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This paper presents a novel control method for stator current regulation in a voltage-source inverter-fed induction motor drive. The control method uses the space vector modulation scheme to predict the current response using a dynamic stator circuit model. The switching mode and the duration of the modulation scheme are determined by minimizing the error between the predicted and the reference current vectors. This control scheme is tested by simulation to control the currents of a 10 HP induction motor in a field oriented loop. Results showing good dynamic performance are presented. List ofsymbols : d q axis stator voltages : d-q axis stator ctments : d q axis rotor currents stator and rotor winding resistance stator leakage inductance rotor leakage inductance statorrotor mutual inductance stator self inductance; Ls = L1 ik : rotor self inductance; L, = L2 i L,,, : stator synchronous angular speed: rotor shatl angular speed : slip angular frequency ws = wewr : differential operator : number of poles : load torque : mechanical damping factor : moment of load and rotor inertia.

Abskacf -Pulse width modulation using the space vector methodology in order to determine the switching instants of the PWM waveforms has been exploited. This scheme offers the extended output voltage capability of the PWM waveform. A microprocessor-based algorithm for PWM waveform generation using the SVM strategy is presented. This algorithm was implemented using an 80286-based PC to generate PWM waveforms in real-time. The characteristics of the PWM waveform, including its harmonic spectra obtained both from the simulation program and fiom the PC-based PWM generator are presented.

Variable frequency AC drives using voltage-source inverters to supply induction motors are increasingly used in industry for high-performance speed response. Such a drive usually employs a vector-controller at the outer speed-loop which will generate the required torque-currentsignal. An inner current control loop is incorporated to ensure that an appropriate reference current is impressed on the stator circuit. However, due to nonlinearity and time varying characteristics of the machine circuit, a fixedparameter regulator cannot give good current control performance in the transient state.The paper presents a model-based predictive current regulator for a vector-con trolled induction motor drive. An extended Kalman filter is employed to estimate the back-EMF of the machine stator circuit model used by the inner current regulator loop. This also estimates the rotor resistance for slip angular velocity calculation in the outer speed-loop. The adaptive feature of this controller leads to improved speed-response performance from the induction machine.