单相半桥三电平并网逆变器中点电压不平衡机理及其均压控制策略

发布时间：2018-02-10 21:22

本文关键词： 半桥逆变器三电平中点电位不平衡均压控制　出处：《中国电机工程学报》2014年06期 　论文类型：期刊论文

【摘要】：针对半桥逆变器的中点电位不平衡问题,以电流控制型三电平半桥并网逆变器的闭环模型为研究对象,给出半桥逆变器中点电位不平衡机理,根据已有文献分析的电感电流初始角度不可控和PI控制器对于交流量存在调节静差相结合,理论推导得到调制波存在直流分量,最终导致输入电容中点电位不平衡。分别从控制电感电流初始角度和选择合适电流调节器的角度出发,提出两种半桥逆变器输入电容中点电位平衡的控制方法:①采用PI调节器,近似控制电感电流初始角度θL0=90°并反馈电感电流直流分量进行补偿均压控制;②采用准PR控制器替代PI控制器作为闭环控制器,消除调制波的直流偏置。仿真和实验结果表明,提出的两种均压控制方法可实现中点电位的平衡,且无需增加硬件成本。
[Abstract]:Aiming at the unbalance of neutral point potential of half-bridge inverter, the closed loop model of current-controlled three-level half-bridge grid-connected inverter is taken as the research object, and the unbalanced mechanism of neutral point potential of half-bridge inverter is given. Based on the analysis of the uncontrollable initial angle of inductance current and the combination of Pi controller to adjust the static error of AC quantity, the DC component of the modulated wave is derived theoretically. Finally, the input capacitance midpoint potential is unbalanced. From the angle of controlling inductance current initial and selecting suitable current regulator respectively, two control methods of half bridge inverter input capacitance midpoint potential balance are put forward: 1 using Pi regulator. Approximate control inductance current initial angle 胃 L090 掳and feedback inductance current DC component to compensate voltage equalizer. 2 Quasi-PR controller is used instead of Pi controller as closed loop controller to eliminate DC bias of modulation wave. Simulation and experimental results show that, The proposed two voltage sharing control methods can balance the midpoint potential without increasing the hardware cost.
【作者单位】：江苏省新能源发电与电能变换重点实验室(南京航空航天大学);电力系统及发电设备控制和仿真国家重点实验室(清华大学电机系);
【基金】：国家自然科学基金项目项目(51177070) 江苏省自然科学基金项目项目(BK2012794) 中国博士后科学基金(2013M530044)~~
【分类号】：TM464

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