JPS58151830A - Power system recovering device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a device that automates recovery after a power system failure.

There have been methods for automatically analyzing and restoring power systems using digital computers, but these were methodologies based on analysis. The analytical methodology involves preparing several quantitative models in advance, and when the various quantities of the power system match one of the quantitative models, numerical calculations are performed using a computer.

It is necessary because it performs logical operations and deals with various problems in power systems.

This methodology has been widely applied.

However, as power systems have become larger and more complex in recent years, there are cases in which a quantitative model cannot be determined clearly, or even if the model is clear, the solution space is wide and it takes a long time to search. Cases have arisen in which it is difficult to handle f'i using scientific methods.

'Also, with conventional methods, when there is a change in a part of the system due to expansion or improvement of electric power equipment, the entire program must be rewritten and the program is created without errors. It had to be inspected, and this work had reached a gigantic scale. Furthermore, what was executed on a computer after restoration using the conventional method is printed out on a TIG writer, which shows the results of numerical calculations and logical operations, but it does not show what kind of failure has occurred in the system. It was difficult for operators to understand the procedure used to restore the system, so a solution method that was easy for operators to understand was needed.

A conventional power system restoration device will be described below with reference to the drawings.

Conventionally, there is a device shown in FIG. 1 that uses a computer to automate the restoration of an electric power system.

In the figure (11 is the power system or part of it, (2)
is a data bank consisting of numerical data such as power flow, IIc pressure, and current measured from the power system (1) and logical data indicating the importance of switching equipment, and (3) is a data bank (
2) is a program in which a procedure for performing arithmetic processing on each data is written; and (4) is an arithmetic processing device that sequentially executes the program's procedures. (5) is (2], (3),
This is a conventional power system operation device consisting of (4). These five data bank (2) and program (3) are usually stored in the computer memory.Next, we will explain the operation.The arithmetic processing unit (4) interprets the program (3) and writes the data written in the program. Numerical and logical operations are performed in accordance with the procedures in the program, while referring to the data bank (2) as appropriate, and when the execution of the program (3) is completed, the f& final result is output to the power system (1) as the power system operation procedure.Conventional The device is characterized in that the process of deriving operating procedures for the power system, such as the operation and control of the power 411 equipment and the control of the power system, is expressed in the form of numerical and logical calculation programs.

Now, in Fig. 2, input 0 is the initial state when a failure occurs in the power system, Bo is the final state when the desired recovery has been performed, and control and operation are performed to derive the final state BO from the initial state 11Ao. think of.

The conventional power system operation equipment using control-driven algorithms shown in Figure 1 applies numerical calculations and logic to the system based on uniform assumptions at each branch point. Calculations are performed, and depending on the results, the process proceeds to the next branch point, and the process is repeated. However, if one were to perform numerical calculations to confirm the entire expansion of the branch school, a huge amount of calculation would have to be done, which would take a lot of time. It will require. In the case of restoring a faulty system, when a large number of interrupters are required for the restoration, the calculations become enormous as all combinations of those interrupters must be calculated and confirmed.

In addition, since program (3) includes a procedure for deriving the operation procedure of the power system, when modifying a part of the procedure for deriving the operation procedure, the entire program (3) must be rewritten. The task of confirming the validity of the modified program becomes enormous, and it takes a great deal of time and effort to change and modify program (3) due to the addition of power equipment, etc.

The purpose of this invention is to propose a power system restoration device that can guide restoration procedures without performing enormous calculations even if the target system is complex, and can easily accommodate program changes. It is something.

To achieve this objective, the present invention is based on the idea of treating the power system qualitatively, rather than fitting the power system to a quantitative model. In other words, by expressing the knowledge and operational philosophy obtained from actual failure recovery experience in power systems in the form of a large number of rules, qualitative treatment becomes possible, and since each rule is a unit of knowledge, it is possible to make changes to the program. can be made possible by simply changing a specific rule without affecting the entire system.

FIG. 3 is a block diagram showing an embodiment of the power system restoration device according to the present invention. To υ is a data bank containing data related to the state of the power system (1), - is obtained from operational experience and represents the next generation rule part, and data bank 1 and rule - are the storage device ( 6) is constructed. This storage device (6) is also called knowledge pace. A rule is expressed as a premise and a conclusion that is derived if the premise holds true, and an inference mechanism (
7) is provided.

The operation of the power system restoration device shown in Figure 3 is explained below.
An example of determining a recovery operation procedure for an accident in the power system shown in the figure will be explained.

In the power system shown in Figure 4, BUS is the bus bar, LINE
is a power transmission line, BANK is a transformer, a white circle is an open breaker, a black circle is a closed circuit breaker, and a mark between the white circle is a breaker that has been opened due to a permanent failure.

If a permanent failure occurs in BUS I, the area surrounded by the broken line is out of power, and the recovery procedure in this case is guided by the system macro flow shown in FIG.

