JPH0526366B2 - - Google Patents

Description

Detailed Description of the Invention [Technical Field of the Invention] The present invention relates to a three-phase solid state relay (hereinafter referred to as three-phase
(denoted as SSR).

[Prior art]

Conventionally, when controlling the drive of a three-phase AC motor, an electromagnetic switch, which is a mechanical relay, is used to control the opening and closing of the electromagnetic switch, thereby controlling the supply of three-phase AC power to the motor. Ta. However, this electromagnetic switch has a problem in that under usage conditions where the electromagnetic switch is frequently opened and closed, its contacts become severely worn, resulting in a shortened lifespan.

By the way, conventional single-phase solid-state relays (hereinafter referred to as single-phase SSR) using semiconductors have been used to control the supply of single-phase AC power to loads. Contacts such as the electromagnetic switch described above are not required, and therefore there is no problem of shortened lifespan due to wear of the contacts.

FIG. 1 shows such a single-phase SSR semiconductor main element circuit 80, in which 81 and 82 are power supply side and load side main terminals, 83 and 84 are first and second thyristors, and 85 and 86 are main terminals on the load side. Control terminals 87 and 88 connected to a control circuit (not shown) are resistors 8 and 88, respectively.
9. First and second gate auxiliary circuits each consisting of a diode 90.

When the control signal externally applied to the control circuit is "H", the control terminals 85, 86
As a result, in the positive half cycle of single-phase AC, the power supply side main terminal 81, the first gate auxiliary circuit 87, between the control terminals 85 and 86, the gate of the second thyristor 84, and the load side main terminal 82. An auxiliary current flows through the path, turning on the second thyristor 84,
As a result, the main current flows from the power supply side main terminal 81 through the second thyristor 84 to the load side main terminal 82,
Similarly, in the negative cycle of single-phase AC, the second gate auxiliary circuit 88 and the first thyristor 83
operates, and the main current flows from the load side to the first thyristor 8.
3 to the power supply side, and as a result, single-phase power is supplied to the load.

On the other hand, when the control signal is "L", the control terminals 85 and 86 are in an open state, and as a result, both thyristors 83 and 84 remain off, and single-phase power is not supplied to the load. Therefore, if this single-phase SSR is used, the supply of single-phase power to the load can be controlled to be connected or disconnected by the control signal.

In such a conventional situation, when controlling the supply of the three-phase AC power to the load, the problem of shortened life can be avoided by combining the single-phase SSR instead of the electromagnetic switch. It is considered possible to do so.

[Summary of the invention]

In view of the above, the present invention provides a three-phase SSR as a device for connecting and disconnecting the supply of three-phase AC power to a load, which can avoid the problem of shortened lifespan due to wear of the contacts in the electromagnetic switch. In addition, power supply side and load side main terminals and gate relay terminals of the power thyristor are alternately arranged via partition walls on the surface of the solid state relay body housing the semiconductor main element circuit composed of the power thyristor. , on this surface, an auxiliary circuit section housing a control circuit and an absorber circuit is configured to be detachably attached so that the main terminal of the solid state relay body, the gate relay terminal, and the connection terminal of the auxiliary circuit section correspond to each other. The object of the present invention is to provide an economically reliable, compact, and convenient three-phase solid-state relay in which each circuit section can be replaced independently.

[Embodiments of the invention]

An embodiment of the present invention will be described below with reference to the drawings. Figure 2 shows a three-phase SSR7 according to an embodiment of the present invention.
0, as shown in FIG.
The main circuit section 61, which includes three circuits similar to the main element circuit 80 shown in the figure, controls the connection/disconnection of the three-phase AC power supply 62 to the motor 63.

As shown in FIG. 2, the three-phase SSR 70 consists of an SSR main body 10 and an auxiliary circuit section 30, each of which is divided into parts.The SSR main body 10 houses the main circuit section 61. has been done. Also, on the front and rear of the top of this SSR main body 10,
Main terminals 11a, 1 for connecting each of the main element circuits 80 to the three-phase cable 64 on the power supply side or load side
2a, 13a and main terminals 11b, 12b, 13b
are formed to face each other, and these main terminals 11a~
13a and the main terminals 11b to 13b are arranged on straight lines parallel to each other. Gate relay terminals 14, 15, 16 for applying control signals to each of the main element circuits 80 are arranged on the same line as each of the main terminals 11 to 13, alternating with each of the main terminals 11 to 13. The gate relay terminal 14~
16 are formed to protrude upward, respectively.
The main terminals 11 to 13 are separated from each other by a U-shaped output barrier 17 with an open outer side.
This ensures the insulation distance between the main terminals 11 to 13 and the gate relay terminals 14 to 16, that is, the creepage distance and the spatial distance. In addition, 1
8 and 19 are screw holes.

