power flow calculation circuit 6 for estimating the virtual concentrated load distribution in the distribution system section 2 is created (S1).

  The estimation method of the present invention treats a voltage by virtually treating a distribution system load distributed in a large number in the distribution system section 2 as a plurality of concentrated loads (hereinafter referred to as virtual concentrated loads). presume.

  In this embodiment, it is assumed that each of the five nodes L1, L2, L3, L4, and L5 (hereinafter referred to as nodes L1 to L5) has a virtual concentrated load in the distribution system section 2. Further, an end point on the measuring instrument 5B side at the power transmission end is set as a reference node L0, and an end point on the measuring instrument 5C side at the power receiving end is set as a node L6.

  Here, it is assumed that the node L1 is closest to the measuring instrument 5C side of the measuring instrument 5B, and the node L5 is closest to the measuring instrument 5B side of the measuring instrument 5C. The section from the nodes L1 to L5 and the distribution system section 2 are treated as the same.

  Further, as measured values, the transmission end voltage Vs, the transmission end active power Ps, and the transmission end reactive power Qs are measured by the measuring instrument 5B, and the receiving end voltage Vr, the receiving end effective power Pr, and the receiving end reactive power Qr are respectively measured by the measuring instrument 5C. It has gained.

  Here, it is assumed that the node L0 is in the immediate vicinity of the measuring instrument 5B opposite to the measuring instrument 5C, and the voltage of the node L0 is equal to the power transmission end voltage Vs in the measuring instrument 5B. Further, it is assumed that the node L6 is in the immediate vicinity of the measuring instrument 5C on the side opposite to the measuring instrument 5B, and the voltage of the node L6 is equal to the voltage of the measuring instrument 5C. Therefore, regarding the measured value, the voltage at the node L6 is assumed to be equal to the power receiving end voltage Vr in the measuring instrument 5C.

  Furthermore, it is assumed that the line impedance Z of the entire distribution system section 2 represented by (Equation 1) is also known based on the type, diameter, and the like of the distribution line 4.

  Z = R + jX (Expression 1)

  Here, Z: line impedance of the entire distribution system section 2 [Ω], R: equivalent resistance of the distribution system section 2 [Ω], j: imaginary unit, X: equivalent reactance of the distribution system section 2 [Ω].

  In addition, the number of nodes on the power distribution system section 2 should just be two or more, and there is no upper limit in particular in the number of nodes. However, in general, the larger the number of nodes, that is, the greater the number of virtual concentrated loads, the higher the estimation accuracy and the more complicated the calculation becomes. Therefore, taking into account the required estimation accuracy and the estimated work amount, etc. The operator sets an appropriate number of nodes.

  Further, a section surrounded by nodes L1 and L2 is surrounded by branch B1, a section surrounded by nodes L2 and L3 is surrounded by branch B2, a section surrounded by nodes L3 and L4 is surrounded by branch B3, and nodes L4 and L5. The section is referred to as branch B4 (hereinafter referred to as branches B1 to B4).

  Further, the section length from the nodes L1 to L5 is D, and the section lengths of the branches B1 to B4 are d1, d2, d3, and d4, respectively (hereinafter referred to as branch section lengths d1 to d4). There are no particular restrictions on the branch section lengths d1 to d4, which are intervals between nodes, and any interval may be used for each node. Preferably, the entire distribution system section is equally divided, and nodes are set at the intermediate points of the equally divided sections. Specifically, in FIG. 3, the distribution system section 2 is divided into three equal parts, and nodes L2 to L4 are set at the intermediate points of the three divided sections (in this case also, the nodes L1 and L5 are measuring instruments). It is premised that it is set in the immediate vicinity of).

  Here, using (Equation 2), the line impedance Z of the entire distribution system section 2 is distributed based on the composition ratio of the branch section lengths d1 to d4 of the branches B1 to B4 with respect to the section length D of the distribution system section 2. To set the line impedance for each of the branches B1 to B4.

  Ri + jXi = di / D * (R + jX) (Expression 2)

  Where subscript i: branch number (1-4), Ri + jXi: line impedance [Ω] of branch Bi (Ri: equivalent resistance of branch Bi, j: imaginary unit, Xi: equivalent reactance of branch Bi), di: branch Bi section length [m], D: section length [m] of distribution system section 2, R + jX: line impedance [Ω] of entire distribution system section 2 (R: equivalent resistance of distribution system section 2, j: imaginary unit, X: equivalent reactance of distribution system section 2).

  Further, when the line impedance changes in the middle of the distribution system section 2, the distribution is similarly performed in proportion to the line length. For example, nodes L2 to L4 are set at the intermediate points of the section obtained by dividing the distribution system section 2 into three equal parts, and the impedance from the node L1 to a point of one third of the section length D is Ra + jXa. When the impedance up to L5 is Rb + jXb, it is distributed using (Equation 2-1) to (Equation 2-4).

  RB1 + jXB1 = 1/2 × (Ra + jXa) (Equation 2-1)

  Here, RB1 + jXB1: Line impedance [Ω] of branch B1.

  RB2 + jXB2 = 1/2 × (Ra + jXa) + 1/4 × (Rb + jXb) (Equation 2-2)

  Here, RB2 + jXB2: line impedance [Ω] of the branch B2.

  RB3 + jXB3 = 1/2 × (Rb + jXb) (Equation 2-3)

  Here, RB3 + jXB3: line impedance [Ω] of the branch B3.

RB4 + jXB4 = 1/4 × (Rb + jXb) (Equation 2-4)
Here, RB4 + jXB4: line impedance [Ω] of the branch B4.

  In addition, although the above is an example in case the displacement point of a line impedance is one place, the number of places of a displacement point is not restricted to one place. Even when there are a plurality of displacement points, each line impedance may be distributed in proportion to the line length in the same manner as described above.

  The virtual concentrated load at the node L1 is set to PL1 + jQL1 using the active power PL1 and the reactive power QL1. Similarly, the virtual concentrated loads in the nodes L2 to L5 are expressed using active powers PL2 to PL5 and reactive powers QL2 to QL5.

(2) Creation of distribution pattern of virtual concentrated load in distribution system section (S2)

  Next, a plurality of virtual concentrated load distribution patterns for distributing the total load of the distribution system section 2 to the virtual concentrated loads of the nodes L1 to L5 are created. The distribution pattern of the virtual concentrated load is that of each of the virtual concentrated loads of the nodes L1 to L5 for allocating the total load of the distribution system section 2 to the virtual concentrated loads of the nodes L1 to L5 of the power flow calculation circuit 6 created in S1. It is a pattern of size. That is, in the present embodiment, since there are five virtual concentrated loads, a plurality of distribution patterns in which the distribution ratio for distributing the total load of the distribution system section 2 to these five virtual concentrated loads is variously changed. Will be created.

  In the present embodiment, seven distribution patterns from patterns A to G are created as virtual concentrated load distribution patterns as shown in FIG.

  The distribution ratios α1 to α5 to the virtual concentrated load for each of the nodes L1 to L5 in the present embodiment are the values shown in Table 1 for each virtual concentrated load distribution pattern A to G.

