CN217469449U

CN217469449U - Coil burning loss prevention protection circuit of power-maintaining high-voltage vacuum contactor for cabinet

Info

Publication number: CN217469449U
Application number: CN202220854035.1U
Authority: CN
Inventors: 何明; 杨晓琴
Original assignee: Jiangsu Chengxiang Electric Appliance Co ltd
Current assignee: Jiangsu Chengxiang Electric Appliance Co ltd
Priority date: 2022-04-13
Filing date: 2022-04-13
Publication date: 2022-09-20
Anticipated expiration: 2032-04-13

Abstract

The invention discloses a coil burning prevention protection circuit for a power-keeping high-voltage vacuum contactor for a cabinet. Including inside loop and control circuit, control circuit includes contactor auxiliary switch FK and with contactor auxiliary switch FK complex combined floodgate relay KM, contactor auxiliary switch FK's normally closed contact FK-3 concatenates in a time relay KT's the control circuit, time relay KT's time delay disconnection normally closed contact KT-1 is established ties in combined floodgate relay KM's the control circuit, combined floodgate relay's normally open contact KM-2 inserts in the contactor inside loop and can make the contactor combined floodgate through switching on of contactor inside loop. The advantages are that: when a fault occurs, the circuit can sense the fault, the closing relay is powered off by opening the normally closed contact KT-1 in a time delay way through the time relay KT, and then the coil of the electric holding contactor is powered off, so that the power supply of the coil of the electric holding contactor is cut off timely, and the problem of burning loss of the coil of the electric holding contactor is also prevented.

Description

Coil burning loss prevention protection circuit of power-maintaining high-voltage vacuum contactor for cabinet

Technical Field

The invention relates to a circuit structure of an electric maintaining contactor, in particular to a coil burning loss prevention protection circuit of an electric maintaining high-voltage vacuum contactor for a cabinet.

Background

In all faults of the electric maintaining high-voltage vacuum contactor, a contactor coil is burnt out when a user most reflects the fault with the most serious problem, the high-voltage vacuum contactor is switched off when the fault is light, and a fire disaster occurs when the fault is serious, so that serious accidents are caused.

As shown in fig. 1, it can be seen from the control circuit diagram that two coils HQ and HQ 'of the contactor are connected in series (note: the power supply 220V is connected in series, the power supply 110V is connected in parallel, only the power supply 220V circuit is analyzed here), and the electric holding contactor coil HQ (HQ') is composed of a closing coil HQ1 (HQ 1 ') and a holding coil HQ2 (HQ 2'); FK-1 is a normally closed contact of an auxiliary switch of the contactor, when a coil of the contactor is not electrified, the FK-1 contact is in a closed state, at the moment, a holding coil of the coil is in a short-circuit state, and a closing coil HQ1 and an HQ 1' are in a series connection state; after the power is switched on, the switching-on coils HQ1 and HQ 1' are electrified, the working current is large, and the generated electromagnetic force is enough to push the contactor contact to switch on at a high speed; when the contactor is switched on to a certain position, a crank arm on the contactor can push an auxiliary switch FK, so that a normally closed contact FK-1 is opened, a switching-on coil and a holding coil are in a series connection state, at the moment, the working current is reduced, the electromagnetic force is also reduced, and the contactor is switched on to continue to move through inertia until the contactor is switched on completely.

As can be seen from the above analysis, when the contact FK-1 of the auxiliary switch cannot be opened after the contactor is completely closed for any reason, the holding coil of the conventional control circuit cannot be connected to the working circuit due to a short circuit, so that the closing coils HQ1 and HQ 1' pass a large current for a long time, the coils rapidly generate heat, when the temperature exceeds the tolerance temperature of the insulating layer of the enameled wire of the coil, the insulating layer is damaged, the coil turns are broken down and short-circuited, the coil burns out, and according to a fault simulation test, the rear coil burns out due to an excessively high temperature after about 15 minutes, so how to solve the above technical problems becomes a technical problem to be solved urgently.

