Auto self test of AC motor system
First Claim
1. An auto self test method, for testing a power converter system having at least one motor means, while the motor means is stopped, the motor means being operatively connected to the power converter system, the power converter having at least one leg, each leg having a first and second series connected control turn-off device wherein each device has a control electrode, the method comprising the steps of:
- selectively generating control signals for coupling to the control electrode of each device to individually render each device conductive such that transient current flows through the motor means and through the control turn-off device rendered conductive;
measuring the transient current;
comparing the transient current to a reference current; and
generating an indication of defect in response to a substantial difference between the transient current and the reference current, and a power converter.
1 Assignment
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Accused Products
Abstract
Apparatus and method for auto-self testing of a power converter and motor system wherein the power converter has three parallel legs, each including two series connected gate-turn-off thyristors (GTO) connected between a pair of DC power source buses. A microprocessor controls the test sequence in which each GTO is individually turned on in a predetermined order so as to create a transient snubber current through the motor and through each GTO when it is turned on. The snubber current and a voltage in each leg is measured and compared to a respective reference to detect wiring errors, and defects in the motor, the GTOs, and other system components. Error messages are generated in response to detection of abnormalities or defects.
33 Citations
20 Claims
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1. An auto self test method, for testing a power converter system having at least one motor means, while the motor means is stopped, the motor means being operatively connected to the power converter system, the power converter having at least one leg, each leg having a first and second series connected control turn-off device wherein each device has a control electrode, the method comprising the steps of:
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selectively generating control signals for coupling to the control electrode of each device to individually render each device conductive such that transient current flows through the motor means and through the control turn-off device rendered conductive; measuring the transient current; comparing the transient current to a reference current; and generating an indication of defect in response to a substantial difference between the transient current and the reference current, and a power converter. - View Dependent Claims (2, 3, 4, 5)
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6. An auto self testing system for a power converter system, the power converter system having a power converter and motor means, operatively connected thereto, without the risk of turning on the motor means during testing, wherein the power converter includes at least one leg, each leg having a first and second series connected control turn-off device each including a control electrode, the auto self testing system comprising:
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means for selectively generating control signals for coupling to the control electrode of each control turn-off device so as to individually render each control turn-off device conductive such that transient current flows through the motor means and the device rendered conductive; means for measuring the transient current operatively connected to the power converter; and means for comparing the transient current to a reference current and for generating an indication of detection of a defect and response to a substantial difference between the transient current and the reference current. - View Dependent Claims (7, 8, 9, 10, 11, 12, 13, 14, 15)
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16. A system for auto self testing a power converter, including at least one motor means, operatively connected to the power converter, without the risk of rotating the motor means during the test, the power converter including at least one leg having a first and second series connected control turn-off device each including a control electrode, the system comprising:
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processor means, for controlling generation of control signals and for selectively generating the control signals for coupling to the control electrode of each control turn-off device so as to individually render each control turn-off device conductive such that transient current flows through the motor means and the device rendered conductive; means for measuring the transient current operatively connected to the power converter; and means for comparing the transient current to a reference current and for generating an indication of detection of a defect and response to a substantial difference between the transient current and the reference current. - View Dependent Claims (17, 18, 19, 20)
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Specification