JPS59230431A - System stabilizer - 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 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 the active power of a synchronous generator (usually called the ΔF method), and a method to detect the frequency from the terminal voltage of the synchronous generator (usually called the ΔF method).
There are two methods: a method for detecting the speed of a synchronous generator (usually called a Δω method), and here, the ΔF 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 the system stabilization device, 3 is an amplification element of the system stabilization device, 4 is an automatic voltage regulator, 5 is a synchronous generator, and 6 is a field magnet. In the circuit breaker, 1 indicates a current transformer (hereinafter referred to as CT) and 8 indicates a transformer (hereinafter referred to as PT). Also 1
0 is an adjustment device, which includes a phase correction element 2 and an amplification element 3.
The operation will be explained next. A regulating device 10 comprising an amplifying element 3 comprising a phase correcting element 2 and an amplifying element 3 transmits the active power signal of the synchronous generator detected by the active power converter 1 as shown in the following equation (1). Function G (represented by 81).

However, here K......Amplification factor (gain constant) TR......First time constant TLD 1...Second time constant TLG 1. ...Third time constant TLG2...Fourth time constant By each time constant of this equation (1), the first... If the second and third phase correction values are determined and the total phase correction value and amplification factor are appropriate values, the amount of excitation of the synchronous generator 5 is changed through the automatic voltage regulator 4 in response to fluctuations in active power. It is possible to stabilize the power system by

In a conventional system stabilizing device of this type, each setting constant of the adjustment device 100, phase correction element 2, and amplification element 3 is uniquely determined under a single system configuration condition, and a wide variety of setting constants are determined. If the system configuration conditions consisting of the transmission line network along the line change, sufficient stability of the system can be ensured by operating disconnectors and circuit breakers installed on each transmission line as adjustment devices. The drawback was that it was impossible to do so.

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 with reference to the drawings. Second
The figure is an exemplary power system system configuration 1 drawn for explaining the operation of the system stabilizing device of this embodiment. Second
In the figure, 11 to 14 indicate power transmission lines, and 15 to 18 indicate bus bars. FIG. 3 is a block diagram showing a system stabilizing device according to an embodiment of the present invention, in which reference numeral 21 denotes an arithmetic unit that calculates the system reactance value Xe based on self-end information of the synchronous generator 5;
2 is a grid side reactance output signal as seen from the terminal of the synchronous generator 5 calculated by the arithmetic unit 21, and 23 is arranged in the adjustment device 6 to 10 based on the reactance output signal 22. Phase correction element 2-2
A selection switching logic unit 24 receives a switching output signal from this selection switching logic unit 23 and performs switching by selecting an adjustment circuit having an optimal constant from among the adjustment circuit power consisting of the amplification elements 3 to 3'. Row 1. It is a contact point. FIG. 4 shows a configuration diagram as a specific example of the selection switching logic section 23 for selecting the phase correction elements 2 to 2' and the amplification elements 3 to 3' shown in FIG. 40 is a resistor that simulates the system reactance value from the reactance output signal 22 of the arithmetic unit 21; 60 is an amplifier; 61 to 6;
1' is a plurality of comparators for comparing the reactance value set in advance and the system reactance value directly calculated by the calculator 21; 11-71 contacts 24-24;
This is a relay that operates each of .

Next, the operation will be explained. In a power system as exemplarily shown in FIG. 2, the system reactance value xe seen from the terminal of the synchronous generator 5 fluctuates depending on the power flow at that time, an accident, etc.

Therefore, the system reactance is calculated by the arithmetic unit 21 based on the edge information of the synchronous generator 5, and the system reactance output signal 22 is used to calculate the phase correction elements 2 to 2' of the adjustment circuit having the optimum constant. An operation for selecting one of the amplification elements 3 to 3' is performed by the selection switching logic section 23.Next, as an example, a method of calculating the system reactance value performed by the arithmetic unit 21 will be described below. Assuming that the active power is P, the reactive power is Q, the terminal voltage is vt, the synchronous reactance value is Xd, and the back voltage is Bfd as self-end information of the synchronous generator 5, the following formula holds true.

・・・・・・・・・・・・・・・(3) If the phase angle δ is eliminated from equations (21 and (3)), the system reactance value Xc as the system reactance output signal 22
can be easily found.

Next, the operation of the selection switching logic section will be explained as a specific example shown in FIG. Here, the variable resistor 40 is changed according to the system reactance value Xe calculated as described above, and each comparison is made to compare the voltage signal of the variable resistor 40 with the output signal of the amplifier 60 that amplifies it or with a preset reactance value. The closest system reactance value is selected by the switches 61 to 61 as the system configuration conditions change moment by moment, and any one of the contacts 24 to 24' at that time is activated. Adjustment circuit IQ with the optimum control constant transfer function for the system reactance value calculated by this
a to 10a' are selected. From the above, it is possible to obtain an optimal system stabilizing device for any system configuration conditions.

In the above embodiment, the hardware of the system stabilization device was explained by referring to contacts, etc., but all of these may be digital devices, or a combination of an analog circuit and a relay circuit, or a combination of a digital circuit and an analog circuit may also be used. Since the system stabilization device was configured to obtain the system reactance value using the self-end information of the synchronous generator, which has a similar effect, and select the optimal element based on the system reactance value,
It is possible to realize a system stabilizing device that always has an optimal effect according to the system configuration conditions.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of a conventional system stabilizing device, and FIG. 2 is a system configuration diagram of an example of a power system to which an embodiment of the present invention is applied.
FIG. 3 is a block diagram of a system stabilizing device according to an embodiment of the present invention, and FIG. 4 is a specific block diagram of a selection switching logic section forming a part of the embodiment of FIG. DESCRIPTION OF SYMBOLS 1... Active power converter, 2-2'... Phase correction element, 3-3'... Amplifying element, 4... Automatic voltage regulator, 5... Synchronous generator, 6...・Field breaker, 1...
・CT, 8...PT, 10...adjustment device, IQa~
I Q a'...adjustment circuit, 11-14...power transmission line, 15-18...bus bar, 21...71-71'...
·relay. In addition, in the figures, the same reference numerals indicate the same or corresponding parts. Agent Masuo Oiwa 1 Figure 2 ++ 12 1,5 Section 14 3 Figure 4 Continued from Figure 1 Page 0 Inventor Makoto Tanaka - Mitsubishi Electric Co., Ltd., 1-1-2 Wadazaki-cho, Hyogo-ku, Kobe City Inside the company control manufacturing facility ■Applicant Mitsubishi Electric Corporation 2-2-3 Marunouchi, Chiyoda-ku, Tokyo

Claims (1)

[Claims] A system stabilization device that detects active power, frequency, or speed signals from the synchronous generator and controls the amount of excitation to the synchronous generator via an automatic voltage regulator based on the input output signal of the regulator, The adjustment device has a plurality of adjustment circuits that have mutually different phase correction values and amplification factors, and the synchronous generator * based on own-end information from the synchronous generator.
, the output signal of the arithmetic unit that calculates the system reactance value seen from the terminal of the machine is supplied to a selection switching logic section, and the selection switching logic section selects an adjustment circuit having an optimal control constant from among the adjustment devices. A system stabilizing device characterized by controlling the stability of a system connected to the synchronous generator.