JP2002157028A - Semiconductor relay device and control method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To dispense with a safety device for preventing the sudden operation of a device or the runaway of the device because of unstoppability when a power supply is ON without being aware of the short-circuit failure of a semiconductor element. SOLUTION: When the power source is ON in a non-power source state where a semiconductor element 8, the relay contact 21-1 of the dummy load relay 21 of a dummy load pat 11, and the relay contacts 22-1 and 23-1 of the breaking relays 22 and 23 of a safety breaker part 12 are in OFF state, an initial check state is formed to perform the failure inspection of the safety breaker part 12. When the safety breaker part 12 is not broken as the result of this failure inspection, the current route of the semiconductor element 8 is ensured in the dummy load part 11 to execute the failure detection of the semiconductor element 8. When the semiconductor element 8 is not broken, the failure detection by the dummy load part 11 is stopped, and the relay contacts 22-1 and 23-1 are ON to set an operating state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a semiconductor relay device used for drive control of a load such as a motor.

[0002]

2. Description of the Related Art Conventionally, there are two types of relay devices, one using an electromagnetic relay for the last stage output and the other using a semiconductor relay having a semiconductor switching element in the last stage.

A semiconductor relay using a semiconductor switching element at the last stage is excellent in terms of high-speed response and long life, but it is difficult to avoid a short-circuit failure, and when a short-circuit failure is dangerous, Always used in combination with an electromagnetic relay.

[0004] In particular, in a relay device used for safety applications, a safety relay with further improved reliability and an electromagnetic relay of a known technique are used, and from the above viewpoint, a semiconductor relay is considered to be inaccurate. Was. Therefore, a structure has been proposed in which the reliability is improved by combining a semiconductor relay and an electromagnetic relay from the beginning.

[0005]

However, in the above-mentioned conventional relay device, it is necessary to supply a current to a circuit in order to actually detect a failure of a semiconductor. If the power is turned on without the
There has been a problem that a worker may not be able to stop the operation, which may pose a danger to the worker, and another part of the apparatus itself may be further broken due to uncontrolled operation.

The present invention has been made in view of the above problems, and a first object of the present invention is to detect a failure in a semiconductor element portion at an early stage to improve the safety of the device. It is an object of the present invention to provide a highly reliable semiconductor relay device capable of improving the safety of the entire system using the device.

A second object of the present invention is to improve the safety of the device by detecting the failure of the semiconductor element portion at an early stage, and to improve the safety of the whole system using the device. An object of the present invention is to provide a highly reliable semiconductor relay device control method that can be enhanced.

[0008]

In order to achieve the first object, a semiconductor relay device according to the present invention comprises a load circuit for driving a load by a load power supply and a semiconductor element for controlling the load circuit. The semiconductor relay device includes a dummy load unit connected in parallel with a load, and a control circuit unit that controls the dummy load unit and the semiconductor element unit.

According to another aspect of the present invention, there is provided a semiconductor relay device comprising a load circuit for driving a load unit by a load power supply and a semiconductor element unit for controlling the load circuit. In the device, a dummy load section connected in parallel with the load, a safety cutoff section having contacts for connecting and disconnecting the load power supply and the load in the load circuit, and a dummy load section, a semiconductor element section, and a safety cutoff section are controlled. And a control circuit section that performs the control.

In order to achieve the first object, a semiconductor relay device according to the present invention comprises: a load circuit for driving a load by a load power supply; a semiconductor element for controlling the load circuit; A safety interrupting unit having a contact for connecting and disconnecting a load power supply and a load, a dummy load unit for executing a failure detection by securing a current route of the semiconductor element unit in a load interrupted state, and a semiconductor element unit;
When the power is turned on and the power is turned on, the dummy load section and the safety cut-off section are both in the off state, and the power is turned on, the initial check state is set, and the safety cut-off section is checked for failure. In this case, control means is provided for executing failure detection of the semiconductor element portion, and connecting and operating the safety shut-off portion to control the load circuit to an operating state when the semiconductor element portion is not faulty.

When the state of the safety cut-off section is normal, the control means secures a current route of the semiconductor element section in the dummy load section and causes a failure detection of the semiconductor element section to be executed for a predetermined time. Is normal, the execution of the failure detection of the semiconductor element unit may be stopped, and the safety shut-off unit may be connected and operated to control the load circuit to the operating state.

Further, when the safety interrupting section is faulty, the control means controls the dummy load section so as not to perform fault detection and to prevent the load circuit from entering the operating state, and the semiconductor element section becomes faulty. If so, control may be performed so that the load circuit does not enter the operating state.

With this configuration, when the power is turned on in a no-power state in which the semiconductor element section, the dummy load section, and the safety cutoff section are each in the off state, the apparatus enters an initial check state and performs a failure inspection of the safety cutoff section. As a result of the failure inspection, if the safety interrupting section has not failed, the failure detection of the semiconductor element section is executed, or the current path of the semiconductor element section is secured in the dummy load section to cause the failure of the semiconductor element section. By performing the detection, the safety shut-off unit can be turned on to be in the operating state.

If a failure is found in the safety shut-off unit as a result of the failure inspection of the safety shut-off unit, the operation is stopped, for example, by issuing a warning to the effect that the failure was found and by issuing a warning. Similarly,
Even when a failure is found in the semiconductor element portion, it is possible to perform control so that the operation is stopped and the load circuit does not enter the operating state, for example, by issuing a warning that the failure has been found.

[0015] For this reason, the failure of the semiconductor element portion can be detected at an early stage, so that the safety of the device can be improved, and the input of the operation signal is permitted after ensuring the safety of the device itself. Therefore, it is possible to enhance the security of the whole system using this.

