KR100559955B1 - Electronic automatic changeover switch with overheat protection - Google Patents

Abstract

An electronic automatic changeover switch with overheat protection is posted. The electronic automatic switching switch of the present invention includes an electronic switching unit composed of a semiconductor switching element and an auxiliary switching unit composed of a non-heating element connected in parallel thereto. The switching operation for switching between the regular power supply and the emergency power supply is performed when the phase of the power supply voltage is zero using a semiconductor switching element, and the supply of the continuous power supply voltage is performed through the auxiliary switching unit. Therefore, heat generation by the semiconductor switching element due to the power supplied to the load after the switching operation is hardly generated. Therefore, it is not necessary to use a heat sink, and it is possible to manufacture a smaller size by not using a heat sink.

 Automatic Switch, ATS, Load, Overcurrent, Photocoupler, Triac, Latch Relay

Description

ELECTRICAL AUTOMATIC TRANSFER SWITCH HAVING THERMAL OVERLOAD PROTECTION

In order to more fully understand the drawings used in the detailed description of the invention, a brief description of each drawing is provided.

1 is a block diagram showing the electrical connection structure of a typical automatic switching switch.

2 is a block diagram showing a circuit configuration of an electronic automatic switch having an overheat protection function according to a preferred embodiment of the present invention.

3 is a diagram illustrating in detail a circuit configuration of the electronic switching unit and the auxiliary switching unit of FIG. 2.

4A and 4B are flowcharts for describing a switching operation of the electronic switching unit and the auxiliary switching unit.

* Description of the symbols for the main parts of the drawings *

2: automatic changeover switch 4: load

10: first rectifier 11, 14: fuse

12, 15: power input connector 13: second rectifier

16, 17: photocoupler 20: internal power generation unit

30: electronic switching unit 40: overcurrent detection unit

50: control unit 60: front panel

80: auxiliary contact portion 82, 84: auxiliary contact connector

100: automatic switching switch 110: auxiliary switching unit

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transfer switch (ATS), and more particularly, to a non-heating electronic automatic transfer switch capable of preventing overheating of a semiconductor switching element used in an electronic switching unit for switching switching. .

Automatic changeover switches are devices that automatically switch one or more loads from one power source to another. As shown in FIG. 1, the automatic switching switch 2 provides power from the constant power to the load 4 in a normal state, and when power is not supplied normally due to an accident or a failure, power from the emergency power source. Automatically switch to this load. Normal power is generally commercial power, and emergency power generally uses power generation power or emergency battery power.

Most of these automatic switching switches use a mechanical method, and it is known that it is difficult to increase the switching speed to some extent due to the physical limitations of the mechanical switch structure. In the case of the mechanical type, the mechanical sound generated during operation and the wear and tear are problems.

In addition, there is a problem that the load may be damaged by noise or arc discharge generated during switching. In particular, malfunction or serious damage may occur due to noise or arc discharge depending on the load characteristics. For example, in the case of automated and unmanned systems, serious accidents can result in personal injury. In the automatic production line, the controller in charge of numerical control may malfunction, resulting in the production of defective products.

This problem occurs because the switching operation is performed regardless of the phase of the input power source. Accordingly, the inventor of the present invention has proposed an electronic automatic switching switch that can overcome this problem in Korean Patent Application No. 10-2005-0002211 dated January 10, 2005. The electronic automatic switching switch can switch the power at the point where the phase of the input power becomes zero when the input power is switched, thereby suppressing noise or arc discharge and preventing damage to the load.

On the other hand, the semiconductor switching element used for the electronic automatic switching switch generates heat during energization. Semiconductor switching elements commonly used in electronic automatic switching switches are, for example, triacs. Since triacs are structurally composed of five layers of PN junctions (anode and cathode), significant conduction heat is generated due to contact resistance at the junction. The heat of junction generates about 1-2W of heat per 1A.

In order to cool down the heat generated by the semiconductor switching element, a heat sink must be used. If the heat sink is small or the heat exchange is not performed smoothly, the fan must be forcedly ventilated.

