JP2517366B2 - Load device for simulator - Google Patents

Description

The present invention relates to a simulator load device, and more particularly to a load connected to a power system.

[Problems to be Solved by Conventional Techniques and Inventions] An example of a conventional power system simulator is “Transmission and distribution engineering (first part)” by Toichiro Koike (Yokendo version) 14.16 AC calculator and transient stability calculator. And simulated transmission line (Page 283)
Are described in.

In the conventional power system simulator, the load device has not been considered in connection with the system, as described in the above-mentioned document. For this reason, when the load is connected to the system, a large disturbance occurs, and the simulation cannot be performed quickly. For this reason, when performing a simulation on a large-scale system,
There was a problem that it took a long time for the system upset to settle down.

Therefore, the main object of the present invention is to reduce the load on a simulator that can converge the system oscillation immediately after connecting the load and can perform the simulation quickly regardless of the scale of the system to be simulated and the size of the load. It is to provide a device.

[Means for Solving the Problems] The present invention relates to a simulator load device used in a simulator simulating an electric power system, including voltage detection means for detecting a supplied voltage, a load element, and a voltage for the load element. It is provided with a thyristor for giving a voltage, and a control circuit for controlling the conduction of the thyristor based on the detected voltage and changing the constant of the load element to a predetermined value while maintaining the state in which the voltage drop and the vibration of the power system do not occur. Consists of

More preferably, the conductance and susceptance or active power P =
Values representing active power and reactive power are used from the relationship of GV ² and reactive power Q = BV ² .

In addition, as a method of changing the constant constituting the load, the load is changed with a constant slope or exponentially changed.

[Operation] The load device for a simulator of the present invention detects the voltage and controls the conduction of the thyristor so as to maintain a so-called low disturbance state in which the voltage and the vibration of the power system do not decrease, and change the value to a predetermined value. As a result, the disturbance given to the power system can be suppressed to a relatively small amount. Therefore, the system is stabilized in a short time after the load is connected, and the simulation can be performed quickly.

[Embodiment of the Invention] FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a specific block diagram of the load shown in FIG.

FIG. 1 shows an example of a simulator simulation system. The synchronous generator G includes a current-voltage transformer CPT and a line reactor L.
And circuit breaker CB and load Lo are connected in series. Current-voltage transformer
An automatic voltage regulator AVR is connected to the CPT.

As shown in FIG. 2, the load Lo is composed of a voltage detector 1, a microcomputer 2, a thyristor 3 and a resistor 4. The voltage detector 1 detects the supplied voltage, and the microcomputer 2 controls the conduction of the thyristor 3 based on the detected voltage. By controlling the conduction of the thyristor 3, it is possible to change the current flowing through the resistor 4 and thus the value of the conductance. Similarly, it is possible to change the value of the susceptance, which is the invalid component.

3 and 4 show the conductance G at the load.
It is a figure which shows the change of the susceptance B.

Next, the specific operation of the embodiment of the present invention will be described with reference to FIGS. In FIG. 1, when connecting the load Lo to the synchronous generator G, a circuit breaker
CB is thrown in. At this time, if the load Lo is set to have the desired values of conductance Go and susceptance Bo, a large current flows in the case of a heavy load, so that the voltage applied to the load Lo is significantly reduced. After that, the current-voltage transformer CPT
Signal causes the generated voltage of the synchronous generator G to rise due to the action of the automatic voltage regulator AVR provided in association with the synchronous generator G, but it takes a long time to recover the voltage.

Therefore, in one embodiment of the present invention, the voltage detector 1 detects the magnitude of the voltage applied to the load Lo, and the microcomputer 2 conducts the thyristor 3 via an analog circuit (not shown) based on the detected voltage. To control. That is, the microcomputer 2 determines the conductance G and susceptance B of the load Lo according to the detected voltage.
Is changed as shown in FIG. That is, circuit breaker CB
Is set to t = 0, and the conductance G and the susceptance B are linearly changed to desired values Go and Bo at a constant time t1. By doing so, the disturbance given to the synchronous generator G becomes small, and the drop of the voltage of the load can be suppressed. Here, the reason why the conductance and the susceptance of the load are used as the amounts of change using the values representing the active power and the reactive power as the constants constituting the load will be described.

It is preferable to use the active power and the reactive power as the input data of the simulator, because the constants constituting the load carried by the person who uses the simulator are the active power and the reactive power, which are the quantities that the user can easily understand.

On the other hand, in order to realize a desired value of active power or reactive power, the microcomputer 2 calculates the values of the active current and reactive current signals, and controls the conduction of the thyristor 3 via an analog circuit. There is a need to. The current value can be facilitated by multiplying the voltage by the conductance and the susceptance in an analog circuit. In general, it is necessary to use a complicated circuit configuration to perform division with an analog circuit, but since multiplication requires a relatively simple circuit configuration, it is advantageous to use conductance and susceptance.

In the above description, the conductance G and the susceptance B are changed with a constant inclination with respect to time. However, as shown in FIG. 4, the conductance G and the susceptance B change exponentially as shown by the following equation. Even if it does, the same effect can be obtained.

G = Go (1-ε- ^{t / To} ) B = Bo (1-ε- ^{t / To} ) where Go and Bo are the final target conductance and susceptance, and G and B are circuit breakers CB. After doing
Indicates the conductance and susceptance at time t, and To indicates the time constant.

Although the load is represented by the conductance G and the susceptance B in the above-described embodiment, the present invention is not limited to this, and is represented by active power and reactive power from the relation of P = GV ² and Q = BV ² , and The same effect can be obtained by changing the slope with a constant slope or changing the slope exponentially.

[Effects of the Invention] As described above, according to the present invention, the thyristor is controlled by the microcomputer to change the constants constituting the load from a state with less disturbance to the system to a desired value. It is possible to suppress a decrease in voltage at the time of turning on, to reduce disturbance to the system and to recover quickly, so that the effect on stability can be increased. In addition, the simulation can be performed quickly and the economic effect is extremely large.

[Brief description of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention. FIG. 2 is a specific block diagram of the load shown in FIG. Third
FIG. 4 and FIG. 4 are diagrams showing changes in the conductance G and the susceptance B of the load. In the figure, G is a synchronous generator, L is a reactance, CB is a circuit breaker, Lo is a load, CPT is a current-voltage transformer, and AVR is an automatic voltage regulator.

Claims (5)

(57) [Claims] 1. A load device for a simulator used in a simulator for simulating an electric power system, a voltage detecting means for detecting a supplied voltage, a load element, a thyristor for applying the voltage to the load element, and the voltage detection. Based on the voltage detected by the means,
A control circuit for controlling the conduction of the thyristor and changing the constant of the load element to a predetermined value while keeping the state of less disturbance so as not to cause the voltage drop and vibration of the power system is provided. , Load devices for simulators. 2. The conductance and susceptance are used as constants constituting the load,
The load device for a simulator according to claim 1. 3. The constant constituting the load is active power P =
GV ² (G is conductance) and reactive power Q = BV ² (B
2. The simulator load device according to claim 1, wherein a value representing active power and reactive power is used from the relationship of (susceptance). 4. The load device for a simulator according to claim 1, wherein a constant gradient is changed as a method of changing a constant constituting the load. 5. The load device for a simulator according to claim 1, wherein the constants constituting the load are changed exponentially.