JP2016208774A - Transformer reverse power flow control system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a transformer reverse power flow control system capable of taking a reverse power flow countermeasure without using a battery.SOLUTION: When reverse power flow generation on the secondary of a second A transformer Tris detected by a reverse power flow generation monitoring unit 12, a bank shift control unit 16 performs bank shift operation on conditions that a Tr overload examination unit 13 determined that "an overload is not generated in the first A transformer Tr(shift side transformer)" based on the first and second bus loads x, yand the first A transformer rated capacity X, and that the voltage variation ΔV calculated by a ΔV calculation unit 14, based on the first and second bus voltage values V, Vand the first and second reactive power values Q, Qis in an allowable range, and the absolute value of voltage difference between the first and second bus voltage values V, Vis a predetermined voltage value or less.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a transformer reverse power flow control system suitable for taking measures against reverse power flow in a high-voltage distribution system.

  In a photovoltaic power plant connected to a high-voltage distribution system, the amount of photovoltaic power generation is larger than the load current in light load periods, so a reverse power flow occurs on the secondary side of the distribution transformer. There is a risk that the accident current will continue in the event of an upper system accident such as a transmission line accident.

  Therefore, conventionally, a method has been proposed in which a reverse power flow is not generated by installing a battery on the secondary side of the distribution transformer and charging the battery with a solar power generation device (distributed power source). (For example, refer to Patent Document 1 below).

JP 2012-34438 A

However, the method for preventing the reverse power flow by charging the battery with the solar power generation device has the following problems.
(1) The place where the countermeasure against reverse power flow can be taken is limited to the place where the battery is installed on the secondary side of the distribution transformer.
(2) In the place where the battery is not installed on the secondary side of the distribution transformer, it is necessary to install a new battery.
(3) A control device for controlling the battery is required.

  An object of the present invention is to provide a transformer reverse power flow control system capable of taking measures against reverse power flow without using a battery.

The transformer reverse power flow control system of the present invention is a transformer reverse power flow control system (10) for taking measures against reverse power flow in a high-voltage distribution system, and includes a supervisory control system (21) and a distribution automation system (31). A transmission / reception unit (11) for performing transmission / reception of various data and signals between the first and second units installed in the substation based on the flow direction data received from the supervisory control system via the transmission / reception unit A reverse power flow generation monitoring unit (12) for constantly monitoring whether or not a reverse power flow has occurred on the secondary side of the two distribution transformers (Tr _A1 , Tr _A2 ), and the reverse power flow generation monitoring unit When a reverse flow generation detection signal indicating that a reverse flow has occurred is input to the secondary side of the second distribution transformer, the first distribution having a rated capacity larger than that of the second distribution transformer. If the transformer is a shift side transformer Monitor the said second distribution transformer as a power failure side transformer, the power failure side transformer primary side and the primary side circuit breaker installed on the secondary side (CB _A12) and a secondary-side circuit breaker ( CB _A22 ) and is provided between the first bus (# 1B _A ) connected to the shift-side transformer and the second bus (# 2B _A ) connected to the power failure-side transformer. _A bank shift control means for carrying out a bank shift operation by turning on a bus bar breaker (BT _A ), the bank shift control means receiving from the distribution automation system via the transceiver Based on the first and second bus loads (x _A , y _A ) of the first and second buses and the shift-side transformer rated capacity (X _A ) that is the rated capacity of the shift-side transformer, When a bank shift operation is performed, there is an overload on the shift side transformer. If it is determined whether or not an overload occurs in the shift-side transformer, the voltage values of the first and second buses received from the supervisory control system via the transmission / reception unit and invalidity A voltage change amount (ΔV) is calculated based on the first and second bus voltage values (V ₁ , V ₂ ) and the first and second reactive power values (Q ₁ , Q ₂ ), which are power values, If the calculated voltage change amount is within an allowable range, it is determined whether or not an absolute value of a voltage difference between the first and second bus voltage values is equal to or less than a predetermined voltage value, and the first and second When the absolute value of the voltage difference between the bus voltage values is equal to or less than a predetermined voltage value, the bank shift operation is performed.
Here, the bank shift control means, if the calculated voltage change amount is not within an allowable range, tap control of the shift side transformer based on the equipment state data of the shift side transformer received from the distribution automation system If it is determined whether or not tap control of the shift-side transformer is possible, a tap switching instruction signal instructing to perform tap switching of the shift-side transformer is sent to the distribution automation system. If the absolute value of the voltage difference between the first and second bus voltage values is not less than or equal to a predetermined voltage value, the equipment state of the power failure side transformer received from the distribution automation system It is determined whether tap control of the power failure side transformer is possible based on the data. When it is determined that tap control of the power failure side transformer is possible, the tap of the power failure side transformer is determined. The tap switching instruction signal for instructing to perform the conversion may be transmitted via the transceiver to the distribution automation system.
When the bank shift control means generates an overload on the shift-side transformer during the bank shift operation, the first and second bus loads received from the distribution automation system via the transmission / reception unit Based on the rated capacity of the shift side transformer and the rated capacity (Y _A ) of the blackout side transformer, which is the rated capacity of the blackout side transformer, an overload occurs in the shift side transformer and the blackout side transformer after recovery. The first and second buses received from the distribution automation system via the transceiver unit when it is determined that no overload occurs in the shift-side transformer and the power failure-side transformer. Based on the voltage value and the first and second reactive power values, a post-recovery voltage change amount is calculated, and when the calculated post-recovery voltage change amount is within an allowable range, the bus bar breaker is shut off. When The bank shift returning operation to inject the primary circuit breaker and the secondary side circuit breaker may be carried out.
If the calculated voltage change after restoration is not within an allowable range, the bank shift control means performs tap control of the shift-side transformer based on the device state data of the shift-side transformer received from the distribution automation system. When it is determined whether or not it is possible, and when it is determined that tap control of the shift-side transformer is possible, a tap switching instruction signal instructing to perform tap switching of the shift-side transformer is sent to the distribution automation system You may transmit via the said transmission / reception part.
Further comprising a commutation control means, wherein the bank shift control means outputs a commutation examination instruction signal to the commutation control means when the bank shift operation is not performed, and the commutation control means comprises the commutation control means, When the rolling load examination instruction signal is input, the section opening / closing installed between the distribution line (a ₃ ) connected to the second bus and the other distribution line (b ₃ ) from another substation The loader (DM ₂ ) is turned on, and a rolling load operation is performed to shut off any of the plurality of distribution line section switches (DM _{B1 to} DM _Bn ) installed in the other distribution lines. When an overload occurs in the second distribution transformer during operation, the load switch is turned off and the load distribution return switch is turned on, or the plurality of distributions are turned on. Distribution line section opening / closing to be cut off It may be carried out a partial rolling load return operation to change.

