Vector PWM Research Articles

Peculiarities of electromagnetic processes in a three-phase, three-level rectifier

The electromagnetic processes of a three-phase, three-level rectifier with a vector PWM are considered. The results are presented for the process analysis in the circuit at the point where the input current passes through zero. The best sinusoidal shape of the input current is shown to take place at the unit coefficient of the input current shift. The possibility of balancing the voltage at the output rectifier capacitors is also shown. Results are obtained from modeling in the Matlab Simulink environment.

Space Vector PWM as a Modified Form of Sine-Triangle PWM for Simple Analog or Digital Implementation

Conventional space vector PWM (CSVPWM) has the advantages of yielding up to 15% higher fundamental line-side voltage for a given DC bus voltage and also less harmonic distortion in line currents over sine-triangle PWM (SPWM). However, no analog implementation of CSVPWM is possible in its traditional form. Digital implementation of CSVPWM is also more complex than that of SPWM. This paper analyses the two techniques. The analysis establishes that CSVPWM can be viewed as a modified form of SPWM, and leads to a simple method to implement CSVPWM. The simplified method does not require evaluation of trigonometric functions, look-up tables, sector identification etc. An existing line of products employing SPWM can easily be upgraded to exploit the benefits of CSVPWM. The work serves to unify the understanding of triangle-comparison based PWM and space vector based PWM techniques. The work is of tutorial value to students and engineers.

Precise vector control of CSI fed induction motor drive

A new, precise vector control algorithm for the current source inverter (CSI) fed induction motor drive is presented. The goal is to obtain the same performance that exists in PWM vector controlled drives. For that purpose, the problems of the existing vector controlled CSI fed induction motor drives are analyzed with the help of an adequate simulation model. For verification of the suggested algorithm, the prototype of the drive is developed. The frequency converter is a standard thyristor CSI and the complete control is implemented by software in the microcontroller. By eliminating the phase angle error and correcting the error of current magnitude the algorithm proposed in this paper can improve the dynamic performance of the CSI fed induction motor drive. The simulation and experimental results confirm the advantage of the proposed algorithm. Copyright © 2005 John Wiley & Sons, Ltd.

A permanent magnet hysteresis hybrid synchronous motor for electric vehicles

This paper presents the design, analysis and PWM vector control of a hybrid permanent magnet hysteresis synchronous (PMHS) motor with a view to improve the performances of motors for electric vehicle applications. This hybrid design combines the advantageous performance features of both conventional hysteresis motors and permanent magnet motors. Electrical equivalent circuits of the PMHS motor are developed for both the synchronous and asynchronous modes of operation. PWM vector control simulation results for the motor drives are given. Finally, a laboratory prototype hybrid hysteresis permanent magnet motor was built. Test results validate the superior performances of the new motor.