摘要：In DC transmission systems,AC filters can effectively reduce the hazards of harmonics, and compensate the reactive power requirements of the converters, thus the type and parameter choice of the filters is important. Therefore, based on the system conditions of Jinping-Sunan ± 800 kV UHV DC (ultra-high voltage direct current) transmission project and the main harmonics,three types of filters were designed. The parameters of filter components were determined according to the reactive power compensation. By calculating the filter performance and rating, the results show that the parallel tuning with greatly over-currents appears in the low-voltage arm of BP11/13 filter. In order to avoid this kind of danger, a filter named BP11/BP13 is designed. Studies show that this type of filter can fully meet the filter performance requirements and avoid the over-current. It is concluded that the filter BP11/BP13 can reduce the rating of the components and enhance the stability in the long-term operation.