The transformer reverse power flow control system of the present invention has the following effects.
(1) When a reverse power flow is detected on the secondary side of the distribution transformer, a bank shift operation is performed, so that a reverse power flow countermeasure can be taken without using a battery.
(2) It is possible to prevent isolated operation by solar power generation at the time of an upper system accident.
(3) Installation of local equipment and modification of trip circuit can be omitted.
(4) As a secondary effect, it is possible to reduce facility construction costs and repair construction costs, to properly operate voltage regulation (LDC circuit), and to reduce the labor of operators.

It is a block diagram which shows the structure of the transformer reverse power flow control system 10 by one Example of this invention. It is a figure for demonstrating the installation relationship of the transformer reverse power flow control system 10 shown in FIG. 1, and a connection relationship with another system. It is a figure which shows an example of the electric power grid | system for demonstrating the transformer reverse power flow control system 10 shown in FIG. 4 is a flowchart for explaining the operation of the transformer reverse power flow control system 10 shown in FIG. 1 when a reverse power flow occurs on the secondary side of the second A transformer Tr _A2 shown in FIG. . 4 is a flowchart for explaining the operation of the transformer reverse power flow control system 10 shown in FIG. 1 when a reverse power flow occurs on the secondary side of the second A transformer Tr _A2 shown in FIG. . It is a flowchart for demonstrating operation | movement of the transformer reverse power flow control system 10 shown in FIG. 1 at the time of bank shift return operation. It is a flowchart for demonstrating operation | movement of the transformer reverse power flow control system 10 shown in FIG. 1 at the time of rolling load return operation and partial rolling load return operation.

  The above object was realized by performing a bank shift operation when it was detected that a reverse power flow occurred on the secondary side of the distribution transformer.

Hereinafter, an embodiment of a transformer reverse power flow control system of the present invention will be described with reference to the drawings.
Hereinafter, the power system shown in FIG. 3A will be described as an example.
In this electric power system, the second A distribution line a ₂ and the B substation out of the first and second A distribution lines a ₁ and a ₂ branched from the first A bus # 1B _A of the A substation. the first and the B bus # 1B second B distribution line b ₂ of the _B first and second B distribution line b ₁ which is branched from, b ₂ of the first section switch DM ₁ Connected through.
Of the third and fourth A distribution lines a ₃ and a ₄ branched from the second A bus line # 2B _A connected to the first A bus line # 1B _A and the A bus line breaker BT _A third a distribution line a ₃ and the first B bus # 1B _B and B busbar breaker BT second B bus # 2B third and fourth branching from _B connected via the _B of Of the B distribution lines b ₃ and b ₄ , the third B distribution line b ₃ is connected via a _second section switch DM ₂ .
In the normal system, the A and B bus bar breakers BT _A and BT _B and the first and second segment switches DM ₁ and DM ₂ are cut off.

The first A bus # 1B _A is connected to the secondary side of the first A transformer Tr _A1 (distribution transformer) via the first A transformer secondary circuit breaker CB _A21 .
The second A bus # 2B _A is connected to the secondary side of the second A transformer Tr _A2 (distribution transformer) and the second A transformer secondary circuit breaker CB _A22 .
The first and second A transformers Tr _A1 and Tr _A2 are capable of switching taps provided on the primary winding to cope with voltage fluctuations of the distribution line when the load or the like changes. It is a tap change transformer at the time of load.
The rated capacity of the first A transformer Tr _A1 (hereinafter referred to as “first A transformer rated capacity X _A ”) is the rated capacity of the second A transformer Tr _A2 (hereinafter referred to as “second A transformer rated capacity Y _A ”)) or more (X _A ≧ Y _A ).

In the A substation, as shown in FIG. 3B, the secondary current value of the first A transformer Tr _A1 (hereinafter referred to as “first secondary current value I ₁ ”) is measured. A _first current transformer CT ₁ is attached between the secondary side of the first A transformer Tr _A1 and the first A transformer secondary circuit breaker CB _A21 .
First voltage transformer PT ₁ for measuring the voltage value of first A bus # 1B _A (hereinafter referred to as “first bus voltage value V ₁ ”) and first A bus # 1B _A first reactive power meter RVA ₁ for measuring the reactive power value of A (hereinafter referred to as “first reactive power value Q ₁ ”) is attached to the first A bus # 1B _A.
The second current transformer CT ₂ for measuring the secondary current value of the second A transformer Tr _A2 (hereinafter referred to as “second secondary current value I ₂ ”) is used as the second A transformer. Between the secondary side of the transformer Tr _A2 and the second A transformer secondary side circuit breaker CB _A22 .
Second instrument transformer PT ₂ for measuring the voltage value of second A bus # 2B _A (hereinafter referred to as “second bus voltage value V ₂ ”) and second A bus # 2B reactive power values of _a (hereinafter, referred to as "second reactive power value Q _2".) the second reactive power meter RVA ₂ for measuring is attached to the second a bus # 2B _a.

In the third A distribution line a ₃ and the third B distribution line b ₃ , as shown by a circle in FIG.
In the following, the two segment switches installed next to the second segment switch DM ₂ of the third B distribution line b ₃ are referred to as “first and second B distribution line segment switches DM _B1 , DM _B2 ".

