孤岛直流微电网DC-DC变换器的非线性控制技术

Nonlinear Control Technology for DC-DC Converter in Islanded DC Microgrid

孤岛直流微电网中的电源一般为各分布式电源和储能设备,但是它们为直流微电网系统提供能量时都会存在波动性,从而影响系统母线电压的稳定性。以含有储能变换器的直流微电网为参考对象,设计一种非线性Backstepping控制器,用于控制母线电压的稳定性。控制器采用非线性设计方法,通过在设计过程中的不同阶段选择相应的李雅普诺夫函数,保证系统的稳定性。在Matlab/Simulink中搭建直流微电网仿真模型,验证直流微电网系统输入端存在波动时,所设计的控制器对维持母线电压稳定的有效性。

The power sources used in islanded DC microgrids are generally distributed generations and energy storage equipment,which will bring in fluctuations when providing energy to a DC microgrid system and further affect the system’s bus voltage stability.In this paper,a DC microgrid with energy storage converter is taken as a reference object,and a nonlinear Backstepping controller is designed to control the bus voltage stability.This controller adopts a nonlinear design method,in which a proper Lyapunov function will be selected at different stages to ensure the system stability.A simulation model of DC microgrid is built in Matlab/Simulink to verify the effectiveness of the designed controller in maintaining the bus voltage stability when there are fluctuations in the input of the DC microgrid system.