Electric power conversion device, compressor motor with the device, and air conditioner with the motor
First Claim
1. An electric power conversion device comprising:
- an electric power conversion circuit including switching elements for converting a DC electric power to an AC electric power,a load connected to an output side of the electric power conversion circuit,a DC current detecting means for detecting a current flowing through a DC side in the electric power conversion circuit, anda control circuit for controlling the switching elements in the electric power conversion circuit,characterized by further comprising a wire breaking detecting means that judges a wire breaking in the load or an abnormality of any of the switching elements in the electric power conversion circuit by making use of a value of DC current detected by the DC current detecting means during a time when a first current flows in a voltage maximum phase, which has the longest turn-on term in a duty cycle for upper arm switching elements of the electric power conversion circuit, which first current flows through the DC side in the electric power conversion circuit, or during a time when a second current flows in a voltage minimum phase, which has the shortest turn-on term in the duty cycle for the upper arm switching elements, which second current flows through the DC side in the electric power conversion circuit.
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Accused Products
Abstract
The device is provided with an electric power conversion circuit including switching elements for converting a DC electric power to an AC electric power, a load connected to an output side of the electric power conversion circuit, means for detecting a current flowing through a DC side in the electric power conversion circuit, a voltage command value preparing means for controlling the operation of the switching elements in the electric power conversion circuit and a wire breaking detecting means. The wire breaking detection means judges a wire breaking in the load or an abnormality of any of the switching elements in the electric power conversion circuit by making use of a DC current detection value in a period when a current of maximum voltage phase or of voltage minimum phase of the electric power conversion circuit is flowing in a DC current.
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Citations
13 Claims
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1. An electric power conversion device comprising:
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an electric power conversion circuit including switching elements for converting a DC electric power to an AC electric power, a load connected to an output side of the electric power conversion circuit, a DC current detecting means for detecting a current flowing through a DC side in the electric power conversion circuit, and a control circuit for controlling the switching elements in the electric power conversion circuit, characterized by further comprising a wire breaking detecting means that judges a wire breaking in the load or an abnormality of any of the switching elements in the electric power conversion circuit by making use of a value of DC current detected by the DC current detecting means during a time when a first current flows in a voltage maximum phase, which has the longest turn-on term in a duty cycle for upper arm switching elements of the electric power conversion circuit, which first current flows through the DC side in the electric power conversion circuit, or during a time when a second current flows in a voltage minimum phase, which has the shortest turn-on term in the duty cycle for the upper arm switching elements, which second current flows through the DC side in the electric power conversion circuit. - View Dependent Claims (2, 3, 4, 5)
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6. An electric power conversion device comprising:
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an electric power conversion circuit including switching elements for converting a DC electric power to an AC electric power, a load connected to an output side of the electric power conversion circuit, a DC current detecting means for detecting a current flowing through a DC side in the electric power conversion circuit, and a control circuit for controlling the switching elements in the electric power conversion circuit, characterized in that the control circuit includes a voltage command value preparing means for outputting a voltage command value, the voltage command value preparing means alters the voltage command value in an integral multiple cycle of ½
of a cycle for controlling the switching elements in the electric power conversion circuit, andcharacterized by further comprising a wire breaking detecting means that judges a wire breaking in the load or an abnormality of any of the switching elements in the electric power conversion circuit by making use of a value of DC current detected by the DC current detecting means, at the time when the voltage command value preparing means alters the voltage command value, in a period when a current of voltage maximum phase or of voltage minimum phase of the electric power conversion circuit is flowing in a DC current. - View Dependent Claims (7, 8, 9, 10, 11)
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12. A compressor motor using an electric power conversion device, wherein the electric power conversion device comprising:
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an electric power conversion circuit including switching elements for converting a DC electric power to an AC electric power, a load connected to an output side of the electric power conversion circuit, a DC current detecting means for detecting a current flowing through a DC side in the electric power conversion circuit, a control circuit for controlling the switching elements in the electric power conversion circuit, and a wire breaking detecting means that judges a wire breaking in the load or an abnormality of any of the switching elements in the electric power conversion circuit by making use of a value of DC current detected by the DC current detecting means during a first time when a first current flows in a voltage maximum phase, which has the longest turn-on term in a duty cycle for upper arm switching elements of the electric power conversion circuit, which first current flows through the DC side in the electric power conversion circuit, or during a time when a second current flows in a voltage minimum phase, which has the shortest turn-on in the duty cycle for upper arm switching elements, which second current flows through the DC side in the electric power conversion circuit. - View Dependent Claims (13)
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Specification