Research on Hybrid Active Power Filter and Its Control and Protection System for LCC-HVDC

Filters are key equipment in LCC-HVDC projects. It filters out characteristic harmonics generated by the converter and prevents the effect of harmonics generated by converters on the AC power grid. Currently, most DC transmission projects use passive filters. The first use of hybrid active power filters in the Fujian Guangdong DC interconnection projectºThis paper introduces the application framework, theory, control and protection system design of hybrid active power filters in LCC-HVDC projects.

I. Introduction

Fujian Guangdong DC Interconnection Project as a Key Construction Project in the 14th Five Year Plan for National Electric Power Development [1]. It Adopts LCC-HVDC back-to-back wiring method, the rated DC voltage is ± 100kV and the transmission capacity is 2000MW. It has bidirectional power transmission capability_º It builds two 500kV circuits on the Fujian side and connects with 500kV Donglin substation. Meanwhile it builds two 500kV circuits on the Guangdong side and connects with 500kV Jiaying substation. In the LCC-HVDC, the converter will produce a large number of characteristic harmonics and inject a large amount of harmonics into the AC power grid system [2]–[4], To ensure that the DC system limits the voltage distortion rate and current waveform distortion coefficient of the AC bus in the converter station within the specified allowable range under various operating conditions, a certain number of filters need to be configured at the converter station to achieve the filtering goal while also providing reactive power support for the converter station [5]–[7].