Method and apparatus for measuring fault diagnostics on insulated gate bipolar transistor converter circuits
First Claim
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1. A fault determination method for assessing a condition of a power converter circuit, the power converter circuit comprising a number N of pairs of insulated gate bipolar transistors (“
- IGBTs”
), each pair of IGBTs comprising an upper IGBT coupled to a first polarity of a DC power source and a lower IGBT coupled to a second polarity of the DC power source, the method comprising;
selectively placing in a conducting state at least one of the upper IGBTs during a first time and selectively placing in a conducting state at least one of the lower IGBTs during the first time; and
determining a set of IGBT operational states in response to at least one of a magnitude and a direction of a current through a load between the at least one upper and the at least one lower IGBT placed in the conducting state during the first time.
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Abstract
A method for diagnosing faults using a load. In the method IGBTs are controlled such that certain currents are expected. If the currents are not as expected, a fault may be diagnosed.
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Citations
38 Claims
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1. A fault determination method for assessing a condition of a power converter circuit, the power converter circuit comprising a number N of pairs of insulated gate bipolar transistors (“
- IGBTs”
), each pair of IGBTs comprising an upper IGBT coupled to a first polarity of a DC power source and a lower IGBT coupled to a second polarity of the DC power source, the method comprising;
selectively placing in a conducting state at least one of the upper IGBTs during a first time and selectively placing in a conducting state at least one of the lower IGBTs during the first time; and
determining a set of IGBT operational states in response to at least one of a magnitude and a direction of a current through a load between the at least one upper and the at least one lower IGBT placed in the conducting state during the first time. - View Dependent Claims (2, 3, 4, 5, 6, 7)
- IGBTs”
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8. A fault determination system for assessing a condition of a power converter circuit, the power converter circuit comprising a number N of pairs of insulated gate bipolar transistors (“
- IGBTs”
), each pair of IGBTs comprising an upper IGBT coupled to a first polarity of a DC power source and a lower IGBT coupled to a second polarity of the DC power source, the method comprising;
means for selectively placing in a conducting state at least one of the upper IGBTs during a first time and selectively placing in a conducting state at least one of the lower IGBTs during the first time; and
means for determining a set of IGBT operational states in response to at least one of a magnitude and a direction of a current through a load between the at least one upper and the at least one lower IGBT placed in the conducting state during the first time.
- IGBTs”
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9. A fault determination method for assessing a condition of a power converter circuit, the power converter circuit comprising a number N of pairs of insulated gate bipolar transistors (“
- IGBTs”
), each pair of IGBTs comprising an upper IGBT coupled to a first polarity of a DC power source and a lower IGBT coupled to a second polarity of the DC power source, the method comprising;
during a first time interval, controlling at least one of the upper IGBTs and at least one of the lower IGBTs such that during at least one first-time-interval expected current will flow through a part of a resistive network if the at least one upper IGBT and the at least one lower IGBT are normal, sensing at least one of a magnitude and a direction of at least one first-time-interval current through the part of the resistive network, comparing the at least one first-time-interval sensed current with the at least one first-time-interval expected current, and determining a state of at least one IGBT in response to the comparing. - View Dependent Claims (10, 11, 12, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26)
- IGBTs”
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13. The method 12, further comprising:
during a second time interval, turning ON the first lower IGBT, the second lower IGBT, and the third upper IGBT such that if the first lower IGBT, the second lower IGBT, and the third upper IGBT are normal, a first expected current will flow through a first resistor in series with the first lower IGBT and a node, a second expected current will flow through a second resistor in series with the second lower IGBT and the node, and a third current will flow through a third resistor in series with the node and the third upper IGBT, sensing at least one of a magnitude and a direction of a current in at least one of the first and the second resistors, comparing the at least one of the magnitude and the direction of the current in at least one of the first and the second resistors with a predetermined current value, and concluding either that the first lower IGBT, second lower IGBT, and third upper IGBT are normal or that the first lower IGBT is potentially shorted in response to the comparison determining that currents in the first and the second resistors are balanced and within tolerance of a negative of a predetermined current value. - View Dependent Claims (14, 15, 16)
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27. A fault determination system for assessing a condition of a power converter circuit, the power converter circuit comprising a number N of pairs of insulated gate bipolar transistors (“
- IGBTs”
), each pair of IGBTs comprising an upper IGBT coupled to a first polarity of a DC power source and a lower IGBT coupled to a second polarity of the DC power source, the method comprising;
means for, during a first time interval, controlling at least one upper IGBT and at least one lower IGBT such that at least one first-time-interval expected current will flow through a part of a resistive network if the at least one upper IGBT and the at least one lower IGBT are normal, sensing at least one of a magnitude and a direction of at least one first-time-interval current through the part of the resistive network, and comparing the at least one first-time-interval sensed current with the at least one first-time-interval expected current, and concluding a state of an IGBT in response to the comparing.
- IGBTs”
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28. A fault determination method for assessing a condition of a power converter circuit, the power converter circuit comprising a number N of pairs of insulated gate bipolar transistors (“
- IGBTs”
), each pair of IGBTs comprising an upper IGBT coupled to a first polarity of a DC power source and a lower IGBT coupled to a second polarity of the DC power source, the method comprising;
during a first time interval and in response to a motor indicating a fault, sequentially controlling at least one of the upper IGBTs and at least one of the lower IGBTs such that at least during one first-time-interval expected current will flow through a part of motor windings if the at least one upper IGBT and the at least one lower IGBT are normal, and sensing at least one of a magnitude and a direction of at least one first-time-interval current through the part of the motor windings, and concluding a state of at least one IGBT in response to the sensing. - View Dependent Claims (29, 30, 31, 32, 33, 34, 35, 36, 37)
- IGBTs”
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38. A fault determination system for assessing a condition of a power converter circuit, the power converter circuit comprising a number N of pairs of insulated gate bipolar transistors (“
- IGBTs”
), each pair of IGBTs comprising an upper IGBT coupled to a first polarity of a DC power source and a lower IGBT coupled to a second polarity of the DC power source, the method comprising;
means for, during a first time interval and in response to a motor indicating a fault, sequentially controlling at least one upper IGBT and at least one lower IGBT such that at least one first-time-interval expected current will flow through a part of motor windings if the at least one upper IGBT and the at least one lower IGBT are normal, and sensing at least one of a magnitude and a direction of at least one first-time-interval current through the part of the motor windings, and comparing the at least one first-time-interval sensed current with the at least one first-time-interval expected current, and concluding a state of at least one IGBT in response to the comparison.
- IGBTs”
Specification