  A transformer reverse power flow control system 10 (hereinafter referred to as “reverse power flow control system 10”) according to an embodiment of the present invention is installed in a control station and installed in a sales office as shown in FIG. The power distribution automation system 31 and the information collection / distribution device 41 installed in the control relay station are connected to the monitoring control system 21 interconnected via the communication network 1.

Here, the distribution automation system 31 is a sales office in which system status data indicating the system status of each substation, device status data indicating the status of each device, load data indicating the load of each bus and each distribution line, and the like are stored. A database (sales office DB) 32 is provided.
In addition, the distribution automation system 31 controls on / off (on / off) of a busbar breaker, breaker, and section switch, and tap switching of a transformer.

The information collection / delivery device 41 is interconnected with a remote monitoring control device (only the remote monitoring control device 51 installed at the A substation is shown in FIG. 2) installed at each substation. Various measurement data transmitted from the remote monitoring and control device of (the bus voltage value of each bus, the secondary current value of each transformer, the reactive power value of each bus, and the power flow direction on the secondary side of each transformer) Data, etc.) is transmitted to the monitoring control system 21 via the communication network 1.
The supervisory control system 21 is a control station database (control station DB) for storing facility information (including the rated capacity of each transformer) at each substation and various measurement data transmitted from the information collection and distribution device 41. ) 22.

The A substation is based on the remote monitoring control device 51 and the first and second secondary current values I ₁ and I ₂ transmitted from the first and second current transformers CT ₁ and CT _2. A converter 52 for determining the flow direction on the secondary side of the first and second A transformers Tr _A1 and Tr _A2 is installed.
The remote monitoring and control device 51 includes first and second secondary current values I ₁ and I ₂ and first and second instrument transformers PT ₁ and PT ₂ transmitted from the first and second instrument transformers PT ₁ and PT 2. The bus voltage values V ₁ and V ₂ , the first and second reactive power values Q ₁ and Q ₂ transmitted from the first and second reactive power meters RVA ₁ and RVA ₂ , and the input from the converter 42. The first and second power flow direction data D ₁ and D ₂ indicating the determination result of the power flow direction on the secondary side of the first and second A transformers Tr _A1 and Tr _A2 to be sent to the information collection and distribution device 41 Send.

  As shown in FIG. 1, the reverse power flow control system 10 includes a transmission / reception unit 11, a reverse power flow generation monitoring unit 12, and a transformer overload examination unit 13 (hereinafter referred to as “Tr overload examination unit 13”). , A voltage change amount calculation unit 14 (hereinafter referred to as “ΔV calculation unit 14”), a bank shift control unit 15, and a rolling load control unit 16.

  Here, the transmission / reception unit 11 transmits / receives various data, signals, and the like to / from the monitoring control system 21, and also transmits / receives various data and signals to / from the distribution automation system 31 via the monitoring control system 21 and the communication network 1. Send and receive signals etc.

The reverse power flow generation monitoring unit 12 is connected to the first and second A transformers Tr _A1 based on the first and _{second power} flow direction data D ₁ and D ₂ received from the distribution automation system 31 via the transmission / reception unit 11. Whether or not reverse power flow has occurred on the secondary side of Tr _A2 is constantly monitored, and when it is detected that reverse power flow has occurred on the secondary side of the first and second A transformers Tr _A1 and Tr _A2 , A reverse flow generation detection signal indicating this is output to the bank shift control unit 15.

  When the Tr overload examination unit 13 receives an overload examination instruction signal and a post-recovery overload examination instruction signal from the bank shift control unit 15 or a post-recovery overload examination instruction signal from the rolling load control unit 16, A load transmission instruction signal for instructing to transmit load data indicating a load of a bus and a distribution line necessary for the examination stored in the sales office database 32 is transmitted to the distribution automation system 31 via the transmission / reception unit 11, and A rated capacity signal instruction signal for instructing to transmit the rated capacity data indicating the rated capacity of the transformer necessary for the examination stored in the control station database 22 is transmitted to the monitoring control system 21 via the transmission / reception unit 11, Load data received from the distribution automation system 31 via the transmission / reception unit 11 and constant data received from the monitoring control system 21 via the transmission / reception unit 11. Consider whether or not to cause an overload on the basis of the volume data, and outputs an overload study result signal ΔV calculation unit 14, the bank shift control unit 15 and the rolling load controller 16.

When the overload examination result signal indicating that no overload occurs and the post-restoration overload examination result signal are input from the Tr overload examination unit 13, the ΔV calculation unit 14 stores the first stored in the control center database 22. And the bus voltage value / reactive power value transmission instruction signal for instructing to transmit the second bus voltage values V ₁ , V ₂ and the first and second reactive power values Q ₁ , Q _2. To the first and second bus voltage values V ₁ , V ₂ and the first and second reactive power values Q ₁ , transmitted from the supervisory control system 21 via the transceiver 11. A voltage change amount ΔV is calculated based on Q _2, and the calculated voltage change amount ΔV is output to the bank shift control unit 15.

  When the reverse power flow generation detection signal is input from the reverse power flow monitoring unit 12, the bank shift control unit 15 controls the Tr overload examination unit 13 and the ΔV calculation unit 14 to perform a bank shift operation to be described later. When the shift operation is performed, the Tr overload examination unit 13 and the ΔV calculation unit 14 are controlled to perform a bank shift return operation described later.

  When the bank shift operation by the bank shift control unit 15 is not performed, the rolling load control unit 16 performs a rolling load operation which will be described later, and when the rolling load operation is performed, the rolling load return operation or part which will be described later. Perform the rolling load return operation.

Next, the operation of the reverse flow control system 10 when a reverse flow occurs on the secondary side of the second A transformer Tr _A2 will be described with reference to the flowcharts shown in FIGS. 4 and 5.
When the reverse power flow generation monitoring unit 12 detects that a reverse power flow has occurred on the secondary side of the second A transformer Tr _A2 based on the second power flow direction data D ₂ (step S11 in FIG. 4), A reverse flow generation detection signal indicating this is output to the bank shift control unit 15.

