三相APF非线性解耦控制的建模与仿真

有源电力滤波器(APF)是电力系统谐波的有效治理手段之一,但APF主电路为电压源逆变器(VSI),由于开关频率的限制,是一个强非线性耦合系统,给控制器设计及应用带来困难。为此,首先建立了三相电压型有源滤波器系统仿射非线性模型;然后基于微分几何理论,提出该模型的状态反馈精确线性化方法以建立其线性化模型;最后对有源滤波器三相进行解耦并实现了精确解耦控制器的设计。仿真结果表明了所建模型及设计控制算法的有效性,经该控制算法补偿,谐波畸变率限制在2%以下。

Modeling and Simulation of Nonlinear Decoupled Control of the Three-phase Active Power Filter

The voltage source inverter,as a key circuit of active power filter(APF),is a strong-coupled and multiple variable nonlinear system,which makes the controller design very difficult and limits the wide application of APF.In this paper,a method of state variable feedback and exact linearization is presented to resolve this problem.First the affine nonlinear model of the shunt three-phase voltage-source active power filter is set up with the definition of switch function.Based on the differential geometry theory,a state variable feedback linearization design is carried out,and the linear model is established after the confirmation of the apply condition of this method.According to the operation objective of the APF system,the controller to make the system decoupled exactly is designed subsequently.As a result,an active power can be controlled separately with reactive power.Simulation was carried out first to verify the validity of the control method and close-loop decoupled model,the total harmonic distortion(THD) is restrained within 2%.