基于阻抗适配的独立光伏系统协调控制方法

An Adaptive Impedance Matching Based Coordinated Control Method for Autonomous Photovoltaic Generation System

以独立光伏发电协调控制系统为研究对象,为了减少系统工作模式转换带来的控制结构切换问题,在动态等效阻抗匹配法的基础上改进提出了阻抗适配法,实现了一种无需系统结构改变的双模式转换协调控制技术。特点是通过对光伏电池等效内、外阻抗的适配,能使光伏电池根据需要连续调节输出功率,完成最大功率跟踪与负载跟踪模式的平滑转换。系统中的双向变换器工作在稳压模式;协调控制系统不需切换判断逻辑,实现相对简单。最后通过实验验证了所提策略的有效性。

Taking autonomous photovoltaic （PV） generation system as research object, based on improved dynamic equivalent impedance matching method an adaptive impedance matching method is proposed to realize a dual mode conversion coordinated control method, in which the change of system structure is not needed, thus the control structure switching caused by operation mode swapping of autonomous PV generation system can be reduced. The feature of the proposed method lies in that by means of adaptive matching between equivalent internal impedance and external impedance of the PV cell the output power of the PV cell can be continuously adjusted according to the demand and the smooth transition between maximum power point tracking （MPPT） mode and load power tracking （LPT） mode can be completed. The bi-directional transducer in the control system operates under the voltage stabilizing mode; the switching of the judging logic is not needed, so it is relatively easy to implement the proposed method. The effectiveness of the proposed method is validated by experiments.