JP2018152935A - Electric power system state estimation device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a power system state estimation device capable of estimating a state of a future power system. An electric power system state estimation device 10 includes each predicted value of an active power of an output of a generator in an electric power system, an invalid electric power or a set voltage or a power factor setting of the generator, and an active electric power of a load system. The input unit 12 into which the operation plan information of the power system is input, the setting unit 13 for setting the PQ relational expression which is the relational expression between the active power and the ineffective power in the load system, and the power system from the operation plan information and the PQ relational expression. A state estimation unit 14 for estimating the state of the above is provided. The state estimation unit 14 estimates the state of the power system using the active power of the load system and the ineffective power of the load system obtained from the PQ relational expression. [Selection diagram] Fig. 1

Description

  The present invention relates to a power system state estimation device that estimates a state of a power system.

  The power system needs to be operated while satisfying restrictions such as the allowable range of the transmission power and the allowable range of the voltage of the transmission facility. Therefore, in the operation of the power system, it is necessary to control necessary equipment in a necessary time zone. However, since the devices to be controlled are regularly inspected for maintenance, not all devices are always controllable. Therefore, it is desirable to be able to predict the future state of the power system in determining the schedule of periodic inspection of each device and the time zone for maintaining each device in a controllable state.

  As a technology for predicting the future state of the power system, for example, a technology for predicting future total demand (active power) in order to create a power generation plan, or power derived from natural energy such as sunlight or wind power is output. Technology for predicting the amount of power generated by the power generation facility (active power) has been developed.

  In addition, state estimation technology that estimates the state of the current or past power system using the amount of electricity measured in the power system (active power, reactive power, voltage, etc. (including measurement error and time lag)) is known. It has been. For example, Patent Document 1 discloses a technique for estimating the current state of the power system based on measurement data of various electric quantities.

  Patent Document 2 discloses a technique for predicting a future power flow state using past performance data of various electric energy amounts.

JP 2011-1115024 A JP 2008-271750 A

  Various prediction techniques, such as load prediction and solar / wind power generation output prediction, have been established for the state of the active power of the power system. However, a technology for predicting voltage and a technology for predicting reactive power having a large influence on the voltage have not been established yet. The active power can be easily predicted because the overall prediction result can be obtained by combining the individual prediction results, whereas the voltage varies depending on the surrounding situation. This is because it is difficult to make accurate predictions. In addition, reactive power and voltage are more affected by control devices than active power, and more easily affected by the surrounding power system, so technologies for predicting reactive power and voltage with high accuracy have been established. Was not.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a power system state estimation device capable of estimating the state of a future power system.

  The power system state estimation device according to the present invention includes each predicted value of the active power of the generator in the power system, the reactive power or set voltage or power factor setting of the generator, and the active power of the load system, From an input unit to which operation plan information of the power system is input, a setting unit that sets a PQ relational expression that is a relational expression between active power and reactive power in the load system, the operation plan information, and the PQ relational expression A state estimation unit that estimates a state of the power system, and the state estimation unit uses the reactive power of the load system obtained from the active power of the load system and the PQ relational expression. Estimate the state.

  According to the power system state estimation apparatus according to the present invention, since the reactive power of the load system can be predicted, the state of the future power system can be estimated.

2 is a functional block diagram showing a configuration of a power system state estimation device according to Embodiment 1. FIG. It is a figure which shows the example of the hardware constitutions of the electric power grid state estimation apparatus which concerns on Embodiment 1. FIG. 3 is a flowchart showing the operation of the power system state estimation apparatus according to Embodiment 1. It is a figure which shows the (pi) type | mold equivalent circuit used for a state estimation calculation. 6 is a block diagram illustrating a functional configuration example of a power system state estimation device according to Embodiment 2. FIG. 6 is a state estimation calculation flowchart of the power system state estimation device according to the second embodiment. 10 is a block diagram illustrating a functional configuration example of a power system state estimation apparatus according to Embodiment 3. FIG. 10 is a state estimation calculation flowchart of the power system state estimation device according to the third embodiment.