Disclosure of Invention

The invention aims to provide a coil burning-loss prevention protection circuit for a cabinet power-consumption maintaining high-voltage vacuum contactor, which can sense circuit faults and prevent accidents caused by burning-out of a contactor coil.

In order to solve the technical problem, the coil burning loss prevention protection circuit of the electric maintaining high-voltage vacuum contactor for the cabinet comprises an internal loop of the contactor with an electric maintaining contactor coil and a control loop for controlling the internal loop of the contactor, wherein the control loop comprises a contactor auxiliary switch FK and a closing relay KM matched with the contactor auxiliary switch FK, a normally closed contact FK-3 of the contactor auxiliary switch FK is connected in series into a control circuit of a time relay KT, a time-delay disconnection normally closed contact KT-1 of the time relay KT is connected in series into the control circuit of the closing relay KM, a normally open contact KM-2 of the closing relay is connected into the internal loop of the contactor and can close the contactor through the conduction of the internal loop of the contactor, when the contactor auxiliary switch FK can not normally act, the relay can be closed and lose electricity through the time-delay disconnection normally closed contact KT-1 of the time relay KT, thereby de-energizing the electrical holding contactor coil.

The electric holding contactor coil is composed of a closing coil and a holding coil, and a normally closed contact FK-1 of the contactor auxiliary switch is connected between the closing coil and the holding coil and can enable the closing coil and the holding coil to carry out state switching through the opening and the closing of the normally closed contact FK-1 of the auxiliary switch.

The normally closed contact FK-3 and the normally closed contact FK-1 of the contactor auxiliary switch FK are in a synchronous opening and closing state.

The control circuit of the switching-on relay KM is also provided with a normally open contact KM-1 which acts synchronously with the normally open contact KM-2 and a switching-on button QA for controlling the normally open contact KM-1.

The delay time of the time relay KT for delaying the opening of the normally closed contact KT-1 is set to be 0.1-0.5 minutes.

The set time for opening the normally closed contact KT-1 in a delayed manner by the time relay KT is longer than the closing time of the contactor and is not longer than 1 minute.

The invention has the advantages that:

normally closed contact FK-3 of contactor auxiliary switch FK is connected in series to a control circuit of time relay KT, and delay disconnection normally closed contact KT-1 of time relay KT is connected in series to a control circuit of closing relay KM, therefore when fault normally closed contact FK-1 can not be disconnected, the circuit can sense fault, delay opening of delay disconnection normally closed contact KT-1 of time relay KT enables closing relay to lose electricity, and then enables electricity to keep contactor coil to lose electricity, thereby cutting off electricity keeping contactor coil power supply in due time, and preventing problem of burning loss of electricity keeping contactor coil.

Drawings

FIG. 1 is a diagram of a conventional contactor control circuit;

fig. 2 is a circuit diagram of a coil burning prevention protection circuit of the electric maintaining high-voltage vacuum contactor for the cabinet.

In the figure, the contacts of the FK auxiliary switch are FK-1, FK-2, FK-3 and FK-4 UR: bridge rectifier, D: diode, C: capacitance, XT, QA, closing button, TA, opening button, RD, fuse KM: the switching-on relay is characterized in that KM-1 and KM-2 are normally open contacts KT: and a time relay KT-1 is a normally closed contact which is opened in a time-delay way.

Detailed Description

The invention provides a coil burning-proof protection circuit of an electric-holding high-voltage vacuum contactor for a cabinet, which is described in detail in the following with reference to the accompanying drawings and the detailed description.