However, since most of the electronic automatic switching switches are mounted on the power distribution panel, it may be difficult to configure vents or other ventilation holes due to the sealed structure due to the characteristics of the power distribution panel.

Accordingly, an object of the present invention is to provide an electronic automatic switching switch that can effectively prevent the heat generation of the semiconductor switching element configured in the electronic automatic switching switch.

One aspect of the present invention for achieving the above technical problem relates to an electronic automatic switching switch having an overheat protection function. An electronic automatic switching switch having an overheating prevention function of the present invention includes: a first rectifying unit configured to receive a constant power and rectify and output a first power voltage (V1); A second rectifying unit configured to receive the emergency power and rectify and output the second power voltage V2; An internal power generator configured to receive the first power voltage and the second power voltage to generate internal operating power; A control unit for detecting an abnormality of the constant power to control the first power voltage to be output to the load when the constant power is normal and to output the second power voltage to the load when the constant power is abnormal; An electronic switching unit under a control of the controller, the switching unit configured to supply one of a first power supply voltage and a second power supply voltage to a load, and to switch when the phases of the first and second power supply voltages are zero; And an auxiliary switching unit including a non-heating switching element configured to operate in conjunction with the electronic switching unit such that one of the first power supply voltage and the second power supply voltage is supplied to the load under control of the controller. The power to be supplied is initially supplied through the electronic switching unit, and then supplied through the auxiliary switching unit after a predetermined time.

Preferably, the electronic switching unit includes: a first switching unit connected between a first power supply voltage and a load, and having four first switching modules configured to perform phase-by-phase switching control and to operate at a zero phase of the first power supply voltage. ; A first switch driver driving the first switching module under control of the controller; A second switching unit connected between the second power supply voltage and the load and having four second switching modules configured to switch at a zero phase of the second power supply voltage; A second switch driver for driving the second switching module under the control of the controller.

Preferably, the auxiliary switching unit comprises: a first auxiliary switching unit having four first latch relay modules respectively connected in parallel to the four first switching modules of the first switching unit; And a second auxiliary switching unit having four second latch relay modules each connected in parallel to four second switching modules of the second switching unit.

Preferably, the auxiliary switching unit is turned on later with a predetermined time difference than the electronic switching unit in the turn-on operation, and is turned off first with a predetermined time difference than the electronic switching unit in the turn-off operation.

DETAILED DESCRIPTION In order to fully understand the present invention, the operational advantages of the present invention, and the objects achieved by the embodiments of the present invention, reference should be made to the accompanying drawings that illustrate preferred embodiments of the present invention and the contents described in the accompanying drawings. In understanding the drawings, it should be noted that like parts are intended to be represented by the same reference numerals as much as possible. And detailed description of known functions and configurations that are determined to unnecessarily obscure the subject matter of the present invention is omitted.

(Example)

Hereinafter, with reference to the accompanying drawings will be described in detail an electronic automatic switching switch having a function of preventing overheating of the present invention in detail.

2 is a block diagram showing a circuit configuration of an electronic automatic switch having an overheat protection function according to a preferred embodiment of the present invention. Referring to the drawings, the electronic automatic switching switch 100 according to the preferred embodiment of the present invention is basically the first rectifying unit 10, the second rectifying unit 13, the internal power generating unit 20, the electronic switching unit 30 ), A controller 50, and an auxiliary switching unit 110.

A first connector 12 that receives constant power is connected to an input terminal of the first rectifier 10, and a second connector 15 that receives emergency power is connected to an input terminal of the second rectifier 13. The first fuse 11 is connected between the input terminal of the first rectifying unit 10 and the first connector 12, and the second fuse 14 is connected between the input terminal of the second rectifying unit 13 and the second connector 15. ) Is connected.

