The Solar Cells and the Battery Charger System Using the Fast and Precise Analog Maximum Power Point Tracking Circuits
The Solar Cells and the Battery Charger System Using the Fast and Precise Analog Maximum Power Point Tracking Circuits
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DOI：
10.1109/isvlsi.2015.36
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发表时间：
2015-07
期刊：
影响因子：
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通讯作者：
Y. Sugimoto
中科院分区：
文献类型：
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作者：
Y. Sugimoto
提出了一种简单、快速、精确的光伏发电系统功率计算电路。根据PV输出电流在与PV输出电压成比例的时间间隔上的积分成为功率的原理来计算功率。该功率计算电路使用简单的模拟电路实现;无需微处理器或DSP即可执行最大功率点跟踪器（MPPT）功能。由于在功率计算电路的输出处的计算结果变为模拟电压，所以使用模拟比较器容易地完成先前结果与当前结果之间的功率比较，其中先前结果被采样并保持。利用比较结果，采用爬山扰动观察法控制升压变换器的占空比，以找到光伏输出电压范围内的最大功率点。采用0.18μ mCMOS工艺设计了光伏发电系统样机。SPICE电路仿真结果表明，光伏输出功率在50 ~ 300 mW范围内的计算误差在±2%以内，在10 ~ 350 mW范围内的计算误差在±5%以内。通过对等效光伏电池电路的电流源施加电流阶跃，在瞬态仿真中验证了整个电力系统的运行。结果表明，当升压型DC-DC转换器输出端负载电阻为50 Ω时，PV输出电流分别为100 mA、300 mA和500 mA时，均能收敛到最大功率点。
We propose a simple, fast and precise power calculation circuit for photovoltaic (PV) power systems. The power is calculated according to the principle that the integration of the PV output current over the time interval proportional to the PV output voltage becomes the power. This power calculation circuit is realized using simple analog circuits; neither a microprocessor nor a DSP is necessary to perform the function of Maximum Power Point Tracker (MPPT). As the calculated result at the output of the power calculation circuit becomes the analog voltage, a power comparison between the previous result and the current result is easily done using analog comparators where the previous result is sampled-andheld. Using the comparison result, the duty ratio of the boost converter is controlled to find the maximum power point in the PV output voltage range by adopting the hill-climbing perturb and observe (P&O) method. The prototype of the PV power system was circuit-designed and laid out using a 0.18μm CMOS IC process. The SPICE circuit simulation results indicated that the PV power calculation achieved within ±2% error for the PV output power from 50 mW to 300 mW, and ±5% for the PV output power from 10 mW to 350 mW. The operation of the whole power system was verified in a transient simulation by applying the current step from the current source of the equivalent PV-cell circuit. The result shows convergence to the maximum power point when the PV output currents are 100 mA, 300 mA and 500 mA with a 50-Ω load resistor at the output of the boost DC-DC converter.