JPH0348734B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a system stabilizing device that contributes to improving the stability of a power system.

Conventionally, this type of system stabilization device uses a method to detect active power as self-end information from a synchronous generator (usually called the ΔP method), and a method to detect frequency from the terminal voltage of the synchronous generator (usually called the ΔF method). , and a method for detecting the rotational speed of a synchronous machine (usually called the Δω method).Here, the ΔP method will be explained as an example.

FIG. 1 shows a configuration diagram of a conventional system stabilizing device. In Fig. 1, 1 is an active power converter, 2 is a phase correction element of a grid stabilization device, 3 is an amplification element of a grid stabilization device, and 4 is an automatic voltage regulator (hereinafter referred to as
5 is a synchronous generator, 6 is a field switch, 7 is a current transformer (hereinafter referred to as CT), and 8 is a transformer (hereinafter referred to as PT).

Next, the operation of the conventional system stabilizing device will be explained. The active power from the synchronous generator 5 detected by the active power converter 1 via the CT 7 and PT 8 arranged in the grid is transferred to the phase correction element 2 and the amplification element 3.
Supplied to AVR4 through. Here, the phase correction element 2 and the amplification element 3 are usually expressed by a transfer function G(s) as shown in equation (1) below. That is, G(s)= _TR S/1+ _TR S・1+T _LD1 S/1+T _LG1 S・1/1+T _LG2 SK...(1) However, here, K...amplification factor (gain constant) T _R ...first time Constant T _LD1 ...Second time constant T _LG1 ...Third time constant T _LG2 ...Fourth time constant The first, second, and third phase correction values are determined by the time constants on the right side of this transfer function G(S). If the total phase correction value and amplification factor are appropriate values, the output signals of the phase correction element 2 and amplification element 3 will change the excitation amount of the synchronous generator 5 through the automatic voltage regulator 4 in response to fluctuations in active power. By doing so, it is possible to stabilize the power system.

In the conventional system stabilizing device, a single adjustment circuit including a phase correction element 2 and an amplification element 3 determines setting constants such as a phase correction value and an amplification factor.
For this reason, if the system configuration conditions change due to the opening and closing of a disconnector or disconnector provided on a power transmission line, the control constants thereof will no longer be optimal. As a result, it is not possible to provide sufficient stability to the system, and even though the control constants should be changed according to changes in the system configuration conditions,
It had the disadvantage of not being able to do this.

The present invention was made in order to eliminate the drawbacks of the conventional devices as described above, and an object of the present invention is to provide a system stabilizing device that can always perform optimal functions in response to changes in system configuration conditions. It is.

An embodiment of the present invention will be described below.
FIG. 2 shows a system configuration diagram of a general power system to which the system stabilizing device of the embodiment of the present invention shown in FIG. 3 is applied. In Figure 2, 5 is a synchronous generator, 11
~14 are power transmission lines, 15~18 are busbars, 19a~1
Reference numeral 9d indicates a power transmission line disconnector, which is provided at both ends of each power transmission line, but is shown as one in the illustrated example.

FIG. 3 shows a configuration diagram of a system stabilizing device according to an embodiment of the present invention. In FIG. 3, 2 and 3 are a first phase correction element, a first amplification element,
Further, 2' and 3' are the ninth phase correction element and the ninth correction element, respectively, and 21 to 29 are the first phase correction element, respectively.
- These are contacts connected in series to the output terminals of the ninth amplification elements 3 to 3', and are closed separately depending on the system configuration conditions.

In the figure, two phase correction elements, amplification elements, and contacts are shown, No. 1 and No. 9, but in reality, as shown with dashed lines, there may be more than one, i.e. In this example, there are nine.

