基于改进滑模控制的光伏系统MPPT控制策略

MPPT CONTROL STRATEGY BASED ON IMPROVED SLIDING MODE CONTROL FOR PHOTOVOLTAIC POWER SYSTEM

针对传统滑模控制在光伏发电MPPT控制中存在响应速度慢、抖振显著等不足,提出一种改进滑模控制的光伏MPPT策略。基于采用Boost升压电路的光伏系统,设计一种采用饱和函数幂次趋近律的改进滑模控制结构,利用幂次项的快速性与饱和函数边界层内的线性反馈的特点,构建趋近过程中不同阶段的分段调节策略,稳定性理论分析证明所设计的改进滑模控制MPPT策略能进一步提高光伏系统的动态响应速度和抗抖振性能。最后,利用Matlab仿真并进行实验验证。结果表明,采用改进滑模控制策略能够实现光伏最大功率点跟踪的精确控制,有助于提升光伏系统在较大扰动下MPPT的快速跟踪和平滑控制性能,具有较好的应用前景。

Due to the he shortcomings of traditional sliding mode control in maximum power point trackers(MPPT)in photovoltaic power system,such as slow response speed and significant chattering,an improved sliding mode control strategy for photovoltaic MPPT is proposed.Based on the photovoltaic power system with Boost circuit,an improved sliding mode control structure with power reaching law of saturation function is designed.Moreover,the piecewise regulation strategy in different stages of the reaching process is constructed by using the rapidity of power term and linear feedback in the boundary layer of saturation function.Besides,the stability theory analysis shows that the improved sliding mode control MPPT strategy has quicker dynamic response speed and more anti buffeting performance of photovoltaic power system.At last,simulations by Matlab and experimental verification are carried out,the results show that the improved sliding mode control strategy is able to achieve accurate control of MPPT in photovoltaic power system,which is helpful to enhance the fast tracking and smooth control performance of MPPT under large disturbances,and has a good application prospect.