JPS63249059A - Abnormality detector of contactless contactor - Google Patents

Abstract

PURPOSE:To detect open trouble and continuity trouble regardless of the phase of trouble, by judging whether a three-phase contactless contactor SSC is normal or abnormal on the basis of the operation signal of SSC and an interpole voltage signal. CONSTITUTION:When a switch 10 and SSC 2 are closed, for example, it is assumed that an R-phase thyristor 2b generates open trouble. Herein, points A, B are H and points C, D are L and, since a switch 80 is opened, a point E is also L. As a result, the output of an OR circuit 87 is L, that of a NAND circuit 86 is H and that of an inverter 88 is L and, therefore, the output of an AND circuit 89 becomes L. Since the output of an OR circuit 90 is H and that of an AND circuit 91 is H, the output of an OR circuit 92 becomes H and a breaker 12 is closed. When the switch 10 and SSC 2 are opened, for example, it is assumed that the R-phase thyristor 2b generates power continuity trouble. At this time, the points A, B are L and the points C, D are H and, when the switch 80 is opened, the point E becomes L. Whereupon, the breaker 12 is closed and a power source RST is connected to SSC 2 and the output H of the circuit 92 shuts off the breaker 12 through a delay circuit 8.

Description

[Detailed Description of the Invention] [Industrial Application Field] - The present invention detects an abnormality in a three-phase non-contact contactor (hereinafter this non-contact contactor will be abbreviated as SSC) using Saili-Meta as a switching element. The present invention relates to an abnormality detection device for SSC.

[Conventional technology]

The SSC is used to open and close a three-phase electric circuit by housing a plurality of thyristors and their respective control circuits in one case. This SSC is used for switching various three-phase loads including three-phase motors because the electrical and mechanical wear parts are resistant to frequent opening and closing, but the thyristors inserted in each phase each have a zero-cross circuit. Since the motor is closed by the ignition circuit, if some of the ignition circuits or thyristors fail, the load may become unbalanced, or if a three-phase motor is operated on a single phase, an accident may occur such as burnout. do.

Therefore, conventionally, an abnormality detection device as shown in Fig. 6 was installed.
A method is used to detect SC abnormalities and handle them at an early stage.0Here, three-phase motor 1 is connected to power supply R8T via 5SC2.
connected to the phase. The abnormality detection device 3 includes an operation input detection circuit 4, a rectification circuit 6, a smoothing circuit 7, a delay circuit 8, and a relay circuit 9. 5S connected to
It is connected in parallel with the ignition circuit 2a of C2. A three-phase full-wave rectifier circuit 6 is connected to the output side UVW phase of the SSC, and the DC output voltage of this rectifier circuit 6 is smoothed by a smoothing circuit 7 via a normally closed contact 5a of an output relay 5, and a delay circuit 8 The signal is delayed and input to the relay circuit 9. The relay circuit 9 includes an output relay 11 having a switching contact 11a, and the contact 11a of this output relay 11 is connected, for example, to a tripping coil of a molded case circuit breaker (not shown) connected in series with this 5SC2 to the power supply side of this 5SC2. However, when 5SC2 is abnormal, the circuit breaker is configured to be shut off by this pull/release coil. Of course, the contact 11a can also operate a light or acoustic notification device.When 08SC2 is healthy, the switch 10
When closed, the ignition circuit 2a is operated by this operation input and 5S is activated.
C2 closes and the motor 1 starts. At this time, the operation input is also given to the operation input detection circuit 4, so the output of the detection circuit 4 and the relay 5 are activated, opening the normally closed contact 5a, and the abnormality detection device 3 is activated. If the operation switch 10 is open, 5SC2 will not close, so no voltage will be applied to the motor IK. However, if 5SC2's Sairisk is damaged at this time,
When the thyristor becomes conductive due to a failure in the ignition circuit 2a, if the thyristors of each phase become conductive at the same time, the operation switch 10
If the motor 1 starts without closing the thyristor and the two-phase thyristor becomes conductive, the motor 1 will not start but there is a risk of burnout, which is dangerous in any case. However, at this time, the output relay 5 is not operating, so the contact 5a is closed. Therefore, the voltage appearing on the UVW phase on the load side is rectified by the rectifier circuit 6, smoothed by the smoothing circuit 7, and then by the delay circuit 8 of 5SC2. It is confirmed whether or not there is an abnormality, and if it is true that the 5SC2 is abnormal, the output relay 11 is operated in the output circuit 9, and, for example, a molded circuit breaker is tripped.

