Control device of a synchronous motor

A method of controlling a synchronous machine, comprising:

• configuring an inverter to provide an output current to a synchronous machine;
• providing a current tracking pulse width modulation method controller and a voltage type pulse width modulation method controller, wherein:
• the current tracking pulse width modulation method controller is configured to control the output current of the inverter at a time when the inverter transitions from not driving the synchronous machine with the output current to driving the synchronous machine;
• and
• the voltage type pulse width modulation method controller is configured to control the output current of the inverter a time after the inverter transitions to driving the synchronous machine;
• choosing only a non-zero vector for generating a gate command;
• generating the gate command based on the current tracking pulse width modulation method by using the chosen non-zero vector;
• estimating a phase angle and an angular velocity of a rotor of the synchronous machine based, at least in part, on an inductance value, an induction voltage value, the gate command, and the output current to be supplied to the synchronous machine;
• and
• controlling of the output current based, at least in part, on the phase angle and the angular velocity.

A control device for a synchronous motor comprising:

• an inverter which generates a current to drive the synchronous motor;
• and
• a control unit,
• wherein the control unit includes:
• a current detector which detects a current between the inverter and the synchronous motor;
• a phase estimation section which estimates a rotation phase based on a detected current by the current detector;
• and
• a command generator which generates, based on the detected current and an estimated rotation phase, a gate command to the inverter so as to drive the synchronous motor,
• wherein the command generator selects only a non-zero vector and generates the gate command for starting the inverter by performing a current-tracking-type PWM during a free-run state, and
• wherein the command generator generates the gate command by performing a voltage-modulating-type PWM after starting of the inverter from the free-run state is completed.