光伏逆变器无源分数阶滑动模态控制器设计

Passive fractional-order sliding-mode controller design for PV inverters

设计了光伏逆变器无源分数阶滑动模态控制器(Passive Fractional-Order Sliding-Mode Controller, PFSMC)来实现不同运行条件下的最大功率跟踪。首先,基于跟踪误差构建储能函数,保留系统阻尼有益项以提高跟踪速率,并完全补偿其他的系统非线性以实现全局一致的控制性能。随后,引入分数阶滑动模态控制(Fractional-Order Sliding-Mode Control, FSMC)作为附加控制输入对储能函数进行能量重塑以提高光伏逆变器的动态响应性能,同时分数阶滑动模态的引入可大幅提高闭环系统的鲁棒性。为验证所提控制器的有效性,进行了两种算例研究,即光照强度变化和电网电压跌落。仿真结果表明,PFSMC与常规PID控制、无源控制(Passivity-BasedControl,PBC)和FSMC相比,其能在各类工况下实现最快的动态响应以及最低的超调量。最后,基于d Space的硬件在环实验(Hardware-in-the-Loop, HIL)验证了所提算法的硬件实现可行性。

This paper designs a Passive Fractional-Order Sliding-Mode Controller(PFSMC) for PV inverter to achieve the Maximum Power Point Tracking(MPPT) under various operation conditions. At first, a storage function is constructed based on the tracking errors, in which the beneficial terms are retained to increase the tracking rate. Meanwhile, other system nonlinearities are fully compensated to realize a globally consistent control performance. Then, the Fractional-order Sliding-Mode Control(FSMC) is employed as the additional input to reshape the energy of the storage function, such that an improved dynamical response of the PV inverter could be realized. Meanwhile, the closed-loop system robustness can be significantly enhanced by the use of FSMC framework. Two case studies are undertaken, e.g. solar irradiation variation and power grid voltage drop, to verify the effectiveness of the proposed approach. Simulation results show that PFSMC can achieve the fastest dynamical responses and the lowest overshoot in comparison to that of conventional PID control, Passivity-Based Control(PBC), and FSMC under different operation conditions. Lastly, a dS pace based Hardware-In-the-Loop(HIL) test is carried out to validate the implementation feasibility of PFSMC.