JP5269524B2 - Distributed control method for each substation in the power system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control method of an electric power system, which performs distributed control of substations of an electric power system. <P>SOLUTION: In an electric power system 10 with a plurality of substations A-T connected from the power transmission end to the power reception end, a controller is added to each of the substations A-T. Letting an active power and reactive power at the power transmission end of each substation A-T be a load of the substation, the controller of each substation A-T calculates the load of the corresponding substation from the power reception end to the power transmission end, and then calculates a transmission voltage which can supply the calculated load at each substation A-T. When any transmission voltage calculated for each substation A-T comes out of a predetermined range, a substation adjacent to the substation of which the transmission voltage comes out of the predetermined range is asked to make voltage adjustment and to perform an adjustment operation of a phase modifier to keep the transmission voltage within the predetermined range. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a distributed control method for each substation in a power system, and more particularly to a technique for performing distributed control of a transmission voltage or the like of each substation in a power system.

Conventionally, as a method of controlling the power system, there is a method of centrally controlling the power system (see, for example, Non-Patent Documents 1 and 2 and Patent Document 1).
In the case of centralized control of the power system, the information is concentrated in the center, so grasp the overall system configuration status (check the switching status of the switch, collect system information in the computer), analyze it, The next state will be determined. Therefore, a matrix calculation is performed based on all information to obtain a solution. And since recalculation is performed every time, accuracy becomes high.
In this case, when a power transmission line failure occurs in the radial power system, a power failure occurs from the power transmission line to the end side. For this reason, in order to restore this power failure, it is necessary to connect to another power system. Therefore, a new connection destination is selected at the time of failure recovery. It must be considered that the voltage up to the end of can be kept within the specified value.
Other than fault recovery, the same algorithm can be used to bring the normal grid state into a state with sufficient margins, and the importance of inquiries such as loads between substations and transmission voltages can be appropriately managed. The data to be used will be centrally managed.
Junji Kondo, Hirohisa Aki, Hiroshi Yamaguchi, Masanobu Murata, Satoshi Ishii, “Voltage Adjustment of Distribution System by Hierarchical Coordination Control”, Electrical Engineering B, Vol. 126, No. 10, published by The Institute of Electrical Engineers of Japan, 2006 Takenori Sugaya, Hiroshi Inoue, Hiroshi Oda, Shigeru Iizuka, “Development of a Disaster Recovery Operation Method in a Local Supply System”, Electrology B, Vol. 109, No. 4, published by the Institute of Electrical Engineers of Japan in 1989 JP 2002-165367 A

However, the above-described centralized control method has a problem that all information on the power system to be managed is necessary. Furthermore, since the information is concentrated, the reliability of the operation of the central portion of the apparatus must be very high.
In the case of centralized control, since all information is collected, calculation similar to distributed control can be performed by incorporating an algorithm. However, in order to centrally control many substations, the system is complicated. It is considered that the construction (construction) of equipment and the renewal and maintenance of equipment become difficult. That is, although the basic algorithm is simple, there is a concern that the method of configuring the algorithm is complicated and a problem occurs.
Therefore, an object of the present invention is to solve the above-mentioned problem, and not to collect all the information in the central part, but to distribute the power transmission voltage etc. of each substation of the power system. It is to provide a control method for each substation.

In order to solve the above-mentioned problem, the invention according to claim 1 is a power system in which a plurality of substations are connected from a power transmission end side to a power receiving end side, and a control device is added to each of the plurality of substations. the active and reactive power at the sending end of the substation and the load of each substation, the substation as a terminal of the receiving end, the control unit calculates the transmission voltage that can supply the load of the substation, was calculated Transmits the transmission voltage data to the adjacent substation on the transmission end side, and then, at each substation where the transmission voltage data is transmitted, the control unit responds to the transmitted transmission voltage data by the substation. Calculate a load, calculate a transmission voltage that can supply the calculated load at the substation, and if the substation where the calculation of the transmission voltage is not a substation at the end of the transmission end, Voltage data to the transmission end The sending to the next substation, further, when the transmission voltage of each substation with the calculated deviates from a predetermined range, the adjustment operation of the voltage regulator and phase modifying equipment to substation next to each substation The distributed control method for each substation of the power system is characterized in that the transmission voltage is requested to fall within the predetermined range.

