【摘要】 针对目前光伏电池最大功率点跟踪(MPPT)算法扰动频率越来越高的问题,设计了一种基于数模混合控制的快速光伏模拟器。模拟器的数字部分采用数字信号处理器(DSP)实现,所提出的算法首先使用四段折线法拟合光伏电池的伏安特性曲线,线性化的拟合结果可简化运算过程;接着采样输出电压、电流,计算出了负载阻抗;最后利用负载阻抗定位法,只用一个运算周期确定光伏模拟器的静态工作点。模拟部分主功率电路为同步BUCK,控制算法采用峰值电流控制以提高电路的响应速度,且其输出电压和电流可跟踪数字部分输出的具有光伏特性的参考值。建立模型分析模拟器的响应时间为0.22 ms,满足光伏变流器的MPPT算法要求。仿真和实验结果表明,理论分析准确,所设计的光伏模拟器具有实用性。更多还原

【Abstract】 Aiming at the increasing perturbation frequency in maximum power point tracking(MPPT)algorithms,a photovoltaic simulator is designed with digital/analog mixed control. The digital part of the simulator was realized by a digital signal processor(DSP),which adopts the four-segment piecewise linear fitting method to build the photovoltaic characteristic curve and uses the load impedance location method to find the accurate steady-state operation point within only one calculation cycle. In the analog part,the power converter was realized by using a peak current controlled synchronous BUCK,whose output voltage and current follows the photovoltaic reference value produced by the digital part. The model of the simulator was built to analyze its response time,which is about 0.22 ms and meets the requirements of the photovoltaic inverters’ MPPT algorithms. The results of simulation and emperiments indicate that the theoretical analyses are accurate and the proposed simulator is feasible.更多还原