基于滑模自适应-LADRC协同优化的三相光伏逆变器VSG控制策略

VSG Control Strategy of Three-Phase Photovoltaic Inverter Based on Sliding Mode Adaptive-LADRC Collaborative Optimization

摘要: 针对三相光伏逆变器非线性强、扰动复杂，且传统控制难兼顾动态响应与鲁棒性的问题，本文提出滑模自适应–线性自抗扰协同的虚拟同步发电机(VSG)控制算法。首先推导三相并网逆变器数学模型以支撑控制设计；在VSG框架下，滑模自适应子算法在线优化虚拟惯量以平衡抗扰能力与响应速度，线性自抗扰(LADRC)子算法通过跟踪微分器、扩张状态观测器及线性状态误差反馈抑制负载突变、参数摄动等扰动，二者经参数传递、误差共享与扰动补偿协同工作。Matlab/Simulink仿真与DSP32F28335硬件测试表明，相较传统双闭环PI算法，所提算法稳态总谐波失真率符合国标，动态并网稳定时间短且无波形畸变，实物测试超调量小、收敛快，有效提升了光伏逆变器系统的动态性能、鲁棒性与实用性。

Abstract: Aiming at the problems of strong non-linearity and complex disturbances in three-phase photovoltaic inverters, and the difficulty of traditional control in balancing dynamic response and robustness, this paper proposes a virtual synchronous generator (VSG) control algorithm based on the collaboration of sliding-mode adaptive control and linear active disturbance rejection control. Firstly, the mathematical model of the three-phase grid-connected inverter is derived to support the control design. Under the VSG framework, the sliding-mode adaptive sub-algorithm optimizes the virtual inertia online to balance the anti-disturbance ability and response speed, and the linear active disturbance rejection control (LADRC) sub-algorithm suppresses disturbances such as sudden load changes and parameter perturbations through a tracking differentiator, an extended state observer, and linear state error feedback. The two sub-algorithms work collaboratively through parameter transfer, error sharing, and disturbance compensation. Matlab/Simulink simulations and hardware tests on DSP32F28335 show that compared with the traditional double-loop PI algorithm, the total harmonic distortion rate of the proposed algorithm in the steady state meets the national standard, the dynamic grid-connection stabilization time is short without waveform distortion, the overshoot in the physical test is small, and the convergence is fast. The proposed algorithm effectively improves the dynamic performance, robustness, and practicality of the photovoltaic inverter system.