<Embodiment 1>
1 is a functional block diagram showing a configuration of a power system state estimation apparatus according to Embodiment 1. FIG. This power system state estimation device 10 is based on predicted values of various electric quantities in a power system of a time section (target time section) to be estimated and a relational expression between active power and reactive power in each load system. The state of the electric power system in a time section is estimated. Hereinafter, the relational expression between the active power and the reactive power in the load system is referred to as “PQ relational expression”.

  As illustrated in FIG. 1, the power system state estimation device 10 includes an information storage unit 11, an input unit 12, a setting unit 13, a state estimation unit 14, and an output unit 15.

  The information storage unit 11 is a storage area that stores various types of information used in calculations for estimating the state of the power system. Based on the power system operation plan information input to the power system state estimation device 10 by the user, the input unit 12 provides information on predicted values of various electric quantities of the power system in the target time section as “system state input information”. Store in the storage unit 11. As shown in FIG. 1, the power system operation plan information input to the input unit 12 includes information on each predicted value of the active power, voltage, and reactive power of each generator, and each of the active power of each load system. Information on the predicted value and information on the system configuration and the control content of the voltage control device are included.

  The predicted value of the active power of each generator and the effective power of each load system is information used when formulating an operation plan for each generator in the power system, and such prediction technology has already been developed. Specifically, by predicting the active power of each load system and economically allocating the power generation required to cover the total value of the load to each generator, A predicted value is obtained. Moreover, since the voltage and reactive power of each generator are related to the control system of each generator and are planned and set in advance, their predicted values can be easily obtained. Instead of the predicted value of reactive power of each generator, the set voltage or power factor setting of each generator may be used. Information on the system configuration (generator, transformer, power line load connection status, etc.) and voltage control device control details are related to the operation of the power system and are planned in advance. Can be easily predicted.

  The setting unit 13 is based on the information on the power system equipment constants (transmission line impedance, admittance, etc.) input by the user and the information on the PQ relational expression that is the relational expression between the active power and the reactive power in the load system. The equipment constant and the PQ relational expression in the time section are stored in the information storage unit 11 as “system state setting information”. A specific example of the PQ relational expression will be described later.

  The state estimation unit 14 reads the system state input information and the system state setting information from the information storage unit 11, and performs estimation calculation of various electric quantities of the power system in the target time section based on the information. For example, various likely electric quantities in the target time section are calculated so that the deviation between the solution of the state equation calculated using the set equipment constants and the predicted values of the various electric quantities input is minimized. . In addition, the calculation results of various amounts of electricity by the state estimation unit 14 are stored in the information storage unit 11 as “power system state estimation results”. The output unit 15 outputs the power system state estimation result stored in the information storage unit 11.

  FIG. 2 is a diagram illustrating an example of a hardware configuration of the power system state estimation device 10. As shown in FIG. 2, the power system state estimation device 10 includes hardware such as a secondary storage device 2, a main storage device 3, and a CPU (Central Processing Unit) 4, and is input to the power system state estimation device 10. The device 1 and the output device 5 are connected.

  That is, the functional block of the information storage unit 11 in the power system state estimation device 10 of FIG. 1 is realized by the secondary storage device 2 or the main storage device 3. The functional blocks of the input unit 12, the setting unit 13, the state estimation unit 14, and the output unit 15 are realized when the CPU 4 executes a program stored in the secondary storage device 2 or the main storage device 3. The main storage device 3 stores data used for calculation by the CPU 4.

  The input device 1 is, for example, a mouse, a keyboard, or the like, and has a function of inputting various information to the input unit 12 and the setting unit 13 in FIG. The input device 1 may be a reading device that reads data and information from an electronic file prepared in advance (for example, a data file in CSV format). The output device 5 is, for example, a display device or a printer, and has a function of presenting a power system state estimation result output by the output unit 15 to the user. The output device 5 may be a transmission device that transmits the power system state estimation result to another device.

