基于Boost变换器的最大功率点跟踪判据及实现算法

摘要

The principle of Maximum Power Poine Tracking(MPPT) control system is analyzed based on boost converter with only the port voltage of sample solar cell.The criterion to reach the maximum power point is deduced.It is pointed out that MPPT system reaches maximum power point when the ratio of the variation of on-time to off-time of the switch is equal to the relative change rate of the solar cell port voltage.According to the output characteristic curve of the solar cell and the obtained criterion,the principle to adjust the change direction and step variation of the duty cycle is concluded.On this basis,a novel control strategy and algorithm realizing MPPT is proposed.The feasibility of the proposed control strategy and criterion is verified by the experimental results.%对基于Boost变换器且仅采样太阳能电池端口电压的最大功率点跟踪(简称MPPT)控制系统组成及原理进行了分析,推导得出了跟踪系统达到最大功率点的判据,并指出当Boost变换器开关管导通时间的变化量相对于开关管关断时间的变化率等于太阳能电池端口电压的相对变化率时,MPPT系统即实现最大功率跟踪.依据太阳能电池的输出特性曲线和所提出的判据,得出了判断变换器开关导通比变化方向的调整原则及开关导通比变化量的确定方法,并在此基础上提出了一种MPPT的新颖控制策略及实现算法,实例及实验结果验证了理论分析及所提出判据的可行性和正确性.