JPH0348735B2 - - 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 has a method of detecting active power from a synchronous machine as self-end information (usually called the ΔP method), a method of detecting the frequency from the terminal voltage of the synchronous machine (usually called the ΔF method), and There is a method to detect the speed of a synchronous machine (usually called the Δω method), but here we will use ΔP as an example.
The method will be explained using 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 machine, and 6 is a field magnet. 7 is a current transformer (CT
(hereinafter referred to as PT) and 8 represent a transformer (hereinafter referred to as PT).

Next, the operation will be explained. The active power signal of the synchronous machine detected by the active power converter 1 via CT7 and PT8 is supplied to the automatic voltage regulator 4 through the phase correction element 2 and the amplification element 3.

Here, the phase correction element 2 and the amplification element 3 are usually expressed by a transfer function G(S) such as the following equation (1).

G(s)=T _R S/1+T _R 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 _TLG1 ...Third time constant _TLG2 ...Fourth time constant The first, second, and third phase correction values are determined by each time constant on the right side of equation (1), and this total phase If the correction value and amplification factor are appropriate values, it is possible to stabilize the power system by changing the amount of excitation of the synchronous machine 5 through the automatic voltage regulator 4 in response to fluctuations in active power. .

A conventional system stabilizing device of this type determines control constants such as phase correction values and amplification factors for each of the phase correction element 2 and the amplification element 3 under a single system configuration condition. For this reason, if the system configuration conditions change due to the opening and closing of disconnectors, cable breakers, etc. installed on power transmission lines, their control constants will no longer be optimal, making it impossible to achieve sufficient system stabilization. It was hot.

The present invention was made in order to eliminate the drawbacks of the conventional ones as described above, and provides a system stabilizing device that exhibits a function that can always provide optimal control constants in response to changes in system configuration conditions. The purpose is to provide the following.

An embodiment of the present invention will be described below with reference to the drawings. Figure 2 shows a system configuration diagram of a general power system. In Fig. 2, 5 is a synchronous machine, 11 to 14 are transmission lines, 15 to 18 are bus bars, and 19a to 19d are disconnectors for the transmission lines 11 to 14, which are installed at both ends of each transmission line. However, in the illustrated example, they are all shown together.

FIG. 3 shows a configuration diagram of a system stabilizing device according to an embodiment of the present invention. In FIG. 3, 2 to 2' are a plurality of phase correction elements connected in parallel to the output side of the active power converter 1, and 3 to 3' are each phase correction element 2 to 3'.
A plurality of amplification elements connected to the output side of 2', 21-
Reference numeral 29 denotes a contact provided on the output side of each amplifying element 3 to 3', which is selectively closed according to a system reactance value corresponding to a change in system configuration conditions.

FIG. 4 shows a conceptual block diagram of a system reactance calculator that calculates a system reactance value based on system configuration conditions that change based on opening/closing information of disconnectors or breakers installed on power transmission lines 11 to 14.
In the figure, 30 is a constant circuit that determines the reactance value of each of the power transmission lines 11 to 14, 31 is an arithmetic unit that calculates a system reactance value based on the reactance value determined in the constant circuit 30 and system configuration information, and 32 is a This is an output circuit that selectively closes the contacts 21 to 19 based on the system reactance value calculated by the calculator 31.

FIG. 5 is a flowchart of a contact operation process that determines the operation of each of the contacts 21 to 29 operated by the system reactance value Xe from the output circuit 32.
2,333 indicates a comparison section.

Figure 6 shows the selection and switching of optimal setting constants based on the system reactance specifically expressed in hardware in consideration of the block diagram of the system reactance calculation section in Figure 4 and the flow diagram of the contact operation process in Figure 5. It is a block diagram of a circuit. In FIG. 6, 40 is an adjustment resistor, 41 to 44 are contacts for inputting operating status information of the power transmission lines 11 to 14, 51 to 54 are resistors simulating power transmission lines, and 60 is an amplifier. A computing unit 31 is configured. 61～
A comparator 71 69 serves as a determination circuit that compares a reactance value Xr set in advance with a reactance Xe calculated by the arithmetic unit 31 and determines the optimal phase correction element and amplification element according to this reactance value Xe. 79 are relays that operate the contacts 21 to 29 shown in FIG. 3, respectively, and these actuate the output circuit 32 in FIG.
It consists of

Next, the operation will be explained. In explaining,
The system stabilization device shown in Figures 3 and 4 is
A case where the present invention is applied to a power system having the system configuration shown in the figure will be explained as an example. In the case of the system configuration conditions shown in Fig. 2, for example, assuming that the transmission line 12 is suddenly cut off, the system reactance value from the synchronous machine 5 to the bus bar 18 changes, but this system information, for example, the sudden break Alternatively, the reactance value Xe of the computing unit 31 system shown in FIG. 4 can be easily calculated from the system configuration information from the disconnector and the reactance value of each power transmission line 11 to 14 set in the constant circuit 30.

