CN205693343U - A kind of on/off switch coil protector - Google Patents

Abstract

The utility model relates to a closing and opening coil protection device, and its technical proposal is: in the closing circuit, the closing coil HQ is disconnected from KM-, the source of the field effect transistor T1, the positive pole of the regulator tube DW, and the field effect The source of tube T2, one end of capacitor C, one end of resistor R3, connected to KM‑, the drain of field effect transistor T1, the positive electrode of diode D, the disconnected end of closing coil HQ and KM‑, the negative electrode of diode D, one end of resistor R1, and resistor R2 One end, the closing coil HQ is connected to the auxiliary switch QF of the circuit breaker, the gate of the field effect transistor T1, the negative pole of the regulator DW, the drain of the field effect transistor T2, the other end of the resistor R1, the other end of the resistor R2, and the other end of the resistor R3 One end, the other end of the capacitor C, and the gate of the field effect transistor T2 are connected; the connection method is the same in the opening circuit. The utility model has the advantages of safety, reliability, easy installation, and low cost.

Description

A closing and opening coil protection device

Technical field

The utility model relates to a closing and opening coil protection device, which belongs to the field of electric control.

Background technique

A lot of work practice shows that due to various reasons, during the transmission test, closing and opening operation, and protection closing and opening actions, the closing and opening coils of circuit breakers sometimes burn out, and the burning of the coils sometimes causes switch cabinet fires ACCIDENT.

Represented by the technical solution disclosed in the patent with the application number CN2015 2064 4740.9, the existing technical solutions to solve the burning of the closing and opening coils have complex circuits, large volumes, poor working reliability, difficult installation, and high installation costs. Defects make it difficult to implement and promote.

Contents of the invention

The utility model provides a closing and opening coil protection device, which can comprehensively and effectively solve many problems mentioned in the background technology.

The technical solution adopted by the utility model to solve the technical problem is: a closing and opening coil protection device, including a diode D, a field effect transistor T1, a voltage regulator DW, a resistor R1, a field effect transistor T2, a capacitor C, and a resistor R2 , resistor R3; in the closing circuit, the closing coil HQ is disconnected from the control bus negative pole KM-, the source of the field effect transistor T1, the positive pole of the regulator DW, the source of the field effect transistor T2, and the capacitor C One end of resistor R3, one end of resistor R3, connected to control bus negative KM-, the drain of field effect transistor T1, the positive pole of diode D, the closing coil HQ is connected to the disconnected end of control bus negative pole KM-, the negative pole of diode D, the resistor One end of R1, one end of resistor R2, one end of closing coil HQ and circuit breaker auxiliary switch QF are connected, the gate of field effect transistor T1, the negative pole of regulator DW, the drain of field effect transistor T2, and the terminal of resistor R1 The other end is connected, the other end of the resistor R2, the other end of the resistor R3, the other end of the capacitor C, and the gate of the field effect transistor T2; in the opening circuit, the connection method is the same.

A further technical solution is: field effect transistor T1, field effect transistor T2 or IGBT devices.

The beneficial effects of the utility model are as follows: firstly, the circuit is simple, safe and reliable. Second, it is small in size and easy to install. The third is low cost, easy to implement and popularize. Fourth, the closing and opening coil protection action signal can be automatically uploaded without a dedicated line.

Description of drawings

Below in conjunction with accompanying drawing and embodiment the utility model is further described.

Fig. 1 is the schematic wiring diagram of the embodiment of the utility model.

Part inside the dotted frame in Fig. 1 is the circuit of the utility model embodiment, wherein D. diode, 1N5408, T1. field effect tube, IXFK27N80Q, DW. regulator tube, 12V1W, R1. resistance, 220kΩ1W, T2. field effect tube, IRF630, C. Capacitance, 15μF25V, R2. Resistor, 1MΩ1W, R3. Resistor, 39kΩ1/4W; the part outside the dotted box is a part of the circuit breaker control circuit when a typical microcomputer protection measurement and control device is used, and the control mother is DC 220V, where HQ is the closing coil, QF is the circuit breaker auxiliary switch, HBJ is the closing holding relay, TWJ is the trip position relay, and R is the series resistance.

detailed description

The technical solution in the embodiment of the utility model will be described in detail below in conjunction with the accompanying drawings. The described embodiment is only one embodiment of the utility model, but not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by persons of ordinary skill in the art without making creative efforts belong to the protection scope of the present utility model.

In Figure 1, a closing and opening coil protection device includes a diode D, a field effect transistor T1, a voltage regulator DW, a resistor R1, a field effect transistor T2, a capacitor C, a resistor R2, and a resistor R3; in the closing circuit , the connection between the closing coil HQ and the negative pole KM- of the control bus is disconnected, the source of the field effect transistor T1, the positive pole of the voltage regulator DW, the source of the field effect transistor T2, one end of the capacitor C, one end of the resistor R3, and the control The negative electrode KM- of the mother is connected, the drain of the field effect transistor T1, the positive electrode of the diode D, the closing coil HQ and the disconnected end of the negative electrode KM- of the control mother are connected, the negative electrode of the diode D, one end of the resistor R1, one end of the resistor R2, The closing coil HQ is connected to one end of the auxiliary switch QF of the circuit breaker, the gate of the field effect transistor T1, the negative pole of the voltage regulator DW, the drain of the field effect transistor T2, the other end of the resistor R1, and the other end of the resistor R2 , the other end of the resistor R3, the other end of the capacitor C, and the gate of the field effect transistor T2 are connected; in the opening circuit, the connection method is the same.

