基于有源负电容的电压源型逆变器直流母线二次功率脉动的抑制方法

Suppressing Secondary Power Pulsation Method for DC Bus of Voltage Source Inverter Based on Active Negative Capacitor

针对电压源型逆变器直流侧存在二次功率脉动的问题,提出一种基于有源负电容的二次纹波电流吸收方法,该方法具有可热插拔,控制简洁,可靠性高等优势。首先,建立有源负电容的概念并分析二次纹波电流抑制机理,描述有源负电容电路的工作原理;然后,进行系统参数设计并提出相适应的调控策略,所提方法通过在逆变器直流侧吸收二次电流纹波,使二次脉动功率仅在逆变器直流侧与该拓扑结构间传递,对交流侧影响少,且拓扑结构实现支路软开关运行,具有较高的效率。此外,含有源负电容的纹波吸收电路可调控对特定谐波为零阻抗,因此,也可以用于抑制系统其他频率的电流谐波。最后,通过仿真和实验验证所提方法的可行性。

To solve the problem of secondary power pulsation on the DC side of the voltage source inverter, this paper proposes a method of secondary ripple current absorption based on active negative capacitors(ANC). This method has the advantages of simple control with high reliability, and it’s able to cut in/out while working. At first, this paper established the concept of active negative capacitor and analyzed the secondary ripple current suppression mechanism. And then the working principles of the active negative capacitance circuit were described. Based on such theory, system parameters and appropriate control strategies were designed. The proposed method can absorb secondary current ripple on the DC side of inverter. The secondary pulsating power is only transmitted between the DC side of inverter and the topology, which has little impact on the AC side. Meanwhile, this topology has soft-switching achievement in the branch circuit, improving the system efficiency. In addition, the ripple absorbing circuit with source negative capacitance can adjust zero impedance to specific harmonics, so it can also be used to suppress current harmonics of other frequencies in the system. Finally,the feasibility of the proposed method was verified by simulation and experiment.