This calculated system reactance value Xe is
In steps 331 to 339 of the flowchart shown in the figure,
System configuration conditions can be identified by comparing and determining the comparators 61 to 69 shown in FIG. Therefore, in the system stabilizing device shown in FIG. 3, the phase correction element 2 and the amplification element 3, each of which is set to the optimal phase correction value and amplification factor, can be adjusted in advance by changing the system configuration conditions. By preparing a plurality of stages, that is, nine stages in this embodiment, depending on the type, it is possible to always select the phase correction element and amplification element with the optimum set constants in response to changes in system configuration conditions.

Next, the operation of this embodiment will be described based on the system reactance calculation processing device shown in FIG. 6, which discloses the system reactance calculation unit shown in FIGS. 4 and 5 as a more specific configuration. That is, the sixth
In the figure, when the opening/closing information of the disconnectors or disconnectors provided on the power transmission lines 11 to 14 is input to the contacts 41 to 44, the system reactance value Xe is outputted as the output signal of the amplifier 60. This system reactance value Xe is compared with each reference value by comparators 61 to 69, and one of the contacts 21 to 29 is operated at the closest system reactance value. Thereby, it is possible to obtain a system stabilizing device that can always select position correction elements and amplification elements having optimal control constants according to the 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. The same effects as in the embodiment are achieved.

As described above, according to the present invention, a plurality of phase correction elements and amplification elements having different control constants are provided corresponding to each of the system configuration conditions of a system to which a synchronous machine is interconnected, and a plurality of phase correction elements and amplification elements are provided in the system. an arithmetic unit that calculates the system reactance value as seen from the terminal of the synchronous machine based on the opening/closing information of the disconnector or disconnector, and a phase correction element having an optimal control constant according to the reactance value from this arithmetic unit. and a judgment circuit for selecting an amplification element, the power system can always be highly stabilized against the system configuration conditions depending on the time, and the system can be controlled with excellent followability. There are effects that the stabilizing device can achieve.

[Brief explanation of drawings]

Figure 1 is a configuration diagram of a conventional grid stabilizing device, Figure 2
The figure is an explanatory diagram of the system configuration of an example of a power system to which a system stabilizing device according to an embodiment of the present invention is applied, FIG.
The figure is a conceptual block diagram of the system reactance calculator which is a part of the same embodiment, Figure 5 is a flow diagram explaining the operation of the operator shown in Figure 4, and Figure 6 is the concept shown in Figures 4 and 5. A configuration diagram of a system reactance calculation processing device that further embodies the system reactance calculation unit is shown. 1...Active power converter, 2-2'...Phase correction element, 3-3'...Amplification element, 4...Automatic voltage regulator, 5...Synchronous machine, 6...Field magnet and disconnector ,7
...CT, 8...PT, 11-14...Power line, 1
5-18...Bus bar, 21-29...Contact, 30...
... Reactance value constant circuit, 31 ... Arithmetic unit, 3
2... Output circuit, 331-339... Step,
40...Adjustment resistor, 41-44'...Contact, 51
~54...Resistor, 60...Amplifier, 61-69...
...Comparator, 71-79...Relay. 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 machine, and an automatic element that inputs the output signal of this phase correction element via an amplification element to control the amount of excitation of the synchronous machine. A system stabilizing device having a voltage regulator, a plurality of phase correction elements and amplification elements having different control constants provided corresponding to respective system configuration conditions of a system to which the synchronous machine is interconnected; It has a computing unit that calculates the system reactance value as seen from the terminal of the synchronous machine based on the opening/closing information of the disconnector or disconnector installed in the grid, and has an optimal control constant according to the reactance value from this computing unit. A system stabilizing device comprising a phase correction element and a determination circuit for selecting an amplification element.