The working process of the embodiment is as follows. When the circuit breaker is in the opening state, after the control mother KM is powered on, because the voltage at both ends of the capacitor C is zero, the field effect transistor T2 is turned off, the field effect transistor T1 is turned on, and the voltage between the cathode of the diode D and the control mother KM- is about 4V. The tripping position relay TWJ operates, and the protection measurement and control device obtains the position signal of the circuit breaker. When the switch is closed, the trip position relay TWJ is de-energized and returns, the gate of the field effect transistor T1 to the control mother KM- voltage rises from about 4V to 12V instantaneously, the field effect transistor T1 is fully turned on, and the closing coil is excited. After the closing is completed, the normally closed contact of the auxiliary switch QF of the circuit breaker is opened, the closing coil HQ and the embodiment are disconnected from the power supply, and the protection measurement and control device obtains the closing signal from the trip circuit at the same time. When the circuit breaker operating mechanism fails to complete the closing operation, the field effect transistor T2 is saturated and turned on after the set time is exceeded, and the field effect transistor T1 is cut off, and the closing coil HQ is protected from power failure. Since then, due to the existence of the TWJ branch of the trip position relay, the voltage between the cathode of the diode D and the control mother KM- can ensure the stable cut-off of the field effect transistor T1, and the subsequent closing command is blocked. In this case, the current flowing through the trip position relay TWJ is much smaller than its operating current, the trip position relay TWJ cannot act, and the protection measurement and control device obtains the control circuit disconnection signal. When the normally closed contact of the circuit breaker auxiliary switch QF cannot be opened after closing, the closing coil HQ can also be protected. At this time, due to the mechanical linkage relationship, the normally open contact of the auxiliary switch of the opening circuit cannot be closed, and the protection measurement and control The device can still obtain the control loop disconnection signal.

In the embodiment, the time delay of the closing coil protection action is about 0.2S, and the time delay should be changed by adjusting the capacity of the capacitor C.

After the closing coil protection action of the embodiment, the control mother KM is powered off for 0.2 seconds and then re-energized to forcibly release the closing blockade.

In the embodiment, the closing coil protection action information is automatically uploaded through the disconnection signal of the control loop, and no special line is required.

The diode D is used to eliminate the back electromotive force of the closing coil, and the capacitor C can also eliminate the sharp cut-off of the field effect transistor T1. These two measures make the field effect transistor T1 effectively protected. Numerous tests have shown that as long as the closing coil HQ has no short-circuit fault, the FET T1 will not be damaged, and the closing coil HQ with a short-circuit fault will cause damage to the FET T1. Even if the field effect transistor T1 is damaged, usually through the damage, it generally does not affect the normal closing operation. As long as the parameters of the field effect tube T1 are not less than 600V5A, there are many available models. The field effect transistor T1 and the field effect transistor T2 may also use IGBT devices.

In the embodiment, the diode D will not affect the closing speed, nor will it affect the reclosing, because the reclosing time is generally set at about 1S.

In the embodiment, the resistance values of the resistors R1 and R2 are halved to adapt to the DC 110V control bus.

The embodiment is also applicable to the conventional circuit breaker control circuit, at this time, the protection action information of the closing coil can be identified through the circuit breaker position indicator light.

For the circuit breaker closing circuit using electromagnetic operating mechanism, the embodiment should be connected with the closing contactor coil. Due to the large closing current, the current electromagnetic operating mechanism is rapidly being eliminated.

When the embodiment is used for circuit breaker opening coil protection, the connection method and working process can be analogized.

The embodiment all adopts conventional components, the circuit is simple and clear, the work is safe and reliable, and the installation is convenient. The size of half a cigarette box, the cost of about 20 yuan, and three connecting wires are the outstanding features of the embodiment.

Claims (2)

1. an on/off switch coil protector, including diode D, field effect transistor T1, stabilivolt DW, resistance R1, field effect transistor T2, electric capacity C, resistance R2, resistance R3；In closing circuit, the connection of closing coil HQ negative pole KM-female with control disconnects, field effect The source electrode of pipe T1, the positive pole of stabilivolt DW, the source electrode of field effect transistor T2, one end of electric capacity C, one end of resistance R3, the female negative pole of control KM-connects, and one end that the drain electrode of field effect transistor T1, the positive pole of diode D, closing coil HQ negative pole KM-female with control disconnect is connected, The negative pole of diode D, one end of resistance R1, one end of resistance R2, closing coil HQ and auxiliary switch for circuit breaker QF be connected one End connects, and the grid of field effect transistor T1, the negative pole of stabilivolt DW, the drain electrode of field effect transistor T2, the other end of resistance R1 connect, electricity The resistance other end of R2, the other end of resistance R3, the other end of electric capacity C, the grid of field effect transistor T2 connect；In sub-gate circuit, Method of attachment is identical.

A kind of on/off switch coil protector the most according to claim 1, is characterized in that: field effect transistor T1, field effect transistor T2 or employing IGBT class device.