JPH06101899B2 - Power system simulation method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a power system simulation system applied to a training device for maintaining and improving system operation techniques and skills of control staff.

[Conventional technology]

Conventionally, this type of power system simulation system
The one shown in FIG. In the figure, 1 is a CRT device, 2 is an accident sequence data file, 3 is a transient stability calculation block, 4 is an SV change data file, and 5 is a power flow calculation and frequency calculation block. Here, the SV-like change data is data indicating a change in the states of the operation relay and the circuit breaker, and specifically includes data indicating the changed state and the time at which the change occurred.

The details of the power flow calculation and frequency calculation block 5 shown in FIG. 5 are shown in FIG. In the figure, 4 is an SV-like variable data file, 6 is a switch change judgment block for judging switching status changes such as chopsticks and disconnectors, 7 is a system separation calculation block, 8 is a discontinuous change such as load interruption or disconnection. Discontinuity change judgment block that determines the power flow, 9 is a power flow calculation block that calculates the power flow for each separation system, 10 is a frequency calculation block that calculates the system frequency of each separation system by one amount, 11 is a frequency drop relay, etc. A frequency response relay simulation block that simulates a relay that responds to the system frequency of, 12 is the frequency calculation in steps of ΔT seconds, and n (= T / Δ
T) Loop that repeats 13 times, 13 is overload relay or voltage
A relay that responds to a power flow voltage such as a reactive power control device or power line power flow and a power flow response relay that simulates the operation of various control devices, a control device simulation block, 14 is a switch change determination block 6 to a power flow response relay, a control device A real-time synchronization block that performs real-time synchronization with a delay process so that the processing time of each block of the simulation block 13 is T seconds, and 15 is a loop that executes the simulation of the power flow and the frequency every T seconds.

Next, the operation will be described.

First, at the training preparation stage for control personnel, the trainer
From the T device 1 screen, the time of failure occurrence in the power system, the failure point, the failure type, and the main protection relay that is considered to operate due to these system failures, or the backup protection relay and its operation relay, trips and breaks. Set (CB) using a light pen. The set respective data are stored in the accident sequence data file 2 and, for the operation relay and trip CB, are also stored in the SV state change data file 4.

Next, since it is difficult to correctly set the operation of the step-out relay by the trainer, the program of the transient stability calculation block 3 is executed with the accident sequence data file 2 as input data, and the operation SO is obtained as a result of the judgment. Store the relay and trip CB in the SV-like data file 4.

When the transient stability calculation block 3 reaches the cutoff time, the stored contents of the SV-like variable data file are rearranged in chronological order according to an instruction from the trainer.

This concludes the training preparation stage.

Next, in the training execution stage, the SV-like data file 4
The CB condition is taken out in chronological order, and the program of the power flow calculation and frequency calculation block 5 is executed to simulate the operation of the overload relay, the frequency reduction relay, or the voltage / reactive power control device, and the power system real-time simulator. Perform a race.

The details of the real-time simulation will be described below with reference to the flow chart of FIG.

The entire operation is performed by connecting the frequency calculation block 10 and the power flow calculation block 9 every T seconds, and the frequency calculation block 10 calculates n (= T / ΔT) times continuously in steps of ΔT seconds. To do.

That is, the frequency calculation block 10 is divided by ΔT seconds,
Repeat (= T / ΔT) times and execute the power flow calculation at that time once. Then, all processing is performed in real time T seconds to realize real-time simulation. Normally, the power flow calculation and the frequency calculation are shared by different computers to realize real-time simulation. Also, as a detailed operation, first, the SV-shaped variable data file 4 at that time is taken out, and it is judged by the switch change judgment block 6 whether or not there is a change. If there is a change, the system separation calculation block 7 is executed. Then, the separated system is judged, the system admittance matrix is modified, and the system capacity of the separated system and the total inertial capacity are calculated. When there is no change, the presence / absence of a change is checked by the discontinuous change determination block 8 of the active power / reactive power of the bus bar due to load or disconnection. If there is a change, the power flow calculation block 9 is executed similarly to the end of the system separation calculation block 7. When there is no change, the system frequency calculation block 10 for each separated system is executed similarly to the end of the power flow calculation block 9, and then the frequency response relay simulation block 11 that responds to the system frequency is executed and these processes are executed. n times (= T / Δ
T) Repeat.

When n times are repeated, the power flow calculation block 9 at that time is executed, and an overload relay that responds to the system voltage, power flow of the transmission line, or the like, or an operation simulation of the voltage / reactive power control device, that is, a power flow response relay Control device simulation block
13 is executed, and finally, the processing (delay) of the real-time synchronization block 14 for synchronizing for one cycle T seconds is executed, the simulation for T seconds is completed, and then the simulation for the next cycle is entered. Here, the T second is usually 3 to 5 seconds, and ΔT is about 0.25 seconds.

T seconds is determined from the information update cycle of the actual power supply automation system, and the simulation that satisfies this performance is defined as real-time simulation.