In addition, since the deterioration of the characteristic value of the semiconductor element portion can be detected by the sensor portion, the load circuit is shut off by the safety shut-off portion before the semiconductor element portion completely fails.
Alternatively, by issuing a warning to the user to alert the user, the apparatus can be stopped before a dangerous state occurs, and the safety of the system can be improved.

Further, the control means monitors the safety interrupting section, and if it is detected that the contact of the safety interrupting section is not released, the control means controls so as not to output a drive signal generated from the element drive circuit section. You may make it.

In addition, when the power supply is turned on, the control means supplies a current to the semiconductor element section through the dummy load section, and after confirming that the semiconductor element section is normal, performs control so as to close the contact of the safety cut-off section. It may be.

Further, the control means controls to open the contact of the safety shut-off section when the failure of the semiconductor element section is confirmed based on the output signal of the element failure detection section during normal operation. Is also good.

Further, the control means may control to open the contact of the safety shut-off unit when the operation is stopped.

The control means detects a failure of the semiconductor element portion based on a sensor output signal of the sensor portion and an element drive signal and outputs an element safety signal. The element failure detection unit compares the element drive signal and the sensor output signal, and outputs an element safety signal if it is confirmed that the state is safe (no short circuit or open failure has occurred). If the safety interrupting section can function normally (no contact welding has occurred) (for example, if it can be confirmed that the contact b of the relay contact of the interrupting relay is closed), the dummy load signal is output to the dummy load signal. To output a cutoff relay safety signal, and if the safety cannot be confirmed, a cutoff circuit monitoring circuit that does not output a cutoff relay safety signal and the power supply are turned on. When the dummy load relay of the dummy load section is turned on for a certain period of time, the safety of the semiconductor element section can be confirmed, and in the above state, the input signal from the outside is shut off, and when the element section starts up It includes an initial control circuit section for inputting a check operation signal to the element drive circuit section, outputting a safety cut-off section check signal to the cut-off section monitoring circuit section in the above-described state, and performing welding confirmation.

The semiconductor element section is constituted by a semiconductor switching element such as a MOSFET, a transistor, a triac, a thyristor, and a GTO.

In order to achieve the first object, a semiconductor relay device according to the present invention includes a load circuit for driving a load by a load power supply, a semiconductor element for controlling the load circuit, and an element drive signal. An element drive circuit section that outputs a signal to drive the semiconductor element section, a safety cut-off section having a contact for connecting and disconnecting a load power supply and a load in the load circuit, and a sensor section for detecting the operation of the semiconductor element section. An element failure detection section that detects a failure of the semiconductor element section based on a sensor output signal of the sensor section and an element drive signal and outputs an element safety signal, and secures a current route of the semiconductor element section when the load is disconnected. A dummy load section for executing failure detection, a shutoff circuit monitoring circuit section for outputting a shutoff relay safety signal if the safety shutoff section can function normally, and Activate the me load unit to enable the safety confirmation of the semiconductor element unit, shut off the external input signal, output the operation start-up check signal to the element drive circuit unit, and monitor the interruption unit monitoring circuit unit. And a logic to output a safety confirmation signal to the safety interruption section when both the element safety signal and the interruption relay safety signal are at a high level. And a circuit.

The sensor section may be constituted by a photo coupler connected in parallel to the semiconductor element section. The sensor section detects a voltage applied to the semiconductor element section and outputs a sensor output signal to the element failure detection circuit section.

In the above-described semiconductor relay device according to the present invention, the safety cut-off section may be constituted by a cut-off relay comprising a safety relay, or a cut-off relay comprising an electromagnetic relay having at least one normally open contact. , Or may be constituted by a cut-off relay composed of a safety relay and a normal relay, or the safety cut-off section may be constituted by a semiconductor element having a high withstand voltage.

Further, the control of the shut-off relay of the safety shut-off unit is
It may be performed at any time according to an element drive signal input to the semiconductor element section. In this case, the shutoff can be reliably performed by appropriately turning off the shutoff relay, and safety can be enhanced.

In the safety relay, all the b-contacts are always turned off when any one a-contact is welded by the forced guide mechanism, and all the a-contacts are always turned off when any one b-contact is welded. A relay that is designed to be turned off and used in control circuits used for safety purposes.

In the semiconductor relay device according to the present invention, the dummy load section may be disposed between the semiconductor element section and the safety cut-off section and may be disposed in parallel with the load. , A resistor and an electromagnetic relay may be connected in series, or a dummy load section may be configured with a resistor,
This resistance may be set to a resistance value that allows a very small current (for example, 1/10 or less) that can be ignored compared to the load current. Further, the electromagnetic relay of the dummy load unit may use the contact b of the safety relay used in the safety shut-off unit.

Further, the sensor section may be constituted by a voltage detection circuit for detecting a voltage applied to the semiconductor element section.

The sensor section may be constituted by a photo coupler connected in parallel to the semiconductor element section. The sensor section detects a voltage applied to the semiconductor element section and outputs a sensor output signal to the element failure detection circuit section.

Further, the sensor section may be constituted by a current detection circuit for detecting a current flowing through the semiconductor element section. The sensor section detects a current flowing through the semiconductor element section and outputs a sensor output signal to the element failure detection circuit section.

Further, the sensor section and the element failure detecting section may each be duplicated so that even if one of the sections fails, the other operates normally to improve the fault tolerance.

Further, the semiconductor relay device according to the present invention comprises:
A function of forcibly opening the safety shut-off unit by receiving a safety control signal from the outside may be provided.