According to the first aspect of the present invention, in a power system in which a plurality of substations are connected from the power transmission end side to the power receiving end side, a control device added to the substation serving as the terminal on the power receiving end side is connected to the terminal on the power receiving end side. The substation load and the transmission voltage that can supply this load are calculated, and then the active power corresponding to the transmission voltage calculated by the substation on the receiving end side in the control device of each substation on the transmission end side and An operation of calculating a load that is reactive power and calculating a transmission voltage that can supply the load is sequentially performed from the power receiving end side toward the power transmitting end side . Further, when the calculated transmission voltage of each substation is out of a predetermined range, the substation adjacent to each substation is requested to perform voltage adjustment and adjustment operation of the phase adjusting equipment, and the transmission voltage is set to a predetermined value. Fit in range. For this reason, the transmission voltage of each substation can be always kept in a predetermined range.

The invention according to claim 2 is the distributed control method for each substation of the power system according to claim 1, wherein when the calculated transmission voltage of each substation is out of a predetermined range, the control device for each substation Adjusts the voltage and phase adjustment equipment of each substation, and if the adjustment cannot be performed only within each substation, the voltage adjustment and adjustment of the phase adjustment equipment to the substation adjacent to each substation. The substation that has requested the operation and the requested substation performs the adjustment operation if the requested adjustment operation is possible. If the requested adjustment operation is not possible, the substation is further transferred to the adjacent substation. wherein by to making a request that the transmission voltage is distributed control method for each substation of the power system, characterized in that accommodated in the predetermined range.

According to the second aspect of the present invention, when the calculated transmission voltage of each substation is out of a predetermined range, the transmission voltage of each substation is predetermined by adjusting the voltage of each substation itself and adjusting the phase adjusting equipment. If it can be within the range, it is not necessary to ask the adjacent substation for voltage adjustment and phase adjustment equipment adjustment. In addition, the substation where the requested adjustment operation is impossible makes a request to the adjacent substation to realize the requested adjustment operation.

Furthermore, in the power system in which a plurality of substations are connected from the power transmission end side to the power receiving end side, a control device is added to each of the plurality of substations, and the power transmission end of each substation is provided. The active power and reactive power at the substations are set as loads of the substations, and the control device calculates the loads of the substations from the power receiving end side to the power transmission end side, and then calculates the calculated loads at the substations. Calculate the transmission voltage that can be supplied, and when the calculated transmission voltage of each substation is out of the predetermined range, request the substation next to each substation to perform voltage adjustment and phase adjustment equipment adjustment operation Then, the power transmission voltage is stored in the predetermined range, and when the load on the power receiving side (including the power receiving end side) is increased or decreased in advance, by the control device for the power receiving side substation, Negative power station substation And, based on the electrical constant of the transmission line connecting the power transmission side substation and the power receiving side substation, calculate the load at the power transmission end of the power transmission side substation transmitting power to the power receiving side substation, Report the calculated load value to the power transmission side substation control device, repeat the load calculation and notification to the power transmission end side substation, and then transmit the power transmission side substation control device. To notify the control device of the power receiving substation of the power transmitting end substation capable of supplying the reported load to the power receiving substation control device, and to increase or decrease the load of the voltage reporting substation It is a distributed control method of each substation of the electric power system characterized by repeating until.

According to the third aspect of the present invention, in the power system in which a plurality of substations are connected from the power transmission end side to the power receiving end side, the control device added to the plurality of substations receives the load of each substation from the power receiving end side. The calculation is sequentially performed up to the power transmission end side, and then the transmission voltage that can supply the calculated load at each substation is calculated. Further, when the calculated transmission voltage of each substation is out of a predetermined range, the substation adjacent to each substation is requested to perform voltage adjustment and adjustment operation of the phase adjusting equipment, and the transmission voltage is set to a predetermined value. Fit in range. For this reason, the transmission voltage of each substation can be always kept in a predetermined range. Further, when increasing or decreasing the load on the power receiving side substation, the power receiving side substation load and the power transmitting side substation and the power receiving side substation are controlled in advance by the power receiving side substation control device. The load at the power transmission end of the power transmission side substation that transmits power to the power receiving side substation is calculated based on the electrical constant of the power transmission line connecting the power transmission line to the power transmission side. For this reason, when increasing or decreasing the load of the substation, it is possible to examine in advance whether the transmission voltage of each substation by the increase or decrease of the load falls within a predetermined range at the substation side that increases or decreases the load. .

