Apparatus, system and method of fault diagnosis for permanent magnet motor
AssigneeKorea Electronics Technology Institute
InventorsJoonsung Park, Jinhong Kim, Byongjo Hyon, Junhyuk Choi
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Abstract
Disclosed are an apparatus, system and method for detecting, based on a mathematical model, a fault of a permanent magnet motor driven by a square wave. A fault diagnosis apparatus for the permanent magnet motor includes a current voltage measurement unit, a phase shift time calculation unit, and a control unit.
Claims9
An apparatus for diagnosing a short-circuit in a motor that comprises a rotor of permanent magnet and stators of three-phases, the apparatus comprising:
- a current voltage measurement unit connected to an inverter configured to drive the motor, the current voltage measurement unit configured to measure a current input and a voltage input to the motor received from the inverter;
- and
- at least one controller configured to, for each phase of the motor;
- compute a phase shift time of the motor indicating a time between a start and an end of a phase shift in the motor,
- compute an inductance using the phase shift time, the current input and the voltage input,
- compute an error value between the computed inductance and a predetermined reference inductance, and
- when the error value is out of a predetermined range of normal operation, determine that a stator of the motor in a corresponding phase is short-circuited such that a short-circuited stator is detected while the motor is in operation,
- wherein the system further comprises an output unit configured to generate a visual or audible alarm when a short-circuited stators detected.
A motor diagnosis system comprising:
- a motor comprising a rotor of permanent magnet and stators of three-phases;
- an inverter configured to drive the motor;
- a current voltage measurement unit connected to the inverter and configured to measure a current input and a voltage input to the motor received from the inverter;
- and
- at least one control unit configured to, for each phase of the motor:
- compute a phase shift time of the motor indicating a time between a start and an end of a phase shift in the motor,
- compute an inductance using the phase shift time, the current input and the voltage input,
- compute an error value between the computed inductance and a predetermined reference inductance, and
- when the error value is out of a predetermined range of normal operation, determine that a stator of the motor in a corresponding phase is short-circuited such that a short-circuited stator is detected while the motor is in operation.
A method of diagnosing a short-circuit in a motor that has a rotor of permanent magnet and stators of three-phases, the method comprising:
- measuring, using a current voltage measurement unit connected to an inverter for driving the motor, a current input and a voltage input to the motor by the inverter;
- computing, by a controller, a phase shift time of the motor indicating a time between a start and an end of a phase shift in the motor;
- computing, by the controller, an inductance using the phase shift time, the current input and the voltage input;
- computing, by the controller, an error value between the computed inductance and a predetermined reference inductance;
- and
- determining, by the controller, that a stator of the motor is short-circuited when the error value is out of a predetermined range of normal operation such that a short-circuited stator is detected while the motor is in operation.
Dependencies are inferred from the claim text.