Further, the semiconductor relay device according to the present invention comprises:
It may have a function of outputting a safety control signal to the outside and a function of controlling the safety control signal when an internal failure state is detected.

Also, the semiconductor relay device according to the present invention may be a semiconductor relay device used with a three-phase power supply, and the safety cutoff unit may cut off two phases.

According to another aspect of the present invention, there is provided a method of controlling a semiconductor relay according to the present invention, wherein the semiconductor element section, the dummy load section, and the safety cut-off section are each in an off state in a no-power state. When the power is turned on, an initial check state is set, and a failure inspection of the safety interrupting section is performed. If the result of the failure inspection indicates that the safety interrupting section has not failed, the semiconductor element section is detected for failure. If there is no failure, the safety breaker is connected and activated to put the load circuit into an operating state. Control so that the load circuit does not enter the operating state without performing detection, and control the load circuit so that it does not enter the operating state if the semiconductor element section is faulty as a result of the failure inspection of the semiconductor element section. Those were Unishi.

Therefore, the failure of the semiconductor element portion can be detected at an early stage, so that the safety of the device can be improved. Further, since the safety of the device itself is ensured, the input of the operation signal is permitted. Thus, the security of the whole system using this can be improved.

Further, since the deterioration of the characteristic value of the semiconductor element part can be detected by the sensor part, the load circuit is cut off by the safety cut-off part before the semiconductor element part completely fails.
Alternatively, by issuing a warning to the user and calling attention, the apparatus can be stopped before the dangerous state is reached, and the safety of the system can be improved.

[0039]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is an explanatory diagram of a configuration of a semiconductor relay device according to the present invention, and FIG. 2 is a flowchart when the semiconductor relay device is started.

The semiconductor relay device A according to the present invention includes an input signal terminal 1, input terminals 3A and 3B of the load circuit 2, and output terminals 4A and 4B.
3B is connected to the load power supply circuit 5, and the output terminals 4A and 4B are connected to the load 6.

The semiconductor relay device A includes a power supply circuit section 7, a semiconductor element section 9, an element drive circuit section 10, a dummy load section 11, a safety cutoff section 12, a sensor section 13
, An element failure detection circuit section 14, and an interruption circuit monitoring circuit section 1
5, an initial control circuit section 16, and a logic circuit (AND
Circuit 18).

The sensor section 13, the element failure detecting circuit section 14, the cutoff circuit monitoring circuit section 15, the initial control circuit section 16, and the logic circuit (AND circuit) 18 constitute a control circuit section (control means). . In addition, the power supply circuit unit 7
A circuit power supply is generated from the load power supply circuit 5 and supplied to each circuit unit.

The semiconductor element section 9 is composed of a semiconductor element (semiconductor switching element, for example, a triac) 8 as a semiconductor relay.
The load circuit 2 is controlled in accordance with the element drive signal H from the control circuit.

The semiconductor element section 9 may be constituted by another type of semiconductor switching element, for example, a MOSFET, a transistor, a thyristor, a GTO, or the like.

The element drive circuit section 10 generates an element drive signal H for driving the semiconductor element 8 of the semiconductor element section 9 according to the input signal. If no phase control signal is input, all 0N / all 0FF control is performed. On the input side of the element driving circuit section 10, a changeover switch for inputting either an external input signal or an element section activation check signal d from the initial control circuit section 16 to the element driving circuit section 10. Section 17 is provided.
Are switched by the initial control circuit unit 16.

The dummy load section 11 secures a current route for confirming the safety of the semiconductor element section 9 when the load is cut off, and includes a resistor 20 and a relay contact (dummy) of a dummy load relay 21 which is an electromagnetic relay. A normal load relay contact 21-1 is connected in series with the load circuit 2 in parallel with the load 6.

The safety shut-off section 12 has a configuration in which relay contacts (normally open relay contacts) 22-1 and 23-1 of shut-off relays 22 and 23 each composed of two electromagnetic relays (forcibly guided safety relays) are connected in series. The safety shut-off unit 12 is connected to the load circuit 2 in parallel with the load 6. Then, when the safety confirmation signal is input, the relay contacts 22-1 and 22-2 of the cut-off relays 22 and 23 are connected.
3-1 is closed, the load circuit 2 is connected, and if the safety of the semiconductor element section 9 (or the safety of the entire system) cannot be confirmed, the load circuit 2 is immediately shut off, and A welding confirmation signal for confirming welding is output to the shutoff circuit monitoring circuit unit 15.

The shut-off relays 22 and 23, which are forcibly guided safety relays, have their b-contacts always turned off when any one of the a-contacts is welded by the forcible guide mechanism, and any one of the b-contacts is turned off. This is a relay used in a control circuit used for safety purposes, in which all a contacts are always turned off when welded.

The sensor section 13 comprises a photocoupler 24, which is a voltage detection circuit connected in parallel to the semiconductor element 8, detects a voltage applied to the semiconductor element 8, and outputs an element failure detection circuit. It outputs a sensor output signal to the section 14.

The element failure detection circuit section 14 compares the element drive signal H with the sensor output signal, and if it is confirmed that the element is in a safe state (no short-circuit or open failure has occurred), the element safety signal H Is output.

Further, the shutoff circuit monitoring circuit unit 15 determines whether or not the safety shutoff unit 12 can function normally based on the welding confirmation signal (for example, the relay contacts 22-1 and 23 of the shutoff relays 22 and 23). If it can be confirmed that the b-contact paired with -1 is closed), it outputs a cut-off relay safety signal B. If it cannot be confirmed that the function can function normally, the safety signal B is not output.

