基于双模式的光伏并网系统最大功率点跟踪控制

Research on MPPT of the PV Grid-connected Controller with Dual Models

干扰观测法具有算法简单、跟踪效率高的特点,但其采用固定的扰动步长,难以同时获得较高的跟踪精度和响应速度。短路电流法控制精度差,但是在外部环境突变情况下,仍能使光伏系统输出功率跟踪日照的变化。提出将短路电流法和干扰观测法相结合构建一种双模式的最大功率点跟踪(Maximum Power PointTracking,MPPT)控制方法,仿真结果表明,该方法能够快速、准确地跟踪光伏阵列的最大功率点,减少了在最大功率点振荡的能量损失,且在日照发生突变的情况下也不会失去MPPT控制的能力。

The conventional perturbation and observation method（PO）is proven to be of succinctness and high tracking efficiency,but its excellent dynamic response and stable performance are difficult to achieve synchronously when adopting fixed perturbation step size.The short-circuit current method is of bad precision,but its output power of the PV module varies rapidly with sunlight.In this paper,the maximum power point tracking（MPPT）control method is presented based on PO and short-circuit current method.The Simulation results show that the MPPT control method can track the maximum power point of the PV array fast and exactly,lower the loss of oscillation energy and ensure the reliability of MPPT even when sunlight varies suddenly.