According to the first aspect of the present invention, only necessary information (load and transmission voltage) of each substation in the power system is transmitted to the adjacent substation on the power transmission end side where the information is necessary, and transmitted. in Rukoto added new information whenever necessary on information substation is transmitted that received, performs calculations only with the relevant location. As a result, when multiple power outages occur or when changing the connection to a power system different from that before the failure, only necessary calculations can be performed at the relevant locations, so even if multiple failures occur, Calculations are possible at the same time with simple rules. In addition, since there is no portion corresponding to the center, calculation is not concentrated.
Moreover, since information is managed individually in the distributed control of each substation, it is possible to prevent complication of the control device of each substation. In addition, the control devices of each substation are approximately the same.
Therefore, the operation of each substation can be automated, the operation cost of each substation can be reduced, the failure recovery of the power system can be speeded up, and the robustness of the power system can be improved.
Further, according to the invention described in claim 2, in addition to the effect of the invention described in claim 1, there is a case where the transmission voltage of each substation can be quickly kept within a predetermined range.
Furthermore, according to the invention described in claim 3, only the necessary information (load and transmission voltage) of each substation of the power system is transmitted to each necessary substation, and the information is updated whenever necessary. Add only relevant information and perform calculations only at relevant locations. As a result, when multiple power outages occur or when changing the connection to a power system different from that before the failure, only necessary calculations can be performed at the relevant locations, so even if multiple failures occur, Calculations are possible at the same time with simple rules. In addition, since there is no portion corresponding to the center, calculation is not concentrated.
Moreover, since information is managed individually in the distributed control of each substation, it is possible to prevent complication of the control device of each substation. In addition, the control devices of each substation are approximately the same.
Therefore, the operation of each substation can be automated, the operation cost of each substation can be reduced, the failure recovery of the power system can be speeded up, and the robustness of the power system can be improved.
Furthermore, when increasing or decreasing the load of each substation in the power system, it is possible to examine in advance whether the load can be increased or decreased.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a wiring diagram schematically showing a power system according to an embodiment of the present invention, and FIG. 2 is a circuit diagram of a substation in the power system of FIG. Further, FIG. 3 is a wiring diagram showing details of FIG. 1, FIG. 4 is a flowchart showing a control method of each substation of the present invention, and FIG. 5 shows a flowchart at the time of abnormal voltage, recovery operation or the like.

The distributed control method of each substation A, B, C, S, T of the electric power system 10 in which a plurality of substations A, B, C, S, T shown in FIG. 1 are connected from the power transmission end side to the power receiving end side is It is as follows. Here, the substations S and T are substations on the power transmission end side, and the substations A, B, and C are substations on the power receiving side. The secondary side of the transformer 20s in the substation S is connected to the primary side of the transformer 20a in the substation A via the switch 22s, the power transmission line 41, and the switch 21a in this order. Furthermore, the primary side of the transformer 20a of the substation A is connected to the primary side of the transformer 20b of the substation B via the switch 22a, the power transmission line 42, and the switch 21b in order. Furthermore, the primary side of the transformer 20b of the substation B is connected to the primary side of the transformer 20c of the substation C via the switch 22b, the power transmission line 43, and the switch 21c in order.
The secondary side of the transformer 20t at the substation T is connected to the primary side of the transformer 20c at the substation C via the switch 21t, the power transmission line 44, and the switch 22c in this order.
Further, a phase adjusting device 23a (for example, a capacitor) is connected to the transformer 20a, and a phase adjusting device 23c (for example, a capacitor) is connected to the transformer 20c.

And the control apparatus 30 (refer FIG. 2) is added to each of several substation A, B, C, S, T, and the active electric power P in the transmission end of each substation A, B, C, S, T and The reactive power Q is set as the load of each substation A, B, C, S, T, and the control device 30 calculates the load of each substation A, B, C, S, T from the power receiving end side to the power transmitting end side sequentially. .
Next, a transmission voltage (effective value) that can supply the calculated load at each substation A, B, C, S, T is calculated, and further, each of the calculated substations A, B, C, S, T is calculated. When the transmission voltage is out of the predetermined range, the control devices 30 of the substations A, B, C, S, and T try to adjust the voltage and the phase adjusting equipment so as to keep the transmission voltage within the predetermined range. However, if this is not possible, the substations adjacent to each substation A, B, C, S, T are requested to perform voltage adjustment and adjustment operation of the phase adjusting equipment 23a, 23c to bring the transmission voltage within the predetermined range. Fit. Specifically, for example, substations next to substation B are substation A and substation C.