Further, the auxiliary circuit section 30 houses a control circuit for controlling the main element circuit 80 on and off, and an absorber circuit for protecting the main element circuit 80 from surge voltages such as those caused by lightning. A pair of input terminals 22a, 22b for inputting control signals to the control circuit are arranged on the side of the circuit section 30, and three pairs of output terminals 23, 22b of the control circuit are arranged on the front and rear sides, respectively. 24, 25 and terminals 32, 33, 34 of the absorber circuit are arranged to face each other. Each of the output terminals 23 to 25 of the control circuit has the terminal 23
~25 and the gate relay terminal 14 of the SSR main body 10 above
Holes 43, 44, 45 are formed for connecting the absorber terminals 32 to 16.
34 is connected to each of the main terminals 11 to 13 of the SSR main body 10, together with the three-phase cable 64 on the power supply side and the load side. Note that 35 is an attachment hole for attaching this attached circuit section 30 to the SSR main body 10.

Next, the effects will be explained.

First, when assembling this 3-phase SSR 70, the attached circuit section 30 is connected to its control signal input terminal 22, control signal output terminals 23 to 25, and absorber terminal 32.
- 34 are placed on the SSR main body 10 so that they are located at the screw holes 19, gate relay terminals 14-16, and main terminals 11-13 of the SSR main body 10, respectively, and these are placed on the SSR main body 10 so that 18 and may be fixed with screws 40.

When in use, the external control signal line is connected to the control signal input terminal 22, and the three-phase cable 64 on the power supply side and the load side is connected to the main terminals 11a to 13.
The above absorber terminal 32a located on a
34a, or the absorber terminals 32b to 34b located above the main terminals 11b to 13b, respectively.

According to the device of this embodiment, the contactless type semiconductor main element circuit 80 connects and disconnects the supply of the three-phase AC power source 62 to the load 63.
Sufficient durability and lifespan can be obtained even under usage conditions that involve frequent opening and closing. In addition, SSR main body 10
The main terminal and gate relay terminal are placed on the surface of the solid-state relay through a partition wall, and the attached circuit section is made to correspond to the main terminal of the solid state relay body, the relay terminal, and the connection terminal of the attached circuit section, respectively, so that it can be attached and detached. Each circuit section can be replaced independently, making it economical, highly reliable, and compact, and the attached circuit section 30 can be replaced with one whose control circuit has, for example, a phase control function and a timer function, and its absorber circuit. It is also possible to replace it with one that has a capacity according to the load, which is very convenient for implementation.

〔Effect of the invention〕

As described above, according to the present invention, the connection and disconnection of the supply of three-phase AC power to the load is performed using a three-phase
Since the three-phase SSR is used, it has sufficient durability and service life even under conditions of frequent opening and closing, and the SSR main body and attached circuit section of the three-phase SSR are configured separately. Since they are mutually detachable, each circuit section can be replaced independently, resulting in a very economical and convenient three-phase solid state relay.

[Brief explanation of drawings]

Fig. 1 is a circuit diagram of the semiconductor main element circuit of a single-phase SSR, Fig. 2 is an exploded perspective view of a three-phase SSR according to an embodiment of the present invention, and Fig. 3 is a diagram showing how the three-phase SSR is used. be. 10... SSR main body, 30... Attached circuit section, 80
...Semiconductor main element circuit. In the figures, the same reference numerals indicate the same or corresponding parts.

Claims (1)

[Scope of Claims] 1. A semiconductor main element circuit composed of power thyristors connected in antiparallel, and a semiconductor main element circuit that disconnects and disconnects the supply from a three-phase AC power source to a load, and each of the semiconductor main element circuits is arranged on its surface. The main terminals on the power supply side and the load side are arranged to face each other, and the gate relay terminals of the power thyristors are arranged alternately through the main terminals and the partition wall on the main terminals on the power supply side and the load side, respectively. a solid-state relay body comprising: a control circuit detachably disposed on the surface of the solid-state relay body for controlling the semiconductor main element circuit on and off in response to an external control signal; 3 characterized by comprising an auxiliary circuit section housing an absorber circuit for protecting the semiconductor main element circuit from abnormal voltage and having connection terminals disposed so as to correspond to the gate relay terminals and the main terminals. phase solid state relay.