JPS6367417B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention enables the grid to be improved by understanding and processing in advance specific or measured data regarding the opening/closing status of switches and equipment loads during normal times for a wide-area power system. This invention relates to a system that uses processed data to perform recovery as quickly as possible when an accident occurs.

In the past, when an accident such as a short circuit or ground fault occurred in the power system, information to that effect was sent from the electric power station in charge to the general control center (meaning central control of multiple electric stations). The general control center will either carry out restoration operations through the electric power station in charge based on its own judgment, or, depending on the type and circumstances of the accident, it will receive a restoration operation command from the power supply station, which is responsible for the overall operation of the power system. The reality is that the general control center performs restoration operations via multiple electrical stations. Electrical stations may also carry out restoration operations using automatic reclosing devices or automatic restoration devices in some cases, but this has the disadvantage that restoration operations cannot be carried out uniformly and smoothly. In other words, not only is the division of responsibility for restoration operations between power supply stations, general control centers, and electric stations not clear, but restoration operations (some of which are automated) by general control centers and electric stations are quick, but only local recovery. In the case of restoration operations performed by power supply stations, wide-area restoration is possible, but it takes a lot of time for restoration, and it is not possible to perform unified automatic restoration operations in a short amount of time.

In order to enable unified automatic recovery operations, it is possible to introduce computers and the like. As shown in Figure 1, this consists of a power supply station 1 and a general control center 2, 2 ₁ ~
A computer is placed in each of the power supply stations 1 to _2o , and signals can be exchanged between the power supply station 1 and the general control center 2, and the power supply station 1 can control each of the general control centers ₂₁ to _2o . Similarly, electric station 3, 3 ₁₁ ~ 3
_1n , 3 ₂₁ ~ 3 _2n , ..., 3 _o1 ~ 3 _on can exchange signals with the general control center in charge, and the general control center in charge can control each of the electric stations in charge. The purpose of this system is to use computers to perform recovery operations quickly, uniformly, and smoothly over a wide area. FIG. 2 shows an outline of the recovery operation processing flow by these computers. The computer in power supply station 1 executes a program to grasp the system status (described in detail later) and prepare for load prediction as part of normal processing, but once an accident occurs in the grid, the processing is temporarily stopped and the process is suspended until recovery. The operation process is started. That is, if an accident occurs, the fact is transmitted to the power supply station computer via the general control center computer, and the power supply station computer detects the accident based on the data obtained through normal processing in step 4. Ru. Accident detection in power systems and equipment is based on the combination conditions of protective relays, trippers and disconnectors,
This is done based on display measurement information and information on changes in the condition of the breaker and relay. After this accident is detected, in Step 5, the computer in the general control center performs preparatory operations to smoothly carry out subsequent recovery operations based on its own judgment without placing a burden on the computer in the power supply station, such as accident tripping or one side disconnection. The disconnector is opened. Thereafter, in step 6, the power supply station computer performs an operation to disconnect the faulty equipment, specifically, to open the disconnector directly connected to the faulty equipment, via the general control center computer. This is a necessary operation when the accidental equipment cannot be isolated from the healthy equipment with only an accident trip or a disconnection.If the accident area spans multiple general control centers, wide-area judgment is required, so it is necessary to perform this operation from the power supply station. It is necessary to issue a command. When the process in step 6 is completed, in step 7, a recovery operation procedure for the power outage equipment/load is created. This involves using appropriate recovery logic and creating a procedure while a computer executes a simulated recovery operation based on the data obtained through normal processing. The operating procedures are converted into specific objective commands and then sent to the general control center. As a result, the restoration operation process is completed and power is supplied to the power outage equipment and loads. Once the restoration operation process is completed, the computer in the power supply station updates the necessary data and resumes normal processing while standing by in preparation for an accident.

By the way, as part of normal processing, the system status grasp involves constantly grasping the operating status of the power system and equipment and the opening/closing status of switches, and the data as a result of this processing is used not only to detect accidents but also to detect accidents during accident recovery operations. This processing is extremely important because it is used to create procedures for disconnecting equipment and procedures for restoring power outage equipment and loads, and speeds up restoration operations. The present invention relates to this processing, and an outline of the processing will be explained below.

Note that among the normal processing, the preparation processing for load prediction refers to the preparation processing that is always performed in order to predict the load after a certain period of time after the accident, but this is not directly related to the present invention. That's true.

In the present invention, switch opening/closing data, split system data, support possible point data are obtained in advance from the operating status of the power system/equipment, switch opening/closing status, etc. during normal times, and when an accident occurs, these data are used to restore the system. The purpose is to quickly determine operations.

Each of the above data will be explained in detail later, but first, the switch opening/closing data will be explained.
This considers a group of combination switches such as lines, disconnectors, and disconnectors that connect equipment such as transmission lines, busbars, and banks as one switch, and stores the open/close status of the switch as logical data in advance. It's something to look for. In addition, divided system data is the division of the system in charge of a power supply station into power system units based on equipment data (for example, graphical representation) and switch switching data, and supportable point data is equipment data, measurement information, switch switching data, etc. The specific load of the transmission line for each substation and route, as well as the supportable points and supportable power used for switching power transmission to power outage equipment and loads, were determined from the switching data and split system data.

