Construction of a broadband impedance spectrum and synchronous DC voltammetry measurement system for solar cells

太阳能电池宽带阻抗谱和同步直流伏安测量系统

The current impedance spectroscopy measurement techniques face difficulties in diagnosing solar cell faults due to issues such as cost,complexity,and accuracy.Therefore,a novel system was developed for precise broadband impedance spectrum measurement of solar cells,which was composed of an oscilloscope,a signal generator,and a sampling resistor.The results demonstrate concurrent accurate measurement of the impedance spectrum(50 Hz-0.1 MHz)and direct current voltametric characteristics.Comparative analysis with Keithley 2450 data yields a global relative error of approximately 6.70%,affirming the accuracy.Among excitation signals(sine,square,triangle,pulse waves),sine wave input yields the most accurate data,with a root mean square error of approximately 13.3016 and a global relative error of approximately 4.25%compared to theoretical data.Elevating reference resistance expands the half circle in the impedance spectrum.Proximity of reference resistance to that of the solar cell enhances the accuracy by mitigating line resistance influence.Measurement error is lower in high-frequency regions due to a higher signal-to-noise ratio.

目前,由于成本、复杂性和准确性等问题,阻抗谱测量技术在诊断太阳能电池故障方面面临诸多困难。为此,基于阻抗谱测量原理和太阳能电池模型,开发了一种精确测量太阳能电池宽带阻抗谱的新型系统,其由示波器、信号发生器和采样电阻组成。结果表明,该系统能够同时准确测量频率范围为50 Hz至0.1 MHz的阻抗谱,并获取直流伏安特性。与Keithley 2450的数据进行比较,全局相对误差约为6.70%,证实了其准确性。在四种激励信号(正弦波、方波、三角波和脉冲波)中,正弦波输入产生了较准确的数据,与理论数据相比,均方根误差约为13.3016,全局相对误差约为4.25%。提高参考电阻会扩大阻抗谱中的半圆。当参考电阻接近太阳能电池的电阻,通过减少线路电阻的影响,可提高测量准确性。由于信噪比较高,高频段的测量误差低于低频段。