When the power is turned on, the initial control circuit 16 sends a dummy load control signal c to the dummy load 1.
1 to the dummy load relay 2 of the dummy load section 11.
1 is turned on for a certain period of time so that the safety of the semiconductor element portion 9 can be confirmed. A signal is input to the drive circuit section 10 and, in the above state, a signal for checking the safety cut-off section is output to the cut-off section monitoring circuit section 15 so that the welding is confirmed.

The logic circuit (AND circuit) 18 is used when both the element safety signal E output from the element failure detecting section 14 and the shutoff relay safety signal B output from the shutoff circuit monitoring circuit section 15 are output. When the signal is at a high level, a safety confirmation signal is output to the safety shut-off unit 12.

Next, the operation of the semiconductor relay device A configured as described above will be described with reference to the flowchart shown in FIG.
This will be described with reference to the time chart shown in FIG.

In the initial state, the semiconductor element 8, the relay contact 21-1 of the dummy load relay 21 of the dummy load section 11, and the relay contacts 22-1 and 23-1 of the two cut-off relays 22 and 23 of the safety cut-off section 12 are closed. Each is in the off state.

Then, the power is turned on and the power supply circuit section 7 is operated, and a start signal A is input from the power supply circuit section 7 to the initial control circuit section 16 (steps S1, S2).
2). The initial control circuit unit 16 includes the changeover switch unit 1
7 to shut off an input signal from the outside, and output a signal for checking the safety cut-off section to the cut-off section monitoring circuit section 15;
The welding of the two shut-off relays 22 and 23 of the safety shut-off unit 12 is confirmed (step S3).

The shutoff circuit monitoring circuit section 15 includes the safety shutoff section 1
2 is determined to be in a state in which the safety shut-off unit 12 can function normally (step S3). A control signal C is output to the dummy load unit 11, and the dummy load relay 21 of the dummy load unit 11 is operated to turn on the relay contact 21-1 for a certain period of time, so that the load power supply unit 5, the semiconductor element unit 9, A loop composed of the dummy load unit 11 and the load power supply unit 5 is formed (Step S4).

Further, the initial control circuit section 16 outputs the element section start-up check signal d to the element drive circuit section 10, and the element drive circuit section 10 generates an element drive signal ch. The data is input to the semiconductor element unit 9 to drive the semiconductor element 8. For this reason, a current flows through a loop including the load power supply unit 5, the semiconductor element unit 9, the dummy load unit 11, and the load power supply unit 5 as the semiconductor element 8 is turned on and off.

The sensor section 13 detects an element voltage applied to the semiconductor element 8 of the semiconductor element section 9 and outputs a sensor output signal to the element failure detection circuit section 14. Further, the element drive circuit section 10 outputs an element drive signal H to the element failure detection circuit section 14. Therefore, in the element failure detection circuit section 14, the sensor output signal is compared with the element drive signal H to determine whether the semiconductor element 8 is operating normally (step S5).

When the element failure detection circuit section 14 determines that the semiconductor element 8 is operating normally,
After a certain period of time, the initial control circuit unit 16 stops outputting the dummy load control signal C to the dummy load unit 11 and turns off the relay contact 21-1 of the dummy load relay 21 of the dummy load unit 11. Then, the initial control circuit unit 16 switches the changeover switch unit 17 (step S
6).

When the element failure detection circuit section 14 determines that the semiconductor element 8 is operating normally,
The element failure detection circuit 14 outputs an element safety signal E.
In addition, the shutoff circuit monitoring circuit unit 15 is in a state where the safety shutoff unit 12 can function normally (no contact welding occurs) (for example, the relay contacts 22 of the shutoff relays 22 and 23).
If it can be confirmed that the b-contact paired with -1, 23-1 is closed), it outputs a cut-off relay safety signal B.

When both the element safety signal E and the cut-off relay safety signal B are input to the logic circuit (AND circuit) 18 (when both the element safety signal E and the cut-off relay safety signal B are at a high level) ), This logic circuit (AND circuit)
From 18, a safety confirmation signal is input to the safety shut-off unit 12. For this purpose, the relay contacts 2 of the cut-off relays 22 and 23
The 2-1 and 23-1 are turned on to input an external input signal to the element drive circuit unit 10 to drive the load circuit 2 and enter an operation state (steps S7 and S8).

If it is determined in step S3 that the safety interrupting section 12 cannot function normally (if contact welding has occurred) (step S9), the interrupting circuit monitoring circuit section 1
5, the output of the interruption relay safety signal B is stopped, a warning is issued, and the operation is stopped (step S10).

In step S5, when the semiconductor element section 9 fails, the sensor section 13 does not output the sensor output signal to the element failure detection circuit section 14. Therefore, in the element failure detection circuit section 14, the semiconductor element section 9
Is not operating normally (step S1).
2), the shutoff circuit monitoring circuit unit 15 stops outputting the shutoff relay safety signal B. For this reason, the relay contacts 22-1 and 23-1 of the cut-off relays 22 and 23 of the safety cut-off unit 12 remain off and do not reach the operation state (Step S).
10).

Next, the case of an open (disconnection) fault and a short (short) fault will be described with reference to the flowchart shown in FIG. 3 and the time charts shown in FIGS.

In the operating state, the semiconductor device 8 is turned on and off.
The off state is determined in step U1 of the flowchart shown in FIG.
-Monitor in the process shown in step U5. Semiconductor element 8
Is considered as a triac here, it is necessary to monitor the firing state of the element in order to monitor the driving state of the element. The ON state of the semiconductor element 8 is a state where the operation flag is 1, and the OFF state of the semiconductor element 8 is a state where the operation flag is 0.