FIG. 3 shows an overview of these normal processes. This processing would generally be performed by a computer, but the reason for performing such processing during normal times is that if it were performed after an accident, it would take a lot of time to recover. Because it will be. Incidentally, steps 11 to 13 in FIG. 3 indicate a switch opening/closing data creation process, a split system data creation process, and a supportable point data creation process, respectively.

Next, the contents of each process will be explained in detail.

(1) Switch opening/closing data creation process This process is performed, for example, as shown in Figure 4a, in equipment A,
In the case where there is one breaker CBi 1 between _{B and two breaker LSi 1 and} LSi ₂ sandwiching it from both sides, these can be considered as one switch CBi as shown in Figure b. Then, the open/close status I of the switch CBi is switched off.
It is intended to be obtained as logical data from the open/close state I ₂ of CBi ₁ and the open/close states I ₁ , I ₃ of disconnectors LSi ₁ , LSi ₂ . That is, if the open state and closed state correspond to logic "0" and "1", respectively, when I (=I ₁ , I ₂ , I ₃ ) is "1", equipment A and B are connected. You can immediately know that there is one. The above logic is also generally applicable to various connection configurations of bridges, disconnectors and disconnectors. For example, as shown in Figure 5a, if there is a circuit breaker and a disconnector between equipment A and C, and their open/close states are as shown in the figure, then equipment A, B, B,
The open/close states I _AB , I _BC , and I _CA between C, C, and A are determined as follows.

I _AB = I ₁ , I ₂ , I ₃ I _BC = I ₃ , I ₄ I _CA = I ₄ , I _{2 ,} I It is expressed. For example, in the case of Fig. 5b, equipment A and B can be connected by either of two routes, so their open/closed state I _AB
is expressed as follows.

I _AB = I ₁・ I ₂・ I ₃ + I ₄ When the results of the above processing are held as data, for example, the open/closed state of the switch CBi and the equipment that can be connected by that CBi are stored. Name/number.

(2) Processing to create divided system data This process investigates which power source the equipment in the responsible system is receiving power from, and attempts to classify the equipment by power source. For example, in Figure 4 a and b above, if equipment A and B can be connected with the switch CBi closed, it is determined that equipment A and B belong to the same power source, and such a determination is applied to each The power supply system is divided into a plurality of systems by searching the system for each switch CBi from the power supply point.

FIG. 6 is an example of dividing the corresponding system by power source. In the figure, _G1 to _G4 are external power supplies, _G1 ' is an internal power supply, and _L1 and _L2 are external loads, respectively.
Naturally, there is no electrical connection between the divided systems A, B, and C. That is, between G ₁ , G ₂ and G ₄ , G ₁ ′, G ₁ ,
There are no electrical connections between G ₂ and G ₃ , and between G ₃ and G ₄ and G ₁ ' within the assigned system. There are only open switches on the boundary line between the divided systems A, B, and C.

The contents of each divided system data include various information included in the divided system, such as switch, no-voltage detection relay (UVR), power supply, load, equipment data, etc.
To determine which division system these data belong to, it is possible to attach information to that effect to each data item, or to divide and hold data for each division system.

(3) Supportable point data creation process This process calculates the specific load, supportable points, and supportable power for each substation and transmission line route.

First, to explain the specific load calculation for each substation and transmission line route, the specific load value for each individual transmission line or bank can be directly determined from measurement information, and these measured values are used to calculate the specific load for each route. be. For example, in Figure 7, power transmission line A (route)
The specific load L in MW is L=L ₁ +
As L ₂ , the specific load T at substation B is T
= T ₁ + T ₂ , and like the specific loads L ₃ and L ₄ , it is directly determined from the power flow value, which is measurement information. For points where measurement information cannot be obtained, tidal current values will be determined using tidal current calculations.

Next, we will discuss how to calculate support points. To charge equipment that has lost power due to an accident, one of the switches connected to the equipment that has voltage on one side and is open must be turned on. Things are points that can be supported. That is,
Among the switch opening/closing data obtained in advance, an open switch whose opening/closing data is "0" and whose equipment on both sides has voltage is a supportable point. Note that voltage data regarding equipment is obtained incidentally when obtaining divided system data.
In the event of an accident, among the supportable points, one of which the voltage has disappeared on one side remains as a switch candidate for actual energization operation, and one point is selected from among them. However, if multiple accidents occur within the system in charge or across the system in charge and the adjacent system, the support possible point data may not be usable.

Finally, the calculation of supportable power will be explained.

Referring to FIG. 6 already mentioned, supportable points are classified as follows.

