Control Strategy for High-voltage Chained SVG Pre-charged De-side Capacitor

With the promotion of the “double carbon” goal, the most clean energy is gradually replacing traditional energy, but the instability of new energy generation, long-distance transmission of electricity, grid aging and other problems will affect the quality of electricity. Reactive power compensation can effectively improve these problems. High-voltage chain SVG is one of the effective reactive power compensation programs in high-voltage field at present. It has the advantages of low harmonic content, fast response speed, continuous adjustment, and low loss. However, the high-voltage chained SVG system also brings a series of instability problems. This paper analyzes the high-voltage chain SVG pre-charging DC side capacitor voltage control, through the DC side capacitor voltage feedback and the equalization coefficient and then change the modulating wave sent, realize the charging and discharging of the DC side capacitor of the unit itself to achieve the DC side capacitor voltage equalization, to ensure the stable operation of the high-voltage chain SVG system