Delta Electronics, Inc.

National Taiwan University

Tian-Hua Liu

Kuan-Sheng Wang

Ming-Yen Wei

A method is for controlling a synchronous motor includes a stator, a rotor with a position and a speed, a direct axis and a quadrant axis. The method includes: providing a position control, a speed control and a current control programs; executing either the position control program or the speed control program to produce a quadrant axis current; executing the current control program; detecting the synchronous motor to obtain a first, a second and a third phase currents, and digitizing the three phase currents; using the three phase currents and the quadrant axis current to calculate a direct axis current; converting the direct axis current and quadrant axis current to a direct axis voltage command and quadrant axis voltage command; executing a pulse width modulation for the direct axis and the quadrant axis voltage commands, to get a trigger signal for controlling the synchronous motor.

Controlling method of synchronous motor

Disclosed is a synchronous forward converter having a reverse current suppressor connected to the gate of a freewheel switch. The reverse current suppressor is configured to receive a control input signal generated by an internal circuitry of a power supply system where the forward converter locates, such as an enable signal, to detect the power-off of the forward converter, and in response thereto turn off the freewheel switch during the interruption of the input power of the forward converter. Alternatively, the reverse current suppressor is configured to detect the decay of the input voltage across the input bulk capacitor located on the primary side of a transformer of the forward converter, and turn off the freewheel switch when the voltage across the secondary side of the transformer is decayed to be smaller than the output voltage of the forward converter.

Growing community of inventors

Taipei, Taiwan

Tian-Hua Liu