When this reverse power flow generation detection signal is input, the bank shift control unit 15 transmits to the distribution automation system 31 a system state transmission instruction signal instructing to transmit system state data indicating the system state of the A substation. Based on the grid state data received from the distribution automation system 31, it is confirmed whether or not the grid state of the A substation is always the grid state (step S12).
As a result, when it is confirmed that the system state of the A substation is always the system state, the bank shift control unit 15 outputs an overload examination instruction signal to the Tr overload examination unit 13.

On the other hand, when it is confirmed that the system state of the A substation is not always the system state, the bank shift control unit 15 determines that “the reverse power flow has occurred on the secondary side of the second A transformer Tr _A2 , A bank shift operation non-execution display signal for displaying “Not implemented” is transmitted to the supervisory control system 21.
As a result, a control console (not shown) connected to the supervisory control system 21 indicates that “the reverse power flow occurred on the secondary side of the second A transformer Tr _A2 but the bank shift operation was not performed”. Is displayed (step S22).

When the overload examination instruction signal is input, the Tr overload examination unit 13 receives loads of the first and second A buses #B _A1 and #B _A2 (hereinafter referred to as “first and second bus load x _A”). , Y _A ”)) is transmitted to the distribution automation system 31, and the first and second bus loads x _A received from the distribution automation system 31 are transmitted to the distribution automation system 31. The bank shift operation based on y _A (in this case, the second A transformer rated capacity Y _A ≦ the first A transformer rated capacity X _A , so the primary of the second A transformer Tr _A2 2nd A substation primary circuit breaker CB _A12 installed on the side and 2nd A substation secondary circuit breaker CB _A22 installed on the secondary side of second A transformer Tr _A2 overload or not occur when carrying out the operation) to inject a busbar breaker BT _a causes the To consider (step S13).
As a result, if X _A [MVA]> x _A [MVA] + y _A [MVA], the Tr overload review unit 13 determines that “no overload occurs” and indicates overload indicating that effect. The result signal is output to the ΔV calculator 14.

On the other hand, if X _A [MVA] ≦ x _A [MVA] + y _A [MVA], the Tr overload examination unit 13 determines that “overload occurs” and indicates an overload examination result signal indicating that effect. Is output to the bank shift control unit 15.
When the overload examination result signal indicating that an overload occurs is input, the bank shift control unit 15 outputs a commutation examination instruction signal to the commutation control unit 16.

When the overload examination result signal indicating that no overload occurs is input to the ΔV calculation unit 14, the first and second bus voltage values V ₁ and V ₂ and the first and second reactive power values Q ₁ , Q ₂ are transmitted to the supervisory control system 21 and the first and second bus voltage values V ₁ , V received from the supervisory control system 21 are transmitted to the supervisory control system 21. ₂ and the first and second reactive power values Q ₁ and Q ₂ are calculated (Step S14).

At this time, the first bus voltage value V ₁ = 6.7 [kV], the second bus voltage value V ₂ = 6.55 [kV], the first reactive power value Q ₁ = −2 [Var], When the second reactive power value Q ₂ = −3 [Var] and the percent reactance% X _A = 8 [%] of the first A transformer Tr _A1 , the voltage change amount ΔV is calculated by the following equation. The
ΔV = V ₁ × [{% X _A × (Q ₁ −Q ₂ )} / 10] / 100
= 6.7 × [{8 × {-2-(-3)} / 10] / 100
= 6.7 × 1.6 / 100
= 0.05 [kV]
The ΔV calculating unit 14 calculates the calculated voltage change amount ΔV = 0.05 [kV], the first bus voltage value V ₁ = 6.7 [kV], and the second bus voltage value V ₂ = 6.55 [kV]. ] Is output to the bank shift control unit 15.

The bank shift control unit 15 determines whether or not the input voltage change amount ΔV = 0.05 [kV] is within an allowable range (step S15).
At this time, if the system reference voltage V ₀ = 6.6 [kV], the system maximum voltage Vmax = 6.765 [kV], and the system minimum voltage Vmin = 6.435 [kV], the allowable range of the voltage variation ΔV is ,
Vmin−V ₁ <ΔV <Vmax−V ₁
6.435-6.7 <ΔV <6.765-6.7
−0.265 [kV] <ΔV <0.065 [kV]
It becomes.

As a result, since the voltage change amount ΔV = 0.05 [kV] is within the allowable range, the bank shift control unit 15 determines the voltage difference between the first bus voltage value V ₁ and the second bus voltage value V _2. absolute value _{(= | V 1 -V 2 |} ) of determining whether or not equal to or less than 2.5% of the system reference voltage V ₀ (operation target voltage value) (step S16).
At this time, the absolute value of the voltage difference between the first bus voltage value V ₁ = 6.7 [kV] and the second bus voltage value V ₂ = 6.55 [kV] = | 6.7−6.55 | = 0.15 [kV], 2.5 [%] of the system reference voltage V ₀ = 0.025 × 6.6 = 0.165 [kV], and therefore, the first bus voltage value V ₁ The absolute value of the voltage difference from the _second bus voltage value V ₂ is 2.5% or less of the system reference voltage V ₀ .
Therefore, the bank shift control unit 15 determines that “the bank shift operation is possible”, and the second A transformer primary circuit breaker CB _A12 and the second A transformer secondary circuit breaker CB _A22. and transmits the circuit breaker closing / interrupting instruction signal instructing to put a busbar breaker BT _a in distribution automation system 31 with blocking.
Thus, the second A transformer primary circuit breaker CB _A12 and A busbar breaker BT _A together with the second A transformer secondary breaker CB _A22 is interrupted is switched on by the distribution automation system 31 Thus, the reverse power flow generated on the secondary side of the second A transformer Tr _A2 is eliminated (step S17).

