Sensorless motor control
AssigneeNidec Motor Corporation
InventorsMile Bozic, Darko Marcetic
Life of this patent
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Abstract
An electric motor control system includes a power inverter and control circuitry configured to control the power inverter either according to a target voltage in a voltage-based control mode or according to a target current in a current-based control mode. A controller is operable to switch operation of the control circuitry between the voltage-based control mode and the current-based control mode. The controller may be configured to operate the control circuitry in the current-based control mode at lower motor operating speeds where stator current margin is of greater significance, and to operate the control circuitry in the voltage-based control mode at higher motor operating speeds where stator voltage margin is of greater significance.
Claims22
A motor control system comprising:
- a power inverter;
- control circuitry configured to control the power inverter either according to a target voltage in a voltage-based control mode or according to a target current in a current-based control mode;
- and
- a controller for switching operation of the control circuitry between the voltage-based control mode and the current-based control mode.
A method of operating a motor control system, the method comprising:
- generating a first motor drive signal according to a target current if a reference motor speed is within a first speed range;
- generating a second motor drive signal according to a target voltage if the reference motor speed is within a second speed range;
- and
- automatically switching operation of the motor control system between generating the first motor drive signal and generating the second motor drive signal as the target speed changes between the first speed range and the second speed range.
A motor control system comprising:
- a power inverter;
- control circuitry configured to control the power inverter either according to a target voltage in a voltage-based control mode or according to a target current in a current-based control mode, the control circuitry including—
- a first regulator for receiving a differential speed signal and generating a torque producing component iqref of a reference current signal based on the differential speed signal, the differential speed signal representing a difference between a reference motor speed and an estimated motor speed,
- a second regulator for receiving a reference speed signal and generating a flux producing component idref of the reference current signal;
- a third regulator for receiving a differential iq signal and generating a torque producing component Vg of a reference voltage signal, the differential iq signal representing a difference between iqref and a measured actual torque producing component iq of a motor driving waveform;
- a fourth regulator for receiving a differential id signal and generating a flux producing component Vd of the reference voltage signal based on the differential id signal, the differential id signal representing a difference between idref and a measured actual flux producing component id of the motor driving waveform;
- and
- a controller for switching operation of the motor control system between the voltage-based control circuit and the current-based control circuit.
Dependencies are inferred from the claim text.