Following the start (step 101), the rules of the knowledge pace (6) are read into the reasoning mechanism (7) (step 102). This is because the rules are not built into the program.
This is because it is necessary to give the inference mechanism (7) what kind of rules there are.

The rules (RUIJ) used here can be broadly classified into three types: (1) [Those that determine whether an element requires an old version or not; (2) Contents and configuration requirements of each restoration condition. (3)
) Related to selection of recovery method RUIJt belongs to (1) FLULE2, RULE3
belongs to (2), and RUIJ4, RUI, and Es belong to (3). Also, following the basic procedure on the 1st day, R, UL
E2 and RUIJ3 will be applied in numerical order.

The specific rules are as follows.

Rule 1 Premise element is uncharged and (RUI
Jx) The element has not failed.Conclusion part.The element requires restoration.Rule 2.Premise part.■Recovery power source is charged (R(J
IJ 2) Ru. ■Recovery power supply is not malfunctioning. ■The element was receiving power from the power source before ◆. ■ The element is not isolated by load shedding from the power source it is located on. (For those disconnected due to overload, we do not consider restoring the element using the original power source as its power source.) Conclusion: Restoring the element using the restored power source satisfies restoration condition 1, so it is effective.

Rule 3 Premise part ■Elements and power sources are topological (RUI)
Js) are connected to each other. (Topologically, connection refers to a positional relationship such that if the circuit breaker is closed, it is electrically connected.) ■The element was not receiving power from the power source before the accident.

Conclusion: Restore the element with its recovery power source What you need to do is restore condition 2. It is valid because it matches.

Rule 4 Premise part Recovery by a certain power source is recovery (RUI)
J4) Conditions are met.Conclusion: Restoration using the power source is effective.

Rule 5 #Probe A certain power source restores (RUI)
Ja) Regarding matter 2, Q.

Conclusion: Restoration using that power source is effective It is.

Next, the inference mechanism (7) reads data on the system status such as tidal current, IIT pressure, flow, and the opening/closing status of the breaker from the data bank diagram of the knowledge pace (6) (step 10).
3). Recommendation! Mechanism (7) selects one element of the system (Stella 7'105). It is determined whether the element requires restoration (step 1o6). For example, a determination as to whether BUS 2 requires restoration is made as follows.

The inference mechanism (7) selects RULEl as an applicable rule based on the current state of the system.

For example, the program list of ULEL is written as follows using the #'1 LISP format.

RU L E 1 (COMPONENT) antecedent part (AND ((NOTCHARGED COMPONE
NT))((NOTFAULTED COMPONEN)
T)) Connection 1mm (CONCLUDE I'J)
QUIRE8 Cofield0NENTRESTORATIO
N) Reasoning machine $1 (7) collates the systematic data of one data bank and determines whether the premise of RULEl is true or not. In this case, since BUS2 is not being charged and has not failed, it is concluded that BUS2 requires restoration. Next, the inference mechanism (7) checks the data bank to see if there is a power source capable of restoring BUS 2 (step 1o7). In this case LI N E 2
Since r 3 and B can be considered as power sources, one of them, for example, LINE 2, is drawn (Step 109), B
RUL whether it is valid or not to restore US2 with LINE2
R4,s,2. Verify a status (step 110)
.

The program list of RULE4, s is expressed as follows.

RULE4 (COMPONENT 5OUR(J
TYPE20F) Prerequisite (AND ((TYPE20F
' RESTORATION (BY COMPONEN
T 80URCE) CONDITIONI) ) M limbus (C0NCLUDE几E8TORATION
(BYCOMPONENT 5OURCE)EFFE
CTIVE) RULE5 (CONPONENT 5
OURCE TYPE20F) fmm Gunbe ARD (
(TYPE20F RESTORATION(BY C
OMPONIIENT 5OUR(J) CONDITI
ON2) ) CONCLUDB RESTORATION
(BYCOMPONENT 5OUR(J)EFFBC
TII) 几ULE4. s respectively relate to recovery condition 1.2. For example, the recovery conditions are as follows.

Restoration condition 1: Receive and restore power based on the usual power reception trend that was the element that caused the power outage.

Restoration condition 2: The power outage element receives power from the backup line and is restored.

If restoring BUS 1 using LINE 2 as a power source meets either restoration conditions 1 or 2, the restoration is valid. Inference machine using this RUIJ2 and 3 @ (7
) is verified. RUL, B2 corresponds to the recovery condition], and its program list is expressed in L18P format as follows.

RUE, B2 (COMPONENT 5OUBI:E
TYPE20F)? n Mk part (AND ((I
5C) LARGED SOURUE)) -・・■((
NOTFAULTBI) 80U E))...■((
FEBD'1080URcE COMPONENT)
)@((NOTCUTLOAD SOURCECOMP
ONENT ) ) ... song, concave, song, ■music Ml
CONCLUL E RJIESTORATION
(BYαmm5OURCE)CONDITION) R, ULg3 corresponds to recovery condition 2, and its program list is as follows.