The first rectifier 10 receives the constant power and rectifies and outputs the first power voltage V1 to the internal power generator 20, the electronic switching unit 30, and the auxiliary switching unit 110. The second rectifier 13 receives the emergency power and rectifies and outputs the first power voltage V2 to the internal power generator 20, the electronic switching unit 30, and the auxiliary switching unit 110. The internal power generator 20 receives the first power voltage V1 or the second power voltage V2 to generate the internal operating power Vcc.

The electronic switching unit 30 and the auxiliary switching unit 110 are switched such that any one selected from the first power supply voltage V1 and the second power supply voltage V2 is supplied to the load 4 under the control of the controller 50. It works. In the switching operation, the electronic switching unit 30 operates to switch when the phases of the first and second power supply voltages V1 and V2 are zero.

The auxiliary switching unit 110 operates in conjunction with the electronic switching unit 30. Although a detailed description will be described later, power is first supplied through the electronic switching unit 30 in the switching operation for power supply, and then power is supplied to the load 4 through the auxiliary switching unit 110. When power is supplied to the load 4 through the auxiliary switching unit 110, the power supply through the electronic switching unit 30 is stopped. Therefore, the semiconductor switching device provided in the electronic switching unit 30 does not generate heat.

The controller 50 detects an abnormality of the constant power and controls the first power voltage V1 to be output to the load 4 when the constant power is normal. When the constant power is abnormal, the second power voltage V2 is loaded. The switching operation of the electronic switching unit 30 is controlled to be output. The first and second photocouplers 16 and 17 are connected between the output terminal of the first and second rectifiers 10 and 13 and the controller 50. The controller 50 detects output states of the first and second power supply voltages V1 and V2 through the first and second photocouplers 16 and 17.

The electronic automatic switching switch 100 may further include an overcurrent detector 40 and an auxiliary contact unit 80. The overcurrent detection unit 40 detects an overcurrent state of the power supply voltage input from the electronic switching unit 30 to the load 4, and inputs an overcurrent detection signal to the controller 50 when overcurrent is detected. The controller 50 controls the switching operation of the electronic switching unit 30 in response to the input overcurrent detection signal so that the power voltage input to the load 4 is switched. The auxiliary contact unit 80 may include first and second auxiliary contacts 82 and 84 and may be connected to other devices as necessary to operate in conjunction with the switching operation of the electronic switching unit 30.
In addition, the electronic automatic switching switch 100 includes a front panel 60 including an input unit 62, a status display unit 64, and a state value display unit 66. The input unit 62 is connected to the control unit 50 and includes a plurality of input switches for operating the electronic automatic switching switch 100. The state value display unit 64 is controlled by the control unit 50 to display the state of the electronic automatic switching switch 100 in numerical values or characters. The state display unit 66 lights up the operation state of the electronic automatic switching switch 100. A more detailed description of these is described in detail in Korean Patent Application No. 10-2005-0002211 filed on January 10, 2005.

3 is a diagram illustrating a circuit configuration of the electronic switching unit 30 and the auxiliary switching unit 110 of FIG. 2 in detail. Referring to the drawings, the electronic switching unit 30 includes a first switching unit 31, a second switching unit 35, a first switch driver 33, and a second switch driver 37. The first switching unit 31 is driven by the first switch driver 33 and performs a switching operation so that the first power supply voltage V1 is input or cut off to the load 4. The second switching unit 35 is driven by the second switch driving unit 37 to switch the second power supply voltage V2 to be input or cut off to the load 4.

The first switching unit 31 is connected between the first power supply voltage (V1) and the load (4) in series or in parallel and the four first switching module (32a, 32b, 32c, 32d) for switching control for each phase ). The second switching unit 35 is connected between the second power supply voltage V2 and the load 4 in series or in parallel and has four second switching modules 36a, 36b, 36c, and 36d for switching control for each phase. ).

Each module of the first switching modules 32a, 32b, 32c, and 32d includes a semiconductor switching element TR30, a photocoupler PC30, and a plurality of resistors R30, R31, and R32. Each module of the second switching modules 36a, 36b, 36c, and 36d includes a semiconductor switching element TR35, a photocoupler PC35, and a plurality of resistors R35, R36, and R37. The semiconductor switching elements TR30 and TR35 are preferably composed of triacs, and the photocouplers PC30 and PC35 are preferably composed of phototriacs.