[Problems to be solved by the invention]

In the conventional power system simulation method, the main protection and backup protection operations are simulated in the form of trainer settings. Therefore, the trainee may mis-operate and ground during training, or accident equipment may be damaged or broken. If the system is turned on again and a system failure occurs again, there is a problem that the main protection and backup protection operations cannot be simulated.

The present invention has been made to solve the above-described problems, and automatically processes the main protection and backup protection operation simulation when a system failure occurs to automatically determine the trip CB, and Even if a system failure occurs again due to an erroneous operation, it is an object of the present invention to enable the movement of the power system to be simulated as in the case of the entire system.

[Means for Solving Problems] In the power system simulation system according to the present invention, the operation simulation of the main protection / reserve protection relay is performed based on the failure calculation, and the result is reflected in the frequency / power flow calculation in real time. It is the one that realizes the simulation.

[Action]

The power system simulation method according to the present invention automatically processes the operation simulation of the main protection / reserve protection relay based on the failure calculation, and eliminates the need for manual setting at the training preparation stage of the trainer. Based on the erroneous operation caused by, the training will be performed in the same way as the actual system when a re-fault is reached.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings. In the figure, the same parts as those in FIG.
In the figure, 3b is a transient stability calculation block, and 5b is a failure calculation block that simulates the operation of the main protection / reserve protection relay. Further, FIG. 2 is a diagram for explaining the movement of the relay operation simulation. 3 is a failure calculation block 5b for simulating the operation of the main protection / reserve protection relay shown in FIG.
In the detailed contents of step 16, the fault equivalent impedance Z _F
Block for calculating the positive phase admittance matrix including Z _F , step 18 for solving the positive phase network equation, and block for calculating each node voltage, step 19 depending on the fault type. Block for obtaining the fault current of the anti-phase or zero-phase circuit, Step 20 is a block for calculating the voltage and current distribution of the anti-phase or zero-phase circuit according to the fault type, and Step 21 is for solving each node of the positive-phase network by solving the equation From the results of the block 18 for calculating the voltage and the block 20 for finding the fault current of the negative-phase or zero-phase circuit, the block and step 22 for obtaining the voltage and current of the three-phase circuit of a, b, c phases are the main protection,
The operation judgment block and step 23 for the backup protection relay alone are the blocks and steps for checking the operation judgment result 22.
24 is a block that updates the timer by Δt, step 25
Is a block that checks the establishment of the timer condition, step 26 is a block that determines the CB that should trip in accordance with the relay operation, and a block that is registered in the SV variable data file, and step 27 is a block that determines whether the system failure is continuing. is there. Further, FIG. 4 shows the detailed contents of the power flow calculation and frequency calculation block 5 in FIG. 1 and is the same as the above-mentioned conventional description. Also, when the system scale is large, it becomes necessary to share the failure calculation block 5b with another computer.

Next, the operation of the present invention will be described. The calculation of the power flow calculation and the frequency calculation block 5 shown in FIG. 1 is the same as the conventional one, and therefore its explanation is omitted.

In the power system simulation method according to the present invention, when the system scale is small, real-time simulation can be realized by executing failure calculation and power flow / frequency calculation in series, but normally, power flow calculation and frequency calculation are performed separately. Real-time simulation is realized by sharing processing with the computer.

In the detailed operation, first, as shown in FIG. 4, the SV-like change data 4 at the time is taken out, and a change is found in the switch change judgment block 6.
When it is determined that there is no change, the system isolation calculation block 7 is executed to determine the isolated system, correct the admittance matrix of the system, and calculate the system capacity of the isolated system and the total inertial capacity.

If it is not established next, the repeat timer is updated by Δt, and if it is established, a trip or breaker is selected by the operation of the relay and registered in the SV-like variable data file.
To do.

Finally, it is judged whether the failure is continuing 27. If the failure is present, the operation proceeds to the main protection / reserve protection relay unit operation determination block 22. If there is no failure, the procedure proceeds to the end.

On the other hand, the simulation of the electric power system, as shown in FIG. 1, takes out the CB-like changes from the SV-like change data file 4 in chronological order, while executing the power flow calculation and the frequency calculation program 5 and overload relays and frequency drop relays. Or, it simulates the operation of the voltage / reactive power control device and performs real-time simulation of the power system.

Details of the real-time simulation will be described below according to the flow of FIG.

As a whole operation, the frequency calculation block 10 and the power flow calculation block 9 are connected every T seconds, and the frequency calculation is performed in steps of ΔT seconds, and is calculated n (= T / ΔT) times continuously. There is.

That is, the frequency calculation block 10 is divided by ΔT seconds,
(= T / ΔT) times are repeated, the power flow calculation at that time is executed once, and all the processing is performed in T seconds of real time to realize real-time simulation.

In the failure calculation, the positive-phase / negative-phase / zero-phase circuits are combined according to the type of failure to form an equivalent circuit. For the negative-phase / zero-phase circuit, the method of inserting the equivalent phase impedance into the positive-phase circuit is used. To use. When the failure type is a three-phase ground fault (short circuit), the failure equivalent impedance is zero.

