JP3610784B2 - Inverter device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an inverter device that drives a motor at a variable speed.
[0002]
[Prior art]
FIG. 2 is a circuit configuration diagram showing a conventional example of this type of inverter device, in which 1 is an AC power source such as a commercial power source, 2 is an inverter device, and 3 is an electric motor driven at a variable speed by the inverter device 2.
The inverter device 2 includes a diode rectifier 4 that rectifies the voltage of the AC power source 1, an electrolytic capacitor 5 that converts the output of the diode rectifier 4 to a smoothed DC voltage, and a DC circuit that converts the DC voltage to a desired voltage and frequency. The abnormality detection circuit 7 that monitors the operation state of the inverter 6 that converts the current into the alternating current and supplies power to the motor 3, the inverter 6, and the motor 3, and detects that these are in an abnormal operation state, and the abnormality detection circuit 7 Includes a relay excitation circuit 8 that excites the relay 9 when the abnormal operation state is detected. The contact 9a of the relay 9 is connected to an external host controller, for example, as 30A, 30B, 30C as shown in the figure. The
[0003]
The inverter 6, the control circuit, the abnormality detection circuit 7, the relay excitation circuit 8 and the like shown in FIG. 2 are configured by a well-known technique.
In the inverter device 2 shown in FIG. 2, when the abnormality detection circuit 7 detects the abnormal operation state, the circuit between 30A and 30C is closed, and the circuit between 30B and 30C is opened, and the inverter 6, the motor 3, etc. Is operating and is in a normal operating state, the circuit between 30A and 30C is open, the circuit between 30B and 30C is closed, and when the inverter device 2 is not energized, the circuit between 30A and 30C is open. And 30C is closed.
[0004]
[Problems to be solved by the invention]
According to the above-described conventional inverter device 2, the circuit between 30A and 30C is open when the inverter 6, the motor 3 and the like are operating and in a normal operation state, and when the inverter device 2 is in a non-energized state. Since there is a closed circuit between 1 and 30C, there is a problem that the higher-level controller cannot determine any of the above from only 30A to 30C.
[0005]
Conventionally, measures have been taken such as adding a function for determining whether or not the inverter device 2 is in an energized state to the host controller, but this measure has been a factor in increasing the cost of the entire equipment.
An object of the present invention is to provide an inverter device that solves the above problems.
[0006]
[Means for Solving the Problems]
According to the present invention, in an inverter device that converts a direct current voltage into alternating current of a desired voltage and frequency and drives the motor at a variable speed by this alternating current, the abnormal operation state of the inverter device and the motor is detected inside the device, and this state When the abnormal operation state is detected, the relay is changed from the non-excited state to the excited state, or the relay is moved from the excited state. It is possible to select whether to change to a non-excited state.
[0007]
According to this invention, by adding a slight function to the conventional inverter device, the inverter device and the motor are operating and in a normal operating state, and when the inverter device is in a non-energized state, It can be easily determined from the outside from the contact.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a circuit configuration diagram of an inverter device showing an embodiment of the present invention. Components having the same functions as those of the conventional circuit shown in FIG. 2 are denoted by the same reference numerals.
That is, the inverter device 10 shown in FIG. 1 includes a changeover switch 11 and an exclusive OR circuit 12 in addition to the diode rectifier 4, the electrolytic capacitor 5, the inverter 6, the abnormality detection circuit 7, the relay excitation circuit 8, and the relay 9. ing.
[0009]
The exclusive OR circuit 12 receives the output of the abnormality detection circuit 7 and the output of the changeover switch 11 and performs a logical operation on whether or not the output of the abnormality detection circuit 7 is inverted by the output of the changeover switch 11. The output of the exclusive OR circuit 12 is input to the relay excitation circuit 8.
For example, the logic “H” level is output when the abnormality detection circuit 7 detects the abnormal operation state, and the relay 8 is excited when the logic “H” level is input to the relay excitation circuit 8. .
[0010]
Under the above setting conditions, when the changeover switch 11 is connected to the logic “H” level side, when the abnormality detection circuit 7 detects the abnormal operation state, the relay 9 changes from the non-excitation state to the excitation state. As a result, the circuit between 30A and 30C is closed, the circuit between 30B and 30C is opened, and the circuit between 30A and 30C is opened when the inverter 6, the motor 3, etc. are operating and in a normal operation state. 30C is closed, and further, when the inverter device 2 is in a non-energized state, the circuit between 30A and 30C is open, and the circuit between 30B and 30C is closed.
[0011]
Similarly, in the state where the changeover switch 11 is connected to the logic “L” level side under the above setting conditions, when the abnormality detection circuit 7 detects the abnormal operation state, the relay 9 changes from the excited state to the non-excited state. As a result, the circuit between 30B and 30C is closed, the circuit between 30A and 30C is opened, and the circuit between 30B and 30C is opened when the inverter 6, the motor 3, etc. are operating and in a normal operation state. The circuit between 30A and 30C is closed. Further, when the inverter device 2 is in a non-energized state, the circuit between 30A and 30C is open, and the circuit between 30B and 30C is closed.
[0012]
That is, in the inverter device 10 shown in FIG. 1, when the changeover switch 11 is connected to the logic “H” level side, the operation is the same as that of the conventional inverter device 2 shown in FIG. In the state of being connected to the logic “L” level side, when the inverter device 10 and the electric motor 2 are operating and in a normal operation state, and when the inverter device 10 is in a non-energized state, the contact 9a (that is, the relay device 9) 30A, 30B, 30C) can be easily determined externally.
[0013]
【The invention's effect】
According to the present invention, by adding a slight function to the conventional inverter device, when the inverter device and the motor are operating and in a normal operation state, and when the inverter device is in a non-energized state, for example, By connecting only the contact point of the relay to the controller, the controller can easily determine.
[Brief description of the drawings]
FIG. 1 is a circuit configuration diagram of an inverter device showing an embodiment of the present invention. FIG. 2 is a circuit configuration diagram of an inverter device showing a conventional example.
DESCRIPTION OF SYMBOLS 1 ... AC power source, 2 ... Inverter device, 3 ... Electric motor, 4 ... Diode rectifier, 5 electrolytic capacitor, 6 ... Inverter, 7 ... Abnormality detection circuit, 8 ... Relay exciter circuit, 9 ... Relay, 10 ... Inverter device, 11 ... Changeover switch, 12 ... Exclusive OR circuit.

Claims (1)

In an inverter device that converts a direct current voltage into alternating current of a desired voltage and frequency, and drives the motor at a variable speed by this alternating current,
When the abnormal operation state of the inverter device and the electric motor is detected inside the device, and this state is transmitted to the outside through the contact of the relay provided in the inverter device,
An inverter device, wherein when the abnormal operation state is detected, it is possible to select whether to change the relay from a non-excited state to an excited state or to change the relay from an excited state to a non-excited state.

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