András Kelemen

Vector Control of Induction Motor Drives with Model Based Predictive Current Controller

The paper presents the design of a model-based predictive current controller (MPC) for induction motor (IM) drive application. Using an input-output linearized model, a systematic design of the long-range predictive current controllers is introduced. The resulting explicit MPC controller achieves the same performance like classical MPC, but with less computational effort, offering the possibility for real-time implementation. The results are compared to the state of the art current controllers, showing the performance of the new controller.

Constrained optimal direct power control of voltage-source PWM rectifiers

The paper presents an online approach to the model-predictive control of the boost type PWM rectifier. The optimization is made on a horizon of one switching period for a cost function based on the instantaneous real and imaginary power errors. The control vectors are synthesized by space-vector modulation and are confined to the hexagonal area defined by the possible switching states of the three-phase bridge. The optimal control algorithm is developed in presence of the grid current limitation, introduced as a practical constraint.

Mathematical model and digital simulation of a current-Fed induction motor system

Abstract The mathematical model and the simulation results of the current regulated induction motor drive are presented. The motor is fed by a dc link, current-source frequency converter, realized with a six-pulse rectifier and an autosequential commutation inverter. The topology of the inverter circuit is changing all the time. The motor works in transient operation conditions due to the current pulses supply. Therefore it was necessary for study to use the space-phasor theory and general equations of the induction motor. Using the same space-phasor method for the inverter, a unitary treatment of the whole system is provided. Consequently, the unitary model of the system permits the study of the reaction effects between the converter and motor. So, the simulation takes into account the dynamic characteristics and nonlinearities of the motor, besides the transient processes in the inverter and dc link. The simulation, which was developed furnishes some data about the converter-motor system design and gives the idea of the microprocessor technique application for the field-oriented control concept.

Constrained optimal control of three-phase AC-DC boost converters

The paper deals with constrained optimal control of three-phase voltage source converters (VSC), based on a mathematical model developed in the synchronous reference frame. The performance of the current controller determines the overall performance of the system. As a consequence, a well defined control strategy is needed, which must handle the constraints. Taking into account the limits of the d-q currents, an explicit model predictive controller was designed, moving the computation effort off-line. The resulting controllers online computation needs are reduced. Simulation and experimental results are presented.