基于非线性ESO的风电并网逆变器改进自抗扰控制

Improved Active Disturbance Rejection Control of Wind Power Gridconnected Inverter Based on Nonlinear ESO

针对永磁直驱风电系统并网逆变器中传统双闭环PI控制策略抗扰性能和控制精度不足的问题,提出一种基于非线性扩张状态观测器(NLESO)的改进型自抗扰控制(ADRC)技术用以提高直流母线电压的控制性能。通过将线性扩张状态观测器(LESO)中的误差增益矩阵变为随时间变化的非线性函数对传统LADRC进行了改进,提高了LESO的动态扰动观测性能,从而增强系统对集总扰动的补偿抑制能力,并对其进行稳定性证明。最后通过仿真对比分析改进NLADRC和传统LADRC控制下并网点电压和逆变器直流侧电压波形,验证了改进NLADRC的正确性和可行性。

Aiming at the insufficient problem of anti-disturbance performance and control accuracy of the traditional double closed-loop PI control strategy in the grid-connected inverter of the magnetic direct drive wind power system,an improved active disturbance rejection controller(ADRC)technology based on the nonlinear extened state observer(NLESO)was proposed to enhance the control performance of the DC bus voltage. The traditional LADRC was improved by changing the error gain matrix in the linear extended state observer(LESO)into a non-linear function that varies with time,and the dynamic disturbance observation performance of LESO was also improved. The compensation inhibition ability against lumped disturbances was enhanced,and its stability was proved. Finally,through simulation and comparative analysis for the grid-connected point voltage and the DC voltage waveforms of the inverter under the control of the improved NLADRC and the traditional LADRC,the correctness and feasibility of the improved NLADRC were verified.