GZ HVDC DC filter C1 unbalance protection analysis and its improvement

Started from wiring form of High-voltage capacitors and the internal structure of the capacitor. Analyzed three principles of DC filters C1 unbalance protection. For the case HVDC project repeatedly malfunction in DC filter C1 unbalance protection, accorded fault recorder, put forward corresponding measures for improvement. RTDS simulation system was used to carry out fault recorder playback and fault simulation. The results show that the improved protection logic can effectively avoid malfunctions by the interference of measuring.