[Problem that the invention seeks to solve]

In this abnormality detection device, when the operation switch 10 is closed, the input detection circuit 4 is activated and the contact 5a is opened due to the operation of the output relay 5. Therefore, if the ignition circuit 2a fails or the thyristor is damaged, the malfunction occurs. If the motor 1 is in a conductive state and no voltage is applied to the load-side W phase, for example, the motor 1 will not start due to the application of a single-phase voltage, and there is a risk of burnout. In other words, this SSC
This abnormality detection device has the disadvantage that only short-circuit abnormalities in the thyristor can be detected, and failures that cannot be turned on cannot be detected.

Further, if one of the three thyristors of the SSC causes a conduction failure, no line voltage is generated on the output side of the SSC, so this abnormality detection device does not operate. In other words, it is impossible to detect one-phase conduction failure, which is the most common failure of three-phase SSCs, and there is a risk of short-circuiting between phases when two SSCs are used to operate a three-phase motor or the like reversibly. Also, if you use this abnormality detection device when performing the same reversible operation,
Although no operational input is applied to the abnormality detection device attached to one SSC, which is supposed to be open, the phase-to-phase voltage of the other SSC appears at the output terminal of this SSC, so this abnormality detection device is connected to one SSC. An abnormality is mistakenly detected as a continuity failure of the SSC.

For this reason, there is a problem that this abnormality detection device cannot be used in the reversible operation device of SSC.The purpose of the present invention is to detect an abnormality in even one thyristor of a three-phase SSC. The purpose is to provide an SSC abnormality detection device that can also be used for SSC of reversible operation equipment.
Means for Solving the Problems] In order to solve the above-mentioned problems, the present invention provides an SSC abnormality detection device that detects an abnormality in an SSC that includes a switching element in each phase and confines a three-phase electric circuit. an operation input detection circuit that detects an operation input and issues an operation signal; an inter-electrode voltage detection circuit that detects an inter-electrode voltage of each of the switching elements and issues an inter-electrode voltage signal;
an abnormality detection logic circuit that issues an operation signal based on the inter-electrode voltage signal; and a delay circuit that delays the operation signal for a predetermined period of time.
The abnormality detection logic circuit may include a switch circuit that prevents a continuity failure of one phase of the electrode-to-electrode voltage detection circuit from being detected. Furthermore, the non-contact contactor is equipped with a power supply voltage discrimination circuit that determines whether or not the power supply voltage is applied and issues a power supply voltage signal, and an abnormality detection logic circuit that detects the operation signal, interpolation voltage signal, and power supply voltage signal. It is also possible to issue an operating signal based on this. Note that it is preferable that this abnormality detection device is integrated into a case that houses this SSC.

[For production]

With the above configuration, when the abnormality detection logic circuit determines that there is a failure in the SSC based on the operation signal and the voltage signal between poles, it issues an operation signal, confirms it with the delay circuit, and activates the alarm device with the relay circuit or controls the power supply side. Performs actions such as turning off a circuit breaker. Furthermore, when two SSCs are connected as a reversible operation device, the abnormality detection logic circuit closes the switch circuit that prevents the interpolation voltage detection circuit from detecting a continuity failure of one phase, and prevents the error detection logic circuit from detecting a continuity failure in one phase. Avoid detection. A power supply voltage determination circuit is provided to determine whether or not a three-phase voltage is applied to the power supply side of the SSC, and when it is not, K stops the operation signal to prevent the SSC from erroneously detecting it. Such an abnormality detection device is easy to handle when integrated into the 5SCVc.