As shown in the drawings, the coil burnout prevention protection circuit of the electric hold high voltage vacuum contactor for cabinets of the present invention includes an internal circuit of contactors having electric hold contactor coils HQ and HQ ', and a control circuit for controlling the internal circuit of the contactors, as can be seen from fig. 2, the electric hold contactor coils HQ and HQ ' are connected in series, and are composed of a closing coil and a holding coil, and the electric hold contactor coils HQ and HQ ' are composed of closing coils HQ1 and HQ1 ' and holding coils HQ2 and HQ2 '; the control circuit comprises a contactor auxiliary switch FK and a closing relay KM matched with the contactor auxiliary switch FK, wherein the contactor auxiliary switch FK is provided with a normally closed contact FK-1, a normally closed contact FK-3 and the like, the normally closed contact FK-1 of the contactor auxiliary switch is connected between a closing coil and a holding coil and can enable the closing coil and the holding coil to carry out state switching through the opening and the closing of the normally closed contact FK-1 of the auxiliary switch, specifically, when the electric holding contactor coil is not electrified, the FK-1 contact is in a closed state, at the moment, the holding coil of the electric holding contactor coil is in a short-circuit state, and the closing coils HQ1 and HQ 1' are in a series connection state;

the normally closed contact FK-3 of the auxiliary contactor switch FK is connected in series to a control circuit of a time relay KT, and the normally closed contact FK-3 and the normally closed contact FK-1 of the auxiliary contactor switch FK are in a synchronous opening and closing state, namely: the contact state of the normally-closed contact FK-3 and the normally-closed contact FK-1 are completely the same (the movement state is synchronized), that is, when the normally-closed contact FK-1 is closed, the normally-closed contact FK-3 is also in the closed state; when the normally-closed contact FK-1 is open, the normally-closed contact FK-3 is also in an open state, so that the normally-closed contact FK-3 can reflect the actual state of the normally-closed contact FK-1; a time-delay disconnection normally closed contact KT-1 of a time relay KT is connected in series to a control circuit of a closing relay KM, as can be seen from figure 2, the control circuit of the closing relay KM is provided with a normally open contact KM-2 connected to an internal loop of a contactor, a normally open contact KM-1 which acts synchronously with the normally open contact KM-2 and a closing button QA for controlling the normally open contact KM-1, under the condition of no fault, the closing button QA is pressed, the closing relay KM is powered on to act, the normally open contacts KM-1 and KM-2 of the closing relay are closed, a closing coil HQ1 and an HQ 1' are powered on to rapidly close the contactor, when the contactor is closed to a certain position, a connecting lever (not shown in the figure) on the contactor can push an auxiliary switch FK, so that the normally closed contacts FK-1 and FK-3 are synchronously opened, the contactor continues to move to be completely closed and then be static, when a fault occurs (the FK of the contactor auxiliary switch can not normally act, namely, a crank arm is deformed, the auxiliary switch is displaced, or the contact of the auxiliary switch of the contactor can not be opened after the contactor is completely closed due to arcing or other reasons), the normally closed contact KT-1 can be opened in a delayed mode through the delayed opening of the time relay KT, so that the closing relay is de-energized, and the coil of the contactor is kept de-energized.

Furthermore, the delay time of the delay opening normally closed contact KT-1 of the time relay KT is set to be 0.1-0.5 minutes, and the delay setting time of the delay opening normally closed contact KT-1 of the time relay KT is longer than the closing time of the electric holding contactor and cannot be longer than 1 minute, so that the malfunction of the contactor or the damage of a coil are prevented.

The specific working principle is as follows:

when the high-voltage vacuum contactor is operated to switch on, the time for a time relay to delay and open the normally closed contact KT-1 needs to be set, wherein the 12kV high-voltage contactor is taken as an example for parameter setting, the switching-on time of the contactor is not more than 150ms according to the mechanical characteristics of the 12kV contactor, in order to ensure the reliable switching-on of the contactor and also ensure that a coil is not burnt out (the burning-out time is about 15 minutes) when the contactor fails, the opening time of the time delay and open the normally closed contact KT-1 is set to be 0.5 minutes (the time parameter is set on site, and the time can be lower than 0.5 minutes under the condition of ensuring the switching-on reliability of the contactor).