The semiconductor switching element TR30 of the first switching module 32a, 32b, 32c, and 32d is connected between the first power supply voltage V1 and the load 4, and the photocoupler PC30 is connected to the anode terminal of the input terminal. Is connected to the internal operating power supply (Vcc), the cathode terminal is connected to the first switch driver 33, the emitter terminal of the output terminal is connected to the first power supply voltage (V1) and the collector terminal of the semiconductor switching element (TR30) It is connected to the gate terminal and the phase of the first power supply voltage V1 operates on / off at zero.

The semiconductor switching element TR35 included in the second switching modules 36a, 36b, 36c, and 36d is connected between the second power supply voltage V2 and the load 4, and the photocoupler PC35 is connected to the anode terminal of the input terminal. Is connected to the internal operating power supply (Vcc), the cathode terminal is connected to the second switch driver 37, the emitter terminal of the output terminal is connected to the second power supply voltage (V2) and the collector terminal of the semiconductor switching element (TR35) The phase of the second power supply voltage V2 is turned on / off at zero.

The first switch driver 33 includes a transistor Q30 and resistors R33 and 34 turned on / off by a first switching control signal provided from the controller 50, and in response to the first switching control signal. The first switching modules 32a, 32b, 32c, and 32d are driven. The second switch driver 37 includes a transistor Q35 and resistors R38 and R39 that are turned on / off by a second switching control signal, and in response to the second switching control signal, the second switching module 36a, 36b, 36c, and 36d) are driven.

On the other hand, the auxiliary switching unit 110 is composed of a first auxiliary switching unit 110a and a second auxiliary switching unit (110b). The auxiliary switching unit 110 uses a non-heating switching element, for example, is configured as a latch relay.

The first auxiliary switching unit 110a includes four first latch relay modules RL10, RL20. RL30, and RL40 connected in parallel to the first switching modules 32a, 32b, 32c, and 32d. The second auxiliary switching unit 110b includes four second latch relay modules RL12, RL22. RL32, and RL42 connected in parallel to the second switching modules 36a, 36b, 36c, and 36d.

The first and second latch relay modules RL10, RL20, RL30, and RL40 (RL12, RL22, RL32, and RL42) comprise a latch relay and a driving circuit for driving the latch relay. The plurality of latch relays are respectively connected in parallel to a corresponding semiconductor switching element, and are turned on or turned off in response to the first and second relay control signals input from the controller 50.

The operation of the electronic switching unit 30 and the auxiliary switching unit 110 for supplying power to the load 4 is performed as follows under the control of the controller 50. This switching operation includes the first switching module 32a, 32b, 32c, 32d, the second latch relay module RL10, RL20, RL30, RL40, and the second switching module 36a, 36b, 36c, 36d and the second latch. The relay modules RL12, RL22, RL32, and RL42 operate in the same manner.

4A and 4B are flowcharts for describing a switching operation of the electronic switching unit 30 and the auxiliary switching unit 110.

Referring to FIG. 4A, the switching operation for supplying power to the load 4 is as follows. First, in step S100, under the control of the controller 50, the corresponding semiconductor switching element of the electronic switching unit 30 is turned on to supply power to the load 4. In operation S110, the latch relay connected to the semiconductor switching device in parallel is turned on. Thus power is supplied to the load 4 via the latch relay. Since the power is supplied through the latch relay, the semiconductor switching element hardly generates heat. When power is supplied to the load 4 through the latch relay, the semiconductor switching device is preferably turned off in step S120.

The semiconductor switching element and the latch relay are turned on with a predetermined time difference. To this end, the controller 50 outputs a control signal for controlling the semiconductor switching element and the latch relay with a predetermined time difference, but may be output at the same time. Because the latch relay has a slower response speed than the semiconductor switching device, the latch relay is turned on after the semiconductor switching device is turned on, and the time difference is approximately 40 to 50 msec.

