Patent ID: 8395336
Filing Date: 2013-03-12
Classification: H02P

Abstract:
1. A control system of a three phase induction motor driver, comprising: a driver control module coupled with a field weakening control module, a power loop module, a current sensing module and an AC motor module, the driver control module using an encoder of the AC motor module to obtain position information of the AC motor module; the field weakening control module comprising a limiter, a field weakening current controller, a subtractor, a low pass filter, an adder and a maximum q-axis current command calculator; an AC power source coupled with the power loop module to act as an input power source; the power loop module further coupled with the current sensing module, and the AC motor module; the current sensing module comprising three current sensors, the current sensing module being further coupled with the AC motor module for feedback of a three phase current of the AC motor; the AC motor module comprising a three phase AC induction motor and the encoder; wherein the system uses a switching period of an inverter PWM control for the AC motor and an inverter control thereof to analyze and obtain a difference value of a sum of effective switching times, and the field weakening control module generates an adaptive magnetizing current command in real time to achieve a maximum utilization of a DC link voltage so as to let the AC motor module achieve maximum output torque under different field weakening regions of different speeds when a rated speed is exceeded.