Three-phase PWM boost rectifier operating under different input voltage conditions

Abstract EN

In this paper, a proposed control strategy is presented to improve the performance of the pulse width modulation (PWM) boost rectifier when operating under different supply voltage conditions (balanced, unbalanced, and distorted three-phase supply voltages).

The proposed control strategy is divided into two parts, the first part is voltage controller and the second part is current controller.

In the voltage controller, Proportional-Integral (PI) controller is used to regulate the output dc voltage at any desired level and Low Pass Filter (LPF) to reduce the even order harmonics which appear in the regulated output dc voltage due to unbalanced input supply voltages.

LPF also reduces the even order harmonics which appear in the reflected dc current (IMAX), this leads to reduce the odd order harmonics which appear in the input currents.

While in the current controller, Enhanced Phase Locked Loop (EPLL) technique is used to obtain sinusoidal and balanced three phases, to construct the reference currents, which are in phase with the fundamental supply voltages Therefore, the supply-side power factor is kept close to unity.

A proportional controller is used to give excellent tracking between the line and the reference currents.

The complete system with the proposed control strategy is simulated using Matlab/Simulink (Version 2012).

The results for the complete system using proposed voltage controller are obtained and compared to the results of the system with the conventional voltage controller (proportional-integral (PI) is used without LPF).

THDs for three-phase input line currents are better when using the proposed voltage controller (less than 5%).