Referring to FIG. 4B, the turn-off process of the latch relay that is being powered to change the power supplied to the load 4 is as follows.

First, the semiconductor switching device is turned on in step S200. Subsequently, in step S210, a reverse voltage is supplied to the latch relay in the turn-on state to turn off. After about 40-50 ms, the semiconductor switching device turned on in step S220 is turned off again.

As described above, a predetermined time difference in turn-on / turn-off of the semiconductor switching element and the latch relay connected in parallel thereto is to be switched when the phase of the power supply voltage of the power supplied to the load 4 is zero. will be. In case of switching, the N phase is turned on first and then the power is turned on later. In turn, the power is turned off first and then the N phase is turned off.

The electronic automatic switching switch 100 of the present invention as described above is switched so that the first power supply voltage V1 is supplied to the load 4 by the power input from the constant power supply. If the continuous power is not input or an overcurrent occurs for some reason, the second power supply voltage V2 is switched to the load 4 by the power input from the emergency power supply. At this time, the electronic switching unit 30 does not cause a problem such as noise or arc discharge since the switching on / off operation of the power supply voltage phase is zero. In addition, since power supplied to the load 4 is supplied through the corresponding latch relay, heat generated by the semiconductor switching element hardly occurs.

As described above, the present invention has been described with reference to the embodiments shown in the drawings, but this is merely exemplary, and those skilled in the art to which the present invention pertains have various modifications and equivalent embodiments. You can see that it is possible. Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

According to the electronic automatic switching switch of the present invention as described above, the switching of the power is made at high speed by switching between power sources electronically, problems such as noise or arc discharge by switching when the power voltage phase is zero This does not occur. In addition, since the power supplied to the load after the switching operation is supplied through the corresponding latch relay, heat generated by the semiconductor switching element is hardly generated. Therefore, it is not necessary to use a heat sink, and it is possible to manufacture a smaller size by not using a heat sink.

Claims (4)

A first rectifying unit configured to receive a constant power and rectify the output power to output a first power voltage V1; A second rectifying unit configured to receive the emergency power and rectify and output the second power voltage V2; An internal power generator configured to receive the first power voltage and the second power voltage to generate internal operating power; A control unit for detecting an abnormality of the constant power to control the first power voltage to be output to the load when the constant power is normal and to output the second power voltage to the load when the constant power is abnormal; An electronic switching unit under a control of the controller, the switching unit configured to supply one of a first power supply voltage and a second power supply voltage to a load, and to switch when the phases of the first and second power supply voltages are zero; An auxiliary switching unit including a non-heating switching element configured to operate in conjunction with the electronic switching unit such that any one of a first power supply voltage and a second power supply voltage is supplied to a load under the control of the controller; The power supplied to the load is initially supplied through the electronic switching unit, the electronic automatic switching switch having an overheat protection function is supplied through the auxiliary switching unit after a predetermined time. The method of claim 1, wherein the electronic switching unit: A first switching unit connected between the first power supply voltage and the load, and having four first switching modules configured to perform switching control for each phase at a zero point of the first power supply voltage; A first switch driver driving the first switching module under control of the controller; A second switching unit connected between the second power supply voltage and the load and having four second switching modules configured to switch at a zero phase of the second power supply voltage; And An electronic automatic switching switch having an overheat protection function including a second switch driver for driving the second switching module under control of the controller. The method of claim 2, wherein the auxiliary switching unit: A first auxiliary switching unit having four first latch relay modules respectively connected in parallel to four first switching modules of the first switching unit; And a second auxiliary switching unit having four second latching relay modules each connected in parallel to four second switching modules of the second switching unit. The overheating of claim 1, wherein the auxiliary switching unit is turned on later by a predetermined time difference than the electronic switching unit in a turn-on operation, and is overheated first by a predetermined time difference than the electronic switching unit in the turn-off operation. Electronic automatic changeover switch with protection function.

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