  Next, the power system state estimation calculation performed by the state estimation unit 14 will be described. The state estimation calculation is to estimate the voltage and the phase angle of all buses in the power system. This is because if the voltages of all buses and their phase angles are known, the states of all systems are uniquely determined from the admittance of each transmission line.

  First, the PQ relational expression of the load system will be described. As a method for expressing the PQ relational expression of the load system, there are a method using a linear equation, a method using a trigonometric function, a method using a polynomial expression using a quadratic expression, a cubic expression, and the like. In the present embodiment, a PQ relational expression for each load system is expressed by a linear equation. That is, the PQ relational expression of each load system is expressed as shown in Expression (1).

In Equation (1), P _i is the active power of the load system i, Q _i is the reactive power of the load system i, and a _i and b _i are coefficients indicating the characteristics of the load system i, respectively. a _i represents the slope of active power and reactive power, and is a feature quantity such as power factor. Further, b _i represents the intercept of reactive power, which is a feature quantity such as a control amount of the earth capacitance and reactive power control devices of the load system. As the values of a _i and b _i , different values may be set according to the day of the week or the time zone. a _i and b _i can be set from load characteristics, facility information such as transmission lines, operation information of reactive power control devices, past results, and the like.

By using the PQ relational expression, the reactive power Q _i of the load system i can be obtained from the active power P _i of the load system i input to the input unit 12. Therefore, the state estimation unit 14 can calculate the reactive power from the PQ relational expression of the load system i even if the reactive power of the load system i that is difficult to predict is not input to the input unit 12, thereby calculating the state estimation calculation. Is possible.

Here, since the input electric quantity is the voltage V _i of the bus of each system, the active power P _i of the generator and the load, and the reactive power Q _i , the input value vector z _s is given by the formula ( It is expressed as 2).

In Equation (2), V _s is a bus voltage vector (input value), P _s is a bus active power vector (input value), Q _s is a bus reactive power vector (input value), and LP _s is a line active power flow vector ( The calculated value and initial input are 0), and LQ _s is the line reactive power flow vector (calculated value and initial input is 0).

In the state estimation calculation, the state quantity x (bus voltage V _i , bus voltage phase angle θ _i ) is obtained using these numerical values. The estimated value x _e of the state quantity x is expressed as in Expression (3).

In Equation (3), V _e is a bus voltage vector (estimated value), and θ _e is a bus voltage phase vector (estimated value).

  When the transmission line is regarded as a π-type equivalent circuit shown in FIG. 4, each element of the calculated value vector z (x) of each input value can be calculated as in the following equations (4) to (8).

G _ii and B _ii are the real part and the imaginary part of the diagonal element of the bus admittance matrix, respectively, and are represented by the following equation (9).

The plausible power system state estimated value x ^* can be obtained by minimizing the evaluation function J (x _e ) as shown in Equation (10).

R ⁻¹ is a matrix for setting the weight for each input value. Since LP _s and LQ _s are not input, their weights are set to zero.

From equations (4) to (8), it can be seen that this is a non-linear problem. Therefore, in the present embodiment, the state estimation unit 14 obtains an estimated value x _e of the state quantity by iterative calculation. The true value of the state amount is _{x t,} the estimated value by r-th calculation and _x ^{e (r),} the relationship between _{x t} and _x ^{e (r),} using the error vector [Delta] x _e ^(r) wherein It is expressed as (11).

Here, when Taylor expansion of z (x _t ) is performed in the vicinity of x _e ^(r) , Expression (12) is obtained.

  H is a Jacobian matrix. Further, when Expression (12) is substituted into Expression (10), Expression (13) is obtained.

When this is differentiated by Δx _e ^(r) and the value is set to 0, the following equation (14) is obtained.

  Therefore, the relationship of Formula (15) is obtained.

Therefore, a new estimated value vector x _e ^{(r + 1)} obtained by the ^{(r + 1)} th calculation can be obtained from the equation (16).

The state estimation unit 14 can obtain an estimated value x ^* of the likely power system state by iteratively calculating Expressions (15) and (16). The state estimation unit 14 stores the likely estimation value x ^* in the information storage unit 11 as the power system state estimation result.

