有源中点钳位型三电平逆变器开关器件损耗均衡调制方法

Loss balance modulation method of switching device for active neutral-point-clamped three-level inverter

三电平有源中点钳位型(Three-Level Active Neutral-Point-Clamped,3L-ANPC)逆变器可以克服传统三电平逆变器内外层开关器件损耗不均衡的问题,但是其实现损耗均衡的控制方法,一般要求在线计算开关器件温度进行直接控制,或者实时采集开关器件温度进行反馈控制,实现过程比较复杂。为在实现损耗均衡的前提下,同时降低控制器的复杂程度,本文提出一种按照工频周期轮换选择零电平开关状态的开关器件损耗均衡调制策略,分析了采用该方法时开关器件的换流过程以及损耗特性。在单相全桥3L-ANPC逆变器上的仿真结果表明,本文提出的方法简单易实现,可以有效减小开关器件的损耗不均衡程度。

Three-Level Active Neutral-Point-Clamped(3L-ANPC)inverters are used to overcome the problem of unbalanced losses of the internal and external switching devices of the traditional three-level inverter,but its loss equilibrium control method generally requires online calculation of device temperature for direct control,or real-time acquisition of device temperature for feedback control,and the control method is more complicated.In order to reduce the complexity of the controller under the premise of achieving the loss balance,this paper proposes a switching device loss balance modulation strategy that selects the zero-level switching state according to the power frequency cycle,and analyzes the commutations and loss characteristics.The simulation results on a single-phase 3L-ANPC inverter show that the method proposed in this paper can effectively reduce the loss of switching devices and is easy to implement.