In the operating state (step T1), when the semiconductor element 8 is on (the operation flag is 1) and the absolute voltage of the semiconductor element 8 is smaller than 1.5 V, the semiconductor element 8 is opened (disconnected). No failure has occurred and it is determined to be normal (step T2, step T3), continuous energization is permitted (step T4), and the operating state is continued.

If the absolute value of the voltage of the semiconductor element 8 is larger than 1.5 V in step T3, it is determined that an open (disconnection) fault has occurred (step T3).
6), the cutoff relays 22 and 23 of the safety cutoff unit 12 are released, the energization of the load circuit 2 is stopped, and the operation is stopped (step T7).

As described above, when an open (disconnection) failure occurs during operation, the time chart shown in FIG.
Although the sensor output signal is low, the input signal (drive signal) is also high in this case. In this state, the element safety signal E goes low. Therefore, even if both the low-level element safety signal E and the high-level cutoff relay safety signal B are input to the AND circuit 18,
Since the safety confirmation signal is not output from the AND circuit 18, the safety relay section 12
The relay contacts 22-1 and 23-1 are turned off, and the operation of the drive circuit 2 is stopped.

In the operating state (step T1), when the semiconductor element 8 is off (the operation flag is 0) and the absolute voltage of the semiconductor element 8 is greater than 10 V, a short-circuit (short-circuit) fault is generated. No occurrence has occurred, and it is determined that the operation is normal (step T8), continuous energization is permitted (step T4), and the operation state is continued.

In step T8, if the absolute value of the voltage of the semiconductor element 8 is smaller than 10 V and the power supply voltage is smaller than 10 V, no short-circuit (short-circuit) fault has occurred and it is determined that the circuit is normal. (Step T8, Step T9), the continuous energization is permitted (Step T8).
4), the operation state is continued.

In step T8, when the absolute value of the voltage of the semiconductor element 8 is smaller than 10 V,
If the power supply voltage is higher than 10 V, a short-circuit (short-circuit) failure has occurred, and it is determined that there is an abnormality (step T1).
0), the cut-off relays 22 and 23 of the safety cut-off section 12 are released, the energization of the load circuit is stopped, and the operation is stopped (step T7).

As described above, when a short-circuit (short-circuit) fault occurs during operation, the time chart shown in FIG.
When both the input signal (drive signal) and the sensor output signal are at a low level, a high level signal F is applied to the sensor output signal.
Occurs. Therefore, the high level element safety signal E becomes a low level state. Even if both the low-level element safety signal E and the high-level cutoff relay safety signal B are input to the logic circuit (AND circuit) 18, the logic circuit (AND circuit) 18 outputs a safety confirmation signal. In order to prevent output, the electromagnetic relays 22, 2
The relay contacts 22-1 and 23-1 are turned off, and the operation of the drive circuit 2 is stopped.

A method for controlling a semiconductor relay device according to the present invention will be described with reference to a control state explanatory diagram shown in FIG.

In the no-power state (initial state), as shown in FIG. 6A, the semiconductor element 8 of the semiconductor element section 9 and the relay contact 2 of the dummy load relay 21 of the dummy load section 11
1-1 and two shut-off relays 22 and 2 of the safety shut-off unit 12
The relay contacts 22-1 and 23-1 of No. 3 are each in the off state (step W1).

When the power is turned on, an initial check state is set (step W2).
The failure inspection of the semiconductor element unit 9 is performed by operating the failure inspections 2 and 23 and the dummy load unit 21. As a result of the failure inspection, if it is confirmed that there is no failure in the cut-off relays 22 and 23 and the semiconductor element unit 9, the cut-off relay 2
The relay contacts 22-1 and 23-1 of the switches 2 and 23 are turned on, and the semiconductor element unit 9 is turned on to be in an operation state (step W3).

In this operating state, as shown in FIG. 6 (2), in the operating state (step W4), the drive signal is turned on by inputting the drive signal (step W5), and when the drive signal is turned off in the operating state. The machine is stopped. In addition, when the power is cut off or the load is cut off from the operation state, the power supply is turned off (initial state).

Further, in the initial check state (step W2), as a result of the failure inspection,
When the third relay contacts 22-1 and 23-1 are welded, conduction of the dummy load unit 11 is not performed, and the failure detection of the semiconductor element unit 9 is stopped.

Further, in a failure state in which the semiconductor element section 9 has failed (step W6), the relay contacts 22-1, 23-1 of the cut-off relays 22, 23 are off, and the semiconductor element section 9 does not operate. And the load is stopped (step W
7).

In the operating state (step W3), if a failure occurs in the semiconductor element section 9, the dummy load section 11 does not conduct, the state becomes a failure state (step W6), and the relay contacts of the cut-off relays 22 and 23 are turned off. 22-1, 23
-1 is in the off state, the semiconductor element section 9 is in the off state, and is controlled so as not to enter the operation state (step W7).

According to the embodiment of the method for controlling a semiconductor relay device according to the present invention described above, the failure of the semiconductor element 8 can be detected at an early stage, so that the safety of the device can be improved. In addition, since the input of the operation signal is permitted after ensuring the safety of the device itself, the safety of the entire system using the operation signal can be improved.

Further, since the deterioration of the characteristic value of the semiconductor element 8 can be detected by the sensor section 13, the load of the load circuit 2 can be reduced by the safety cutoff section 12 before the semiconductor element 8 completely fails.
By shutting off the device or issuing a warning to the user to call attention, the device can be stopped before a dangerous state is attained, and the safety of the system can be improved.