On the other hand, in step S14, the first bus voltage value V ₁ = 6.7 [kV], the first reactive power value Q ₁ = −4 [Var], and the second reactive power value Q ₂ = −6 [Var. ] And the percent reactance% X _A = 8 [%] of the first A transformer Tr _A1 , the voltage change amount ΔV is
ΔV = V ₁ × {% X _A × (Q ₁ −Q ₂ ) / 10} / 100
= 6.7 * [8 * {-4-(-6)} / 10} / 100
= 6.7 × 1.6 / 100
= 0.1 [kV]
Therefore, in step S15, −0.265 [kV] <ΔV <0.065 [kV] is not satisfied.
Therefore, the bank shift control unit 15 transmits a device state transmission instruction signal that instructs to transmit device state data indicating the device state of the first A transformer Tr _A1 (shift side transformer) to the distribution automation system 31. Then, it is determined whether tap control of the first A transformer Tr _A1 is possible based on the device state data received from the distribution automation system 31 (step S18).

As a result, when the tap control of the first A transformer Tr _A1 is possible, the bank shift control unit 15 instructs the tap switching instruction signal to perform the tap switching of the first A transformer Tr _A1. Is transmitted to the distribution automation system 31 (step S19), and the operation from step S14 is repeated.

In step S16, when the first bus voltage value V ₁ = 6.7 [kV] and the second bus voltage value V ₂ = 6.5 [kV], the first bus voltage value V The absolute value of the voltage difference between ₁ and the second bus voltage value V ₂ = | 6.7−6.5 | = 0.2 [kV], and the first bus voltage value V ₁ and the second bus voltage The absolute value of the voltage difference from the value V ₂ is larger than 2.5% (= 0.165 [kV]) of the system reference voltage V ₀ .
Therefore, the bank shift control unit 15 transmits to the distribution automation system 31 a device state transmission instruction signal instructing to transmit device state data indicating the device state of the second A transformer Tr _A2 (power failure side transformer). Then, it is determined whether or not the tap control of the second A transformer Tr _A2 is possible based on the device state data received from the distribution automation system 31 (step S20).

As a result, when the tap control of the second A transformer Tr _A2 is possible, the bank shift control unit 15 instructs the tap switching instruction signal to perform the tap switching of the second A transformer Tr _A2. Is transmitted to the distribution automation system 31 (step S21), and the operation from step S16 is repeated.

On the other hand, if the tap control of the first A transformer Tr _A1 is not possible in step S18 or the tap control of the second A transformer Tr _A2 is not possible in step S20, the bank shift control unit 15 outputs a rolling load examination instruction signal to the rolling load control unit 16.

When the commutation control instruction signal is input, the commutation load control unit 16 receives the grid state data of the A substation and the B substation, the second A transformer Tr _A2, and the second B substation distribution transformer Tr. A system state / load data transmission instruction signal instructing to transmit the load data of _B2 is transmitted to the distribution automation system 31.
The commutation load control unit 16 receives the system state of the A substation and the B substation received from the distribution automation system 31 and the loads of the second A transformer Tr _A2 and the second B substation distribution transformer Tr _B2. Based on this, whether or not the rolling load operation is possible is examined as follows.

The rolling load control unit 16 is connected between an additional load (= first division switch DM ₁ and first B distribution line division switch DM _B1 added by a rolling load operation in the first pattern. It is determined whether or not the first load zb ₁ ) is greater than the required rolling load z ₀ (step S30 in FIG. 5).

As a result, when the additional load (= zb ₁ ) is larger than the required amount of rolling load z ₀ , the rolling load control unit 16 determines whether or not the rolling load operation is possible (whether the facility is overloaded, the rolling load). It is determined whether or not the source is a reverse power flow, whether there is a working / power failure line, or there is no problem in the system configuration (step S31).

As a result, when it is determined that “the rolling load operation is possible”, the rolling load control unit 16 turns on the second section switch DM ₂ and inputs the first division switch DM ₂ in order to perform the rolling load operation in the first pattern. The B distribution line division switch DM _B1 is transmitted to the distribution automation system 31 (step S32).
As a result, the second section switch DM ₂ is turned on, the first B distribution line section switch DM _B1 is shut off, and the first load zb ₁ is disconnected from the third B distribution line b _3. Connected to the third A distribution line a ₃ .

On the other hand, when the additional load (= zb ₁ ) is less than or equal to the required amount of rolling load z ₀ in step S30 or when it is determined in step S31 that “the rolling load operation is not possible”, the rolling load control unit 16 Additional load (= (first load zb ₁ ) + (first and second B distribution line section switches DM _B1 and DM _B2 connected between the first and second B distribution line switches) is added by the rolling load operation in the second pattern. It is determined whether or not the _second load zb ₂ )) is greater than the required rolling load z ₀ (step S33).

As a result, when the additional load (= zb ₁ + zb ₂ ) is larger than the required amount of rolling load z ₀ , the rolling load control unit 16 determines whether or not the rolling load operation is possible (step S34). If it is determined that the rolling load operation is possible, the second segment switch DM ₂ is turned on and the second B distribution line segment switch DM _B2 is shut off in order to perform the rolling load operation in the second pattern. The division switch on / off instruction signal instructing to do is transmitted to the distribution automation system 31 (step S35).
As a result, the second section switch DM ₂ is turned on, the second B distribution line section switch DM _B2 is shut off, and the first and second loads zb ₁ and zb ₂ are switched to the third B distribution. It is cut off from the electric wire b ₃ and connected to the _third A distribution line a ₃ .

On the other hand, if the additional load (= zb ₁ + zb ₂ ) is less than or equal to the required amount of rolling load z ₀ in step S33 or if it is determined that “the rolling load operation is not possible” in step S34, the rolling load control unit 16 Is the same up to the maximum additional load (= (first load zb ₁ ) + (second load zb ₂ ) +... + (Nth load zb _n )) that can be added by the rolling load operation. Operation is performed (steps S36 to S38).

If the additional load (= zb ₁ + zb ₂ +... + Zb _n ) is less than or equal to the required amount of rolling load z _{0 in} step S 36 or if it is determined in step S 37 that “the rolling load operation is not possible”, The load control unit 16 monitors and controls a non-loading operation non-execution display signal for displaying that “the reverse power flow has occurred on the secondary side of the second A transformer Tr _A2 but the rolling load operation has not been performed”. The data is output to the system 21 (step S39).
As a result, the control console connected to the supervisory control system 21 displays that “the reverse power flow has occurred on the secondary side of the second A transformer Tr _A2 but the commutation operation has not been performed”. .

