Harmonics and Reactive Power Compensation of the LCC in a Parallel LCC-VSCs Configuration for a Hybrid AC/DC Network

Abstract

This article presents a harmonics compensation control scheme for parallel LCC-VSCs interlinking converters (ICs) in a hybrid ac/dc network. The proposed technique addresses the harmonic issue of the LCC unit with higher performance and lower cost by taking advantage of parallel LCC-VSCs configuration. It is important to note that system stability and power quality are fundamental aspects of such a system. The mitigation method is designed for medium/high voltage converters with a low switching frequency, a common environment for the LCC-based units. The harmonics mitigation technique is designed to avoid any interference with the normal operation of the parallel LCC and VSCs in a hybrid ac/dc network. Furthermore, the reactive power consumption issue of the LCCs is also addressed. The proposed system is modelled in detail, and stability studies are conducted. Also, the controlling parameters design procedure is explained thoroughly, assuming proper stability is achieved. The peak current capacity of the VSCs for the anticipated harmonic orders and reactive power compensation is calculated. Eventually, the performance of the proposed control strategy under different operation conditions is investigated. Case study results with MATLAB Simulink and an experimental platform are provided to verify the effectiveness of the proposed control strategy.