First, according to the current system condition, the fault equivalent impedance Z _F is calculated by step 16 in FIG. 3, and then this Z _F
Is inserted into the positive phase circuit, and in step 17, the admittance matrix of the positive phase circuit including Z _F is calculated. Then, at step 18, the equation of the positive-phase network is solved, and the voltage of each node,
Calculate the branch current.

Next, in step 19, the fault current of the anti-phase or zero-phase circuit is obtained, and using this, the voltage / current distribution of the anti-phase or zero-phase circuit is calculated in step 20.

Next, the voltage of the positive phase, negative phase or zero phase circuit of steps 18 and 20
Calculate the current distribution and use the three-phase circuit (a,
Obtain the voltage and current of phases b and c) in step 21.

Further, in Step 22, the operation of each of the main protection / reserve protection relays is judged by simulating each relay logic.

As a result, if there is no operation in step 23, the process proceeds to the end.

If there is an operation, the timer is updated by .DELTA.t in step 24, and it is determined in step 25 whether or not the relay timer condition is satisfied.

Next, in the training execution stage, the failure calculation 5b including the operation simulation of the main protection / reserve protection relay shown in FIG. 1 and the power flow / frequency calculation 5 which is the simulation of the power system are executed in parallel.

First, from the start of the training execution stage to T seconds, the operation judgment of the main protection / reserve protection relay is performed by the transient stability calculation block 3b in the training preparation stage, so the failure calculation block.
Do not execute 5b, but execute the power flow calculation and frequency calculation block 5.

After that, in the simulation step, the failure calculation block 5b, the power flow calculation and the frequency calculation block 5 are processed in parallel.

The failure calculation block 5b extracts the failure occurrence time, the failure point and the failure type from the accident sequence data file 2, and if a failure occurs between the time mT and (m + 1) T,
The failure calculation block 5b is executed and the operation relay and trip CB data are stored in the SV-like variable data file 4 following the operation simulation of the main protection / reserve protection relay.

For details of the operation of the failure calculation block 5b, as shown in Fig. 2, the failure calculation is executed once only when a failure occurs, and the failure voltage and current are not changed during the failure. Continue while updating the time by Δt.

Next, details of the failure calculation block 5b will be described according to the flow of FIG.

First, in the training preparation stage, the trainer sets the failure occurrence time, failure point, and failure type in the power system from the screen of the CRT device 1 using a light pen. The set data is stored in the accident sequence data file 2. Subsequently, the operation judgment of the main protection / reserve protection relay including the step-out relay is executed, the program of the transient stability calculation block 3b is executed with the accident sequence data file 2 as the input data, and the step-out relay is included as the judgment result. Store the main protection / rear protection operation relays and trip CB in the SV-like data file 4.

This transient stability calculation needs to be performed until the operation determination of the step-out relay is completed, but is performed until T seconds (normally 3 to 5 seconds) which is one cycle of the power flow / frequency calculation.

Since the operation determination of the step-out relay is usually 1-2 seconds, the above-mentioned termination time is sufficient.

〔The invention's effect〕

As described above, according to the present invention, since the operation simulation of the main protection / reserve protection relay is realized based on the failure calculation, even if the trainee is erroneously operated during training,
This has the effect of simulating the movement of the system as in the actual system and improving training results.

[Brief description of drawings]

FIG. 1 is a conceptual diagram of the overall processing of one embodiment of the present invention, and FIG.
FIG. 4 is a diagram for explaining the movement of the relay operation simulation of the present invention, FIG. 3 is a detailed flow chart of the failure calculation of the present invention, and FIG. 4 is a detailed flow chart of the power flow / frequency calculation of the present invention.
The figure is a conceptual diagram of the overall processing of the conventional method. In the figure, 1 is a CRT device, 2 is an accident sequence file, 3b is a transient stability calculation block, 4 is an SV-like variable data file, 5 is a power flow calculation and frequency calculation block, and 5b is a failure calculation block.

Claims (1)

[Claims] 1. An accident occurrence data of a power system is set in a CRT device by using a light pen or the like, the data set in the CRT device is stored in an accident sequence data file, and the stored contents of the accident sequence data file are stored. Using the input data as input data, the main protection and backup protection relay trip CB simulation calculation is executed in the transient stability calculation block, and the SV status change data indicating the status change of the main protection and backup protection relay, which is the result of the above calculation, is converted into SV status. Stored in a variable data file,
In the power system simulation method, which takes the required data from the SV-like variable data file, calculates the power flow and frequency of the system with the power flow calculation and frequency calculation block, and performs the real-time simulation of the operation of the power system devices based on the result of the power flow and frequency calculation. A power system simulation method characterized in that when a system failure occurs, the operation of the main protection / reserve protection relay is automatically simulated by a failure calculation block and the operation of the trip CB is automatically determined.