Further, when the load of the substations A, B, and C on the power receiving end side is increased or decreased, the control device 30 of the substations A, B, and C on the power receiving end side beforehand controls the substation A, Based on the electrical constants of the transmission lines 41, 42, 43, 44 connecting the load of B, C and the substation (S, T, etc.) on the power transmission side and the substations A, B, C on the power receiving side, The load at the power transmission end of the substation (S, T, etc.) on the power transmission side that transmits power to the substations A, B, and C on the power receiving end side is calculated. The electric constants of the power transmission lines 41, 42, 43, and 44 are a resistance R, an inductance L, and a capacitance C.
Then, the calculated load value is reported to the control device 30 of the power transmission side substation (S, T, etc.), and the calculation and notification of the load are sequentially repeated up to the power transmission end side substations S, T. The voltage at the power transmission end of the power transmission end side substation (S, T, etc.) that can supply the reported load is controlled by the control device 30 of the power transmission end side substation (S, T, etc.). A, B, and C control devices 30 are notified, and the voltage notification is repeated up to substations A, B, and C on the receiving end side.

  Specifically, as shown in FIG. 2, in substation A, for example, power transmission lines 41 and 47 are each configured by arranging a plurality of power transmission lines in parallel. The power transmission line 47 is a power transmission line that transmits power to the load of the substation A. For this reason, the transformer 20a also includes a plurality of transformers arranged in parallel. If it does in this way, restoration at the time of failure of electric power system 10 will become easy, and it will become easy to cope with when a power transmission place differs. A plurality of power transmission lines constituting the power transmission line 41 are connected to each other by a primary bus 41a, and a plurality of power transmission lines constituting the power transmission line 47 are connected to each other by a secondary bus 47a. The switch 21a is composed of switches 21au, 21av, 21ax, 21ay on both sides of the primary bus 41a, and the switches 24u, 24v, 24x, 24y of the power transmission line 47 are arranged on both sides of the secondary bus 47a. . Also, the instrument current transformers 51, 52, 55, 56 are arranged on the power transmission line 41 on both sides of the primary bus 41a, and the instrument current transformers 53, 54, 57, 58 are sent on both sides of the secondary bus 47a. The electric wire 47 is disposed. Further, an instrument transformer 61 is connected to the primary bus 41a, and an instrument transformer 62 is connected to the secondary bus 47a. Further, the secondary bus 47a is connected to the phase adjusting equipment 23a via the switch 23x, and an instrument current transformer 59 for detecting the current flowing through the phase adjusting equipment 23a is provided.

The control device 30 attached to the substation A includes a control circuit body 31, a first switch operating circuit 32, a second switch operating circuit 33, a third switch operating circuit 34, a first input circuit 35, and a second input. A circuit 36, a transformer tap control circuit 37, and a communication circuit 38 are provided.
The control circuit main body 31 is the same as the control computer, and has input means, calculation means, storage means, and display means, and the input means is a program and various data (rated capacity, The characteristics of the device to be controlled, the allowable current of the transmission line, and the electrical characteristics, such as the rated voltage and the number of taps, etc. Depending on the conditions, the electrical characteristics of the transmission line can also be obtained by synchronous calculation with the opposing substation. ) To the storage means, the storage means stores a program and various data, and the calculation means calculates according to the program and various data stored in the storage means. The display means displays various calculation results and the like as necessary. According to the calculation result, the control circuit body 31 includes a first switch operating circuit 32, a second switch operating circuit 33, a third switch operating circuit 34, a first input circuit 35, a second input circuit 36, and a transformer tap. The control circuit 37 and the communication circuit 38 are controlled.