Next, the operation of the reverse power flow control system 10 when an overload occurs during the bank shift operation will be described with reference to the flowchart shown in FIG.
When the bank shift operation is performed in step S <b> 17 shown in FIG. 4, the bank shift control unit 15 outputs an overload monitoring instruction signal to the Tr overload review unit 13.

When the overload monitoring instruction signal is input, the Tr overload examination unit 13 instructs to transmit load data indicating the load of the first A transformer Tr _A1 (shift-side transformer). Is transmitted to the distribution automation system 31, and based on the load of the first A transformer Tr _A1 received from the distribution automation system 31, it is monitored whether or not an overload occurs in the first A transformer Tr _A1 . When overload occurs, an overload generation signal is output to the bank shift control unit 15 (step S41 in FIG. 6).

  When the overload generation signal is input, the bank shift control unit 15 transmits a system state transmission instruction signal instructing to transmit system state data indicating the system state of the substation A to the distribution automation system 31, and Based on the system state of the A substation received from the automation system 31, it is determined whether recovery is possible (that is, whether the system state of the A substation can always be returned to the system state) (step S42).

As a result, if it is determined that “restoration is possible”, the bank shift control unit 15 examines whether or not an overload occurs in the first and second A transformers Tr _A1 and Tr _A2 after the restoration. The post-recovery overload examination instruction signal instructing the above is output to the Tr overload examination unit 13.

When the post-restoration overload examination instruction signal is input, the Tr overload examination unit 13 outputs a load transmission instruction signal that instructs to transmit load data indicating the first and second bus loads x _A and y _A. A load / rated capacity transmission instruction signal for instructing to transmit the rated capacity data indicating the first and second A transformer rated capacities X _A and Y _A is transmitted to the distribution control system 31 and to the monitoring control system 21. To do.
The Tr overload examination unit 13 includes the first and second bus loads x _A and y _A received from the distribution automation system 31 and the first and second A transformer rated capacities X _A and Based on Y _A , it is examined whether or not an overload occurs in the first and second A transformers Tr _A1 and Tr _A2 after restoration (step S43).

As a result, when the first and second bus loads x _A and y _A are smaller than the first and second A transformer rated capacities X _A and Y _A (x _A <X _A and y _A <Y _A ) The Tr overload review unit 13 determines that “no overload occurs” and outputs a post-recovery overload review result signal indicating that to the ΔV calculation unit 14.

On the other hand, when the first bus load x _A is greater than or equal to the first A transformer rated capacity X _A or the second bus load y _A is greater than or equal to the second A transformer rated capacity Y _A (x _{When A} ≧ X _A or y _A ≧ Y _A ), the Tr overload review unit 13 determines that “overload occurs” and sends a post-recovery overload review result signal indicating that to the bank shift control unit 15. Output to.

When the post-restoration overload examination result signal indicating that no overload occurs is input to the ΔV calculation unit 14, the first and second bus voltage values V ₁ and V ₂ and the first and second reactive power values A bus voltage value / reactive power value transmission instruction signal instructing to transmit Q ₁ and Q ₂ is transmitted to the supervisory control system 21, and the first and second bus voltage values V ₁ received from the supervisory control system 21. , V ₂ and the first and second reactive power values Q ₁ , Q ₂ are calculated, and the calculated voltage change ΔV is output to the bank shift controller 15 (step S44). .

  When the voltage change amount ΔV is input from the ΔV calculation unit 14, the bank shift control unit 15 determines whether or not the voltage change amount ΔV is within an allowable range (step S45).

As a result, if it is determined that "the voltage change amount ΔV is within the allowable range" bank shift control unit 15, to implement the bank shift returning operation, as well as blocking the A busbar breaker BT _A second A circuit breaker on / off instruction signal instructing to _turn on the A substation primary circuit breaker CB _A12 and the second A substation secondary circuit breaker CB _A22 is transmitted to the distribution automation system 31 (step S46). .

On the other hand, if it is determined that “the voltage change amount ΔV is not within the allowable range”, the bank shift control unit 15 transmits device state data indicating the device state of the first A transformer Tr _A1 (shift-side transformer). It transmits a device status transmission instruction signal instructing to the distribution automation system 31, tap control of the first of the first based on the device status data of the a transformer Tr _A1 of a transformer Tr _A1 received from the distribution automation system 31 It is determined whether or not it is possible (step S47).

As a result, when it is determined that “the tap control of the first A transformer Tr _A1 is possible”, the bank shift control unit 15 instructs the tap switching of the first A transformer Tr _A1 to perform the tap switching. After transmitting the instruction signal to the distribution automation system 31 (step S48), the operation from step S44 is repeated.

The bank shift control unit 15 determines that “restoration is not possible” in step S42, receives a post-restoration overload examination result signal indicating that overload occurs in step S43, If it is determined that the tap control of the A transformer Tr _A1 is not possible, a message is displayed indicating that an overload occurred during the bank shift operation but the bank shift return operation was not performed. A bank shift return operation non-execution display signal is output to the supervisory control system 21 (step S49).
As a result, the control console connected to the supervisory control system 21 displays that “overload occurred during the bank shift operation but the bank shift return operation was not performed”.

Next, with regard to the operation of the reverse power flow control system 10 when an overload occurs during the execution of the rolling load operation, a case where the rolling load operation is performed in the nth pattern in step S38 shown in FIG. This will be described with reference to the flowchart shown in FIG.
When the rolling load operation is performed in the nth pattern, the rolling load control unit 16 outputs an overload monitoring instruction signal to the Tr overload examination unit 13.

When the overload monitoring instruction signal is input, the Tr overload examination unit 13 sends a load transmission instruction signal for instructing to transmit load data indicating the load of the second A transformer Tr _A2 to the distribution automation system 31. transmitted monitors whether the overload to the second a transformer Tr _A2 based on the load data of the second a transformer Tr _A2 received from the distribution automation system 31 does not occur, the overload occurs, excessive The load generation signal is output to the rolling load control unit 16 (step S51 in FIG. 7).

