JPS58119115A - Breaker control 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 The present invention relates to a method for quickly eliminating the no-current phenomenon.

In the conventional switching system, when detecting the absence of current zero, a resistor installed on the neutral point side of the star-shaped connection is inserted in series with the corresponding Ainokura circuit to quickly resolve the absence of p1 current. Good friend. This type of method aims to speed up the attenuation of the DC component and accelerate the generation of the zero point, so it has the disadvantage that it is necessary to install an introductory resistor in order to expect a large effect. One object of the present invention is to provide a method for preventing pipe breakage in a circuit breaker, maintaining stability, and quickly resolving the no-current phenomenon.

Zero current occurs when the transient DC component exceeds the AC component, and the attenuation of the transient DC component is determined by the actance and resistance up to the fault point.In this case, a capacitance is inserted in series in the circuit. By doing so, the reactance decreases, and since it is a circuit of inductance, capacitance, and resistance, harmonics are generated and zero points are likely to occur. Try to resolve it early.

In the power transmission system shown in FIG.
is supplying electricity to. In the same figure, when an accident occurs below the point, the current passing through the circuit breakers CBI and CB2=i is detected by the current transformers CTI and CT2, and the transmission circuit @
When it is determined that there is an accident in the internal direction, that is, between CB, 1 and CB2, the protective relay devices RYI and RY2 are activated to switch breaker CB.
Issue a cutoff command to I and CB2 to eliminate the accident. However, if an accident occurs while generator G is in phase advance operation,
The alternating current component of the current is lower than the transient direct current component, no zero point occurs in the current, and the circuit breaker opens, but it cannot be shut off and there is a risk that it will be destroyed.

Therefore, in order to prevent the breaker from breaking, the protective relay BYIQ operates to open the switch S and connect the capacitor/
Scr-input. The second part shows this part in detail.
It is a diagram. That is, the protection relay RYI is connected to the current transformer C
If a p accident and no zero are detected by the output of 'I', , ~CT, , switch S, ~8. By issuing an open command to , a capacitance C1) Cb, C- is injected in series into the circuit. The circuit in this case is shown in FIG. Here, Lt is the inductance up to the fault point, and R is the resistance up to the fault point. If there is no zero, the reactance up to the accident point is large and it is easy to cause a failure.
It is generally known that C is selected so that the inductance L causes a non-zero time that is harmful.

Sea urchin, ・・・・・・・・・(1) Here, the fundamental wave component increases due to the input of capacitance. Therefore, the absence of zero acts toward cancellation, and furthermore, the natural vibration coefficient determined by the above-mentioned β is generated, and the absence of zero tends to disappear as shown in Figure 1j45.

That is, if the present application is not adopted, the non-zero time will continue for a long time as shown by the curve - in the figure, whereas if the present application is adopted, the time 1. A zero point occurs at , and the time without zero is greatly shortened.

So far, we have described an example in which capacitance is introduced into the neutral point of a transformer, but it is also possible to introduce capacitance into a generator as shown in FIG.

Here, faults can be detected using overcurrent detection or undervoltage detection, which are conventionally used, and non-zero detection can be performed by measuring the cycle of current, etc. To determine whether or not the glue actance is above a certain value, extract the basic voltage from the current and voltage, sample it at a certain time interval, and use this information t'' (s) e v(t) from these t / 2 (red ) Distant information t-Todoroki (t''g4), (*-t/@),
Reactance ωL1 can be obtained as follows.

According to the present invention, it is possible to simultaneously expect an increase in alternating current component due to a decrease in inductance and the generation of a zero point due to the generation of harmonics, and due to the effects of these two, the time for the occurrence of the zero-zero phenomenon can be reduced. It can be shortened, and prevents damage to the interrupter.
This has a great effect on maintaining stability as well as speeding up the interruption time.

[Brief explanation of drawings]

1@Expanded diagram showing the applied-b power transmission system of the present invention, #1
Figure 2 is a diagram showing an embodiment of the present invention, Figure #13 is a diagram explaining the generation of harmonics, Figure #14 is a diagram of an applied example, and Figure jIs is an example showing the effects of the present invention. G... Generator, 'rr, e Ttl... Transformer,
8... Grid, t... Transmission line, CBI, CB2...
Breaker, CT1゜CT2...Current transformer, RYl,
RY2...Protection relay, C...Capacitance, 8
661 + Switch, C... Condolence Diagram 3

Claims (1)

[Claims] 1. In a system for controlling circuit breakers installed in a power system, when a transmission line fault is detected and no current is detected, a capacitance is inserted in series in the circuit. Circuit breaker control method with t4I indication. 2. In Claim 4 M1, the inductance of the power transmission line up to the fault point is greater than or equal to a predetermined value L (H), and the resistance up to the fault point determined by the transmission line impedance angle is R (Ω). and the system frequency is f(Hi)
A breaker control method characterized by being connected in series with the circuit. 3. In claim 1, the capacitance inserted in series in the circuit is a capacitance installed in advance on the neutral point side of a star-connected transformer or generator, and a capacitance installed in parallel with this. A breaker control method characterized by being inserted in series in a circuit by opening and closing a circuit switch.