变压器对LCL型SVG多模块并联系统稳定性的影响

Effect of Transformer on the Stability of Multi-module Parallel LCL-SVG System

采用LCL滤波器的SVG(static var generator)多模块并联补偿时,受并联模块数量以及系统变压器的影响,使得原本可单独稳定运行的SVG模块,不能满足此类系统的稳定性要求。在研究变压器对SVG多模块并联系统影响的基础上,验证了传统有源阻尼设计方法适用性的不足;进而对传统有源阻尼的设计进行了修正,给出了电容电流反馈系数和电流调节器参数的取值范围。改进的整定方法使得此类系统控制参数的设计更为准确,系统的响应和稳定裕度改善明显。仿真结果验证了所提方法的正确性与有效性。

When anLCL-type static var generator(SVG)is under multi-module parallel compensation,itwill be affected by the number of parallel modules and the system transformer.As a result,the SVG module,which can originally op?erateindependently and stably,cannot meet the system’sstability requirements.On the basis of studying the effect of the transformer on the SVG multi-module parallel system,it is verified that the traditional active damping design method is not applicable.For this reason,the design methodis modified,andranges of capacitance current feedback coefficient and current regulator parametersare given.The improved tuning method can more accuratelyacquire the control parameters of this kind of systemandobviously improve thesystems’response performance and stability margin.Simulation results verify the correctness and effectiveness of the proposed method.