JPS59127524A - Stationary time limiting relay - 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 [Technical Field of the Invention] The present invention relates to a static counter-time relay, and particularly to a static counter-time relay whose counter-time characteristics are not affected by accident response.

[Technical background of the invention]

There are various types of protective relays that protect power systems, but among them, the method that protects power lines by using multiple time-limited overcurrent relays is well known as one of the overcurrent protection methods. FIG. 1 is a diagram for explaining the principle. In the figure, A, B, and C are the busbars of each electric station, RY
A I RYn + RYC is the anti-time overcurrent relay installed at each electrical station, 1゜2.3 is each anti-time overcurrent relay R
Operating time characteristics of YA, FtYB, RYc, T1 is the time required for relay RYA to operate in the event of a fault at point FA of the transmission line, T2 is the time required for relay RYB to operate in the event of a fault at point FB, T' 1, T'
2, T3 is the relay RY when a failure occurs at the Fc point.
It shows the time required for A, RYB, and RYc to operate.

Now, if a failure occurs at point FC shown in the diagram, relay RYc with a short operating time will operate, and the circuit breaker of the electrical station where relay RYC is installed will be tripped, and electrical stations A and B will continue to operate in a healthy state. It will be continued. in this way,
Relay RYA is used to isolate only the protected section where a failure has occurred from other healthy sections.

RYB and RYc are coordinated in their operating time.

Figure 2 is a diagram showing the configuration of the reverse time limit overcurrent relay RYA.
4 is a circuit that full-wave rectifies the input current I and generates the output e1;
5 is a circuit that integrates the output of circuit 4 and generates output e2; 6
7 is a level detection circuit that generates an output when the output e2 of the integrating circuit 5 exceeds a predetermined value LD, and 7 is the input current I.
This level detection circuit functions as a starting element that resets the integrator circuit 5 using its output e3 when the integrator circuit 5 is below a predetermined value.

FIG. 3 is a block diagram showing details of the integrating circuit 5 in FIG. 2, where IC is an operational amplifier, R is an operational resistor connected to the inverting input terminal of the operational amplifier IC, and C is an inverting terminal of the operational amplifier IC. Integrating capacitor connected to the output terminal, XI
is a normally closed contact controlled by the output e3 of the level detection circuit 7, and when the input current I introduced into the level detection circuit 7 is below a predetermined value, the capacitor C is short-circuited by the contact X, and the integrating circuit 5 is closed. It has been reset.

In static protective relays using semiconductor elements such as transistors and operational amplifiers, it is generally practiced to check the operation by applying simulated human power to improve reliability.

Inspections are performed using the trip output of the protective relay device, so as a countermeasure against accidents occurring during inspection, if an accident is detected in a protective relay that is not subject to inspection, the inspection input for the protective relay being inspected is canceled. A method is used to have the victims participate in protection (generally referred to as accident response).

[Problems with background technology]

FIG. 4 shows a time chart for responding to an accident with the reverse time limit overcurrent relay RYA.

Inspection input is generally applied by superimposing it on the input vehicle flow I of the relay. In Fig. 4, the signal e'1 is the integrator circuit 5.
0 represents the average value of the input signal e1, and is an electrical quantity proportional to the input current and the inspection input current applied superimposed on the input current.In Fig. 4, before time t1, the signal e'l Since the value of is small and no operational output is generated in the level detection circuit 7 as the activation element explained in FIG. 2, the output e2 of the integration circuit 5 is reset to O.

Time 1. The inspection is started, the input current for inspection is superimposed on the input current, and the integration circuit 5 outputs a signal e2 determined by the magnitude of the signal e'1 and the integration time constant CR.

The magnitude of the signal e2 is the detection level LD of the level detection circuit 6.
At time t4, an operational output is generated in the level detection circuit 6.

Inspection input application time 1. By determining whether the time from the time t4 to the time t4 at which an output is generated to the level detection circuit 6 is within a predetermined range, it is possible to check whether the inverse time characteristic of the relay RYA is good or not.

Next, a case where an accident occurs at time t2 during relay RYA inspection will be described.

When an accident occurs at time t2, the inspection input terminal and the fault current are superimposed, and the signal e'l becomes a broken line, and the signal e2
reaches the detection level LD at time t14, and the relay R
YA works.

Note that t3 indicates the time when accident response is activated by the relay not subject to inspection and the inspection input to relay RYA is canceled.

Originally, the accident should have occurred at time t2, and signal e2 had the characteristics shown by the dashed line at time t5 after time T5 had elapsed.
When the detection level LD is reached, the relay RY should be activated, but as mentioned above, at time T4 (T4<T5)
It will be shortened to .

As a result, in the overcurrent protection system shown in Figure 1, for example, in the case of an accident at fault point FC, relay RYC operates first to eliminate the fault, and even if relay RYA does not operate, the accident Depending on the timing of the occurrence, the operating time of relay RYA may be shorter than the operating time T3 of relay RYC.Relay RYA operates first and connects all the transmission lines from bus A to bus B and C. It will be cut off.

