柔性有载调压变压器电压无功协调控制策略

Voltage and reactive power coordinated control strategy forflexible on-load tap changer

随着可再生能源和电力电子设备在电网中占比不断升高,电压波动也越来越频繁。针对现有配电网调节电压和无功补偿需求,文中设计了一种集成传统变压器和电力电子变换装置的新型柔性有载调压变压器,可同时具备电压调节和无功补偿能力。首先,分析电力电子变换器串联侧和并联侧电压调节、无功补偿原理。然后,考虑有载调压分接开关动作,分别提出基于最小电压幅值和最小有功损耗的串并联电压无功协调控制策略,实现电压连续调节,同时提供最大范围的无功功率。最后,通过仿真和实验验证有载调压变压器的结构合理性和电压无功协调控制策略的正确性。使用柔性有载调压变压器电压无功协调控制策略可实现多种目标下的电压无级调节和无功功率补偿。

As the increasing proportion of renewable energy and power electronic devices in the power grid,voltage fluctuations are becoming frequent.In response to the current voltage regulation and reactive power compensation requirements of the distribution network,a new type of flexible on-load tap changer is designed that integrates traditional transformers and power electronic converters.This novel transformer can simultaneously provide voltage regulation and reactive power compensation capabilities.Firstly,the principles of voltage regulation and reactive power compensation on the series and parallel sides of the power electronic converter are analyzed.Then,considering the operation of the on-load tap changer,two series parallel voltage and reactive power coordination control strategies based on minimum voltage amplitude and minimum active power loss are proposed to achieve continuous voltage regulation while providing maximum range of reactive power.Finally,the structural rationality of the on-load tap changer and the correctness of the voltage and reactive power coordination control strategy are verified through simulation and experiments.The stepless voltage regulation and reactive power compensation under multiple objectives can be realized by the voltage and reactive power coordinated control strategy for flexible on-load tap changer.