Current Error Space Phasor Based Hystersis Controller Applied to Bi-Directional Front-End Boost-Converter for Unity Power Factor and Low THD

Abstract

Three-phase pulse width modulated (PWM) frontend converter (FEC) has now become an essential part of many power electronic systems such as uninterruptible power supplies (UPS), battery chargers, and motor drives, etc. This paper presents simulation analysis of two-level front-end boostconverter which employs current error space phasor based hysteresis controller. The proposed controller is an effort towards overcoming the limitations of conventional hysteresis controller; like, limit cycle oscillation, overshoot in current error, generation of subharmonics in the input current, and random switching of voltage vectors. The proposed controller ensures switching of only adjacent voltage vectors for position of reference voltage vector in a given sector of voltage space phasor structure of FEC. The controller is self-adaptive in nature and keeps the current error space phasor within the prescribed hexagonal boundary. Unity power factor and low total harmonic distortion (THD) in line current under various steady state conditions with bi-directional power flow capability are quite evident from the presented studies for the proposed controller based FEC. The transient performance of the proposed controller is also studied and results are presented depicting good dynamic response and effectiveness of the controller. Performance of FEC with conventional hysteresis controller is verified by hardware implementation and results are also discussed in presented work.