Another embodiment of the control method of the semiconductor relay device according to the present invention is as shown in FIGS. 7 (1) and 7 (2). Controls 22 and 23 are performed at any time according to an element drive signal H input to the semiconductor element section 9.

In this operation state, as shown in FIG. 7 (2), in the stop state (step W4), the semiconductor element section 9 and the cutoff relays 22 and 23 are in the off state. As a result, a driving state (step W5) is established. In this operation state, the semiconductor element section 9 and the cut-off relay 2
Reference numerals 2 and 23 are on. Then, when the drive signal is turned off in the operation state, the operation is stopped. In addition, when the power is cut off or the load is cut off from the operation state, the power supply is turned off (initial state). The other control is the same as the control method according to the embodiment of the control method of the semiconductor relay device according to the present invention described above with reference to FIGS.

According to another embodiment of the method for controlling a semiconductor relay device according to the present invention described above, the shutoff can be reliably performed by appropriately turning off the shutoff relay, and safety can be improved. it can.

In the above-described embodiment of the present invention,
Although the shutoff relays 22 and 23 of the safety shutoff unit 12 are configured by safety relays, the safety shutoff unit 12 may be configured by an electromagnetic relay having at least one normally open contact. Alternatively, the safety relay and the normal relay may be configured, and the safety shut-off unit 12 may be configured with a semiconductor element having a higher withstand voltage than the semiconductor element 8.

In the above-described embodiment of the present invention,
The dummy load unit 11 is configured by connecting the resistor 20 and the relay contact 21-1 of the dummy load relay 21 which is an electromagnetic relay in series. However, the current is negligible compared to the load current. 10) may be constituted by a resistor set with a resistance value enough to flow.

Further, as the dummy load relay 21 of the dummy load section 11, the contact b of the safety relay used in the safety shut-off section 12 may be used.

The sensor section 13 and the element failure detecting section 1
4 may be duplicated so that one may fail and the other may operate normally. In this case, fault and tolerance are improved.

In the above-described embodiment of the present invention,
Although the phase of the semiconductor relay device A is controlled, the cycle may be controlled.

In the above-described embodiment of the present invention, a structure may be provided which has a function of forcibly opening the safety shut-off section 12 by receiving a safety control signal from the outside, or Has the function of outputting control signals,
In addition, a function of shutting off the safety control signal when an internal failure state is detected may be provided.

FIG. 8 shows a state where the semiconductor relay device according to the present invention is incorporated in the control circuit of the three-phase motor M2.

In this case, one load circuit 2
-1 and the other load circuit 2-2, and one load circuit 2-1 is composed of a load line R and a load line S,
The other load circuit 2-2 includes a load line S and a load line T. And the input terminals 3A of the load lines R, S, T,
3B and 3C are connected to a load power supply circuit 5, and output terminals 4A, 4B and 4C of the load lines R, S and T are connected to a three-phase motor M2 as a load 6.

One load circuit 2-1 incorporates one semiconductor relay device A-1, and the other load circuit 2-2 incorporates the other semiconductor relay device A-2. In this case, the relay contacts 22-of the shut-off relays 22 and 23 of the safety shut-off unit 12 of one semiconductor relay device A- 1.
Reference numerals 1 and 23-1 are provided on the load lines R and S, and relay contacts 22-1 and 23-1 of the cutoff relays 22 and 23 of the safety cutoff unit 12 of the other semiconductor relay device A-2 are connected to the load lines. S and T are provided. The other configuration of the one and the other semiconductor relay devices A-1 and A-2 is the same as the configuration of the semiconductor relay device A described above.

The basic algorithm in this case is that if an element voltage is generated when the semiconductor element 8 is in the ON state (ignition command ON), it is an open (disconnection) failure, and the semiconductor element 8 is in the ON state (point If no element voltage is generated when the arc command is ON, it is a short-circuit (short-circuit) failure.

Further, as the voltage detection algorithm, in the method 1, a check is performed for each half-wave period by applying a mask at the time of ignition and at the time of ignition. In method 2, monitoring is performed constantly, and if the element voltage is equal to or less than a predetermined value for a predetermined time or more, it is determined that a short circuit has occurred.

When a failure is detected, two or three of the load lines R, S, and T are disconnected by the safety shut-off unit 12. Even if one of the three wires is welded, the power can be cut off.

The semiconductor relay devices A, A-
1 and A-2, the sensor unit 13 can be configured by a detection circuit that detects a current flowing through the semiconductor element 8. As this detection circuit, as shown in FIG. 1, a CT 30 which is a current detector (current detection circuit) is disposed on a load line, and a sensor output of the CT 30 is output to the element failure detection unit 14.

As shown in FIG. 9, when the failure is detected (step V1), when the semiconductor element 8 is in the ON state (the operation flag is 1), the load current absolute value of the semiconductor element 8 is constant. If the value is larger than the value x [A], it is determined that no open (disconnection) failure has occurred and that it is normal (step V2, step V3, step V4),
The continuous energization is permitted (step V5).

In step V3, if the absolute value of the load current of the semiconductor element 8 is smaller than the constant current value x [A], it is determined that an open (disconnection) fault has occurred (step V6), and the safety cutoff is performed. Cut-off relay 22 of section 12,
23 is released, the energization of the load circuit 2 is stopped, and the operation is stopped (step V7).

In the failure state (step V1), when the semiconductor element 8 is in the off state (the operation flag is 0), the load current absolute value of the semiconductor element 8 is a constant current value x [A].
If it is smaller than the threshold value, no short-circuit (short-circuit) failure has occurred and it is determined to be normal (step V8, step V8).
4), a continuous energization is permitted (step V5).