RULga (COMPONKNT 5OURCE
TYPkzOF) Prerequisite (AND ((ISCHAR
GEDSOURCB))((NOTF'AULTED
5OURCE))((CONNECTED COMPO
NENT80URCE ) ) ・・・・・・・・・
・・・・・・・・・・・・■((NOTFIDTOSO
URCE COMPONENT) )・・・・・・・・・・・・
...■Conclusion part (CONCLUDERESTORAT
ION (BYCOMPONENTSOUR(J)C
0NDITION2) Inference mechanism (7) is the prerequisite for LINE2 and UIJ2■.

It is judged based on the system initial state II (103) whether BUS2 satisfies RULU2O5 requirements (2) and (2). In this case, both assumptions are satisfied, so LI
Recovery of BUs2'Ik by NE2 satisfies the recovery condition l, so it can be verified that it is effective (step 1
lO). Inference II tit (7) as the next step
determines restoration candidates for the system that may be restored (
Step 111), if BUS2 is restored, LIN
E4.5, 6, 7.1g, and BUS11 can be restored, so the area surrounded by the broken line in Figure 6 is considered a restoration candidate.If all of these are restored, there is a risk of overload, so the current Calculation is performed (step 112). The power flow calculation is performed as a subroutine elsewhere and is used as a known value. As a result of the power flow calculation, if it is found that there will be an overload (step! 13), LINE 5 is first selected as the load to be disconnected and disconnected (step 115).

If the power flow is calculated again under this condition and an overload check is performed, there will no longer be an overload. In the above process, LINE2
BUS2. as the power source. It can be seen that LINE 4 and 6.7 can be restored. The range of the system that can be restored is ultimately the range shown by the broken line in FIG.

It is verified by executing the flow shown in FIG. 5 that the BUS 11 can be restored using the protection line LINE 17. In this case, RULEt,s,3 is used. Based on the conclusion obtained in this way, the operator performs specific operations to open and close the circuit breaker.

It is not impossible to know the recovery procedure by omitting RULE 4, s and verifying RULE 2.3, but when an operator deciphers the result of the operation typewritten on a typewriter, RULE 4, s must be omitted. If omitted,
It is difficult to understand that restoration was performed because restoration conditions 1.2 were met.

LIMP, like FORTRAN, is a language used for computers, and while FORTRAN is suitable for numerical calculations and logical calculations, LISF is a language suitable for symbolic processing.

FIG. 8 is a block diagram showing another embodiment of the present invention in which the inference mechanism is divided into an inference program (9) and a central processing unit. The inference program (9) is a program that advances the steps shown in FIG. 5, for example, and the central processing unit QO verifies the rule bag based on the information in the database (II).

The present invention has been described above using an example in which a restoration procedure is determined to determine how far the power system can be restored without overloading.

This invention makes it possible to qualitatively handle power systems based on knowledge gained from experience in power system failure recovery. Therefore, knowledge is expressed as rules having a premise part and a conclusion part, making it independent from the program, and regular verification is performed based on systematic data. Numerical calculations are not used in the rule verification process. Since the rules are independent from the program of the inference mechanism, when changing the system operation method, it is only necessary to change part of the rules; there is no need to change the entire program.

As explained above, the power system restoration device according to the present invention expresses qualitative knowledge regarding power system failure recovery in rules, and derives restoration procedures by verifying the rules based on data indicating the state of the power system. As a result, even if there are a plurality of target power systems, a recovery procedure can be derived without performing huge calculations, and it is possible to easily respond to changes in the program.

[Brief explanation of drawings]

Figure 1 is a configuration diagram showing an example of a conventional power system restoration device.
Fig. 2 is a diagram showing the relationship between the initial state and the desired final state of the power system; Fig. 3 is a configuration diagram showing an embodiment of the power system restoration device according to the present invention; A system diagram showing an example of a power system to be restored by a system restoration device, Fig. 5 is a flowchart for restoring the power system, Fig. 6 is a system diagram showing restoration candidates, and Fig. 7 shows a restored system. The system diagram shown in FIG. 8 is a configuration diagram showing another embodiment of the power system restoration device according to the present invention. In the figure, (1) is the power system, (6) is the storage device, (
7) is an inference mechanism, (9) is an inference program, and aO is an arithmetic processing unit. The same reference numerals in each figure indicate the same or corresponding parts. Agent Shin Tameno - Figure 1 Figure 2 A. Figure 33 Figure 4 Figure 5 Figure 6 Figure 7

Claims (2)

[Claims] (1) [A storage device that stores rules that express qualitative knowledge regarding power system restoration procedures divided into a premise and a conclusion that is derived if the premise is true, as well as data indicating the state of the power system. and an inference mechanism that determines based on the data whether or not the above-mentioned condition holds true. (2) The inference mechanism is characterized by comprising an inference program having instructions regarding the order of selection of rules, and an arithmetic processing unit that determines whether or not the premise of the rule holds true according to the inference program. Claim 1
Squid system restoration device described in section.