The first switch operating circuit 32 operates the switches 21au and 21ax, the second switch operating circuit 33 operates the switches 21av, 24u, 21ay and 24x, and the third switch operating circuit 34 is the switch. 24v, 24y, 23x are operated. In addition, the first input converter 35 receives the output of the instrument current transformers 51, 52, 55, 56 and detects the current flowing through the power transmission line 41, and the second input converter 36 detects the current transformer 53, The current flowing through the power transmission line 42 is detected in response to the outputs 54, 57, and 58. Each of the input converters 35 and 36 has a function of converting the measured voltage and current into a size used in the control circuit main body 31 and converting it into active power and reactive power. The function of converting into active power and reactive power can also be performed by calculation in the control circuit body 31.
The transformer tap control circuit 37 controls the tap value of the transformer 20a. Further, the communication circuit 38 communicates data of the load and transmission voltage with another control device 30 of the substation (by a dedicated line, IP network, LAN, etc.), and further, if necessary, the transformer to the adjacent substation. Request tap adjustment and operation of phase adjusting equipment.

  FIG. 3 shows a system that further embodies FIG. (The switch 22c or the switch 21t in FIG. 1 is turned off.) In FIG. 3, for example, the substation S receives a voltage of 154 kV and lowers the voltage to 77 kV. The substation S transmits a 77 kV transmission voltage to the substation A via the transmission line 41 and to the substation E via the transmission line 45. Substation A receives power at 77 kV and transmits power to substation B at 77 kV via transmission line 42. Similarly, substation B transmits power to substation C via power transmission line 43 at 77 kV to substation D via power transmission line 46. In addition, “each load” 11, 12, 13, 14, 15, 16 shown in the figure of the substation S to the substation E is transformed into each substation S, A, B, C, D, E. Indicates a load that is being sent at a voltage other than 77 kV through the transformer.

Although the rated voltage sent from the substation S to the substations A to E is 77 kV, the voltage distribution on the transmission lines 41 to 46 is actually different. This voltage distribution is determined by the load of each substation A to E, the tap of the transformer 20s of the substation S, and the introduction and release of the phase adjusting equipment (capacitor, reactor, etc.) of the substations A to E. For example, the voltage at substation C is determined by the load at substation C and the potential reached via substation B, and the voltage at substation B is the load transmitting to substation C and substation D at 77 kV. It is determined by the load at substation B and the potential reached via substation A.
Since the substation C has no further power transmission at 77 kV, the voltage of 77 kV may be in the regulated voltage range (here, “rated voltage + 10%” to “rated voltage−10%”). . However, the substation B is within the range regulated by the voltage at the substation C, and the voltage of the substation B itself must be within the regulated range. At the same time, since the voltage at substation B depends on the load at substation C, the load and voltage status of substation C is communicated to substation B, and substation B is the voltage that it should enter based on that information. You must decide the range.

Next, FIG. 4 is a flowchart showing a basic algorithm for obtaining a voltage range in each of the substations S to E in FIG. 3, and shows a control operation of each substation.
“Start” (step S1) is triggered by a change in the load (such as addition and reduction of loads caused by turning on and off phase-adjusting equipment, failure recovery, etc.) or a change in voltage caused by fluctuations in the load. .

The flowchart of FIG. 4 will be described as follows based on FIG. The program for executing the flowchart of FIG. 4 is stored in the storage means of the control circuit body 31 of the control device 30.
1. The operation of the control device 30 is started (step S1), and it is determined whether each substation S to E transmits power to another substation with the same voltage (step S2). Here, the “same voltage” means 77 kV which is generated by 77 kV in the transformer 20 s (see FIG. 1) of the substation S and is transmitted to the substations A to E and not received through the transformer in the middle. Indicates. Substations S, A, and B are transmitting at the same voltage. On the other hand, substations C, D, and E do not transmit power at the same voltage.
Since the voltage stepped down from 154 kV to 77 kV at the substation S becomes the power source of the substations A to E without passing through any transformer other than the substation S, basically, power is transmitted from the substation S to the substations A to E. Is done. Therefore, substation E receives power from substation S, substation C and substation D receive power from substation B, substation B receives power from substation A, and substation A receives power from substation S. That is, substations S, A, and B transmit power to another substation at the same voltage, but substations C, D, and E transmit only the load through their own transformer, so the same voltage The power is not transmitted to another substation.

2. When power is not transmitted to another substation with the same voltage, the power receiving side voltage is set to a regulation value for both maximum and minimum (step S3).
Since the substations C, D, and E only have loads 14, 15, and 16 having different voltages through their own transformers, they are “terminal” substations that have no destination to transmit at the same voltage. Therefore, the voltage of its own substation should just be in a regulation value. For the sake of explanation, the minimum voltage is “rated voltage−10%” and the maximum voltage is “rated voltage + 10%” from the determined value for the time being.
If we focus on substation B and explain it, substations sent at the same voltage (downstream substation) are substation C and substation D. Substation C and substation D are the terminal substations. The minimum voltage within the limits of substation C and substation D is “rated voltage −10%” at substation C and substation D, and the maximum voltage is “Rated voltage + 10%”. The voltage of the substation B is regulated by a value that allows for a voltage change value in the transmission lines 43 and 46 to the substations C and D.

