微电网双向变流器的复合控制策略

摘要

The stability control and power quality improvement of micro-grid systems using a bidirectional converter is studied.In consideration of the fact that the traditional converters like dynamic voltage regulator (DVR), static var generator ( SVG) , active power filter ( APF) cannot be directly applied to micro grids due to the reasons of their dynamic response , power level and economy , a compound control method based on the nonlinear control theory is proposed .The method uses feedback linearization to control the inner current loop to turn the complex nonlinear system into a linear system , and fully decouples active and reactive current to improve the tracking precision and dynamic response of the inner current roop , and also improve fast response capability of the voltage outer loop; at the same time, it uses the sliding mode to control the voltage outer loop to solve the problem of time-varying param-eters and to improve the robustness and anti-interference of the outer loop voltage .The experiments show that this composite control method has the abilities of fast dynamic response , higher precision , smaller harmonic of the AC side current , and the DC side voltage has the fast dynamic response .%研究了采用双向变流技术的微电网的稳定控制和电能质量改善方法.考虑到大电网中的动态电压恢复器(DVR)、静止无功发生器(SVG)、有源电力滤波器(APF)等由于动态响应、功率等级和经济性的原因并不适用于微电网,提出了一种基于非线性控制理论的复合控制方法.该方法对电流内环通过状态反馈使非线性系统精确线性化,并完全解耦有功和无功电流,从而提高了内环电流的跟踪精度及动态响应速度,提升了电压外环的快速响应能力.对电压外环采用滑模控制,解决了系统时变参数的问题,提高了外环电压的鲁棒性.实验表明,该复合控制方法具有网侧电流动态响应速度快、跟踪精度高、谐波电流小,直流侧电压动态响应快速的特点.