  A more specific example of the state estimation calculation is also disclosed in Japanese Patent Application Laid-Open No. 2015-77034, which is a patent application by the present applicant. In Japanese Patent Application Laid-Open No. 2015-77034, it is estimated that the power system state in which the amount of deviation from the input amount of electricity is minimum is likely. In addition, if necessary, weights are set for each of the various electric quantities, and the estimated value of the power system state that minimizes the sum of the divergence amounts of the various weighted electric quantities is determined to be an estimated value if likely. Also good.

  As described above, the state estimation unit 14 can estimate the power system state by calculating the reactive power of each load system in the target time section using the PQ relational expression. However, the above calculation method may cause the following problems.

  That is, in the above calculation method, for the active power, a numerical value close to the input value of the active power is calculated as the estimated value of the active power. That is, if the estimated value of active power deviates from the input value, the value of the evaluation function becomes worse. However, for the reactive power, a value close to “the value of the reactive power calculated from the PQ relational expression using the input value of the active power” is calculated as the estimated value of the reactive power. That is, when the estimated value of reactive power deviates from “the value of reactive power calculated from the PQ relational expression using the input value of active power”, the value of the evaluation function becomes worse. In other words, in the above calculation method, the deviation amount of the estimated value of reactive power from “the value of reactive power calculated from the PQ relational expression using the estimated value of active power” is not considered. Therefore, when the deviation amount of the estimated value of active power increases, there is a possibility that the relationship between the estimated value of active power and the estimated value of reactive power deviates from the PQ relational expression.

  Therefore, in this embodiment, in order to prevent the occurrence of this problem, a new evaluation function that takes into account the PQ relational expression of each load system is introduced.

In general, the evaluation function J (x _e ) in power system state estimation is expressed by the following equation (2) where P _i ^* is an estimated value of active power obtained by the state estimation calculation and Q _i ^* is an estimated value of reactive power. 17) can be defined as follows.

  In the present embodiment, Expression (18) obtained by applying the PQ relational expression of Expression (1) to Expression (17) is defined as a new evaluation function.

  When the evaluation function of Expression (18) is used, if the amount of deviation between the estimated value of reactive power and the value of reactive power calculated from the PQ relational expression using the estimated value of active power becomes small, the evaluation function The value becomes smaller. Therefore, the state estimation unit 14 determines that the estimated state of the power system is more likely as the deviation between the estimated value of the active power and the estimated value of the reactive power of the load system and the PQ relational expression is smaller. To do. Therefore, it is possible to prevent the relationship between the estimated value of active power and the estimated value of reactive power from the state estimation calculation from deviating from the PQ relational expression.

  Next, the operation of power system state estimation apparatus 10 according to Embodiment 1 will be described. FIG. 3 is a flowchart showing the operation. As shown in FIG. 3, the power system state estimation device 10 includes the following various electric quantity input processing (step S11), equipment constant setting processing (step S12), PQ relational expression setting processing (step S13), and state estimation calculation processing. (Step S14), the power system state estimation result output process (Step S15) is sequentially executed, so that the state of the power system is estimated. The execution order of steps S11, S12, and S13 may be any order.

  In various electric quantity input processing (step S11), based on the operation plan information input by the user using the input device 1, the input unit 12 provides information on various electric quantities of the power system in the target time section as system state input information. Store in the storage unit 11. As shown in FIG. 1, the operation plan information includes the active power of each generator, the voltage of each generator, the reactive power of each generator, the active power of each load system, the system configuration, and the control content of the voltage control device. (Instead of the predicted value of reactive power of each generator, the set voltage or power factor setting of each generator may be used).

  In the equipment constant setting process (step S12), based on the equipment constant input by the user using the input device 1, the setting unit 13 sets the equipment constant of the power system in the target time section as part of the system state setting information. The information is stored in the information storage unit 11.

  In the PQ relational expression setting process (step S13), based on the PQ relational expression of each load system input by the user using the input device 1, the setting unit 13 calculates the PQ relational expression of each load system in the target time section, The information is stored in the information storage unit 11 as a part of the system state setting information.