The rolling load controller 16, an overload occurrence signal is input, the second B bus # 2B _B to the connected load (hereinafter. Referred to as "B bus loads y _B") loads data indicating the A load transmission instruction signal for instructing transmission is transmitted to the distribution automation system 31, and the rated capacity of the second B transformer Tr _B2 (hereinafter referred to as “B transformer rated capacity Y _B ”) is transmitted. A load / rated capacity transmission instruction signal is transmitted to the supervisory control system 21.
The commutation load controller 16 receives the B bus load data y _B received from the distribution automation system 31 in order to determine whether or not recovery is possible (that is, whether or not the system state of the B substation can be always returned to the system state). and based on the B transformer and the rated capacity Y _B received from the monitoring control system 21, greater than the second B bus # 2B rolling load can amount Y _B -y _B is the rolling load in the load amount y ₀ to _B It is determined whether or not (step S52).

As a result, when it is determined that “the possible load amount Y _B −y _B is greater than the load amount y ₀ during the load,” the load control unit 16 determines whether or not the load change return operation is possible (at the B substation). If there is no working / power outage line or if there is no problem in the system configuration, etc.) (step S53), and if it is determined that “the operation to return the load can be performed”, the nth B distribution line section switch DM A section switch on / off instruction signal for instructing to shut off the _second section switch DM2 is transmitted to the distribution automation system 31 by turning on _Bn , and a rolling load return operation is performed (step S54).

On the other hand, the rolling load control unit 16 determines in step S52 that “the possible load load Y _B −y _B is less than or equal to the load amount y ₀ during the rolling load and cannot always be returned to the system state” or “ If it is determined that the rolling load return operation is not possible, it is determined whether or not a partial rolling load return operation in the first pattern (operation to return the first B distribution line section switch DM _B1 to a shut-off state) is possible. to determine, the rolling load can amount Y _B return amount rolling load -y _B is the second B bus # 2B _B obtained when cutting off the first B distribution line sectionalizing switches DM _B1 y ₀ -zb ₁ It is determined whether it is larger than (step S55).

As a result, when it is determined that “the possible amount of rolling load Y _B −y _B is greater than the amount of rolling load return y ₀ −zb ₁ and the partial rolling load return operation in the first pattern is possible”, the rolling load control unit 16 determines whether or not the rolling load return operation is possible (step S56). When it is determined that “the rolling load return operation is possible”, the n-th B distribution line section switch DM _Bn is turned on. A section switch on / off signal for instructing to disconnect one B distribution line section switch DM _B1 is transmitted to the distribution automation system 31 to perform a partial load reversion operation in the first pattern (step S57). ).

On the other hand, the rolling load control unit 16 determines in step S55 that “the possible rolling load Y _B −y _B is less than or equal to the rolling load return amount y ₀ −zb ₁ , and the partial rolling load return operation in the first pattern is not possible”. Or when it is determined in step S56 that “the rolling load return operation is not possible”, the partial rolling load operation in the second pattern (the second B distribution line section switch DM _B2 is returned to the shut-off state). to determine whether the operation) is possible, rotation of the second B bus # 2B _B at the time when the rolling load can amount Y _B -y _B blocked the second B distribution line section switch DM _B2 It is determined whether or not the load return amount y ₀ − (zb ₁ + zb ₂ ) is larger (step S58).

As a result, when it is determined that “the possible amount of rolling load Y _B −y _B is larger than the amount of rolling load return y ₀ − (zb ₁ + zb ₂ ), a partial rolling load return operation in the second pattern is possible” The roll load control unit 16 determines whether or not the roll load return operation is possible (step S59). If it is determined that the roll load return operation is possible, the nth B distribution line division switch DM _Bn is set. When the switch is turned on, a section switch on / off signal is sent to the distribution automation system 31 to instruct to shut off the second B distribution line section switch DM _B2 , and a partial load reversal operation is performed in the second pattern. (Step S60).

On the other hand, in step S58, the rolling load control unit 16 determines that the “possible rolling load amount Y _B −y _B is less than or equal to the rolling load return amount y ₀ − (zb ₁ + zb ₂ ), and the partial rolling load return operation in the second pattern. If it is determined that "the rolling load return operation is not possible" in step S59, the same operation is repeated until the partial rolling load return operation in the nth pattern is possible. (Steps S61 to S63).

In step S61, the rolling load control unit 16 determines that “the loadable amount Y _B −y _B is equal to or less than the rolling load return amount y ₀ − (zb ₁ + zb ₂ +... + Zb _n ), If it is determined that the partial load-returning operation is not possible, or if it is determined in step S62 that the partial load-returning operation is not possible, an error message indicating that an overload has occurred during the execution of the rolling load operation. Then, a roll load return operation non-execution display signal indicating that “the roll load return operation and the partial roll load return operation have not been performed” is output to the monitoring control system 21 (step S64).
As a result, the control console connected to the supervisory control system 21 displays that “the overload occurred during the rolling load operation, but the rolling load return operation and the partial rolling load return operation were not performed”. The

DESCRIPTION OF SYMBOLS 1 Communication network 10 Reverse power flow control system 11 Transmission / reception part 12 Reverse power flow generation | occurrence | production monitoring part 13 Tr overload examination part 14 ΔV calculation part 15 Bank shift control part 16 Roll load control part 21 Monitoring control system 22 Control station database 31 Distribution automation system 32 Sales office database 41 Information collection / distribution device 51 Remote monitoring control device 52 Converters #B _A1 , #B _A2 first and second A buses #B _B1 , #B _{B 2} first and second B buses a ₁ to a ₄ of the first to fourth a distribution line b ₁ ~b ₄ of the first to fourth B distribution line Tr _A1, Tr _A2 first and second a transformer Tr _B1, Tr _B2 first and second B transformers CB _A11 , CB _A12 first and second A transformer primary circuit breakers CB _A21 , CB _A22 first and second A transformer secondary circuit breakers BT _A , BT _B A and B buses Communication breaker DM ₁ , DM ₂ first and second section Switches DM _B1 , DM _B2 first and second B distribution line section switches CT ₁ , CT ₂ first and second current transformers PT ₁ , PT ₂ first and second instrument transformers RVA ₁ , RVA ₂ first and second reactive power meters I ₁ , I ₂ first and second secondary current values V ₁ , V ₂ first and second bus voltage values V ₀ system reference voltage Vmax system maximum voltage Vmin system minimum voltage D ₁ , D ₂ first and second power flow direction data X _A , Y _A first and second A transformer rated capacity Y _B B transformer rated capacity x _A , y _A first and second 2 bus load y _B B bus load y ₀ load amount during z load z ₀ required load zb _{1 to} zb _n 1st to nth loads S11 to S21, S30 to S39, S41 to S49, S51 to S64 Steps