〔Example〕

FIG. 1 shows a block diagram of an embodiment of an SSC abnormality detection device according to the present invention, and the same components as in FIG. 6 are given the same reference numerals as in FIG. 6. In Figure 1, motor 1 is 5SC
2 and the circuit breaker 12 are connected to the power supply R8TK through a series circuit. The abnormality detection device 3 includes an operation input detection circuit 4,
Power supply voltage discrimination circuit 50, electrode voltage detection circuit 60, abnormality detection logic circuit 70. The operation input detection circuit 4 includes a delay circuit 8 and a relay circuit 9, and the operation input detection circuit 4 is a circuit for detecting the operation input of the 5SC2, and is connected to the power supply R8 phase via the operation switch 10.
It is connected in parallel with the ignition circuit 2a of the SC2, and as shown in FIG. 2, the voltage of the R8 phase of the power supply is divided by a voltage dividing resistor 41.
◇The power supply voltage discrimination circuit 50 applied to 5SC2:
This is to determine whether the power supply voltage is applied or not, and as shown in FIG. 3, the input terminal of the three-phase full-wave rectifier circuit 51 is
The DC output end of the rectifier circuit 51 is voltage-divided by voltage-dividing resistors 52 and 53, and this divided voltage is connected to the light-emitting diode 54a of the photocoupler. The electrode-to-electrode voltage detection circuit 60 detects the electrode-to-electrode voltage of each thyristor of the SSC, and as shown in FIG.
At 62.63, each light emitting diode 64a of each photocoupler,
65a, 66a, and each 2 with opposite polarities connected to each other.
Three sets of circuits in which Zener diodes 67, 68, and 69 are all connected in series are connected between the poles of each thyristor 2b, 2c, and 2d of 5SC2. The abnormality detection logic circuit 7°, as shown in FIG.
1a.

Each phototransistor for 62 L 63 a / 6
1b, 62b.

63b are the respective resistors 71.72, 73.74,
Smoothing circuits 75, 76, 77 consisting of resistors and capacitors
78 to form four series circuits.

Each smoothing circuit 75, 76, 77, 78 removes signal pulsation on the phototransistor side since each light emitting diode 43a, 61a, 62a+ 63a is driven by alternating current, and each resistor 71, 72, 73, 74 In addition to this circuit, a switch 80 and a resistor 79 are connected in series to remove noise that enters each photocoupler. When the two SSCs are used as a reversible operation device, this switch 80 is closed. @These five series circuits are connected to the control power supply VCCK. Resistance 72. The connection point of the smoothing circuit 76 (the point at the bottom is called point B) and the resistor 74
．． The connection point of the smoothing circuit 78 (this point is referred to as point D) is connected to the input terminals of the NAND circuit 86 via resistors 81 and 82, respectively, and resistors 73 and 73, respectively. The connection point of the smoothing circuit 77 (this point is referred to as the 0 point) and the switch 80
．． The connection point of the resistor 79 (this point is referred to as point E) is connected to each input terminal of the OR circuit 87 via the resistor 8-3.84, and the output terminal of the OR circuit 87 is connected to the NAND circuit 8.
0 NAND circuit 8 connected to the other input terminal of 6
6 is connected to one input terminal of an AND circuit 89, and the other input terminal of this AND circuit 89 is connected to a resistor 71.6 through a series circuit of a resistor 85 and an inverter 88. Smoothing circuit 7
5 connection points (this point will be referred to as point A) are connected.

Furthermore, the two input terminals of the NAND circuit 86 and the OR circuit 871
The two input terminals are respectively connected to the respective input terminals of the OR circuit 90, and the output terminal of the OR circuit 90 is connected to the AND circuit 9.
1, and the other input terminal of the AND circuit 91 is connected to a connection point between the resistor 85 and the inverter 88. The output terminal of the AND circuit 91 and the output terminal of the AND circuit 89 are connected to respective input terminals of an OR circuit 92, and the output terminal of the OR circuit 92 is connected to the output terminal of the abnormality detection logic circuit 70 via a resistor 93. A collector of a transistor 94 is connected between the output terminal of the abnormality detection logic circuit 70 and the negative terminal of the power supply vCC, which is connected to the next delay circuit 8 as its terminal.