  In the state estimation calculation process (step S14), the state estimation unit 14 performs a power system state estimation calculation based on the system state input information and the system state setting information stored in the information storage unit 11. That is, the state estimation unit 14 calculates estimated values of various electric quantities that satisfy the state equation of the power system and minimizes the evaluation function, and uses the calculated estimated values of various electric quantities as the results of the power system state estimation. Is stored in the information storage unit 11. Further, in the state estimation calculation process, if an evaluation function like Expression (18) is used, the relationship between the estimated value of active power and the estimated value of reactive power by the state estimation calculation is prevented from deviating from the PQ relational expression. be able to.

  In the power system state estimation result output process (step S15), the output unit 15 outputs the power system state estimation result of the target time section stored in the information storage unit 11 in step S14 to the output device 5.

  As described above, according to the first embodiment, by interpolating using the PQ relational expression, which is a characteristic of each load system, without inputting reactive power of a load system that is difficult to predict, The system state can be estimated. Furthermore, by introducing an evaluation function that considers the amount of deviation between the estimated value of reactive power and the value of reactive power calculated from the PQ relational expression using the estimated value of active power, the estimated value of active power and The estimated value of reactive power can be obtained so as to satisfy the PQ relational expression, and the state estimation accuracy can be prevented from deteriorating.

<Embodiment 2>
In the second embodiment, even when the system configuration of the load system is changed, the power system state estimation device capable of estimating the power system state of the target time section by appropriately setting the PQ relational expression in the changed load system Propose.

  FIG. 5 is a block diagram illustrating a functional configuration example of the power system state estimation apparatus 20 according to the second embodiment. The power system state estimation device 20 shown in FIG. 5 has a configuration in which a PQ relational expression correcting unit 21 is added to the power system state estimation device 10 of FIG.

  In addition, the operation plan information input to the input unit 12 of the power system state estimation device 20 includes load system connection change information indicating a load connection change plan in each load system in addition to the information shown in FIG. include. Furthermore, for the load system in which the connection change of the load is performed, the PQ relational expression of the load system to which the load was connected before the connection change, and the PQ relational expression of the load system to which the load is connected after the connection change, Input to the setting unit 13 of the power system state estimation device 20.

  When estimating the power system state in the target time section after the connection change of the load in each load system is performed, the PQ relational expression correcting unit 21 determines the PQ relation of each load system based on the load system connection change information. Correct the expression. Moreover, the state estimation part 14 performs the state estimation calculation of an electric power system using the PQ relational expression after the PQ relational expression correction part 21 corrects.

  In the present embodiment, the load system connection change information includes the active power of the load system whose connection is changed, and information on various electric quantities of the load system before the connection change and the load system after the connection change. Shall. Here, the active power of the load whose connection is changed is P ′, and the PQ relational expression before the connection change of the load system i1 to which the load is connected before the connection change is expressed by Expression (19), It is assumed that the PQ relational expression before the connection change of the load system i2 to which the load is connected after the connection change is expressed by Expression (20).

P _i1 and Q _i1 represent the active power and reactive power of the load system i1 before the load connection is changed, respectively. P _i2 and Q _i2 represent the active power and reactive power of the load system i2 before the load connection change, respectively.

  Further, the PQ relational expression of the load system i1 at the time after the connection change of the load is expressed by Expression (21), and the PQ relational expression of the load system i2 at the time after the connection change of the load is expressed by Expression (22). Assume that

P _i1 ′ and Q _i1 ′ represent the active power and reactive power of the load system i1 at the time after the connection change of the load, respectively. P _i2 ′ and Q _i2 ′ represent the active power and reactive power of the load system i2 at the time after the load connection is changed, respectively.

In the present embodiment, it is assumed that P ′ has the characteristic of the load i1, and the coefficients a _i1 ′, a _i2 ′, b _i1 ′, b _i2 ′ of the equations (21) and (22) are used. Is obtained by the equation (23), thereby correcting the PQ relational expression of the load systems i1 and i2.