In step V8, if the absolute value of the load current of the semiconductor element 8 is larger than the constant current value x [A], a short-circuit (short-circuit) fault has occurred and it is determined that there is an abnormality (step V9). Breaking relay 2 of breaking section 12
2 and 23 are released, the energization of the load circuit 2 is stopped, and the operation is stopped (step V7).

[0104]

As described above, according to the semiconductor relay device of the present invention, the failure of the semiconductor element can be detected at an early stage, so that the safety of the device can be improved. Since the input of the operation signal is permitted after ensuring the safety of the device itself, the safety of the entire system using the operation signal can be improved.

Further, since the deterioration of the characteristic value of the semiconductor element portion can be detected by the sensor portion, the load circuit is shut off by the safety shut-off portion before the semiconductor element portion completely fails.
Alternatively, by issuing a warning to the user to alert the user, the apparatus can be stopped before a dangerous state occurs, and the safety of the system can be improved.

Further, according to the method for controlling a semiconductor relay device according to the present invention, a failure of a semiconductor element portion can be detected at an early stage, so that the safety of the device can be improved and the device itself can be improved. After the safety is secured, the input of the operation signal is permitted, so that the safety of the whole system using the operation signal can be improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of a configuration of a semiconductor relay device according to the present invention.

FIG. 2 is a flowchart at the time of startup in the semiconductor relay device.

FIG. 3 is a flowchart at the time of operation in the semiconductor relay device.

FIG. 4 is a time chart at the time of an open failure in the semiconductor relay device.

FIG. 5 is a time chart at the time of a short circuit failure in the semiconductor relay device.

FIGS. 6 (1) and (2) are explanatory diagrams of control states of the semiconductor relay device.

FIGS. 7 (1) and (2) are control state explanatory diagrams of the semiconductor relay device.

FIG. 8 is a circuit diagram when the semiconductor relay device is used in a drive circuit of a three-phase motor.

FIG. 9 is a failure detection flowchart when a current detection circuit is used for a sensor unit in the semiconductor relay device.

[Explanation of symbols]

Reference Signs List A Semiconductor relay device A-1 Semiconductor relay device A-2 Semiconductor relay device 1 Input signal terminal 2 Load circuit 3A Input terminal 3B Input terminal 4A Output terminal 4B Output terminal 5 Load power circuit 6 Load 7 Power circuit section 8 Semiconductor element 9 Semiconductor element section 10 Element drive circuit section 11 Dummy load section 12 Safety interruption section 13 Sensor section (control circuit section) (control means) 14 Element failure detection circuit section (control circuit section) (control means) 15 interruption circuit monitoring Circuit part (control circuit part) (control means) 16 Initial control circuit part (control circuit part) (control means) 17 Changeover switch part (control circuit part) (control means) 18 Logic circuit (AND circuit) (control circuit part)
(Control Means) 20 Resistance 21 Dummy Load Relay (Electromagnetic Relay) 21-1 Relay Contact (Normal Open Relay Contact) 22 Shutdown Relay (Forced Guided Safety Relay) 22-1 Relay Contact (Normal Open Relay Contact) 23 Interruption Relay ( Force-guided safety relay) 23-1 Relay contact (normally open relay contact) 24 Photocoupler (voltage detection circuit) 30 CT (current detector) (current detection circuit) b Start signal b Cut-off relay safety signal c Dummy load control Signal D Element start-up check signal E Element safety signal To safety confirmation signal G Input signal H Element drive signal Re-sensor output signal Welding confirmation signal W Safety cut-off part check signal

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Takaaki Yamada Inventor 801 Fudo-term, Omron Co., Ltd. Fudom (reference) 5F420 BB12 BB13 CC04 CC05 DD03 DD04 DD06 EA05 EA37 EA47 EB01 EB32 EB38 FF03 FF23 LL00

Claims (27)

