JPS59117417A - Inspecting circuit for protecting 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 an improvement in an inspection circuit for manually inspecting a protective relay, particularly a static protective relay having a contact output.

[Technical background of the invention and its problems]

Recently, a large number of static protection relays using semiconductor elements such as transistors have been adopted, but there are some concerns about their reliability because they have more parts than conventional electromagnetic mechanical relays. Therefore, it is generally practiced to apply a simulated operation check input to the protective relay to check its operation and improve its reliability.゛During inspection, the protection and relays to be inspected are actually operated to generate output signals, so this output signal is locked before applying the inspection input to prevent malfunctions of circuit breakers, etc., and false alarms. It is necessary to prevent this. Conversely, when the inspection is completed, it is necessary to cut off the inspection input and then unlock the output signal.

FIGS. 1 and 2 show a configuration for manual inspection according to the prior art, taking as an example a static overcurrent relay having a contact output.

In Figure 1, ■ is an input current, CT is a current transformer for introducing the input current, LD is a level detection circuit, TDD is a time-limited return circuit for making the output signal of the level detection circuit continuous, and Xl is a circuit. The auxiliary relay is operated by the output signal of the TDD, la is the normally open contact of the auxiliary relay This is to introduce the inspection current i from the AC power supply E to the level detection circuit LD via the resistor R when the connection plug is inserted. There is.

When the magnitude of the input current, that is, the current transformer secondary current iI, exceeds a predetermined detection level of the level detection circuit LD, the auxiliary relay XI operates via the circuit TDD, and the contact 1a closes to generate a trip output. .

During inspection, switch SW1 should be opened. After locking the trip output by contact 1a, connect the connection plug to jack Jl, apply inspection current 12 to current transformer secondary current 11, simulate overcurrent input, and operate auxiliary relay XI. .

By the way, in the inspection method shown in Figure s1, (1) During inspection, SWl is first opened, the trip output is locked, and then the connection plug is inserted into jack Jl and an inspection input is applied.

■ When canceling inspection, reverse this process by handling the connection plug from jack Jl and then closing switch SWI.

It is necessary to perform inspection operations in the following order,
If this order is incorrect due to human error or the like, there is a risk of malfunction of the circuit breaker or the like and false alarms.

Figure 2 shows the configuration of Figure 1 with a normally open switch SW2 interlocked with switch SW1, and on condition that switch SW1 is operated to the open side, the trip output is locked. The configuration is such that the application of inspection input is permitted under the condition that .

Below, elements with the same reference numerals as those in the configuration shown in Figure 1 are m1.
It shall mean that the same effect as in the figure is performed.

The configuration of the inspection circuit shown in Figure 2 can prevent malfunction of the breaker due to incorrect insertion of the connection plug, but when the inspection is canceled, the connection plug must be placed in the jack Jl when the switch SWI
If an erroneous operation such as returning SW2 was performed, the switch SWI would return before the contact point 1a returned, resulting in a malfunction of the circuit breaker.

[Purpose of the invention]

The present invention has been made to solve the above problems, and aims to provide a highly reliable protective relay inspection circuit that can prevent breaker malfunctions due to human inspection and insertion errors. .

[Summary of the invention]

When manually inspecting a static protective relay, the present invention uses a component that locks the trip circuit and a component that applies an inspection input, and if there is no error after the IJ tube circuit is locked, the inspection input is not applied. This is a protective relay inspection circuit designed to reliably prevent malfunctions of circuit breakers, etc. and false alarms due to human inspection operation errors.

[Embodiments of the invention]

FIG. 3 is a circuit diagram of an embodiment of the present invention.

The configuration of FIG. 3 will be described below, focusing on the points that are different from the background art shown in FIGS. 1 and 2.

In the figure, J2 is a jack that shares the connection plug PL with the jack Jl, and the plug is always inserted into the jack J2 except during inspection. The connection plug PL is always placed in the position of the jack J2, forming a trip circuit. During inspection, the connecting plug PL is pulled out from the jack J2 and placed in the position of the junk J1 after the trip circuit is locked.

8W3 has an automatic return function for applying inspection input,
For example, it is a push button switch that automatically returns to its original state by the action of a spring.

Switch SW3 is connected in series with jack J1 to power supply E, and from power supply E to resistor R, switch SW3
, a check current 12 is applied to the level detection circuit LD via the jack Jl.

The pushbutton switch SW3 is composed of a normally open contact, and when the pushbutton switch S'W3 is pressed with the connection plug PL in the jack position, the switch S
The contact W3 is closed and the inspection current 12 flows, and when the push button switch SW3 is released at the end of the inspection, the contact of the switch SW3 is automatically restored by the force of the spring and the supply of the inspection current 12 is stopped.

The operation of the embodiment of the present invention shown in FIG. 3 will be explained below in accordance with the order of inspection operations.

The connection plug PL is always connected to the jack J2, forming a trip circuit.

At this time, the jack Jl is open, and even if the pushbutton switch 8W3 for applying the inspection input is operated by mistake, the inspection current 12 will not flow, and therefore the relay BY will not malfunction.

During inspection, if you pull out the connection plug PL from jack J2,
The trip circuit is locked open.

