JPS6237021A - Power system stabilizing system - 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] [Field of Application of the Invention] The present invention relates to excitation control of a synchronous machine, and is particularly applicable to a power system stabilizing device for improving the dynamic stability of a power system (PSS:
Power System 5tabilizer
) is related to an excitation control device for a synchronous machine.

[Background of the invention]

A conventional excitation device is composed of an automatic voltage regulator that performs constant voltage control at generator terminals and a power system stabilization device that improves the dynamic stability of the power system. However, in such an excitation system, when a major disturbance such as a three-phase short circuit accident is applied to the excitation system, the excitation system enters a nonlinear region, causing a relaxation oscillation phenomenon and a hunting phenomenon between the excitation system and the system. There is. However, the conventional excitation method is 1, for example,
As in No. 0-16809, the response in the linear region was considered.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a power system stabilizing device that does not cause unstable phenomena such as tension oscillation even when an automatic voltage regulator enters a nonlinear operating region, and constantly improves the dynamic stability of a power system in an optimal manner. be.

[Summary of the invention]

The present invention detects when an automatic voltage regulator enters a nonlinear region, and adaptively controls the gain, time constant, limiter value, etc. of a power system stabilizer according to a function of this duration, thereby optimizing the dynamic state. The present invention relates to the realization of an excitation device that improves stability.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to FIG. 1st
The figure shows a self-excited thyristor excitation device in which the terminal voltage of a synchronous machine 1 is detected by an instrument transformer 6, this output is compared with a voltage setting circuit 8 of an automatic voltage regulator, and the deviation is amplified by an amplifier 9. This is further converted into a phased pulse, the firing angle of the thyristor 3 is rectified and controlled by this pulse, and this rectified voltage is applied to the electromagnetic coil 5 of the synchronous machine via the field breaker 4, Controls terminal voltage.

Further, since automatic voltage control alone causes a decrease in the dynamic stability of the power system, the power system stabilization device 11 is installed to improve the dynamic stability of the power system. The above is a normal excitation device configuration, but in the present invention, in addition to this, a nonlinear operation detection bag @12 is provided to detect when the automatic voltage regulator enters a nonlinear operation region, and by performing optimal control in the nonlinear region. ,
Dynamic stability can always be ensured even when the excitation device enters the nonlinear region.

By providing the non-linear operation detection circuit 12 in this way, in a normal excitation system, if the disturbance caused by a system fault is large as shown in FIG. 2, the excitation device will cause a relaxation oscillation phenomenon with the system and become unstable.

That is, since the movement of the internal phase difference angle δ, which is system fluctuation, is large, the output of the power system stabilizing device Vpss is saturated, and accordingly, the output of the automatic voltage regulator Va is also saturated.

This further promotes internal phase difference angle fluctuation. However, the present invention provides a nonlinear operation detection circuit 1 for an automatic voltage regulator.
2 to perform optimal control, power fluctuations after a system fault occurs rapidly attenuate as shown in FIG.

An example of the configuration of the nonlinear operation detection circuit 12 is shown in FIG. Fourth
The figure shows an example of a first-order lag; the output deviation between the output of the first-order lag 1 and the simulation circuit 2 of the first-order lag circuit is
Find V'out and calculate its absolute value I Vout-V'ou
When tl exceeds a certain value, it is detected that the first-order delay has entered the nonlinear operation region. Next, regarding the response in the nonlinear operation region, as shown in Figure 5, optimal control is performed to apply reverse forcing after a certain period of time (approximately 20 degrees) after the internal phase difference angle reaches the maximum value δWAX. I do.

〔Effect of the invention〕

According to the present invention, it is possible to detect when the excitation device enters a nonlinear operation region, and perform nonlinear optimal control such as bang-bang control in the nonlinear region, so that optimal excitation control is always performed in all operating conditions of the excitation device. It becomes possible to do so.

[Brief explanation of the drawing]

Fig. 1 is a block diagram of an embodiment of the present invention, Fig. 2 is an explanatory diagram of the response of the conventional excitation method, Fig. 3 is an explanatory diagram of the response when the present invention is applied, and Fig. 4 is nonlinear motion detection. FIG. 5 is an explanatory diagram of the PSS control signal in the nonlinear region. 1...Synchronous power generation material, 2...Excitation transformer, 3...
Thyristor, 4... Field breaker, 5... Field coil, 8... Automatic voltage setter, 10... Automatic phase shift pulse generator, 12... Nonlinear operation detection circuit.

Claims (1)

[Claims] 1. Synchronization consisting of an automatic voltage regulator that controls the terminal voltage of the synchronous machine to be constant, and a power system stabilization device that inputs power system stabilization signals such as active power, rotation speed, or frequency and improves the dynamic stability of the power system. The mechanical exciter is equipped with a nonlinear operation detection circuit that detects when the automatic voltage regulator or power system stabilization device enters a nonlinear control region, and when there is no output from this nonlinear operation detection circuit, linear control is performed. , a power system stabilization method that performs nonlinear control such as bang-bang control when the nonlinear operation detection circuit operates, and always performs optimal control against disturbances of any size to the exciter.