  Pattern A is a case where the virtual concentrated load of the node L1 is equal to the total load of the distribution system section 2. That is, only the node L1 has a virtual concentrated load, and the virtual concentrated loads of other nodes are zero.

  Pattern B is a case where the virtual concentrated load of the node L2 is equal to the total load of the distribution system section 2. That is, only the node L2 has a virtual concentrated load, and the virtual concentrated loads of other nodes are zero.

  In pattern C, the virtual concentrated load of node L2 occupies two-thirds of the total load of distribution system section 2, and the virtual concentrated load of node L3 occupies one-third of the total load of distribution system section 2, This is a case where the virtual centralized load of other nodes is zero.

  Pattern D is a case where each of the virtual concentrated loads of the nodes L2, L3, and L4 is one third of the total load of the distribution system section 2, and the virtual concentrated loads of the other nodes are zero.

  In the pattern E, the virtual concentrated load of the node L3 occupies one third of the total load of the distribution system section 2, and the virtual concentrated load of the node L4 occupies two thirds of the total load of the distribution system section 2. This is a case where the virtual centralized load of other nodes is zero.

  The pattern F is a case where the virtual concentrated load of the node L4 is equal to the total load of the distribution system section 2. That is, only the node L2 has a virtual concentrated load, and the virtual concentrated loads of other nodes are zero.

  The pattern G is a case where the virtual concentrated load of the node L5 is equal to the total load of the distribution system section 2. That is, only the node L5 has a virtual concentrated load, and the virtual concentrated loads of other nodes are zero.

  Here, patterns A and G assume a case where the estimation of the distribution of the virtual concentrated load does not converge in patterns B to F. Specifically, since the power transmission end voltage Vs of the node L0 is constant, the pattern A has a situation in which the power reception end voltage of the node L6 is the highest, that is, all or almost all the loads are in the immediate vicinity of the measuring device 5B at the power transmission end. The pattern G is a situation where the power receiving end voltage of the node L6 is the lowest, that is, a case where all or almost all loads are concentrated in the immediate vicinity of the measuring device 5C at the power receiving end.

  The distribution pattern of the virtual concentrated load is not limited to these patterns, and the distribution ratios α1 to α5 of the virtual concentrated loads of the nodes L1 to L5 may be more diverse. For example, in the present embodiment, the distribution ratios α2 and α3 of the virtual concentrated loads of the nodes L2 and L3 are set to 2: 1 in the pattern C. However, the present invention is not limited to this. You may create it.

  When creating the distribution pattern of the virtual concentrated load, as shown in FIG. 4, the load is gradually shifted from the power transmission end side (the measuring instrument 5B side) to the power receiving end side (the measuring instrument 5C side). The power receiving end voltage of the node L6 is gradually decreased. Specifically, in the present embodiment, the receiving end voltage of the node L6 of the virtual concentrated load distribution pattern A is Va, and the receiving end voltages of the virtual concentrated load distribution patterns B to G are similarly Vb, Vc. ,..., Vg, Va> Vb> Vc> Vd> Ve> Vf> Vg, and the receiving end voltage decreases in the order of pattern A to pattern G.

  Note that the number of virtual concentrated load distribution patterns is not particularly limited, and may be smaller or larger than seven in the present embodiment. In general, the greater the number of distribution patterns, the higher the estimation accuracy, but the more complicated the calculation becomes. Therefore, the operator must take into account the required estimation accuracy and the estimated amount of work. Judging.

(3) Calculation of power receiving end voltage for each distribution pattern of virtual concentrated load (S3)

  Next, using the power flow calculation circuit 6 created in S1, power flow calculation is performed for each of the virtual concentrated load distribution patterns A to G created in S2 to calculate calculated power receiving end voltages Va to Vg (S3).

  Calculation of the calculated power receiving end voltages Va to Vg is performed according to the flow shown in FIG. 5 for each of the virtual concentrated load distribution patterns A to G.

  First, in the power flow calculation circuit 6, the relationship of (Equation 3) and (Equation 4) is established.

  Ps = PL + Pr + Ploss (Equation 3)

  Here, Ps: transmission end active power, PL: total load (active power) in distribution system section 2, Pr: receiving end active power, Ploss: line loss (active power) of distribution line 4 in distribution system section 2. All units are [W].

  Qs = QL + Qr + Qloss (Equation 4)

  Here, Qs: power transmission end reactive power, QL: total load (reactive power) in distribution system section 2, Qr: power receiving end reactive power, Qloss: line loss (reactive power) of distribution line 4 in distribution system section 2. All units are [Var].

  In (Equation 3) and (Equation 4), since Ploss and Qloss are unknown, they are set to zero as an initial condition (S3-1).

  Thereby, (Equation 5) and (Equation 6) are obtained from (Equation 3) and (Equation 4), respectively.

  PL = Ps−Pr (Equation 5)

  QL = Qs−Qr (Expression 6)

  Next, the total load of the distribution system section 2 is distributed to the virtual concentrated loads of the nodes L1 to L5 in accordance with the virtual concentrated load distribution pattern of Table 1 described above (S3-2).

  Distribution of the total load (total active power component, total reactive power component) in the distribution system section 2 is performed using (Equation 7), thereby calculating the active power and reactive power for each of the nodes L1 to L5.

  PLi + jQLi = αi / Σαi × (PL + jQL) (Equation 7)

  Here, subscript i: node number (1-5), PLi + jQLi: virtual concentrated load [VA] of node Li (PLi: effective power of virtual concentrated load of node Li, j: imaginary unit, QLi: virtual concentrated of node Li Reactive power of load), αi: distribution ratio of virtual concentrated load of node Li, PL + jQL: total load of distribution system section 2 [VA] (PL: active power of load of distribution system section 2, j: imaginary unit, QL : Reactive power of load in distribution system section 2). Note that Σαi = α1 + α2 + α3 + α4 + α5.

  The distribution ratios α1 to α5 of the virtual concentrated load for each of the nodes L1 to L5 for the virtual concentrated load distribution patterns A to G are as shown in Table 1.

  Next, since the load for each of the nodes L1 to L5 is obtained as a result of S3-2, the power flow is calculated using the node L0 as a reference node (S3-3).

  The power flow calculation here is to solve the power equation of the power system to find the voltage, phase angle, power, reactive power flow, especially if it is a power flow calculation of AC method including Newton-Raphson method. Regardless of the method.

  As a result of the power flow calculation, a line loss (active power) Ploss and a line loss (reactive power) Qloss are calculated.

  Next, for the distribution system section 2, convergence determination is performed using the measured power transmission end power and power reception end power and the calculated values load and line loss (S3-4).

  First, a difference between an actual measurement value and a calculation value that is a determination index for convergence determination is calculated using (Equation 8) and (Equation 9).

  ΔP = Ps− (PL + Pr + Ploss) (Equation 8)

  Here, ΔP: difference between the measured value and the calculated value (active power), Ps: transmission end active power, PL: total load (active power) of distribution system section 2, Pr: receiving end effective power, Ploss: distribution Line loss (active power) of the distribution line 4 in the system section 2. All units are [W].

  ΔQ = Qs− (QL + Qr + Qloss) (Equation 9)

  Here, ΔQ: difference between the measured value and the calculated value (reactive power), Qs: transmission end reactive power, QL: total load (reactive power) in distribution system section 2, Qr: receiving end reactive power, Qloss: power distribution Line loss (reactive power) of the distribution line 4 in the system section 2. All units are [Var].

