三电平中点钳位变换器电容电压自平衡机理与均压控制策略

发布时间：2018-08-21 12:14

【摘要】：三电平中点钳位(3L-NPC)半桥拓扑输入端为电容串联结构,由于电路的非理想因素,存在电容电压不均衡问题。文中根据推导出的3L-NPC半桥等效电路,从时域角度详细分析了电容压差与电容电流的关系,表明3L-NPC具有自平衡特性,且其自平衡电流主要来自于负载电流的直流分量。基于此总结出2类均压控制策略:第1类,采用传统比例—积分或比例—谐振等调节器,加入特定变量反馈,以恢复3L-NPC自平衡特性;第2类,采用不破坏3L-NPC自平衡特性的调节器。根据第2类均压控制思想,提出了采用准谐振调节器的均压控制策略,可简化系统控制,降低系统成本。此外还给出了具备自平衡特性的双环控制方案,改善了系统的响应速度。仿真与实验结果证明了理论分析的正确性。
[Abstract]:The three-level neutral point clamp (3L-NPC) half-bridge topology input terminal is a capacitor series structure. Because of the non-ideal factors of the circuit, the capacitance voltage is unbalanced. According to the equivalent circuit of 3L-NPC half-bridge, the relationship between capacitance voltage difference and capacitance current is analyzed in detail from the point of view of time domain. It is shown that 3L-NPC has self-balancing characteristics and its self-balancing current is mainly derived from the DC component of load current. Based on this, two types of voltage sharing control strategies are summarized: in the first category, the traditional proportional integral or proportional resonance regulators are used to restore the self-equilibrium characteristics of 3L-NPC by adding specific variable feedback. Adopt regulator that does not destroy 3L-NPC self-balance characteristic. According to the idea of the second type of voltage sharing control, a voltage sharing control strategy with quasi resonant regulator is proposed, which can simplify the system control and reduce the system cost. In addition, a double loop control scheme with self-balance is presented, which improves the response speed of the system. The simulation and experimental results show that the theoretical analysis is correct.
【作者单位】：南京航空航天大学自动化学院;
【基金】：国家自然科学基金资助项目(51077070) 江苏省科技支撑计划资助项目(BE2010188)~~
【分类号】：TM46

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