Claims (5)

A transformer reverse power flow control system (10) for taking measures against reverse power flow in a high voltage distribution system,
A transmission / reception unit (11) for performing transmission / reception of various data and signals between the monitoring control system (21) and the distribution automation system (31);
Based on the power flow direction data received from the supervisory control system via the transmitter / receiver, reverse power flows to the secondary side of the first and second distribution transformers (Tr _A1 , Tr _A2 ) installed in the substation. A reverse power flow generation monitoring unit (12) for constantly monitoring whether or not
When a reverse power flow generation detection signal indicating that a reverse power flow has occurred is input from the reverse power flow generation monitoring unit to the secondary side of the second power distribution transformer, the rated capacity becomes the second power distribution transformer. The first distribution transformer that is larger than the first distribution transformer is a shift-side transformer and the second distribution transformer is a blackout-side transformer, and is installed on the primary side and the secondary side of the blackout-side transformer. In addition, the primary circuit breaker (CB _A12 ) and the secondary circuit breaker (CB _A22 ) are cut off, and the first bus (# 1B _A ) connected to the shift-side transformer and the blackout-side transformer are connected. Bank shift control means for performing a bank shift operation by inserting a bus bar breaker (BT _A ) provided between the second bus bar (# 2B _A ) and
The bank shift control means is
The first and second bus loads (x _A , y _A ) of the first and second buses received from the power distribution automation system via the transceiver unit and the shift side which is the rated capacity of the shift side transformer Based on the rated transformer capacity (X _A ), when the bank shift operation is carried out, whether or not an overload occurs in the shift side transformer,
When it is determined that no overload occurs in the shift-side transformer, the first and second voltage values and reactive power values of the first and second buses received from the supervisory control system via the transmission / reception unit Voltage variation (ΔV) is calculated based on the bus voltage values (V ₁ , V ₂ ) and the first and second reactive power values (Q ₁ , Q ₂ ),
When the calculated voltage change amount is within an allowable range, it is determined whether or not the absolute value of the voltage difference between the first and second bus voltage values is equal to or less than a predetermined voltage value;
When the absolute value of the voltage difference between the first and second bus voltage values is equal to or lower than a predetermined voltage value, the bank shift operation is performed.
This is a transformer reverse power flow control system. The bank shift control means is
If the calculated voltage change amount is not within an allowable range, it is determined whether tap control of the shift-side transformer is possible based on device state data of the shift-side transformer received from the distribution automation system. When it is determined that tap control of the shift-side transformer is possible, a tap switching instruction signal instructing to perform tap switching of the shift-side transformer is transmitted to the distribution automation system via the transmission / reception unit,
If the absolute value of the voltage difference between the first and second bus voltage values is not less than or equal to a predetermined voltage value, based on the equipment state data of the power failure side transformer received from the power distribution automation system, the power failure side transformer When it is determined whether tap control is possible, and when it is determined that tap control of the power failure side transformer is possible, a tap switching instruction signal for instructing to perform tap switching of the power failure side transformer is transmitted to the power distribution Transmitting to the automation system via the transceiver.
The transformer reverse power flow control system according to claim 1, wherein: The bank shift control means is
When an overload occurs in the shift-side transformer during the bank shift operation,
The first and second bus loads, the shift-side transformer rated capacity, and the power failure-side transformer rated capacity (Y _A ) that is the rated capacity of the power failure-side transformer received from the power distribution automation system via the transmission / reception unit. ) And whether or not an overload occurs on the shift side transformer and the power failure side transformer after restoration,
When it is determined that no overload occurs in the shift-side transformer and the power failure-side transformer, the first and second bus voltage values received from the distribution automation system via the transmission / reception unit, and the first and second Based on the reactive power value of 2, calculate the amount of voltage change after recovery,
When the calculated post-recovery voltage change amount is within an allowable range, a bank shift return operation is performed in which the bus bar breaker is cut off and the primary breaker and the secondary breaker are turned on.
The transformer reverse power flow control system according to claim 1 or 2, characterized by the above.   If the calculated voltage change after restoration is not within an allowable range, the bank shift control means performs tap control of the shift-side transformer based on the device state data of the shift-side transformer received from the distribution automation system. When it is determined whether or not it is possible, and when it is determined that tap control of the shift-side transformer is possible, a tap switching instruction signal instructing to perform tap switching of the shift-side transformer is sent to the distribution automation system The transformer reverse power flow control system according to claim 3, wherein the transmission is performed via the transmission / reception unit. A rolling load control means;
When the bank shift control means does not perform the bank shift operation, outputs a commutation consideration instruction signal to the commutation control means,
When the commutation control means receives the commutation examination instruction signal, the distribution line (a ₃ ) connected to the second bus and another distribution line (b ₃ ) from another substation Rolling load that shuts off any of the distribution line division switches (DM _{B1 to} DM _Bn ) installed in the other distribution lines while turning on the division switch (DM ₂ ) installed between Perform the operation,
When an overload occurs in the second distribution transformer during the execution of the rolling load operation, the rolling load return operation or the plurality of load switching operations to shut off the section switch and to input the blocked distribution line section switch Carry out partial rolling load return operation to change the distribution line section switch to be cut off among the individual distribution line section switches.
The transformer reverse power flow control system according to any one of claims 1 to 4, wherein

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