FIG. 4 is a circuit configuration diagram of a system identification logic circuit that identifies changes in system configuration conditions as the four power transmission lines 11 to 14 in the power system shown in FIG. 2 are normal or abnormal. I ₁₁ to _{I 14} are all power transmission lines 1
It is an input signal terminal for each normal/abnormal state signal of 1 to 14. Further, L ₁ to _{L 9} are logic elements constituting an AND circuit. _O1 to _O9 are output signal terminals of the system identification logic circuit, and each output signal selects and closes contacts 21 to 29.

Next, the operation of the embodiment shown in FIG. 3 will be explained with reference to FIGS. 2 and 4.

Let us now consider the operation when the system stabilizing device of this embodiment is applied to the power system shown in FIG. In the system configuration diagram shown in Figure 2, the normal and abnormal states of each of the transmission lines 11 to 14 are detected from the open/close status signals of the disconnectors or breakers installed on each transmission line. By inputting this signal to the input signal terminals I ₁₁ to _{I 14} of the system identification logic circuit shown in Fig. 4, nine system configuration conditions can be identified by this system identification logic circuit. and respective identification signals are output from output terminals _O1 to _O9 .

Therefore, since each system configuration condition determined from the system identification logic circuit shown in FIG. 4 is determined in advance, each of the first to ninth phase correction elements 2 and amplification elements 3 is If the respective phase correction values and control constant values such as amplification factors are selected in advance, the phase correction element and amplification element of the control constant corresponding to the system configuration conditions are determined by the identification signal from the system identification logic circuit. can be selected, and the optimal systemization can always be achieved.

In the above embodiment, the hardware of the system stabilization device was explained by referring to contacts, etc., but all of these can easily be replaced with digital devices, or a combination of analog circuits and relay circuits, or a combination of analog circuits and relay circuits, or digital circuits and analog It is obvious to those skilled in the art that the same effects as in the above embodiment can be achieved by using a combination of circuits.

In addition, in explaining the operation of this embodiment, the power system shown in Fig. 2 was disclosed as an example, but the system configuration is as follows.
It is obvious that the system identification logic circuit shown in FIG. 4 can be designed in any configuration other than that shown in the figure, and may be modified accordingly.

As described above, the system stabilization device according to the present invention includes a plurality of phase correction elements and amplification elements each having different control constants provided corresponding to each of the system configuration conditions of the system to which the synchronous generator is interconnected; The power system state is identified by logically using the switching information of the breakers or disconnectors installed in the power system, and the phase correction element and amplification element having the optimum control constant for the identified power system state are selected. Since the present invention is equipped with a system identification logic circuit, it is possible to realize a system stabilizing device that always has optimal controllability adapted to the system configuration conditions.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a conventional grid stabilizing device, Figure 2
The figure is a system configuration diagram of an example of a power system to which a system stabilization device according to an embodiment of the present invention is applied, FIG. 3 is a configuration diagram of a system stabilization device according to an embodiment of the present invention, and FIG. FIG. 4 is a system identification logic diagram for identifying system configuration conditions from the diagram system; 1... Active power converter, 2, 2'... Phase correction element, 3, 3'... Amplification element, 4... AVR, 5...
...Synchronous generator, 6...Shiya breaker, 7...CT, 8
...PT, 11-12...Power line, 15-18...
...Bus bar, 21-29...Contact, _I11 - _I14 ...Input signal terminal, _L1 - _L9 , _O1 - _O9 ...Output signal terminal. In addition, in the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Claims] 1. A phase correction element that inputs status output signals such as active power, frequency, or rotational speed from the synchronous generator, and an output signal of this phase correction element that is input via an amplification element to control the amount of excitation of the synchronous generator. In a system stabilizing device having an automatic voltage regulator, a plurality of phase correction elements and amplification elements having different control constants are provided corresponding to respective system configuration conditions of a system to which the synchronous generator is interconnected. and,
The power system state is identified by logically using the switching information of the breakers or disconnectors installed in the power system, and the phase correction element and amplification element having the optimum control constant for the identified power system state are selected. A system stabilizing device characterized by comprising a system identification logic circuit.