非对称级联H桥逆变器通用倍频调制与功率均衡方案推广OA

Asymmetric cascaded H-bridge inverters adopting hybrid carrier level-shifted or phase-shifted modulation cannot simultaneously achieve excellent harmonic performance and solve power imbalance issues.To address this limitation,a generalized improved hybrid frequency-doubling modulation and power balancing control scheme is proposed for a class of asymmetric cascaded H-bridge inverters with input voltage ratios of 1:1:…:1:k:k:…:k.The proposed modulation scheme achieves output power balance in the low-voltage H-bridge by re-arranging the spatial positions of the triangular carrier wave and combining phase-shifting techniques.The output voltage waveform of the high-voltage H-bridge is dynamically controlled based on the level-rotating and shifting strategy,ensuring power balancing among individual units in a single high-voltage H-bridge configuration and among same-voltage units in multiple high-voltage H-bridge configurations.The proposed modulation scheme not only doubles the average equivalent switching frequency of the inverter,but also achieves power balancing without inducing power backflow.Moreover,a unified generalized modulation model is established for this class of expandable H-bridge structures.Simulation and experimental results verify the accuracy,feasibility,and generalizability of the proposed scheme.