宽温度补偿恒压式MPPT光伏发电技术的研究

Research on a Improved Constant Voltage MPPT Method for Photovoltaic Generation

为了最大限度的提升太阳能面板利用率,研究了一种改进的宽温度补偿恒压式最大功率点跟踪(MPPT)技术。通过在控制电路中增加负温度系数(NTC)电阻模拟最大功率点(MPP)电压与温度变化曲线。功率变换器能在较宽的温度变化范围内跟踪太阳能面板MPP,克服了传统恒电压MPPT控制方式不能适应环境温度变化的缺点,可提升太阳能面板利用率达40%。功率变换器采用恒定导通时间变频控制环路反馈技术,在轻载时进入间歇工作模式,工作周期仅为2 ms,在重载时频率达到340 kHz,兼顾了功率变换器的效率和体积。在12 V输入电压条件下,功率变换器效率达90%以上。与基于数字控制器的电导式、扰动式等MPPT方法相比,该方法动态特性好,经济性能佳,在小功率、低成本光伏发电系统中具有较好的推广价值。

Based on analysising the working characteristic model of solar cell, a improved constant voltage control max- imum power point tracking（MPPT） technique for small power application is studied.Because of a negative temperature coefficient（NTC） resistor is used in control circuit, the reference voltage of MPPT has the same change tendency with solar cell under the different temperatures.Adopting this method, good MPPT performance can be obtained even when the environmental temperature is varied.The experimental results show that the improved method has good dynamic performance, and has excellent application prospects in low cost, micro-power photovoltaic generation system.