The emitter is connected to the base, and the power supply VCC is connected to this base through a resistor 95.
A light emitting diode 54a of the discrimination circuit 500 is connected between the negative electrode side of the
A phototransistor 54b is connected to the phototransistor 54b.

Next, we will show the operation of this abnormality detection circuit. First, when 5S02 is normal, when switch 10 is closed, 5SC2 is closed, so the voltage between electrodes of 5SC2 becomes almost 0, and each phototransistor 61b, 62b, 63b becomes non-conductive. be. However, since the operation input is applied to the light emitting diode 43a, the phototransistor 43b is closed. Therefore, point A in Figure 5 is at a high level (hereinafter this high level will be referred to as H).
, B, C, and D points are low level (hereinafter, this low level is referred to as L
), and if switch 80 is open, point E will also be L.
Therefore, the output of the OR circuit 87 is L and the output of the NAND circuit 86 is H. Further, the output of the inverter 88 becomes LK, the output of the AND circuit 89 becomes L, the output of the 0/M9 OR circuit 90 becomes L, and the output of the AND circuit 91 becomes L. Therefore, the output of OR circuit 92 is L, and transistor 9
40 is on or off, the relay circuit 9 does not operate and the circuit breaker 12 is not cut off. Next switch 1
When 0 is opened, SSC2 is opened, but at this time each thyristor 2b.

Since a snubber circuit (not shown) is connected to thyristors 2c and 2d, a voltage appears between the poles of each thyristor 2b, 2c, and 2d via the motor 1, so points B, C, and D become H, and at this time, the operation input Since no voltage is applied, point A is at L, and if switch 80 is open, point E is also at L. Therefore, the output of the OR circuit 87 is H1, and the output of the NAND circuit 86 is L1.
The output of the AND circuit 89 is L1 and the output of the OR circuit 90 is H1.
The output of the AND circuit 91 becomes L, and the output of the OR circuit 92 becomes L. Therefore, regardless of whether transistor 94 is on or off, relay circuit 9 does not operate and the circuit breaker does not shut off.

Next, a case where SSC2 is abnormal will be described. switch 1
For example, if the R-phase thyristor 2b has an open failure when 0 is closed and 5SC2 is closed, points A and B are both HSC, point D is both L, and since switch 80 is open, point E is also closed. It is L. Therefore, the output of the OR circuit 87 is L, the output of the /do circuit 86 is H1, and the output of the inverter 88 is L, so the output of the AND circuit 89 is L.

Also, the output of the OR circuit 90 becomes H, and the output of the AND circuit 91 becomes H, so the output of the OR circuit 92 becomes HK.
When the phase and T phase thyristors 2b and 2d each individually cause an open failure, or when two or more phases simultaneously cause an open failure, the output of the OR circuit 92 becomes H. When the circuit breaker 12 is closed and the power supply voltage is healthy, the phototransistor 54b for the light emitting diode 54a is closed, so the transistor 94 is in the off state, and the output H of the OR circuit 92 connects the relay circuit 9 via the delay circuit 8. 0 to operate and shut off the circuit breaker 12
Also, if the R phase has caused a continuity failure when switch 10 is opened and 5SC2 is opened, points A and B will be together, and C
, D points are both KHK.