3. If power is being transmitted to another substation at the same voltage, data from the transmitting substation is awaited (step S4).
Substations S, A, and B transmit power to another substation with the same voltage. Therefore, in order to determine the range of the voltage at the site, the range of the voltage to which the power is transmitted is necessary. Wait until data in this voltage range is transmitted.

4). Select the maximum voltage (select the smallest value among the multiple maximum values) and the minimum value (select the largest value among the multiple minimum values) sent from the downstream substation (select the largest value) Step S5).
As described above, the minimum voltage in the regulation range of the substation C and the substation D is “rated voltage −10%” in the substation C and the substation D. Substation C and substation D have their own loads. Assuming that the voltage drops due to the transmission line from the substation B due to this load, the voltage to be sent from the substation B can be calculated from the load (see Equation (1) below). Therefore, in order to maintain the minimum voltage of substation C and substation D, the minimum voltage required for substation B can be calculated, and the minimum voltage required by substation C or substation D for substation B is the highest. The voltage is the minimum voltage required for substation B. Similarly, consider the maximum voltage required for substation B.

5. It is determined whether the higher voltage is a different voltage (step S6).
The substation S has a different voltage. Substations A to E do not have different voltages. It is determined whether the power is received from other than the same voltage. In the case of the substation S, the voltage falls from 154 kV to 77 kV and is transmitted at 77 kV. (Substations A to E receive power at 77 kV, and further transmit power to the load at other voltages.) When the upper level is a different voltage, the flowchart of FIG. 4 ends.

6). If the higher voltage is not a different voltage, the voltage at the power transmission end is calculated based on the received PQ (step S7).
The voltage at the power transmission end that is the maximum and minimum voltage of the substation is calculated using Equation (1) described later. (Here, the contents to be performed have already been described for the explanation of the item 4).

7). The maximum voltage and the minimum voltage at the power transmission end are transmitted to the upper substation (step S8).
The communication circuit 38 in FIG. 2 transmits the minimum voltage and the maximum voltage necessary for the substation to the substation serving as the power transmission end.
With this flowchart, the allowable range of voltage from the substation (substation C, substation D, substation E in FIG. 3) to the substation (substation S in FIG. 3) serving as a power source is determined. When each substation deviates from this allowable voltage range, it is understood that the voltage is more likely to be out of the specified range on the load side than the own substation in the same system. (The maximum and minimum voltages of the terminal substation are the upper and lower limits of the specified range.)

If the voltage at your own substation deviates from the specified range, it operates to adjust the phase adjustment equipment at your own substation to fall within the specified range. As a result, the phase adjustment equipment at your own substation If the voltage cannot be kept within the specified range, the adjustment operation is requested to the adjacent substation so that the voltage falls within the above-mentioned allowable range.
When the substation requested to operate has phase control equipment that can be operated, the phase control equipment that performs the phase adjustment operation is subjected to the power device operation determination described later, and as a result, the operation is determined to be possible. If it is determined that is improved from the current state, the operation is executed. If operation is impossible, request voltage adjustment to the next substation.
How to cancel an operation request. The voltage of the substation that requested the operation is within the specified range, and even if an operation that competes with the operation performed by the request is performed, the voltage is within the allowable range. In this case, it is assumed that the request has been canceled.
As a result, the facility operated by the request can operate the substation having the facility regardless of the request.

ここで、Ｖｒは受電端の電圧、Ｖｓは送電端の電圧、Ｘは送電線のインダクタンス、Ｒは送電線のレジスタンス、Ｑｒは受電端における無効電力、Ｐｒは受電端における有効電力である。 (Calculation of minimum and maximum voltage allowable at substation)
For example, the control device 30 can obtain the voltage on the power transmission side from the power reception side of the power transmission line using the following calculation formula. This calculation formula is an approximate formula, but may be a strict formula.

