This paper proposes a fixed frequency modulation scheme for a three-phase PWM rectifier operating at unity power factor. It provides a constant and reduced switching frequency for all the switches of the rectifier by controlling the occurrence and duration of the zero vector states indirectly. The two legs of the converter are operated in hysteresis current tracking mode and the third leg is controlled by a square pulse of user-defined frequency. The low harmonic distortion and high input power factor are added advantages of this scheme. Also, it offers simplicity, fast response and robustness. The feasibility of the proposed method is verified through extensive simulation results. ©2010 IEEE.

Mahesh Kumar Mishra

Department of Electrical Engineering

CONSTANT SWITCHING FREQUENCY

CURRENT CONTROL

Extensive simulations

Fast response

Fixed frequency

HIGH INPUT POWER

Hysteresis current

Modulation schemes

REDUCED SWITCHING

SQUARE PULSE

THREE-PHASE PWM RECTIFIERS

Unity power factor

USER-DEFINED FREQUENCY

ZERO VECTORS

Electric current control

Electric power factor

Electric power supplies to apparatus

Frequency modulation

Pulse modulation

Pulse width modulation

Switching frequency

Electric rectifiers

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

A simplified three phase PWM rectifier with fixed frequency modulation

2010 The 2nd International Conference on Computer and Automation Engineering, ICCAE 2010

A novel current control strategy called user-defined constant switching frequency method for a four-leg voltage source inverter is presented. This scheme allows the user to directly set the switching frequency of all the legs. Unlike the hysteresis current control where the switching frequency is variable and the fourth leg operates at a very high frequency, the proposed method ensures a constant and reduced switching frequency for all the switches of the inverter. This is achieved by exercising an indirect control on the occurrence and duration of the uncontrollable (zero vector) states. The three legs of the inverter are operated in hysteresis current tracking mode and the switches of the fourth leg are controlled with a square pulse of fixed user-defined frequency. The above advantages supplemented with the simplicity, fast response and robustness make this an attractive scheme. The feasibility of the proposed strategy is verified through extensive simulation and experimental studies on a distribution static compensator to compensate for unbalanced and non-linear loads in a distribution power network. © 2009 The Institution of Engineering and Technology.

IET Power Electronics

User-defined constant switching frequency current control strategy for a four-leg inverter

A novel current control strategy for a three-phase three-leg distribution static compensator is propounded in this paper. Improvement is achieved in terms of constancy and reduction in switching frequencies of all the switches of the voltage source inverter. The switching commands for one of the three inverter legs are given directly from a square pulse of a user-defined frequency. The other two legs are operated in hysteresis current tracking mode. The proposed controller unlike the other controllers allows the user to directly set the switching frequency of all the inverter switches and is devoid of any transformation, modulation, look-up table or complexity to achieve the objectives. The proposed scheme is validated through extensive simulation results in a three-phase three-wire distribution system with non-linear unbalanced load. © 2008 IEEE.

Canadian Conference on Electrical and Computer Engineering

A novel constant switching frequency strategy for a three-leg DSTATCOM

IEEE Transactions on Power Electronics

Three-dimensional space vector modulation for four-leg voltage-source converters

A novel SVM-based hysteresis current controller

IEEE Transactions on Industrial Electronics

Comparison of current control techniques for active filter applications

Journal	2010 The 2nd International Conference on Computer and Automation Engineering, ICCAE 2010
Open Access	No