Title: New current references calculation for dual vector controlled three level active rectifiers under asymmetrical voltage operation

Authors: Hany A. Hamed; Ahmed Fathi Abdou; Ehab H.E. Bayoumi; E.E. EL-Kholy

Addresses: Department of Electrical Engineering, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt ' Department of Electrical Engineering, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt ' Department of Electrical and Electronics Engineering Technology, Abu Dhabi Men's College (ADMC), Higher Colleges of Technology, Abu Dhabi 25035, UAE ' Department of Electrical Engineering, Faculty of Engineering, Menoufiya University, Shebin El-Kom, Egypt

Abstract: This paper introduces an effective nonlinear current references calculation to enhance the performance of the dual vector control under asymmetrical grid for three level neutral point active (NPC) rectifiers. Maintaining the DC-link voltage at the desired level without oscillation is the main target for such kind of application. The asymmetrical grid voltage or voltage dip introduces negative sequence components with badly penetrates through the rectifier control loop casing DC-link to oscillate with twice grid frequency. Conventional vector control (VC) technique failed to meet the control targets under unbalance operation of grid voltage as twice grid frequency ripple pollutes the DC-link voltage. Dual vector control (DVC) concept is implemented to control the positive and negative sequence currents separately. The conventional DVC control scheme can be enhanced by incorporating line power losses for calculating the reference currents. Maintaining the DC-link voltage at the desired level without any symptom of twice grid frequency ripples is one of the control targets which can be achieved by selecting the proper constrains for calculating the current references. The proposed enhanced DVC scheme performance is verified under asymmetrical voltage dip test. The entire system is modeled and simulated with real system parameters of a 7 MW multilevel NPC-type active rectifier.

Keywords: NPC rectifiers; dual vector control; power quality; industrial grid; current reference calculation; asymmetrical voltage; voltage dip; neutral point active rectifiers; power losses.

DOI: 10.1504/IJIED.2015.076295

International Journal of Industrial Electronics and Drives, 2015 Vol.2 No.4, pp.251 - 261

Received: 30 Nov 2015
Accepted: 26 Dec 2015
Published online: 30 Apr 2016 *

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