【摘要】 针对传统载波同相层叠(PD)调制策略应用于级联H桥逆变器时存在的功率不均衡问题,提出一种新型PD优化调制策略。在此首先基于载波自由度控制原理,对三角载波进行拆分与重构,实现PD调制策略的一次优化;然后基于调制波自由度减少载波数量,实现调制策略的二次优化。在新型PD优化调制策略下,各级联单元输出功率在一个新载波周期内达到均衡,输出电压谐波特性与采用传统PD调制策略时完全一致,调制复杂度得到简化。最后以三单元级联H桥逆变器为例,通过仿真和实验验证理论分析的正确性与调制策略可行性。更多还原

【Abstract】 Aiming at the power imbalance problem when the traditional phase disposition(PD) modulation strategy is applied to cascaded H-bridge inverters,a new optimized PD modulation strategy is proposed.Firstly,splits and reconstructs the triangular carrier based on the carrier degree of freedom control principle to realize the one-time optimization of the PD modulation strategy;and then reduced the number of carriers based on the degree of freedom of the modulating wave to achieve the secondary optimization of the modulation strategy.Under the new optimized PD modulation strategy,the output power of each cascaded unit is balanced within one new carrier cycle,and the harmonic characteristics of the output line voltage are exactly the same as those of the traditional PD modulation strategy,and the modulation complexity is simplified.Finally,a three-unit cascaded H-bridge inverter is taken as an example to verify the correctness of the theoretical analysis and the feasibility of the modulation strategy through simulation and experiment.更多还原