(a) Points that can be supported within the divided system (excluding (c)) (b) Points that can be supported that exist on the boundary between divided systems (c) Points that can be supported that exist on the boundary between the system in charge and other systems (Generally, the border with other systems is drawn not on the switch but on the transmission line, but it is a supportable point that results in receiving support power from other systems when the switch is turned on. In other words, the border between the switch and the boundary line is drawn on the transmission line.) A switch with no load in between is a supportable point.) How to determine the supportable power will be explained below with reference to FIG. In the figure, K is the transmittable power, Ci is the supportable point, Si is the transmission line capacity, Pi is the supportable power, T is the bank capacity, Bi is the outage bus to be energized, k is the predicted transmitted power, si, t are predicted specific loads, Li is load, and prediction here means predicting a value after a certain period of time from the present using an appropriate method.

First, an example of how to obtain the supportable power P regarding (a) is as follows. Assuming that load L ₂ loses power due to a ground fault that occurs at point A, load L ₂ energizes bus B ₁ by closing the switch at point C ₁ . This can be salvageable. At this time, the only thing that limits the supportable power P ₁ is the transmission line capacity S ₁ , S ₂ , and the transmittable power (power supply capacity) K and bank capacity T are the load
Since it is common to L ₁ and L ₂ , it is not subject to any restrictions. That is, for the power supply and equipment common to the supporting side and the supported side, only the capacity of the power transmission line existing in the middle is a problem. Therefore, the margin value is obtained by subtracting the predicted specific load value of the equipment from S ₁ and S ₂ , and the smaller of them is calculated as C ₁
Let the supportable power P of a point be ₁ .

P ₁ =Min {(S ₁ −s ₁ ), (S ₂ −s ₂ )} (However, s ₂ =0) For one supportable point C, the supportable power from both is calculated.

Next, regarding (b), how to find the supportable power P is as follows.

In FIG. 8, assuming that a power failure occurs in the adjacent divided system and load L ₃ loses power, load L ₃ is relieved by closing the switch at point _C2 . What limits the supportable power P ₂ in this case is all the equipment from the supportable point C ₂ to the power supply,
It is the power source, and therefore the transmittable power K, the bank capacity T and the transmission line capacity _S3 . Therefore, P ₂ can be obtained from the following equation.

P ₂ = Min {(K-k), (T-t), (S ₃ -s ₃ )} (However, s ₃ =0) Finally, how to obtain the supportable power regarding (c) will be explained. In this case, it can be obtained in the same manner as in case (b), but the supportable power in this case is sent to the other power supply station as supportable power information about the supportable point. On the other hand, when the system in charge is supported by another system, on the other hand, information on power that can be supported is received from the power supply station of the other system.

Although the present invention is as described above, it is conceivable that supportable power calculation is performed not only before an accident but also after an accident occurs.

As explained above, the present invention is designed to prevent accidents from occurring in a wide-area power system by understanding and processing in advance specific or measured data regarding the switching status of switches and equipment loads during normal times in a wide-area power system. When an accident occurs, the data that has been grasped and processed is used to quickly determine the recovery operation procedure, and this is used to carry out accident recovery uniformly, automatically, and as quickly as possible. According to the present invention, even if there is any change in the equipment load, accident recovery operations are always determined based on a fixed method.
Not only will recovery be uniform no matter what the accident, but above all, accident recovery can be done quickly. This is because data is processed in advance in a form suitable for determining accident recovery operations during normal times, but since speeding up accident recovery is a matter that directly leads to improved services, the present invention will benefit society. There is something big.

[Brief explanation of drawings]

Fig. 1 is a hierarchical configuration diagram showing the relationship between the power supply station, the general control center, and the electric power plant; Fig. 2 is a flow chart showing the determination of accident recovery operations according to the present invention; Flowcharts showing the outline of the process, FIGS. 4a, b, and 5a, b are explanatory diagrams of the switch opening/closing data creation process according to the present invention, and FIG. 6 is a flowchart showing the divided system data also according to the present invention. 7 and 8 are explanatory diagrams of the creation process, and FIGS. 7 and 8 are also explanatory diagrams of the supportable point data creation process according to the present invention. 1...Power supply station, 2,2 ₁ ~ 2 _o ...General control center,
3, 3 _o to 3 _on ... Electrical station, 11... Switch opening/closing data creation processing step, 12... Divided system data creation processing step, 13... Supportable point data creation processing step.

Claims (1)

[Claims] 1. A computer installed at a power supply station based on previously known opening/closing information on disconnectors and disconnectors existing between facilities, equipment data, supportable power information from other power supply stations, and measurement information about the system and equipment. After determining the recovery operation when a power outage accident occurs, when attempting to recover from the accident by executing the operation related to the decision via the general control center that also has a computer, the computer installed at the power supply station will not open or close as described above during normal times. A switch opening/closing data creation process that logically determines the connection status between equipment that has been determined to be connectable based on the information and equipment data, and a switch opening/closing data creation process that logically determines the connection status between equipment that has been determined to be connectable based on information and equipment data, and A division system data creation process that divides the equipment into each power source according to which power source supplies power, and the division system data obtained by this process, the above-mentioned switch opening/closing data, equipment data, and measurement information. The system is designed to calculate the specific load of each substation and transmission line, extract switchgears as supportable points, and create supportable point data to calculate supportable power.In the event of an accident, the above processes An automatic recovery operation determination method is characterized in that the recovery operation is quickly performed based on the obtained data.