Winding fault detection using inverter harmonics
AssigneeTexas Instruments Incorporated
InventorsRajan Lakshmi Narasimha, David Patrick Magee
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Abstract
A controller for driving a motor includes a multiphase driver, an analog-to-digital converter (ADC), impedance estimation circuitry, and fault detection circuitry. The multiphase driver is configured to generate drive signals for energizing each motor phase winding. The ADC is configured to digitize voltage and current from each motor phase winding. The impedance estimation circuitry is configured to determine a phasor value for the digitized voltages and for the digitized currents at a predetermined harmonic frequency, and to determine a sequence impedance value based on the phasor values. The fault detection circuitry is configured to identify a fault in the windings of the motor based on the sequence impedance value.
Claims16
A controller, comprising:
- an analog-to-digital converter (ADC) having ADC inputs and ADC outputs, the ADC inputs adapted to be coupled to phase windings of a motor, the ADC configured to provide digital values at the ADC outputs responsive to voltages and currents from the phase windings;
- and
- fault detection circuitry having circuitry inputs and impedance estimation circuitry, the circuitry inputs coupled to the ADC outputs, and the fault detection circuitry configured to:
- using the impedance estimation circuitry, determine phasor values at a harmonic frequency responsive to the digital values, and determine a sequence impedance value based on the phasor values;
- and
- identify a fault in the phase windings based on the sequence impedance value.
A system, comprising:
- low-pass filters having filter inputs and filter outputs, the filter inputs adapted to be coupled to windings of a motor, the windings driven by voltage and current signals having frequency components, and the low-pass filters configured to:
- modify the voltage and current signals by attenuating ones of the frequency components above a cut-off frequency;
- and provide the modified voltage and current signals at the filter outputs;
- an analog to digital converter (ADC) having ADC inputs and ADC outputs, the ADC inputs coupled to the filter outputs, and the ADC configured to provide digital values at the ADC outputs responsive to the modified voltage and current signals;
- and
- a processor having processor inputs coupled to the ADC outputs, the processor configured to:
- responsive to the digital values, determine phasor values at an inverter harmonic frequency of the voltage and current signals;
- determine a sequence impedance value based on the phasor values;
- and identify a fault in the windings based on the sequence impedance value.
Dependencies are inferred from the claim text.