  If | ΔP | ≦ Plimit and | ΔQ | ≦ Qlimit, it is determined that the power flow calculation has converged (S3-4; Yes), and otherwise, it is determined that it has not converged (S3-4). No).

  Here, Plimit and Qlimit are indices for determining the convergence of the calculated value with respect to the actual value represented by (Equation 8) and (Equation 9), and are threshold values for the difference between the actual value and the calculated value. There are no particular restrictions on the values of Plimit and Qlimit, and the operator sets an appropriate threshold number in consideration of the required estimation accuracy and the like. Specifically, for example, it is conceivable to set about 1% of the transmission end power Ps and Qs as Plimit and Qlimit.

  When one or both of | ΔP | and | ΔQ | exceed the thresholds Plimit and Qlimit for convergence determination (S3-4; No), a new load is calculated using (Equation 10) and (Equation 11). The total PL ′ and QL ′ are calculated (S3-5).

  PL ′ = PL + ΔP (Equation 10)

  Here, PL ′: the total load (active power) of the new distribution system section 2, ΔP: difference between the actually measured value and the calculated value for the active power (the calculation result of (Equation 8) in S 3-4). All units are [W].

  QL ′ = QL + ΔQ (Expression 11)

  Here, QL ′: the total load (reactive power) of the new distribution system section 2, ΔQ: difference between the measured value and the calculated value of the reactive power (calculation result of (Equation 9) of S 3-4). All units are [Var].

  Then, the processes from S3-2 to S3-4 are performed again by using the new load totals PL 'and QL'.

  On the other hand, when it is determined in S3-4 that the tidal current calculation has converged (S3-4; Yes), the calculation for the distribution pattern of the virtual concentrated load as the calculation target is terminated (S3-6). .

  Then, the load for each of the nodes L1 to L5 and the voltage of the node L6 at this time are the virtual concentrated load (PLi + jQLi) and the calculation for each of the nodes L1 to L5 of the virtual concentrated load distribution pattern (A to G) to be calculated. It is a receiving end voltage (any one of Va-Vg).

The processes from S3-1 to S3-6 are repeated for each of the virtual concentrated load distribution patterns A to G, and when the calculation for all of the virtual concentrated load distribution patterns A to G is completed, the process proceeds to S4. Move.

(4) Selection of distribution patterns of two virtual concentrated loads having calculated receiving end voltages close to the actually measured receiving end voltages (S4)

  Subsequently, the receiving end voltage Vr actually measured by the measuring instrument 5C is compared with the calculated receiving end voltages Va to Vg according to the distribution patterns A to G of the virtual concentrated load calculated in S3, and the calculated receiving end voltage becomes the receiving end voltage Vr. Two distribution patterns of close virtual concentrated loads are selected (S4).

  As described above, the calculated power receiving end voltages Va to Vg for the virtual concentrated load distribution patterns A to G have a relationship of Va> Vb> Vc> Vd> Ve> Vf> Vg.

  In the present embodiment, when all of the power receiving end voltage Vr measured by the measuring instrument 5C and the calculated power receiving end voltages Va to Vg according to the distribution patterns A to G of the virtual concentrated load are arranged in descending order, for example, Va> Vb> Vc It is assumed that the relationship is> Vr> Vd> Ve> Vf> Vg.

  At this time, among the calculated receiving end voltages Va to Vg for the virtual concentrated load distribution patterns A to G, Vc and Vd are close to the receiving end voltage Vr measured by the measuring instrument 5C, and the receiving end voltage Vr is reproduced. Distribution patterns C and D are selected as possible distribution patterns of the virtual concentrated load.

(5) Calculation of distribution of distribution system load by combination of distribution patterns of two selected virtual concentrated loads (S5)

  Next, of the virtual concentrated load (PLi + jQLi) and the calculated receiving end voltage (any one of Va to Vg) calculated in S3, the virtual concentrated load and the calculated receiving end voltage relating to the distribution pattern of the two virtual concentrated loads selected in S4. Is used to calculate the distribution of the load in the final distribution system section 2 (S5).

  Specifically, the virtual concentrated load (active power) of the node L2 of the virtual concentrated load distribution pattern C calculated in S3 is set as PL2c, and the virtual concentrated load (active power) of the node L2 of the virtual concentrated load distribution pattern D is set as PL2c. Assuming that PL2d, the relationship of (Equation 12) is established by linear interpolation of the virtual concentrated load pattern from S4.

  (PL2−PL2c): (PL2d−PL2c) = (Vr−Vc): (Vd−Vc) (Equation 12)

  Here, PL2: final load (active power) [W] of the node L2, PL2c: virtual concentrated load (active power) [W] of the node L2 of the distribution pattern C of the virtual concentrated load, PL2d: virtual concentrated load Virtual concentrated load (active power) [W] at node L2 of distribution pattern D, Vr: power receiving end voltage [V] measured by measuring instrument 5C, Vc: calculated power receiving end voltage [V] of virtual concentrated load distribution pattern C , Vd: Calculated power receiving end voltage [V] of the distribution pattern D of the virtual concentrated load.

  In (Expression 12), the calculated power receiving end voltage Vc and the virtual concentrated load PL2c are obtained from the conditions when the pattern C converges (S3-6), and Vd and PL2d are also obtained from the conditions when the pattern D converges. It is done. Since Vr is actually measured by the measuring instrument 5C, the final load (active power) PL2 of the node L2 can be obtained.

  Similarly to (Equation 12), PL3 can be obtained for the node L3 and PL4 can be obtained for the node L4.

  Furthermore, since the virtual concentrated load QL2c is obtained from the conditions when the pattern C converges, and similarly QL2d is obtained from the conditions when the pattern D converges, the expression QL2 can be obtained using (Equation 13). Further, QL3 and QL4 can be obtained in the same manner.

  (QL2-QL2c): (QL2d-QL2c) = (Vr-Vc): (Vd-Vc) (Equation 13)

  QL2: final load (reactive power) [Var] of the node L2, QL2c: virtual concentrated load (reactive power) [Var] of the node L2 of the virtual concentrated load distribution pattern C, QL2d: virtual concentrated load Virtual concentrated load (reactive power) [Var] at node L2 of distribution pattern D, Vr: power receiving end voltage [V] measured by measuring instrument 5C, Vc: calculated power receiving end voltage [V] of virtual concentrated load distribution pattern C , Vd: Calculated power receiving end voltage [V] of the distribution pattern D of the virtual concentrated load.

  Note that in both the distribution patterns C and D, the virtual concentrated load of the nodes L1 and L5 is zero, and thus the above processing is not necessary for the nodes L1 and L5.

  As described above, the final load size for each of the nodes L1 to L5 can be obtained, and the final load distribution in the power distribution system section 2 can be calculated.

  Here, the selection of the distribution pattern of the virtual concentrated load (S4) that can reproduce the actually measured power receiving end voltage Vr is preferably the above-described method described in the present embodiment. The distribution pattern of the virtual concentrated load that becomes the calculated power receiving end voltage that minimizes the absolute value of the difference from the end voltage Vr may be selected. In this case, it is not necessary to perform the process of S5, and the distribution pattern of the virtual concentrated load selected in S4 becomes the final load distribution in the distribution system section 2.

