基于扰动观测器的永磁同步发电机最大功率跟踪滑模控制

Maximum power point tracking of permanent magnetic synchronous generator using per-turbation observer based sliding-mode control

中文关键词  永磁同步发电机  扰动观测器  滑模控制  最大功率跟踪

英文关键词  permanent magnetic synchronous generator  perturbation observer  sliding-mode control  maximum power point tracking

中文摘要

      本文设计了一款基于扰动观察器的滑模控制(perturbation observer based sliding-mode control, POSMC)来实现永磁同步发电机(permanent magnetic synchronous generator, PMSG)的最大功率跟踪(maximum power point tracking, MPPT)。首先，将发电机非线性、参数不确定、未建模动态、随机风速聚合成一个扰动，并通过扰动观察器对其进行在线估计。随后，采用滑模控制(sliding-mode control, SMC)对该扰动估计进行实时完全补偿，从而实现不同工况下的控制全局一致性以及各类不确定环境下的鲁棒控制。同时，POSMC采用扰动实时估计值进行补偿来代替传统SMC中所使用的扰动上限值进行补偿，因此可有效解决传统SMC过于保守的缺点，使得控制成本更为合理。最后，POSMC无需精确的PMSG模型，仅需测量d轴电流和机械转速，易于实现。本文进行了三个算例研究，即阶跃风速，随机风速，和发电机参数不确定。仿真结果表明，与矢量控制(vector control, VC)和SMC相比，POSMC在各类工况下均可捕获最大风能并具有较强的鲁棒性。基于dSpace的硬件在环实验(hardware-in-loop, HIL)验证了所提算法的可行性。

英文摘要

      This paper designs a perturbation observer based sliding-mode control (POSMC) of permanent magnetic synchronous generator (PMSG）for maximum power point tracking (MPPT). Firstly, the generator nonlinearities, parameter uncertainties, unmodelled dynamics, stochastic wind speed are all aggregated into a perturbation, which is estimated online by a perturbation observer. Then, sliding-mode control (SMC) is employed to fully compensate the perturbation estimate, such that a globally consistent control performance under various operation conditions and significant robustness against different uncertainties can be achieved. Meanwhile, POSMC adopts the perturbation estimate to replace the upper bound of perturbation used in SMC, thus POSMC can effectively resolve the over-conservativeness of SMC hence more proper control costs could be resulted in. Lastly, POSMC is easy to be implemented as it does not require an accurate PMSG model while only the measurement of d-axis current and mechanical rotation speed is needed. Three cases are carried out, including step change of wind speed, stochastic wind speed, and generator parameter uncertainties. Simulation results demonstrate that POSMC can extract the optimal wind power and provide the greatest robustness in various operation conditions compared to that of vector control (VC) and SMC. At last, dSpace based hardware-in-loop (HIL) test validates the implementation feasibility of the proposed approach.