Research On Alternative Filter Operation In Converter Station

This paper focuses on APF technique, discuss the feasibility of the application of APF under the ac side of converter in HVDC. Initially, the topology of APF is researched, based on the cost and compensation characteristic, the hybrid APF technique is studied and treated importantly, then concentrating on DRHAPF which can be designed with lower capacity, its operation theory, compensation characteristic,and control strategy are studied deeply, respectively.Firstly, the advantages and features of DRHAPF on topology are analyzed. some problems which should be paid attention to are proposed. Then, the method of choosing parameter of DRHAPF in HVDC converter is analyzed. Meanwhile, due to the advantages of structure, some technique questions of applying DRHAPF in FACTS and middle voltage class system are analyzed.This paper analyzes and studies the technique of harmonic current detection and control strategy deeply. Building the harmonic current detection circuit of DRHAPF, then comparing the features among the traditional PI, PR, repeat control strategy and 6k±1 fast repeat control strategy, confirming that the fast repeat control is adopted in DRHAPF. The fast repeat control not only can realizes the non-error control, but also can improve the convergence rate of error.Combining with the practical operation circumstances. proposing 12k±1 fast repeat control which can fit the operation of DRHAPF under converter, and the stability and dynamic characteristic are analyzed. Finally the control parameter is optimized, simulating the operation of DRHAPF in converter via Simulink simulation platform. the consequence verifies DRHAPF can be applied in the converter and operate well. The achievement of this paper is not limited in high voltage class, it not only can expand the fields such as FACTS and low voltage class system, but also own the value of reference on the APF application in the future.