Here, Vr is the voltage at the receiving end, Vs is the voltage at the transmitting end, X is the inductance of the transmission line, R is the resistance of the transmission line, Qr is the reactive power at the receiving end, and Pr is the active power at the receiving end.

ここで、Ｖｒは受電端電圧、Ｚは送電線のインピーダンス（Ｚ＝Ｒ＋ｊＸ）を示す。
なお、電圧が変化するとＰＱも変化するが、この例では定電力負荷として扱う（これは、実情に合わせて変更することができる。）。 (Calculation of PQ and voltage at both ends of transmission line)
For example, the control device 30 obtains the power transmission end power (Ss = Ps + jQs) from the power reception end power (Sr = Pr + jQr) using the following equation.

Here, Vr represents the receiving end voltage, and Z represents the impedance (Z = R + jX) of the transmission line.
When the voltage changes, PQ also changes, but in this example, it is treated as a constant power load (this can be changed according to the actual situation).

Ｖｓは送電端電圧（式（２）で計算したもの）、Ｖｒは送電線の受電端側電圧、Ｓｓは送電線の送電端電力（潮流）で式（２）で計算したものである。
この結果、図１の場合、変電所Ｃから変電所Ｓまで電力（負荷）を合計し、その電力を元に変電所Ｓから変電所Ｃに対して逐次電圧を返す。 In the case of a constant power load, the current changes as the voltage changes, and as a result, the amount of voltage drop also changes. Therefore, the PQ at the power transmission end is obtained, and the voltage Vr at the power reception end is calculated based on the PQ. In the case of this method, since voltage and power each change, repeated calculation is required until the value converges. However, in practice, it is considered that round trip or two round trips are sufficient. The voltage calculation is performed as follows, for example.

Vs is a power transmission end voltage (calculated by Expression (2)), Vr is a power receiving end side voltage of the transmission line, and Ss is a power transmission end power (tidal current) of the transmission line, which is calculated by Expression (2).
As a result, in the case of FIG. 1, the power (load) is totaled from the substation C to the substation S, and the voltage is sequentially returned from the substation S to the substation C based on the power.

(Evaluation of power device operation)
The flowchart of FIG. 5 shows a flowchart of the basic operation for determining whether or not the power device can be operated at the time of abnormal voltage, recovery operation, or the like. A program for executing the flowchart of FIG. 5 is stored in the storage means of the control circuit body 31 of the control device 30. The abnormal voltage can be measured with instrument transformers 61 and 62 (see FIG. 2) installed at each substation.
That is, a method for confirming whether or not the voltage can be in an appropriate range when performing one operation (turning on the phase adjusting equipment and turning on the load equipment) in advance will be described.
The basic operation is as follows when attention is paid to substation B by taking FIG. 3 as an example. The substation B starts when a voltage confirmation inquiry is received from the substation C and the substation D or when a voltage confirmation inquiry is generated as necessary due to a voltage abnormality or a recovery operation (step S11). (Inquiry conditions are described in the description of FIG. 5 below).
At this time, if another inquiry has not already been made (step S12), or if another inquiry has already been made and the priority does not conflict (step S13), the amount of change in PQ due to the above operation is obtained. (Step S15).
If another inquiry has already been made (step S12) and the priorities conflict (step S13), the process waits (step S14). Then, after the standby condition is resolved, the amount of change in PQ due to the above operation is obtained (step S15).
Next, the PQ is accumulated at the power receiving end (step S16), and the Q is adjusted by the auxiliary operation (step S17). Here, the auxiliary operation includes the introduction of phase adjusting equipment.
Next, the PQ at the power transmission end is calculated (step S18), the PQ is notified (inquiry) to the upper substation (step S19), and a reply from the upper substation is waited (step S20).

For example, the substation B notifies the substation A of “power at the transmission end of the transmission line from the substation A to the substation B” as an inquiry, and the substation A is based on the notified power. Calculates the power at the power transmission end from the substation S to the substation A and notifies the substation S as an inquiry.
When it reaches the substation S, the voltage of the substation S is answered to the inquiry source based on the notified power and the current voltage. In the substation A that inquired the substation S, the voltage at the substation S, which is the transmission end voltage, is calculated using the power at the time of the inquiry, and the source of the inquiry to the substation A A certain substation B is answered with its own voltage (when viewed from substation B, it becomes the transmission end voltage).
In this manner, the voltage is returned to the inquiry source (step S24), and the waiting inquiry is returned (step S25).