  Further, by providing a no-load node at an arbitrary point of the power flow calculation circuit 6 created in FIG. 2, and performing the power flow calculation using the load distribution of the distribution system section 2 obtained at S5, the voltage at the arbitrary point Can be estimated (S6).

  There is no particular limitation on the number of no-load nodes, but the calculation becomes more complicated as the number of nodes increases, so the operator needs to determine and set the point where it is needed.

  Furthermore, if there is a known load between the measuring instrument 5B and the measuring instrument 5C, a load node is provided at a corresponding location on the tidal current calculation circuit 6 when the tidal current calculation circuit 6 is created (S1). It is also possible to input the load as a fixed value. In this case, the present method estimates an unknown load excluding a known load.

  The above-described load distribution and voltage estimation method and apparatus for the distribution system can also be realized by executing the distribution distribution and voltage estimation program 13 on the computer. An example of this implementation is shown below.

  The load distribution of the distribution system and the load distribution of the distribution system for executing the voltage estimation program 13 and the overall configuration of the voltage estimation device 7 are shown in FIG. The load distribution and voltage estimation device 7 of the distribution system includes a control unit 8, a storage unit 9, an input unit 10, a display unit 11, and a memory 12, and is connected to each other by a signal line such as a bus. Further, the load distribution and voltage estimation device 7 of the distribution system is connected to measuring instruments 5B and 5C via a communication line or the like, and transmission / reception of signals such as data and control commands (input / output) via the communication line etc. ) Is performed.

  The control unit 8 controls the distribution distribution system load distribution and the voltage estimation device 7 as a whole, and the calculation related to the distribution distribution load distribution and voltage estimation by the distribution system load distribution stored in the storage unit 9 and the voltage estimation program 13. For example, a CPU. The storage unit 9 is a device that can store at least data and programs, and is, for example, a hard disk. The input unit 10 is an interface for giving at least an operator command to the CPU, and is, for example, a keyboard. The display unit 11 displays characters, graphics, and the like under the control of the control unit 8 and is, for example, a display. The memory 12 becomes a memory space that becomes a work area when the control unit 8 executes various controls.

  The control unit 8 of the voltage control device 7 executes the distribution distribution of the distribution system and the voltage estimation program 13, thereby setting the power flow calculation circuit 6 and the distribution of the virtual concentrated load in the distribution system section 2. Virtual centralized load distribution pattern setting unit 8b for setting a pattern, first load total calculating unit 8c for calculating the total of loads (active power and reactive power) in distribution system section 2, and calculating loads for nodes L1 to L5 A virtual concentrated load calculation unit 8d, a line loss calculation unit 8e that calculates line loss (active power, reactive power), a comparison unit 8f that compares a difference between an actual measurement value and a calculation value of power and a threshold value of the difference, Second load total calculation unit 8g for calculating the total of new loads (active power and reactive power) in distribution system section 2, and selection of distribution pattern of virtual concentrated load of calculated receiving end voltage close to measured receiving end voltage value Selection Part 8h, final load (active power, reactive power) for each node L1~L5 load distribution calculation section 8i that calculates a voltage estimate unit 8j configured to calculate the voltage at the node position of the no-load.

  First, the circuit setting unit 8a of the control unit 8 inputs the setting contents of the power flow calculation circuit 6 through, for example, the input unit 10 and stores them in the storage unit 9 in advance (S1). The setting content of the power flow calculation circuit 6 is a variable necessary for estimating the virtual concentrated load distribution in the distribution system section 2, and specifically, for example, the number of virtual concentrated loads in the distribution system section 2 (that is, the number of virtual concentrated loads in the distribution system section 2). The number of nodes), the position, the line impedance Z of the entire distribution system section 2, and the like. Further, the voltage Vs, active power Ps and reactive power Qs at the power transmission end, and the voltage Vr, active power Pr and reactive power Qr at the power receiving end are transmitted from the measuring device 5B at the power transmission end and the measuring device 5C at the power receiving end via a communication line or the like. The data is input and stored in the storage unit 9.

  Next, the virtual concentrated load distribution pattern setting unit 8b of the control unit 8 inputs, for example, the setting content of the virtual concentrated load distribution pattern in the distribution system section 2 through the input unit 10 and stores it in the storage unit 9 in advance. (S2). The setting contents of the distribution pattern of the virtual concentrated load are specifically values of the distribution ratios α1 to α5 to the virtual concentrated load for each of the nodes L1 to L5 for each of the virtual concentrated load distribution patterns A to G, for example. .

  Next, calculated power receiving end voltages Va to Vg are calculated according to the distribution patterns A to G of the virtual concentrated load (S3).

  First, the first load total calculation unit 8c of the control unit 8 reads the active power Ps and reactive power Qs of the power transmission end and the active power Pr and reactive power Qr of the power receiving end stored in the storage unit 9, and (Equation 5) And the total PL of the load (active power) and the total QL of the load (reactive power) of the distribution system section 2 are calculated by (Equation 6) (S3-1). Then, the calculated total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section 2 are stored in the memory 12 or the storage unit 9.

  Next, the virtual concentrated load calculation unit 8d of the control unit 8 stores the setting content of the power flow calculation circuit 6 and the setting content of the virtual concentrated load distribution pattern stored in the storage unit 9 in advance, and the memory 12 or the storage in S3-1. The total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section 2 stored in the unit 9 are read, and the total load of the distribution system section 2 is calculated in the virtual of the nodes L1 to L5 by (Equation 7). The load for each of the nodes L1 to L5 is calculated by allocating to the concentrated load (S3-2). Then, the calculated loads for the nodes L1 to L5 are stored in the memory 12 or the storage unit 9.

  Next, the line loss calculation unit 8e of the control unit 8 includes the settings of the power flow calculation circuit 6 stored in the storage unit 9 in advance and the loads for the nodes L1 to L5 stored in the memory 12 or the storage unit 9 in S3-2. The load is calculated using the node L0 as a reference node to calculate line loss (active power) Ploss and line loss (reactive power) Qloss (S3-3). The calculated line loss (active power) Ploss and line loss (reactive power) Qloss are stored in the memory 12 or the storage unit 9.

  Next, the comparison unit 8f of the control unit 8 uses the memory 12 or the storage unit 9 with the active power Ps and reactive power Qs of the power transmission end and the active power Pr and reactive power Qr and reactive power Qr and S3-1 stored in the storage unit 9. The total load PL (active power) and the total load Q (reactive power) QL stored in the distribution system section 2, and the line loss (active power) Ploss and the line loss stored in the memory 12 or the storage unit 9 in S3-3. (Reactive power) Qloss is read, and the difference between the actual value and the calculated value (active power) ΔP and the difference between the actual value and the calculated value (reactive power) ΔQ are calculated by (Equation 8) and (Equation 9). Then, | ΔP | and Plimit are compared, and | ΔQ | and Qlimit are compared (S3-4). Here, for example, the values of Plimit and Qlimit are input by the input unit 10 and stored in the storage unit 9 in advance, and the comparison unit 8f reads them out at the stage of processing S3-4. Furthermore, the difference (active power) ΔP between the calculated actual value and the calculated value and the difference (reactive power) ΔQ between the actual measured value and the calculated value are stored in the memory 12 or the storage unit 9.