  As a method for correcting the PQ relational expression, in addition to the above-described method, there is a method for correcting the coefficient of the PQ relational expression such as the equipment information such as the transmission line whose connection has been changed or the information on the installation location of the reactive power control device. Conceivable.

  FIG. 6 is a flowchart showing the operation of the power system state estimation apparatus 20 according to the second embodiment. This flowchart is obtained by adding a PQ relational expression correction process (step S21) to the flow of FIG.

  In various electric quantity input processing (step S11), equipment constant setting processing (step S12), and PQ relational expression setting processing (step S13), processing similar to that in the first embodiment is performed.

  Subsequently, in the PQ relational expression correction process (step S21), the PQ relational expression correction unit 21 corrects the PQ relational expression of the load system after the connection change based on the load system connection change information as in the above example. To do. In addition, the PQ relational expression correcting unit 21 stores the corrected PQ relational expression in the information storage unit 11.

  In the state estimation calculation process (step S14), the state estimation calculation of the power system is performed by the same process as in the first embodiment. However, for the load system in which the connection change of the load is made, the reactive power is calculated using the PQ relational expression corrected in step S21.

  In the power system state estimation result output process (step S15), the output unit 15 outputs the power system state estimation result stored in the information storage unit 11 in step S14 to the output device 5, as in the first embodiment. .

  According to the second embodiment, in addition to the effects of the first embodiment, even when a load system connection change is expected in the target time section, the PQ relationship is such that the characteristics of the load system before the connection change are inherited. Since the coefficient of the equation is set, it is possible to prevent the power system state estimation accuracy from being lowered.

<Embodiment 3>
In the third embodiment, even when a power generation facility that outputs power derived from natural energy such as sunlight or wind power is introduced in the load system, the power system that can estimate the state of the power system while maintaining accuracy A state estimation device is proposed. In the present embodiment, a power generation facility whose output fluctuates, such as a power generation facility that outputs electric power derived from natural energy, is defined as “output fluctuation power generation facility”.

  Here, natural energy is a concept different from renewable energy, and renewable energy is a broader concept than natural energy. The power generation facilities that output power derived from natural energy include power generation facilities that use sunlight, wind power, and the like. For example, power generation facilities that use hydropower are not necessarily included in the output fluctuation power generation facilities. Among hydroelectric power generation facilities, the type that has diversion adjustment capability (for example, pumped-storage power generation using a large dam) is easy to adjust the output of power generation artificially. Is not included. On the other hand, a hydroelectric power generation facility of a type having no flow rate adjustment capability is included in the output fluctuation power generation facility.

  FIG. 7 is a block diagram illustrating a functional configuration example of the power system state estimation device 30 according to the third embodiment. The power system state estimation device 30 shown in FIG. 7 has a configuration in which a PQ relational expression correcting unit 31 is added to the power system state estimation device 10 of FIG.

  Further, the operation plan information input to the input unit 12 of the power system state estimation device 30 includes an output predicted value (a predicted value of the power generation amount) of the output fluctuation power generation facility in addition to the information shown in FIG. Yes. The input unit 12 stores the output predicted value of the output fluctuation power generation facility in the target time section in the information storage unit 11.

  The PQ relational expression correcting unit 31 corrects the PQ relational expression of each load system using the output predicted value of the output fluctuation power generation facility. Moreover, the state estimation part 14 performs the state estimation calculation of an electric power system using the PQ relational expression after the PQ relational expression correction part 31 corrects.

Here, an example of a PQ relational expression correction method performed by the PQ relational expression correction unit 31 will be described. For example, when the output predicted value of the power fluctuation power generation facility connected to the load system i is R _i , the pure load not including the output of the power generation facility is Pl, and the active power flowing out from the load bus is Pf, the equation (24) The relationship holds.

Here, it is assumed that the active power P _i of the load system as an input value is Pf in Expression (24), and the PQ relational expression in the load system i before correction is expressed by Expression (25). .

