为了治理电力系统负序、无功和谐波电流等电能质量问题,研究了一种简化型三电平铁路功率调节器,它由1个两相三线制逆变器、2个输出电感和2个单相降压变压器组成。与三相有源电能质量补偿器相比,该调节器只需要一对三电平开关臂,减少了器件数量、降低了装置成本。通过分析两相三线制逆变器的开关控制原理,提出了一种电压外环比例一积分控制和电流内环无差拍控制的双环控制方法。为了实现直流侧动态均压,研究了一种低成本、可靠性高的均压电路,并提出了一种基于电流闭环的均压控制方法。最后,仿真和实验结果验证了所提出补偿结构及方法的正确性。
In order to manage the power quality of railway, a simplified three-level railway power regulator is presented. The regulator consists of two-phase three-wire converter, two step-down transformers and two output inductors. Compared with active power quality compensator (APQC), this regulator only needs a pair of three-level switch arms, which reduces the switch number and the system cost. Base on the switch control mode analysis, a voltage and current dual-loop control is established. It is composed of an outer loop proportional-integral control and an inner loop deadbeat control. To achieve dynamic balance of the DC-link voltage, a voltage-balanced circuit and its control method are researched. Simulation and experimental results verify the correctness of the proposed structure and the control method.