Ky Cho

New rotor parameter estimation for a flux and speed control of induction machine considering saturation effects

A novel rotor parameter estimation algorithm for a flux and speed control of an induction machine considering the saturation effects in the indirect field-oriented controller using the current regulated PWM (pulse-width-modulated) inverter is presented. This algorithm is based on the direct decomposition into d-q current components controlling the rotor flux and torque, with the d-axis being aligned to the axis of the actual rotor flux. A flux and speed controller with the rotor parameter estimation algorithm is designed. It is shown through digital simulation that the proposed controller shows good static and dynamic responses and the correct rotor parameter and slip frequency for a proper field-orientation can be obtained at any load and speed.<<ETX>>

Deadbeat current control for a voltage-fed PWM inverter with delayed input voltage feedback

A novel current control technique for the voltage-fed PWM (pulse-width-modulated) inverter is presented. This control method consists of two main parts. One is the pulse-width modulator realized by the symmetrical uniform equilateral triangular sampling method; this part is easily implemented using a microprocessor-based system. The other is the discretized stabilizing current controller independent of EMFs, using delayed input voltage feedback, this part is designed to reduce the error currents as fast as possible by the deadbeat control strategy with parameter adaptation. Computer simulation for the proposed controller has been carried out, and the results show good static and dynamic performances.<<ETX>>