When the switch 80 is open, the E point becomes L. Then, in accordance with the above-mentioned procedure, the output of the OR circuit 92 is output from the OR circuit 92 in the same way when the HK phase, S phase, and T phase each cause a conduction failure individually, or when two or more phases simultaneously cause a conduction failure. The output of becomes H. Of course, at this time, if the circuit breaker 12 is closed and the power source R8T is healthy and connected to 5SC2, the phototransistor 54b is closed, so the transistor 94 is in the off state, and the output H of the OR circuit 92 is sent to the delay circuit 8. relay, - circuit breaker 1 via circuit 9
When performing reversible operation such as Tanabata using two SSCs, the S-phase of the two SSCs are connected in parallel, so during reversible operation, the parallel-operated S-phase thyristor 2c is always conductive. Therefore, there is a risk that the abnormality detection device connected to the SSC on the open side may determine that the thyristor 2c has a conduction failure and detect an abnormality. Therefore, as shown in FIG. 5, a switch 80 for reversible operation and a resistor 7 are used.
A switch circuit consisting of 9 is provided. That is, when the switch 80 is closed, the E point always becomes KM, so even if the S phase iris closes and the 0 point becomes L, the output of the OR circuit 87 is always KH, and the output of the OR circuit 92 does not become H.
That is, when two SSCs are used to form a reversible operation device, when the switch 80 is closed, the thyristor connected in parallel can be set so as not to be detected as a conduction failure and the circuit breaker 12 not to be cut off.

〔Effect of the invention〕

As described above, according to the present invention, since the normality or abnormality of the SSC is determined based on the SSC operation signal and the voltage signal between electrodes, an open failure when the SSC should be closed can be prevented. Continuity faults when should be open can also be detected regardless of the number of phases in which the fault occurs. In addition, when two SSCs are used to operate a motor etc. in a reversible manner, a switch circuit is provided to prevent parallel phases from being detected as continuity failures, so it can be used without false detection even during reversible operation, which widens the range of applications and is highly effective. 0

[Brief explanation of the drawing]

1 to 5 each show an embodiment of the SSC abnormality detection device according to the present invention, FIG. 1 is a block diagram showing the abnormality detection device, FIG. 2 is a wiring diagram of an operation input detection circuit,
Fig. 3 is a wiring diagram of the power supply voltage discrimination circuit, Fig. 4 is a wiring diagram of the voltage between poles detection circuit, Fig. 5 is a wiring diagram of the abnormality detection logic circuit, and Fig. 6 is an example of the conventional SSC abnormality detection circuit. FIG. 2: SSC, 4: Operation input detection circuit, 8: Delay circuit, 9: Relay circuit, 50: Power supply voltage discrimination circuit, 60: Electrode voltage detection circuit, 70: Abnormality detection logic circuit. Figure 2 Figure 3

Claims (1)

[Scope of Claims] 1) An abnormality detection device for a non-contact contactor that detects an abnormality in a non-contact contactor that has a switching element in each phase and opens and closes a three-phase electric circuit, in which an operation input of the non-contact contactor is detected. an operation input detection circuit that detects and issues an operation signal; an inter-electrode voltage detection circuit that detects an inter-electrode voltage of each switching element and issues an inter-electrode voltage signal; and operates based on the operation signal and the inter-electrode voltage signal. An abnormality detection device for a non-contact contactor, comprising an abnormality detection logic circuit that emits a signal, a delay circuit that delays the operation signal for a predetermined period of time, and a relay circuit that operates according to the operation signal from the delay circuit. . 2) In the abnormality detection device for a non-contact contactor according to claim 1, the abnormality detection logic circuit includes a switch circuit that prevents the electrode-to-electrode voltage detection circuit from detecting a continuity failure in one phase. An abnormality detection device for a non-contact contactor. 3) In the non-contact contactor abnormality detection device according to claim 1, the non-contact contactor includes a power supply voltage discrimination circuit that determines whether or not a power supply voltage is applied and issues a power supply voltage signal. An abnormality detection device for a non-contact contactor, characterized in that the abnormality detection logic circuit emits an operation signal based on an operation signal, an inter-electrode voltage signal, and a power supply voltage signal. 4) In the abnormality detection device for a non-contact contactor according to any one of claims 1 to 3, the abnormality detection device is integrated into a case housing the non-contact contactor. An abnormality detection device for a non-contact contactor, characterized in that: