为了提高三相四开关变换器并网电能质量,提出一种适用于不平衡电网条件的有限控制集模型预测直接功率控制策略。分析三相四开关变换器的工作机制和电压矢量变化关系,并建立其功率预测模型。使用αβ静止坐标系下的电网电压以及其90°延迟信号计算功率补偿值,设计价值函数,选择最优电压矢量对应的开关状态。该控制策略无需传统的正负序分离控制及锁相环技术,易于实现。仿真和试验结果表明,在不平衡电网条件下,所提出的控制策略能够有效降低并网电流畸变,消除功率波动,提高并网电能质量。

In order to improve the power quality of threephase fourswitch (TPFS) converter in unbalanced grid, a finite control sets model predictive power control scheme was proposed. The operation principle and voltage vectors were analyzed and the power predictive model was established. A reference power calculation method using the grid voltages and their quadrature signals was designed. The optimal voltage vector could be selected based on the cost function. It was unnecessary to use phase lock loop to extract sequence components, and easy to be implemented. The simulation and experimental results showed that, under unbalanced grid voltages, the proposed method could reduce the gridconnected current harmonic distortion, eliminate power fluctuation and improve the power quality of the TPFS converter.

TN 624

国家自然科学基金项目(51607159)；河南省科技攻关项目(172102410068)；河南省高校科技创新人才支持计划(18HASTIT025);河南省高等学校青年骨干教师资助计划(2015GGJS180)