  When one or both of | ΔP | and | ΔQ | exceed the thresholds Plimit and Qlimit for convergence determination (S3-4; No), the second determination is made based on the determination result of the comparison unit 8f of the control unit 8. The load total calculation unit 8g includes the load PL (active power) total PL and the load (reactive power) total QL stored in the memory 12 or the storage unit 9 in S3-1 and the memory 12 or S3-4 in S3-4. The difference (active power) ΔP between the actually measured value and the calculated value stored in the storage unit 9 and the difference (reactive power) ΔQ between the actually measured value and the calculated value are read, and a new load is calculated by (Equation 10) and (Equation 11). Total PL ′ and QL ′ are calculated (S3-5). Further, the calculated total new loads PL ′ and QL ′ are stored in the memory 12 or the storage unit 9. Then, the virtual concentrated load calculation unit 8d returns to the process (S3-2) for calculating the loads for the nodes L1 to L5, and the line loss calculation unit 8e calculates the line loss (active power) Ploss and the line loss (reactive power) Qloss. The calculation process (S3-3) and the comparison unit 8f calculate the difference between the actual value and the calculated value (active power) ΔP and the difference between the actual value and the calculated value (reactive power) ΔQ, and also | ΔP | and Plimit The process of comparing and comparing | ΔQ | with Qlimit (S3-4) is repeated.

  On the other hand, when | ΔP | ≦ Plimit and | ΔQ | ≦ Qlimit (S3-4; Yes), the calculation for the distribution pattern of the virtual concentrated load to be calculated is terminated (S3-6), and S3-2 The virtual concentrated load distribution pattern (A to G) for calculating the load for each of the nodes L1 to L5 stored in the memory 12 or the storage unit 9 and the voltage at the node L6 stored in the memory 12 or the storage unit 9 in S3-3. The virtual concentrated load and calculated power receiving end voltage (Va to Vg) for each of the nodes L1 to L5 are stored in the memory 12 or the storage unit 9.

  The load distribution and voltage estimation program 13 of the power distribution system repeats the process from S3-1 to S3-6 for each of the virtual concentrated load distribution patterns A to G, and performs S3- for each of the virtual concentrated load distribution patterns A to G. In step 6, the virtual concentrated load and the calculated power receiving end voltage for each of the nodes L1 to L5 are stored in the memory 12 or the storage unit 9. Then, when the calculation for all of the virtual concentrated load distribution patterns A to G is completed, the process proceeds to S4.

  Subsequently, the selection unit 8h of the control unit 8 reads the actually measured power receiving end voltage Vr stored in the storage unit 9 and the calculated power receiving end voltages Va to Vg stored in the memory 12 or the storage unit 9 in S3-6, all of them. Are arranged in descending order, and two calculated receiving end voltages that are values before and after the actually measured receiving end voltage Vr are specified. Then, the distribution pattern of the virtual concentrated load of the specified calculated power receiving end voltage is selected (S4), and the types of the selected two virtual concentrated load distribution patterns are stored in the memory 12 or the storage unit 9.

  Next, the load distribution calculation unit 8i of the control unit 8 reads the types of the two virtual concentrated load distribution patterns selected in S4, and stores the two distribution patterns in the memory 12 or the storage unit 9 in S3-6. The virtual concentrated load and the calculated power receiving end voltage for each of the nodes L1 to L5 are read out. Further, the measured power receiving end voltage Vr stored in the storage unit 9 is read out. Then, the final load (active power) for each of the nodes L1 to L5 is calculated based on the relationship (Expression 12) given as an example in the case of the node L2, and similarly given as an example in the case of the node L2 (Expression 13). ) To calculate the final load (reactive power) for each of the nodes L1 to L5 (S5). Furthermore, the calculated final loads (active power and reactive power) for each of the nodes L1 to L5 are stored in the memory 12 or the storage unit 9.

  Subsequently, when the operator's command with the content of estimating the voltage at an arbitrary point is input via the input unit 10, the voltage estimation unit 8 j of the control unit 8 first stores the tidal current stored in the storage unit 9. The setting contents of the calculation circuit 6 are read, and a no-load node is provided in the power flow calculation circuit 6. Here, the position of the no-load node is displayed on the display unit 11 with a message requesting the designation of the position where voltage estimation is performed when the operator's voltage estimation command is input. Is input via the input unit 10. Then, the final load (active power, reactive power) for each of the nodes L1 to L5 stored in the memory 12 or the storage unit 9 with the voltage Vs, the active power Ps, the reactive power Qs, or the S5 stored in the storage unit 9 is stored. To calculate the current, and calculate the voltage at the no-load node position (S6). Further, the calculation result is displayed on the display unit 11 and stored in the storage unit 9 when necessary.

  In addition, although the above-mentioned form is an example of the suitable form of this invention, it is not limited to this, A various deformation | transformation implementation is possible in the range which does not deviate from the summary of this invention. For example, in this embodiment, the case where estimation is performed for one distribution system section has been described as an example. However, the present invention is not limited thereto, and a plurality of adjacent distribution system sections may be estimated as a unit.

  As an embodiment of the present invention, as shown in FIG. 7, the voltage at the position of the sensor-equipped switch 5b is targeted for the actual distribution system 14 in which the substation 3 ′ and the sensor-equipped switches 5a, 5b and 5c are installed. Was estimated.

  In this example, voltage estimation was performed by applying the method of the present invention based on the information of the sensor-side sensor-equipped switch 5a and the terminal-side sensor-equipped switch 5c.

  Moreover, in order to compare with the estimation result using the voltage estimation method of the present invention, as another method, the conventional voltage calculation method according to the distribution technology manual and the voltage of the power source side sensor-equipped switch 5a and the terminal side sensor-equipped switching Estimation was also performed using a simple voltage calculation method based on a simple average of the voltage of the device 5c.

  Furthermore, the comparison with the measured value of the voltage by the switch with sensor 5b was also performed. The error of the voltmeter among the actually installed switch sensors was 1%.

  Each of the four kinds of voltages arranged as described above was analyzed every 30 minutes for 24 hours (the number of data was 48), and the result of FIG. 8 was obtained. In FIG. 8, the symbol + indicates the sensor actual measurement value, Δ indicates the calculated value by the conventional voltage calculation method, □ indicates the calculated value by the simple voltage calculation method, and ■ indicates the result of the calculated value by the voltage estimation method of the present invention. From this result, it was confirmed that the calculated value (■) by the voltage estimation method of the present invention as a whole best matched with the tendency of the sensor actual measurement value (+).

  Each of the three types of estimated voltages was evaluated using the evaluation function E of the voltage estimation error expressed by (Equation 14), and the results of Table 2 were obtained.

  Here, E: evaluation function of voltage estimation error (= square root of root mean square of voltage estimation error), V (k): estimated value [V], v (k) of voltage at position of sensor-equipped switch 5b in data k ): Actual measured voltage [V] of the sensor-equipped switch 5b, n: number of data (= 48).

  From the results of Table 2, the voltage estimation method of the present invention is E = 19.2 [E] while E = 1121.6 [V] of the conventional voltage calculation method and E = 36.5 [V] of the simple voltage calculation method. V], and it has been confirmed that the voltage estimation method of the present invention can perform good estimation with higher accuracy than the conventional method and the simple method.

It is a flowchart explaining an example of embodiment of the load distribution estimation method and voltage estimation method of the distribution system of this invention. It is a figure which shows the power distribution system of this embodiment. It is a figure which shows the tidal current calculation circuit of this embodiment. It is a figure explaining the distribution pattern of the virtual concentrated load of this embodiment. It is a flowchart explaining the calculation method of the receiving end voltage for every distribution pattern of the virtual concentrated load of this embodiment. It is a functional block diagram of the load distribution of a power distribution system when implementing the load distribution estimation method and the voltage estimation method of a power distribution system of this embodiment using a program. It is a figure which shows the power distribution system of an Example. It is a figure which shows the result of the comparison of the sensor actual value of an Example, and the calculated value according to a calculation method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Distribution system 2 Distribution system section 3 Transformer 4 Distribution line 5A, 5B, 5C, 5D Measuring instrument 6 Power flow calculation circuit 7 Distribution distribution system load distribution and voltage estimation device 8 Control unit 9 Storage unit 10 Input unit 11 Display unit 12 Memory

Claims (12)

A step (S1) of creating a power flow calculation circuit by expressing the distribution system load distributed and distributed in the distribution system section as a virtual concentrated load in a plurality of nodes in the distribution system section, and receiving power in the distribution system section A step (S2) of creating a plurality of virtual concentrated load distribution patterns having different end voltages, and initial conditions for the transmitting end active power Ps and the transmitting end reactive power Qs in the power flow calculation circuit expressed by Equation 1 and Equation 2 Assuming that Ploss and Qloss are zero, the total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section are calculated (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The load for each of the plurality of nodes is distributed by distributing the total PL of the load (active power) and the total load QL of the load (reactive power) to the virtual concentrated load in the plurality of nodes according to the distribution pattern of the virtual concentrated load. Is calculated (S3-2)
The power flow is calculated using the load for each of the plurality of nodes to calculate the line loss (active power) Ploss and the line loss (reactive power) Qloss of the distribution lines in the distribution system section (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged. With (S3-5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
For each distribution pattern of the virtual concentrated load, the processes from S3-2 to S3-4 are performed again using the total PL ′ of the new load (active power) and the total QL ′ of the load (reactive power). having a step of calculating a calculated receiving end voltage before Symbol distribution system section (S3), a step of difference between the calculated receiving end voltage and the measured receiving end voltage is selected distribution pattern of the smallest imaginary concentrated load A load distribution estimation method for a distribution system, characterized by: A step (S1) of creating a power flow calculation circuit by expressing the distribution system load distributed and distributed in the distribution system section as a virtual concentrated load in a plurality of nodes in the distribution system section, and receiving power in the distribution system section A step (S2) of creating a plurality of virtual concentrated load distribution patterns having different end voltages, and initial conditions for the transmitting end active power Ps and the transmitting end reactive power Qs in the power flow calculation circuit expressed by Equation 1 and Equation 2 Assuming that Ploss and Qloss are zero, the total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section are calculated (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The load for each of the plurality of nodes is distributed by distributing the total PL of the load (active power) and the total load QL of the load (reactive power) to the virtual concentrated load in the plurality of nodes according to the distribution pattern of the virtual concentrated load. Is calculated (S3-2)
The power flow is calculated using the load for each of the plurality of nodes to calculate the line loss (active power) Ploss and the line loss (reactive power) Qloss of the distribution lines in the distribution system section (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged. With (S3-5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
For each distribution pattern of the virtual concentrated load, the processes from S3-2 to S3-4 are performed again using the total PL ′ of the new load (active power) and the total QL ′ of the load (reactive power). the actual pre-Symbol distribution and step (S3) of calculating a calculated receiving end voltage of the system section, measured voltage at reception end and side by side the calculated receiving end voltage of each distribution pattern of the virtual concentrated load in descending order or ascending order of the values in The step of selecting the distribution pattern of the virtual concentrated load of the calculated receiving end voltage before and after the receiving end voltage, and the load in the distribution system section by linearly interpolating the load distribution of the two selected virtual concentrated load distribution patterns A load distribution estimation method for a power distribution system. A step (S1) of creating a power flow calculation circuit by expressing the distribution system load distributed and distributed in the distribution system section as a virtual concentrated load in a plurality of nodes in the distribution system section, and receiving power in the distribution system section A step (S2) of creating a plurality of virtual concentrated load distribution patterns having different end voltages, and initial conditions for the transmitting end active power Ps and the transmitting end reactive power Qs in the power flow calculation circuit expressed by Equation 1 and Equation 2 Assuming that Ploss and Qloss are zero, the total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section are calculated (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The load for each of the plurality of nodes is distributed by distributing the total PL of the load (active power) and the total load QL of the load (reactive power) to the virtual concentrated load in the plurality of nodes according to the distribution pattern of the virtual concentrated load. Is calculated (S3-2)
The power flow is calculated using the load for each of the plurality of nodes to calculate the line loss (active power) Ploss and the line loss (reactive power) Qloss of the distribution lines in the distribution system section (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged. With (S3-5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
For each distribution pattern of the virtual concentrated load, the processing from S3-2 to S3-4 is performed again using the total PL ′ of the new load (active power) and the total QL ′ of the load (reactive power). a step of selecting the step of calculating the calculated receiving end voltage before Symbol distribution system section (S3), the distribution pattern of the smallest imaginary concentrated load difference between the calculated receiving end voltage and the measured voltage at reception end, the said selection A voltage estimation method for a distribution system, comprising: estimating a voltage at each point in the distribution system section by performing a power flow calculation using the distribution pattern of the virtual concentrated load. A step (S1) of creating a power flow calculation circuit by expressing the distribution system load distributed and distributed in the distribution system section as a virtual concentrated load in a plurality of nodes in the distribution system section, and receiving power in the distribution system section A step (S2) of creating a plurality of virtual concentrated load distribution patterns having different end voltages, and initial conditions for the transmitting end active power Ps and the transmitting end reactive power Qs in the power flow calculation circuit expressed by Equation 1 and Equation 2 Assuming that Ploss and Qloss are zero, the total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section are calculated (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The load for each of the plurality of nodes is distributed by distributing the total PL of the load (active power) and the total load QL of the load (reactive power) to the virtual concentrated load in the plurality of nodes according to the distribution pattern of the virtual concentrated load. Is calculated (S3-2)
The power flow is calculated using the load for each of the plurality of nodes to calculate the line loss (active power) Ploss and the line loss (reactive power) Qloss of the distribution lines in the distribution system section (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged. With (S3-5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
For each distribution pattern of the virtual concentrated load, the processing from S3-2 to S3-4 is performed again using the total PL ′ of the new load (active power) and the total QL ′ of the load (reactive power). the actual pre-Symbol distribution and process (S3) for calculating a calculated voltage at reception end of the system section, measured voltage at reception end and side by side the calculated receiving end voltage of each distribution pattern of the virtual concentrated load in descending order or ascending order of the values in The step of selecting the distribution pattern of the virtual concentrated load of the calculated receiving end voltage before and after the receiving end voltage, and the load in the distribution system section by linearly interpolating the load distribution of the two selected virtual concentrated load distribution patterns A step of estimating a distribution, and a step of estimating a voltage at each point in the distribution system section by performing a power flow calculation using the load distribution obtained by the linear interpolation. Voltage estimation method of the distribution system to symptoms. Means for creating a power flow calculation circuit by representing the distribution system load distributed and distributed in the distribution system section as virtual concentrated loads at a plurality of nodes in the distribution system section, and the receiving end voltage of the distribution system section A means for creating a plurality of different virtual concentrated load distribution patterns, and Ploss and Qloss as zero as initial conditions for the transmission end active power Ps and the transmission end reactive power Qs in the power flow calculation circuit expressed by Equation 1 and Equation 2 And calculating the total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The load for each of the plurality of nodes is distributed by distributing the total PL of the load (active power) and the total load QL of the load (reactive power) to the virtual concentrated load in the plurality of nodes according to the distribution pattern of the virtual concentrated load. Is calculated (S3-2)
The power flow is calculated using the load for each of the plurality of nodes to calculate the line loss (active power) Ploss and the line loss (reactive power) Qloss of the distribution lines in the distribution system section (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged. With (S3-5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
For each distribution pattern of the virtual concentrated load, the processing from S3-2 to S3-4 is performed again using the total PL ′ of the new load (active power) and the total QL ′ of the load (reactive power). means for calculating the calculated receiving end voltage before Symbol distribution system section in a feature that the difference between the measured receiving end voltage the calculated receiving end voltage and means for selecting a distribution pattern of the smallest imaginary concentrated load Load distribution estimation device for distribution system. Means for creating a power flow calculation circuit by representing the distribution system load distributed and distributed in the distribution system section as virtual concentrated loads at a plurality of nodes in the distribution system section, and the receiving end voltage of the distribution system section A means for creating a plurality of different virtual concentrated load distribution patterns, and Ploss and Qloss as zero as initial conditions for the transmission end active power Ps and the transmission end reactive power Qs in the power flow calculation circuit expressed by Equation 1 and Equation 2 And calculating the total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The load for each of the plurality of nodes is distributed by distributing the total PL of the load (active power) and the total load QL of the load (reactive power) to the virtual concentrated load in the plurality of nodes according to the distribution pattern of the virtual concentrated load. Is calculated (S3-2)
The power flow is calculated using the load for each of the plurality of nodes to calculate the line loss (active power) Ploss and the line loss (reactive power) Qloss of the distribution lines in the distribution system section (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged. With (S3-5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
For each distribution pattern of the virtual concentrated load, the processes from S3-2 to S3-4 are performed again using the total PL ′ of the new load (active power) and the total QL ′ of the load (reactive power). before SL distribution means for calculating the calculated receiving end voltage of the system section, measured receiving end voltage and the virtual concentration load distribution pattern each of the calculated receiving end voltage value of the descending order or ascending order Tile the measured receiving end voltage The means for selecting the distribution pattern of the virtual concentrated load of the calculated receiving end voltage before and after the load and the load distribution of the distribution pattern of the two selected virtual concentrated loads are linearly interpolated to estimate the load distribution in the distribution system section A load distribution estimating device for a power distribution system. Means for creating a power flow calculation circuit by representing the distribution system load distributed and distributed in the distribution system section as virtual concentrated loads at a plurality of nodes in the distribution system section, and the receiving end voltage of the distribution system section A means for creating a plurality of different virtual concentrated load distribution patterns, and Ploss and Qloss as zero as initial conditions for the transmission end active power Ps and the transmission end reactive power Qs in the power flow calculation circuit expressed by Equation 1 and Equation 2 And calculating the total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The load for each of the plurality of nodes is distributed by distributing the total PL of the load (active power) and the total load QL of the load (reactive power) to the virtual concentrated load in the plurality of nodes according to the distribution pattern of the virtual concentrated load. Is calculated (S3-2)
