一种动态调节电压暂降补偿深度的统一电能质量控制器

摘要

Traditional MMC-UPQC uses series transformers with constant transformation ratio structure, which cau-ses a constant maximum voltage sag compensation depth and the series converter cannot utilize its full rated capacity to compensate the voltage sag when the feeder load does not reach its rated capacity. A novel MMC-UPQC is pro-posed to fully utilize the rated capacity of the series converter and increase the voltage sag compensation depth of the MMC-UPQC, in which multi-winding transformer and bidirectional switches are used. Voltage sag compensation ca-pability of the traditional MMC-UPQC and the novel MMC-UPQC are analyzed, which points out the advantage on changing the transformation ratio of the series transformer. Simulations based on the traditional MMC-UPQC and the novel MMC-UPQC are done and the simulation results verify the effectiveness of the novel MMC-UPQC. Compared with the traditional one, novel MMC-UPQC can piecewise dynamically adjusts voltage sag compensation depth and increases the voltage sag compensation capability when the feeder load does not reach its rated capacity without in-creasing the rated capacity of the MMC-UPQC.%传统模块化多电平变换器统一电能质量控制器（ MMC-UPQC）的串联变压器采用固定变比结构，该结构导致UPQC装置电压暂降补偿深度最大值为固定值，在馈线负荷未达到额定容量时串联变换器不能输出额定容量来补偿电压暂降。为充分利用串联变换器的容量补偿电压暂降，提出了新结构的MMC-UPQC以提高电压暂降补偿深度。分析了传统及新结构MMC-UPQC的电压暂降补偿能力，并通过仿真研究验证了新结构MMC-UPQC的正确性。与传统MMC-UPQC相比，新结构MMC-UPQC在保持装置容量不变的前提下，可分段动态调节电压暂降补偿深度，增大各段馈线负荷容量范围下MMC-UPQC装置的电压暂降能力。