并网逆变器并联运环流分析与控制.pdf

并网逆变器并联运行环流分析与控制 The analysis and control of circulating current for direct parallel grid-connected inverters 上海大学 杨勇，阮毅，汤燕燕，叶斌英 Email: yangy1981@ 摘要： 并网逆变器直接并联运行时，可使系统体积减少、成本降低。但并网逆变器直接并联时会产生环流。为此，详 细分析了并网逆变器直接并联运行时环流产生的机理，建立了并网逆变器并联运行时旋转坐标系下的状态平均模型。在这模 型的基础上，分析并网逆变器并联运行时的相互影响；分析了并网逆变器采用间矢量脉宽调制（SVPWM）算法时零矢量对 环流的影响。通过控制 SVPWM 算法中不同零矢量在每一个 PWM 周期的作用时间来抑制环流。对并网逆变器在不同情况 下的并联运行进行了实验。实验结果表明：该控制策略能有效的抑制环流，从而验证该控制策略的可行性和正确性。 ABSTRACT: It is desirable to have a directly connected structure for grid-connected inverter because of compact size and low cost. The circulating current will be generated when grid-connected inverters are in direct parallel operation. So the mechanism of circulating current is analysed in detail for grid-connected inverters in direct parallel operation and the state average model of the parallel grid-connected inverters is constructed in rotating coordinates. Based on this model, interaction between the parallel grid-connected inverters is analyzed and the influence on circulating current when it is adopted zero vector with space vector pulse width modulation(SVPWM) is also analysed. The circulating current can be effectively inhibited by controlling the operation time for different zero vectors in each PWM cycle. The parellel grid-connected inverters are tested under different circumstance. The experimental results show that the control strategy can effectively inhibite circulating current, so the feasibility and correctness for the control strategy is verified. 关键词：并网逆变器；直接并联；环流；平均模型 KEY WORDS: grid-connected inverter; direct parallel operation ; circulating current; average model 1 引言 法无流抑制低频环流。文献[8]和文献[9]提出在 dq 常规能源（煤、石油等）不仅资源有限，而且 坐标系下，采用非线性控制来抵制环流，但这种控 造成了严重的环境污染。因此，可再生能