Gate Trigger Unit for Voltage Reinjection Multilevel-VSC with Cascaded H-Bridges

A gate trigger unit (GTU) design is proposed based on cascaded H-bridge voltage reinjection multilevel voltage source configuration (MLVR-HB-VSC) for use in large power and voltage ratings. Specific Implementation of gate-level trigger was analysis to guarantee dynamic voltage balance of compactors in the circuit. Grid synchronization, judgment of edge state changes, capacitor voltage balance and some crucial technical issues what should be pay attention to are analyzed in detail. To verify the steady state and dynamic behavior of gate-level trigger unit, extensive simulation is carried out with reference to the STATCOM application.