[Claims] 1. A semiconductor relay device comprising a load circuit for driving a load by a load power supply and a semiconductor element unit for controlling the load circuit, wherein: a dummy load unit connected in parallel with the load; A semiconductor relay device comprising: a control circuit unit that controls a semiconductor element unit. 2. A semiconductor relay device comprising: a load circuit for driving a load by a load power supply; and a semiconductor element unit for controlling the load circuit, wherein: a dummy load unit connected in parallel with the load; A semiconductor, comprising: a safety cut-off unit having a contact for connecting and disconnecting a load power supply and the load; and a control circuit unit for controlling the dummy load unit, the semiconductor element unit, and the safety cut-off unit. Relay device. 3. A safety circuit having a load circuit for driving a load by a load power supply, a semiconductor element unit for controlling the load circuit, and a contact for connecting and disconnecting the load power supply and the load in the load circuit. A dummy load unit that secures a current route of the semiconductor element unit and performs failure detection in the load cutoff state; and the semiconductor element unit, the dummy load unit, and the safety cutoff unit are each in an off state. When the power is turned on in the initial power-off state in the no-power state, the safety shut-off unit is inspected for failure. As a result of the failure inspection, if the safety shut-off unit has not failed, the semiconductor element unit has failed. Control means for performing the detection, connecting and operating the safety shut-off unit when the semiconductor element unit is not faulty, and controlling the load circuit to an operation state. Semiconductor relay device, characterized in that was e. 4. The control unit executes a failure detection of the semiconductor element unit for a predetermined time by securing a current route of the semiconductor element unit in the dummy load unit when the state of the safety interrupting unit is normal. 4. The semiconductor device unit according to claim 3, wherein when the semiconductor device unit is normal, the execution of the failure detection of the semiconductor device unit is stopped, and the safety shut-off unit is connected and operated to control the load circuit to an operating state. Semiconductor relay device. 5. The control unit controls the dummy load unit so that the failure detection is not performed and the load circuit does not enter an operation state when the safety cut-off unit is faulty. 4. The semiconductor relay device according to claim 3, wherein when the semiconductor element portion is out of order, the load circuit is controlled so as not to enter an operation state. 5. 6. The control means monitors the safety shut-off unit, and when it is detected that the contact of the safety shut-off unit is not released, sends a drive signal generated from the element drive circuit unit. The semiconductor relay device according to claim 3, wherein the semiconductor relay device is controlled so as not to output. 7. When the power supply is turned on, the control unit supplies power to the semiconductor element unit through the dummy load unit and confirms that the semiconductor element unit is normal. The semiconductor relay device according to claim 3, wherein the semiconductor relay device is controlled to be closed. 8. The control device according to claim 1, wherein, during normal operation, when a failure of the semiconductor device is confirmed based on an output signal of the device failure detector, the contact of the safety shut-off unit is opened. The semiconductor relay device according to claim 3, wherein the semiconductor relay device is controlled. 9. The semiconductor relay device according to claim 3, wherein the control means controls to open the contact of the safety shut-off unit when the operation is stopped. 10. A load circuit for driving a load by a load power supply, a semiconductor element section for controlling the load circuit, an element drive circuit section for outputting an element drive signal to drive the semiconductor element section, and the load circuit. A safety cut-off unit having a contact for connecting and disconnecting the load power supply and the load, a sensor unit for detecting an operation of the semiconductor element unit, and a sensor output signal of the sensor unit and the element drive signal. An element failure detection unit that detects a failure of the semiconductor element unit based on the failure and outputs an element safety signal; and a dummy load unit that secures a current route of the semiconductor element unit and performs failure detection when the load is cut off. And a cut-off circuit monitoring circuit that outputs a cut-off relay safety signal if the safety cut-off section can function normally, and the dummy load section when power is turned on. In this way, the semiconductor element portion can be checked for safety, an input signal from the outside is shut off, an operation signal for starting the element portion check is output to the element drive circuit portion, and a safety signal is output to the shutoff portion monitoring circuit portion. An initial control circuit unit that outputs a signal for checking a cut-off unit to perform welding confirmation; and outputs a safety confirmation signal to the safety cut-off unit when both the element safety signal and the cut-off relay safety signal are at a high level. A semiconductor relay device comprising a logic circuit. 11. The semiconductor relay device according to claim 3, wherein the safety interrupting section is configured by an interrupting relay including a safety relay. 12. The semiconductor relay device according to claim 3, wherein the safety cut-off section is configured by a cut-off relay including an electromagnetic relay having at least one normally open contact. 13. The semiconductor relay device according to claim 3, wherein the safety interrupting section is configured by an interrupting relay including a safety relay and a normal relay. 14. The semiconductor relay device according to claim 3, wherein said safety cut-off portion is constituted by a semiconductor element having a high withstand voltage. 15. The semiconductor relay device according to claim 3, wherein the control of the shut-off relay of the safety shut-off unit is performed at any time in accordance with an element driving signal input to the semiconductor element unit. 16. The semiconductor relay according to claim 3, wherein the dummy load section is disposed between the semiconductor element section and the safety cut-off section, and is disposed in parallel with the load. apparatus. 17. The semiconductor relay device according to claim 3, wherein the dummy load section has a configuration in which a resistor and an electromagnetic relay are connected in series. 18. The semiconductor relay device according to claim 3, wherein the dummy load section is constituted by a resistor. 19. The semiconductor relay device according to claim 18, wherein the resistance is set to such a value that a small current that can be ignored as compared with a load current can flow. 20. The semiconductor relay device according to claim 11, wherein the contact b of the safety relay used in the safety shut-off unit is used for the electromagnetic relay of the dummy load unit. 21. The semiconductor relay device according to claim 10, wherein the sensor section is configured by a voltage detection circuit that detects a voltage applied to the semiconductor element section. 22. The semiconductor relay device according to claim 10, wherein the sensor section is configured by a current detection circuit that detects a current flowing through the semiconductor element section. 23. The semiconductor relay device according to claim 10, wherein the sensor section and the element failure detection section are each duplicated, and even if one of the elements fails, the other operates normally. 24. The semiconductor relay device according to claim 4, wherein the semiconductor relay device has a function of forcibly opening the safety shut-off unit by receiving a safety control signal from the outside. 25. The apparatus according to claim 3, further comprising a function of outputting a safety control signal to the outside, and a function of controlling the safety control signal when an internal failure state is detected.
0. The semiconductor relay device according to 0. 26. The semiconductor relay device according to claim 3, wherein the safety shut-off unit is configured to cut off two phases. 27. The semiconductor device section, the dummy load section and the safety cut-off section are each turned off in a non-power supply state in which the power supply is turned off, an initial check state is set, and a failure test of the safety cut-off section is performed. As a result of the inspection, if the safety cut-off section has not failed, the failure detection of the semiconductor element section is executed, and if the semiconductor element section has not failed, the safety cut-off section is connected and activated to load circuit. If the safety shut-off unit is faulty as a result of the failure inspection of the safety shut-off unit, the dummy load unit does not execute the fault detection and does not enter the operating state. As a result of the failure inspection of the semiconductor element portion, when the semiconductor element portion is faulty, the load circuit is controlled so as not to enter an operation state. Control method of the semiconductor relay that.