基于内模控制的双闭环并网逆变器设计

Improvement of Internal Model on Double Closed Loop Grid Inverter

为解决传统PI控制的逆变器在实现跟踪性能时,抗扰动能力较差,尤其在三相逆变器控制中,IGBT非线性影响大,电力系统自身干扰源强,负载时反馈值误差难以补偿等问题,通过采用一种基于内模控制的电流内环和自抗扰控制的电压外环构成的双闭环逆变器控制策略,并考虑到三相逆变器存在强耦合作用,引入第二个自由度构成二自由度内模控制器,以实现主动解耦及增强抗干扰性能的作用。通过MATLAB进行仿真,结果表明与PI双闭环控制相比,采用内模控制的双闭环控制的逆变电路具有更好的THD值、及稳态和动态性能。

In order to solve the problems of traditional controlled inverters,such as poor anti-interference ability in achieving tracking performance,large nonlinear effects in threephase inverter control,strong interference sources in the power system itself,and difficulty in compensating feedback value errors during load,a dual closed-loop inverter control strategy based on an internal model control(IMC)internal current loop and an automatic disturbance rejection control external voltage loop is adopted,taking into account the strong coupling effect of three-phase inverters,A second degree of freedom is introduced to form a two degree of freedom internal model controller to achieve active decoupling and enhance anti-interference performance.Through simulation,the results show that compared with dual closed-loop control,the inverter circuit using internal model control with dual closed-loop control has better value,steady-state and dynamic performance.