Under the condition of no fault, a closing button QA is pressed, a closing relay KM is electrified to act, a normally open contact KM-1 and a normally open contact KM-2 of the closing relay are closed, closing coils HQ1 and HQ 1' are electrified, the contactor is quickly closed, when the contactor is closed to a certain position, a connecting lever on the contactor pushes an auxiliary switch FK, so that a normally closed contact FK-1 and a normally closed contact FK-3 of the contactor are synchronously opened, the contactor continuously moves to be static after complete closing, the normally closed contact FK-3 is opened, a control loop of a time relay KT is disconnected,

the time relay is not electrified and does not work any more, because the closing time of the contactor is far shorter than the set opening time of the delay opening normally closed contact KT-1 of the time relay, the delay opening normally closed contact KT-1 of the time relay KT is still in a normally closed state, the control loop works normally, the normally open contact KM-1 and the normally open contact KM-2 of the closing relay KM are in a closed state, and the contactor keeps in a closing state.

When a fault occurs, the normally closed contact FK-1 of the contactor auxiliary switch FK is still in a closed state after the contactor is switched on, then the normally closed contact FK-3 is also in a switched-on state, at the moment, the time relay KT is kept electrified, the protection circuit starts to work, when the time reaches the time set by the time-delay switching-off normally closed contact KT-1, the time-delay switching-off normally closed contact KT-1 is opened, the switching-on relay is powered off, the normally open contact KM-1 and the normally open contact KM-2 are disconnected, the contactor coil is powered off, and the contactor is switched off, so that the contactor is prevented from being burnt out under the condition that only the switching-on coil participates in working.

It is to be understood that the above description is not intended to limit the present invention, and the present invention is not limited to the above examples, and those skilled in the art may make modifications, alterations, additions or substitutions within the spirit and scope of the present invention.

Claims

1. The utility model provides a cabinet is with electric power maintenance high pressure vacuum contactor prevents coil scaling loss protection circuit, includes the inside circuit that has the contactor of electric power maintenance contactor coil and is used for carrying out the control circuit that controls to the contactor inside circuit, control circuit includes contactor auxiliary switch FK and with contactor auxiliary switch FK complex combined closing relay KM, its characterized in that: normally closed contact FK-3 of contactor auxiliary switch FK concatenates to a time relay KT's control circuit, time relay KT's time delay disconnection normally closed contact KT-1 establishes ties to the control circuit of combined floodgate relay KM in, combined floodgate relay's normally open contact KM-2 inserts in the contactor inner loop and can make the contactor combined floodgate through switching on of contactor inner loop, can pass through when contactor auxiliary switch FK can't normally act through time relay KT's time delay disconnection normally closed contact KT-1's time delay is opened and is made combined floodgate relay lose electricity, and then makes electricity keep contactor coil lose electricity.

2. The cabinet power consumption keeps high-voltage vacuum contactor to prevent coil scaling loss protection circuit according to claim 1 characterized in that: the electric holding contactor coil is composed of a closing coil and a holding coil, and a normally closed contact FK-1 of the contactor auxiliary switch is connected between the closing coil and the holding coil and can make the closing coil and the holding coil switch states by the opening and closing of the normally closed contact FK-1 of the auxiliary switch.

3. The cabinet power consumption keeps high-voltage vacuum contactor to prevent coil scaling loss protection circuit according to claim 2 characterized in that: the normally closed contact FK-3 and the normally closed contact FK-1 of the contactor auxiliary switch FK are in a synchronous opening and closing state.

4. The cabinet power consumption maintaining high-voltage vacuum contactor coil burning-loss prevention protection circuit according to any one of claims 1 to 3, characterized in that: the control circuit of the switching-on relay KM is also provided with a normally open contact KM-1 which acts synchronously with the normally open contact KM-2 and a switching-on button QA for controlling the normally open contact KM-1.

5. The cabinet power consumption keeps high-voltage vacuum contactor to prevent coil scaling loss protection circuit according to claim 4, characterized in that: the delay time of the time relay KT for delaying the opening of the normally closed contact KT-1 is set to be 0.1-0.5 minutes.

6. The cabinet power consumption keeps high-voltage vacuum contactor to prevent coil scaling loss protection circuit according to claim 5, characterized in that: the set time for opening the normally closed contact KT-1 in a delayed manner by the time relay KT is longer than the closing time of the contactor and is not longer than 1 minute.