The power flow is calculated using the load for each of the plurality of nodes to calculate the line loss (active power) Ploss and the line loss (reactive power) Qloss of the distribution lines in the distribution system section (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged. With (S3-5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
For each distribution pattern of the virtual concentrated load, the processes from S3-2 to S3-4 are performed again using the total PL ′ of the new load (active power) and the total QL ′ of the load (reactive power). means for pre-Symbol selection means for calculating the calculated receiving end voltage of the distribution system section, the distribution pattern of the smallest imaginary concentrated load difference between the calculated receiving end voltage and the measured voltage at reception end, the virtual concentration was the chosen A voltage estimation device for a distribution system, comprising means for estimating a voltage at each point in the distribution system section by performing a power flow calculation using a load distribution pattern. Means for creating a power flow calculation circuit by representing the distribution system load distributed and distributed in the distribution system section as virtual concentrated loads at a plurality of nodes in the distribution system section, and the receiving end voltage of the distribution system section A means for creating a plurality of different virtual concentrated load distribution patterns, and Ploss and Qloss as zero as initial conditions for the transmission end active power Ps and the transmission end reactive power Qs in the power flow calculation circuit expressed by Equation 1 and Equation 2 And calculating the total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The load for each of the plurality of nodes is distributed by distributing the total PL of the load (active power) and the total load QL of the load (reactive power) to the virtual concentrated load in the plurality of nodes according to the distribution pattern of the virtual concentrated load. Is calculated (S3-2)
The power flow is calculated using the load for each of the plurality of nodes to calculate the line loss (active power) Ploss and the line loss (reactive power) Qloss of the distribution lines in the distribution system section (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged. With (S3-5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
For each distribution pattern of the virtual concentrated load, the processing from S3-2 to S3-4 is performed again using the total PL ′ of the new load (active power) and the total QL ′ of the load (reactive power). before SL distribution means for calculating the calculated receiving end voltage of the system section, measured receiving end voltage and the virtual concentration load distribution pattern each of the calculated receiving end voltage value of the descending order or ascending order Tile the measured receiving end voltage A means for selecting the distribution pattern of the virtual concentrated load of the calculated power receiving end voltage before and after the load, and estimating the load distribution in the distribution system section by linearly interpolating the load distribution of the two selected virtual concentrated load distribution patterns And means for estimating a voltage at each point in the distribution system section by performing a power flow calculation using the load distribution obtained by the linear interpolation. Voltage estimation apparatus of the distribution system. Means for creating a power flow calculation circuit by representing at least a distribution system load distributed and distributed in the distribution system section as a virtual concentrated load at a plurality of nodes in the distribution system section; Means for creating a plurality of virtual concentrated load distribution patterns having different receiving end voltages , Ploss as the initial conditions for the transmitting end active power Ps and the transmitting end reactive power Qs in the power flow calculation circuit represented by Equation 1 and Equation 2 The total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section are calculated with Qloss as zero (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The load for each of the plurality of nodes is distributed by distributing the total PL of the load (active power) and the total load QL of the load (reactive power) to the virtual concentrated load in the plurality of nodes according to the distribution pattern of the virtual concentrated load. Is calculated (S3-2)
The power flow is calculated using the load for each of the plurality of nodes to calculate the line loss (active power) Ploss and the line loss (reactive power) Qloss of the distribution lines in the distribution system section (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged. With (S3-5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
For each distribution pattern of the virtual concentrated load, the processing from S3-2 to S3-4 is performed again using the total PL ′ of the new load (active power) and the total QL ′ of the load (reactive power). calculating the calculated receiving end voltage before Symbol distribution system section to section, the measured receiving end voltage and the calculated receiving end voltage and the difference is the distribution system to function as means for selecting the distribution pattern of the smallest imaginary concentrated load Load distribution estimation program. Means for creating a power flow calculation circuit by representing at least a distribution system load distributed and distributed in the distribution system section as a virtual concentrated load at a plurality of nodes in the distribution system section; Means for creating a plurality of virtual concentrated load distribution patterns having different receiving end voltages , Ploss as the initial conditions for the transmitting end active power Ps and the transmitting end reactive power Qs in the power flow calculation circuit represented by Equation 1 and Equation 2 The total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section are calculated with Qloss as zero (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The load for each of the plurality of nodes is distributed by distributing the total PL of the load (active power) and the total load QL of the load (reactive power) to the virtual concentrated load in the plurality of nodes according to the distribution pattern of the virtual concentrated load. Is calculated (S3-2)
The power flow is calculated using the load for each of the plurality of nodes to calculate the line loss (active power) Ploss and the line loss (reactive power) Qloss of the distribution lines in the distribution system section (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged. With (S3-5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
For each distribution pattern of the virtual concentrated load, the processes from S3-2 to S3-4 are performed again using the total PL ′ of the new load (active power) and the total QL ′ of the load (reactive power). calculating the calculated receiving end voltage before Symbol distribution system section to section, the measured voltage at reception end and said virtual load concentration distribution of the calculated receiving end voltage value of each pattern descending order or less arranged in order of the measured receiving end voltage Means for selecting the distribution pattern of the virtual concentrated load of the calculated power receiving end voltage before and after, and means for estimating the load distribution in the distribution system section by linearly interpolating the load distribution of the distribution pattern of the two selected virtual concentrated loads Load distribution estimation program for distribution system to function as Means for creating a power flow calculation circuit by representing at least a distribution system load distributed and distributed in the distribution system section as a virtual concentrated load at a plurality of nodes in the distribution system section; Means for creating a plurality of virtual concentrated load distribution patterns having different receiving end voltages , Ploss as the initial conditions for the transmitting end active power Ps and the transmitting end reactive power Qs in the power flow calculation circuit represented by Equation 1 and Equation 2 The total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section are calculated with Qloss as zero (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The load for each of the plurality of nodes is distributed by distributing the total PL of the load (active power) and the total load QL of the load (reactive power) to the virtual concentrated load in the plurality of nodes according to the distribution pattern of the virtual concentrated load. Is calculated (S3-2)
The power flow is calculated using the load for each of the plurality of nodes to calculate the line loss (active power) Ploss and the line loss (reactive power) Qloss of the distribution lines in the distribution system section (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged. With (S3-5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
For each distribution pattern of the virtual concentrated load, the processing from S3-2 to S3-4 is performed again using the total PL ′ of the new load (active power) and the total QL ′ of the load (reactive power). calculating the calculated receiving end voltage before Symbol distribution system section to section, means the difference between the calculated receiving end voltage and the measured receiving end voltage is selected distribution pattern of the smallest imaginary concentrated load, the virtual concentrated load to the selected A distribution system voltage estimation program for functioning as a means for estimating a voltage at each point in the distribution system section by performing a power flow calculation using a distribution pattern. Means for creating a power flow calculation circuit by representing at least a distribution system load distributed and distributed in the distribution system section as a virtual concentrated load at a plurality of nodes in the distribution system section; Means for creating a plurality of virtual concentrated load distribution patterns having different receiving end voltages , Ploss as the initial conditions for the transmitting end active power Ps and the transmitting end reactive power Qs in the power flow calculation circuit represented by Equation 1 and Equation 2 The total PL of the load (active power) and the total QL of the load (reactive power) in the distribution system section are calculated with Qloss as zero (S3-1)
(Equation 1) Ps = PL + Pr + Ploss
Where Ps: active power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 2) Qs = QL + Qr + Qloss
Where Qs: reactive power at the transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
The load for each of the plurality of nodes is distributed by distributing the total PL of the load (active power) and the total load QL of the load (reactive power) to the virtual concentrated load in the plurality of nodes according to the distribution pattern of the virtual concentrated load. Is calculated (S3-2)
The power flow is calculated using the load for each of the plurality of nodes to calculate the line loss (active power) Ploss and the line loss (reactive power) Qloss of the distribution lines in the distribution system section (S3-3)
The difference between the measured value and the calculated value (active power) ΔP and the difference between the actually measured value and the calculated value (reactive power) ΔQ are calculated using Formula 3 and Formula 4, and the convergence is determined based on these ΔP and ΔQ. (S3-4)
(Expression 3) ΔP = Ps− (PL + Pr + Ploss)
Where ΔP: difference between the actual measurement value and the calculated value (active power) [W]
Ps: Effective power at the transmission end [W]
PL: Total load (active power) in the distribution system section [W]
Pr: Receiving end active power [W]
Ploss: Line loss (active power) of distribution lines in the distribution system section [W]
(Equation 4) ΔQ = Qs− (QL + Qr + Qloss)
Where ΔQ: difference between the measured value and the calculated value (reactive power) [Var]
Qs: Reactive power at transmission end [Var]
QL: Total load (reactive power) in the distribution system section [Var]
Qr: Receiving end reactive power [Var]
Qloss: Line loss (reactive power) of distribution lines in the distribution system section [Var]
As a result of the convergence determination, a new load (active power) total PL ′ and a load (reactive power) total QL ′ are calculated using Formula 5 and Formula 6 until it is determined that the power flow calculation has converged. With (S3-5)
(Equation 5) PL ′ = PL + ΔP
Here, PL ′: total load (active power) in the new distribution system section [W]
ΔP: Difference between measured value and calculated value (active power) [W]
(Expression 6) QL ′ = QL + ΔQ
Here, QL ′: total load (reactive power) in the new distribution system section [Var]
ΔQ: Difference between the measured value and the calculated value (reactive power) [Var]
For each distribution pattern of the virtual concentrated load, the processing from S3-2 to S3-4 is performed again using the total PL ′ of the new load (active power) and the total QL ′ of the load (reactive power). calculating the calculated receiving end voltage before Symbol distribution system section to section, the measured voltage at reception end and said virtual load concentration distribution of the calculated receiving end voltage value of each pattern descending order or less arranged in order of the measured receiving end voltage Means for selecting the distribution pattern of the virtual concentrated load of the calculated power receiving end voltage before and after, means for estimating the load distribution in the distribution system section by linearly interpolating the load distribution of the two selected distribution patterns of the virtual concentrated load The distribution system for functioning as a means for estimating the voltage at each point in the distribution system section by performing a power flow calculation using the load distribution obtained by the linear interpolation Pressure estimation program.

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