具有精确限压限流功能的光伏发电最大功率点跟踪变换器控制方法

A Control Strategy of Maximum Power Point Tracking Converter with Precise Voltage and Current Limiting Function for Photovoltaic Power Generation

光伏变换器通常采用两级变换器级联工作,一级实现光伏发电的最大功率跟踪,另一级实现输出的精确稳压和限流,这将导致系统成本升高、可靠性降低、发电效率降低、光伏利用效率降低。针对光伏变换器提出一种具有精确限压限流功能的光伏发电最大功率点跟踪变换器的控制策略,在一级DC/DC变换器功率电路的基础上,将电压控制、电流控制和最大功率跟踪控制3种控制模式有机结合,实现在最大功率跟踪条件下输出的精确限压和限流。

Photovoltaic converter usually works via the cascade operation two-stage converter,in which one stage realizes the maximum power tracking of photovoltaic power generation,and the other realizes the accurate voltage stabilization and current limitation of output.This operating mode leads to heightened system cost,low reliability,low power generation efficiency,and low photovoltaic utilization efficiency.In this paper,a control strategy of maximum power point tracking converter with precise voltage and current limiting function is proposed for photovoltaic converters.Based on the power circuit of the first-stage DC/DC converter,three control modes which include voltage control,current control and maximum power tracking are organically combined to realize the precise limitation of output voltage and current under the condition of maximum power tracking.