A Novel Clustered Voltage Balance for Cascaded H-Bridge STATCOM with CCS-MPC

In addition to the poor transient response, the traditional clustered voltage equalization scheme of the cascaded H-bridge STATCOM also causes some problems, such as harmonic pollution to the power grid. To solve the above problems, this paper improves the traditional scheme: Combining with the continuous control state set model predictive control (CCS-MPC) algorithm, a new clustered voltage equalization scheme is proposed. The proposed scheme can improve the dynamic performance of the cascaded H-bridge STATCOM clustered voltage equalization by dynamically adjusting the injected zero-sequence voltage, and suppress the DC side capacitor voltage fluctuation to a certain extent. Furthermore, the scheme of zero-sequence voltage injection prevents the system from overmodulation under inductive or capacitive conditions, using residual voltage modulation of the system. Finally, a MATLAB/Simulink simulation model is built to verify the effectiveness and feasibility of the proposed control strategy.