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Design of Hybrid Active Filter Applied in LCC HVDC Project

There are some restricted features of AC filters installed in LCC HVDC, which is no longer suited to the new power system. There's an urgent need to improve the filtering design in LCC HVDC and active filter is the most promising technology. In the research we designed a new type hybrid filter, which is simply combined by passive filter and an IGBT valve. We chose the reasonable passive filter capacity and passive filter topology. We designed two control strategies and combined used them according to the passive filter property. We designed the starting capacitor and the clamping arrester, furthermore we raised starting strategies and fault protection strategies. We calculated the filter performance in Harmonic Numerical Calculation Progress, compared it with traditional passive filter and found that an active filter can replace all passive filters. We simulated the filtering performance in EMTDC program and validated the dynamic performance. Finally, we calculated the cost and occupation of active filter scheme.