That is, there is a drawback that time coordination cannot be achieved using the inverse time characteristic of the relay, which is the basis of the overcurrent protection system.

[Purpose of the invention]

The present invention was made with the aim of solving the above-mentioned drawbacks, and an object of the present invention is to provide a highly reliable static type counter-limiting time relay that does not affect time coordination even when an accident response is performed. It is said that

[Summary of the invention]

In the present invention, when an accident response is required during the inspection operation of a protective relay having inverse time-limiting characteristics, the inverse time-limiting time measuring circuit of the protective relay is reset, and the operation with inverse time-limiting characteristics is started again, with the condition that the accident response is activated. This is what I'm trying to get started.

[Embodiments of the invention]

Examples will be described below with reference to the drawings. Figures 5 and 6
The figure is a configuration diagram of an embodiment according to the present invention.

In the drawings, constituent elements labeled with the same symbols as in FIGS. 2 and 3 have the same purpose and function, and will not be fully described below.

The explanation will be focused on the differences in configuration from FIGS. 2 and 3.

In FIG. 5, 8 is a check circuit, and e4 is a control signal given from the check circuit 8 to the integrating circuit 5 of the relay RYA. Details of the integrating circuit 5 are shown in FIG. In Figure 6,
Reference numeral 2 denotes a normally open contact controlled by a control signal e4, and when contact X2 is closed, the portion of capacitor C that performs inverse time measurement is short-circuited and the output of relay RYA is reset.

The present invention will be explained in detail below. In FIG. 4, time t
2, when an accident occurs and accident response is activated by a relay not subject to inspection, for example, an instantaneous overcurrent relay, the inspection input is canceled at time t3. At this time, in Figs. 5 and 6, a control signal e4 is generated from the inspection circuit 8 under the condition that the accident response is started, and the contact X2 is closed for a predetermined period of time, for example, until time t3 when the inspection input is released. The output of the integrating circuit 5 is reset to e2kO.

FIG. 7 shows the time chart at this time using a solid line, and for comparison, the case of a relay according to the prior art is shown using a broken line.

At time t3, the inspection input is canceled and at the same time contact X2
Since the reset of the integrating circuit 5 is also released, from this point on, integration is performed by the signal e'l proportional to the fault current, and at time t6, the output signal e2 of the integrating circuit 5 reaches the detection level LD, so the relay RYA is activated. produces an output.

Therefore, in the prior art, the disadvantage that the operation time is shortened depending on the timing of the occurrence of an accident, and as a result, time coordination cannot be achieved and the outside of the protected area is erroneously cut off does not occur.

Note that the operation time of the relay RYA is delayed by the time T6 from the occurrence of the accident at time t2 until the inspection input is canceled at time t3, but during this time T6, the operation output is generated after the inspection input is canceled. Since it is sufficiently short compared to time T7, it does not affect time coordination using anti-time characteristics.

In the configuration diagram of the embodiment shown in FIG. 6, the contact point is X for simplicity.

and X2 have been explained as being separate from each other. For example, the control signal e4 from the inspection circuit 8 is converted into the output e of the level detection circuit 7.
3, the contact X1 may be closed for a period of time until the inspection input is released.

Further, instead of a contact point, a semiconductor switch using a transistor or the like may be used. In short, any means or circuit may be used as long as it is capable of giving a reset to the inverse time measurement.

〔Effect of the invention〕

As explained above, the present invention is capable of resetting the anti-time measuring circuit of the anti-time relay being inspected once an accident has been detected in the relay that is not subject to inspection, and a countermeasure for the accident has been activated. Therefore, it is possible to provide a highly reliable static type anti-time relay with almost no influence on the anti-time characteristic due to accident response.

[Brief explanation of the drawing]

Figure 1 is an explanatory diagram of an overcurrent protection system using a counter-time overcurrent relay, Figures 2 and 3 are block diagrams of a counter-time overcurrent relay according to the prior art, and Figure 4 is a diagram showing the configuration of a counter-time overcurrent relay according to the prior art. A time chart diagram for responding to an accident in a current relay, FIGS. 5 and 6 are block diagrams of an embodiment of the anti-time overcurrent relay according to the present invention, and FIG. 7 is a time chart for responding to an accident in the anti-time overcurrent relay according to the present invention. It is a chart diagram. RYA + RYn, RYc...Reverse time limit overcurrent relay 4...Full wave rectifier circuit 5 Integrating circuit 6.7...
・Level detection circuit (7317) Agent Patent attorney Kensuke aide (and 1 other person) Figure 1 Figure 6

Claims (1)

[Claims] In a static type anti-time relay in which a protective operation is performed in response to an accident during the inspection operation of a protective relay with anti-time characteristics, the anti-time measurement circuit of the protective relay being inspected is temporarily activated on the condition that the accident response is activated. A static counter-time relay characterized by restarting counter-time operation after being reset.