The output predicted value R _i of the output fluctuation power generation facility included in P _i can set the ratio of active power to reactive power according to the characteristics and settings of the power generation facility. Is assumed to be a photovoltaic power generation facility, and the most general power factor of 1 (no reactive power input / output) is assumed. Assuming that a _i and b _i are set as features of the net load, the characteristics cannot be accurately reflected by the output fluctuation power generation facility output, so the PQ relational expression is corrected as shown in Expression (26).

  The state estimation unit 14 performs a state estimation calculation of the power system using the PQ relational expression modified as in Expression (26). Equation (26) is a correction method that can be applied even when the output power generation facility is controlled to have a constant power factor, and its generality is not lost.

Further, it is assumed in the example above, the active power _{P i} of the load system, it is assumed that the Pf of the formula (24), assuming a _{P i} and Pl of formula (24), a _{P i} and Pf The PQ relational expression can be corrected by applying the same idea as in the case.

  FIG. 8 is a flowchart showing the operation of the power system state estimation apparatus 20 according to the third embodiment. This flowchart is obtained by adding a PQ relational expression correction process (step S31) to the flow of FIG.

  In various electric quantity input processing (step S11), equipment constant setting processing (step S12), and PQ relational expression setting processing (step S13), processing similar to that in the first embodiment is performed.

  Subsequently, in the PQ relational expression correction process (step S31), the PQ relational expression correction unit 31 corrects the PQ relational expression of each load system based on the predicted output value of the output fluctuation power generation facility as in the above example. To do. In addition, the PQ relational expression correcting unit 31 stores the corrected PQ relational expression in the information storage unit 11.

  In the state estimation calculation process (step S14), the state estimation calculation of the power system is performed by the same process as in the first embodiment. However, the reactive power is calculated for the load system to which the output fluctuation power generation facility is connected, using the PQ relational expression corrected in step S31.

  In the power system state estimation result output process (step S15), the output unit 15 outputs the power system state estimation result stored in the information storage unit 11 in step S14 to the output device 5, as in the first embodiment. .

  According to the third embodiment, in addition to the effects of the first embodiment, even when the output power generation facility derived from natural energy is introduced in the load system, the state of the power system is utilized using the predicted value. It is possible to maintain the estimation accuracy. Further, the PQ relational expression correcting unit 31 of the third embodiment can be applied to the power system state estimating apparatus in combination with the PQ relational expression correcting unit 21 of the second embodiment.

  It should be noted that the present invention can be freely combined with each other within the scope of the invention, and each embodiment can be appropriately modified or omitted.

  10, 20, 30 Power system state estimation device, 11 information storage unit, 12 input unit, 13 setting unit, 14 state estimation unit, 15 output unit, 21, 31 PQ relational expression correction unit, 1 input device, 2 secondary storage Device, 3 main storage device, 4 CPU, 5 output device.

Claims (4)

Operation plan information of the power system is entered, including the active power of the generator output in the power system, the reactive power or set voltage or power factor setting of the generator, and the predicted values of the active power of the load system An input section;
A setting unit for setting a PQ relational expression that is a relational expression between active power and reactive power in the load system;
A state estimation unit that estimates the state of the power system from the operation plan information and the PQ relational expression,
The state estimation unit estimates the state of the power system using the reactive power of the load system obtained from the active power of the load system and the PQ relational expression.
Electric power system state estimation device. When the state estimation unit estimates the state of the power system, the state estimation unit estimates the smaller the amount of deviation between the relationship between the estimated value of the active power and the estimated value of the reactive power and the PQ relational expression. Judging that the state of the power system is plausible,
The power system state estimation apparatus according to claim 1. The operation plan information further includes load system connection change information indicating a connection change of a load in the load system,
A first PQ relational expression correcting unit that corrects the PQ relational expression based on the load system connection change information;
The power system state estimation apparatus according to claim 1 or 2. The operation plan information further includes an output prediction value of the output fluctuation power generation facility in the load system,
A second PQ relational expression correcting unit that corrects the PQ relational expression based on an output predicted value of the output fluctuation power generation facility;
The power system state estimation apparatus according to any one of claims 1 to 3.

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