When the answer is made, if the answer voltage exceeds the maximum and minimum voltages obtained in the flowchart of FIG. 4 (step S21), the answer is not “response to the own voltage”. "Do not perform the operation that triggered the inquiry (similarly, reply as" inoperable "when power exceeding the transmission capacity such as a transmission line is received as an inquiry) (step S22) .
The standby data of the next rank is processed (step S23), and the amount of change in PQ due to the operation is obtained (step S15).

In the above embodiment, the number of substations is not limited to that shown in FIGS.
Moreover, the control apparatus 30 is attached to each substation.
In addition, the phase adjusting equipment does not need to be provided at all of the substations, and may be provided as necessary. The phase adjusting equipment is a capacitor, a reactor, a synchronous phase adjuster (rotary capacitor), a static reactive power compensator (SVC), or the like.

It is a wiring diagram which shows the outline of the electric power system which concerns on embodiment of this invention. It is a circuit diagram of the substation in the electric power system of FIG. It is a wiring diagram which shows the detail of FIG. It is a flowchart which shows the control method of each substation of this invention. It is a flowchart at the time of abnormal voltage, recovery operation, etc.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Electric power system A, B, C, S, T Substation P Active power Q Reactive power 20a-20t Transformer 23a, 23c Phase-adjusting equipment 30 Control apparatus 37 Transformer tap control circuit 38 Communication circuit 41-47 Transmission line

Claims (3)

In an electric power system connecting multiple substations from the power transmission end side to the power receiving end side,
Adding a control device to each of the plurality of substations;
The active power and reactive power at the transmission end of each substation as the load of each substation,
Transmitted in substations the end of the receiving end, the control device calculates a transmission voltage that can supply the load before Symbol variable power stations, the data of the calculated transmission voltage next to the substations of the transmission end and, then, at each substation to the data of the transmission voltage is transmitted, the controller, in response to data transmitted transmission voltage to calculate the load of the substation, the calculated before Symbol substation If the substation where the transmission voltage is calculated is not the substation at the end of the transmission end, the calculated transmission voltage data is used for the substation next to the transmission end. Send to
Further, when the calculated transmission voltage of each substation is out of a predetermined range, the substation next to each substation is requested to perform voltage adjustment and adjustment operation of the phase adjusting equipment to set the transmission voltage to the predetermined The distributed control method of each substation of the electric power system characterized by staying in the range of. In the distributed control method of each substation of the electric power system according to claim 1,
When the calculated transmission voltage of each substation is out of a predetermined range, the control device of each substation performs voltage adjustment of each substation and adjustment of the phase adjusting equipment, and the adjustment is performed in each substation. If the substation next to each substation is requested to perform voltage adjustment and phase adjustment equipment adjustment operation, the substation that has received the request can perform the requested adjustment operation. by executing the adjustment operation, power, characterized in that to accommodate the transmission voltage by the performing the further request to the next substation case is impossible is requested by said adjustment operation in the predetermined range Distributed control method for each substation in the grid. In an electric power system connecting multiple substations from the power transmission end side to the power receiving end side,
Adding a control device to each of the plurality of substations;
The active power and reactive power at the transmission end of each substation as the load of each substation,
The control device calculates the load of each substation sequentially from the power receiving end side to the power transmission end side, and then calculates a transmission voltage that can supply the calculated load at each substation,
Further, when the calculated transmission voltage of each substation is out of a predetermined range, the substation next to each substation is requested to perform voltage adjustment and adjustment operation of the phase adjusting equipment to set the transmission voltage to the predetermined Within the range of
Further, when increasing or decreasing the load on the power receiving side substation, the power receiving side substation load and the power transmitting side substation and the power receiving side substation are controlled in advance by the power receiving side substation control device. The load at the power transmission end of the power transmission side substation that transmits power to the power receiving side substation is calculated based on the electrical constant of the transmission line that connects to the power transmission side, and the calculated load value is calculated for the power transmission side substation. Report to the control device,
Repeat the load calculation and notification sequentially to the substation on the power transmission end side,
Next, the control device of the substation on the power transmission end side reports the voltage at the power transmission end of the substation on the power transmission end side that can supply the reported load to the control device of the substation on the power reception side, and the voltage The distribution control method for each substation of the power system is characterized in that the notification is repeated up to the substation on the power receiving side that increases or decreases the load.

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