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Prepared by:
N. Ravisankar Reddy
T. Brahmananda Reddy
J. Amarnath
D. Subba Rayudu

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Abstract

This paper presents simplified space vector pulse width modulation (SVPWM) based vector controlled induction motor drive. The conventional SVPWM algorithm constructs the required voltage vector in the average sense by using active and zero voltage vectors. Moreover, complexity involved in conventional SVPWM algorithm is more. Whereas, the proposed SVPWM algorithm calculates the switching times using the concept of imaginary switching times. The proposed algorithm does not need the calculation of sector and angle information. To validate the proposed algorithm, simulation studies have been carried out on vector controlled induction motor drive and the results are presented in this paper.


INTRODUCTION
The development of high speed power switching devices has brought high frequency switching operations to power electronic equipments and has improved the dynamic performance of inverter fed ac drives. Many schemes have been proposed for the speed control [1] of induction motor drives, among which the vector control is most effective method.


However, the current controlled vector control induction motor drive uses hysteresis controllers, which causes variable switching frequency of the inverter. This problem can be overcome by using SVPWM algorithm . The conventional SVPWM algorithm uses two zero voltage vectors and two active voltage vectors in each sector to obtain the required reference voltage vector. Hence, the complexity involved in conventional SVPWM is more. To reduce the complexity involved in conventional SVPWM algorithm, a simplified approach is developed in by using the concept of offset time. Moreover, imaginary switching times based SVPWM algorithm is used in
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This paper presents an imaginary switching times based SVPWM algorithm for vector controlled induction motor drive. In the proposed algorithm, the zero vector time is distributed by using a factor k0.

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for more details, please visit
http://academypublisherijrte/vol02/no05/ijrte0205288291.pdf

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