Next, when the plug PL is inserted into the jack Jl provided in the inspection input circuit, preparation for inspection is completed. In this state, by pressing the pushbutton switch SW3, the switch S
W3 is closed, inspection current 12 is applied to level detection circuit LDK, and operation inspection of relay RY is performed.

The inspection is canceled by the reverse operation, and when the pushbutton switch SW3 is released, the contact of the switch SW3 is returned to its original state by the force of the spring, and the inspection current 12 becomes zero. Next, the connection plug PL is moved from the jack Jl to the jack J2 position to return to the normal state.

Therefore, in this inspection method, the means to lock the trip circuit (
(plug) and the means (plug) for allowing the application of inspection input by the pushbutton switch SW3 are shared.■ During inspection, inspection input cannot be applied unless the trip circuit is locked. In other words, when the plug is inserted into the jack J2, the operation of the pushbutton switch 8W3 is invalid.

■ When canceling inspection, the trip circuit cannot be unlocked unless inspection input is rejected.

1 and 2, it is possible to prevent the circuit breaker from malfunctioning due to a human error in inspection operation as described in the prior art shown in FIGS. 1 and 2.

In addition, when canceling inspection, there is a problem in the return time of contact la caused by the time delay of time-limited return circuit TDD and auxiliary relay X1, etc., but this return time is generally several 10? ? Z
If it is about S, the time required to release the pushbutton switch 8W3 and artificially return the plug PL from the jack Jl to the jack J2 position is sufficiently small and an erroneous output will occur in the trip circuit. do not.

In the above description, the contact output of the auxiliary relay X1 is only la, but the present invention is also applicable to inspection of relays R and Y having two or more contact outputs.

In this case, it is possible to obtain the same effect even if the plug PL and jacks Jl and J2 are multiple jacks.

In addition, as shown in Fig. 4, an auxiliary relay X2 is provided that is connected in series with the jack J2, and during inspection, the auxiliary relay X2 is reset by pulling out the connecting plug PL from the jack J2, and the contacts 2a and 2a2 are opened and auxiliary. It is possible to lock each of the trip circuits constituted by normally open contacts 1a and la2 of relay XI.

Next, an applied modification of the embodiment according to the present invention will be shown using FIG.

When checking the connection plug PL to jack J3,
Auxiliary relay x3 connected in series with jack J3 operates,
Normally closed contact 3b of X3 opens to lock the trip circuit. At the same time, the normally open contact 3a of X3 provided in the inspection input circuit is closed, and in this state, by pressing the pushbutton switch SW3, inspection current 12 is applied to the level detection circuit LD, and the operation of the relay) LY is inspected. .

Therefore, ■ During inspection, inspection input cannot be applied unless the trip circuit is locked. In other words, if you do not connect the connection plug to jack J3, press button switch SW3.
operation is invalid.

■ When canceling inspection, the trip circuit cannot be unlocked unless inspection input is rejected.

This feature has the effect of preventing breaker malfunctions due to human inspection errors, similar to the embodiment of FIG. 3.

Although FIG. 5 shows a method of connecting the plug to jack J3 during inspection, the present invention is not limited to this in any way. For example, in FIG. 5, 3a is a normally closed contact and 3b is a normally open contact for inspection. It is also possible to allow the output circuit to be locked and the inspection input to be applied by the pushbutton switch SW3 by removing the plug from the jack J3.

The manual inspection method according to the present invention has been described above using an overcurrent relay as an example. However, the present invention is not limited thereto, and the relay to be inspected may be an overvoltage relay, an undervoltage relay, or a relay based on other detection principles. It's okay.

[Effects of the Invention] As explained above, according to the present invention, when performing manual inspection of a static protective relay, a connection plug that locks a trip circuit and a connection plug that allows application of inspection input by a switch having an automatic reset function are provided. Since it is configured to be shared, it is possible to reliably prevent malfunctions of circuit breakers and the like due to human inspection errors and false alarms in a simple and inexpensive manner.

[Brief explanation of drawings]

1 and 2 are block diagrams of a check circuit according to the prior art, FIGS. 3 and 4 are block diagrams of an embodiment of a check circuit according to the first invention, and FIG. 5 is a block diagram of an embodiment of a check circuit according to the second invention. FIG. Jl, J2. J3... Jack XI, X2. X3...Auxiliary relay PL...Connection plug SWI, SW2, SW3...Switch Y.
...Protective relay (7317) Patent attorney Kensuke Norichika (and 1 other person) Figure 1 Trip soil force Figure 3 Figure 4 Figure 5 Figure 83

Claims (2)

[Claims] (1) Al that is inserted into the output circuit of the protective relay to be inspected or a control circuit that controls whether this output circuit is open or closed, a connecting plug is always inserted, and is pulled out during inspection to lock the output circuit. a second jack that is provided in a circuit that provides an inspection input for the protective relay to be inspected and that connects the connecting plug only during inspection; A protective relay/electrical equipment inspection circuit characterized by comprising a switch having the following functions. (2) A switch with an automatic return function that allows inspection input to be applied to the protective relay to be inspected, and a jack that is installed on the protective relay to be inspected and allows either the connection plug to be inserted or pulled out only during inspection. and
At the time of inspection, by either pushing or pulling out the connection plug from the jack, a switch that allows the inspection input to be applied is enabled, and the output circuit of the protective relay to be inspected is locked. A protective relay inspection circuit characterized in that: