空间电容分压式表面电位探测器输出漂移分析及优化方法

表面充放电是引起航天器异常和故障失效的常见原因之一，表面电位探测器是监测航天器表面充电效应的有效载荷。目前测量表面电位的应用较多的技术方案是电容分压式，但这种方案的探测器长期工作时会出现输出电压漂移的现象。针对此问题进行详细的理论分析，得出诱导输出电压漂移的主要因素是电容分压自身的指数型传递函数特性、反向输入偏置电流、前放输入阻抗有限和静电荷泄漏。最后，提出了增加偏置到地回路和增大输入阻抗、增大指数项时间常数、数据校正、电荷清零等优化方法，并通过分析和测试最终得出了电容分压式表面电位探测器的应用结论。

Analysis and optimization methods of output drift for capacitive divider surface potential detector in space

Surface charge and discharge was one of the common causes of spacecraft abnormality and lose efficacy. The payload of surface potential detector was used to monitor surface charging effect. Capacitive divider surface potential detector was more applied technical solutions in measuring surface potential, but the detector of this solution would have the phenomenon of output voltage drift. The paper provides a detailed theoretical analysis of this problem, the main factors that induce the output voltage drift are the exponential transfer function characteristics of the capacitor divider itself, reverse input bias current, limited pre-amplifier input impedance, and electrostatic charge leakage. Finally, optimization methods such as increasing the bias-to-ground loop and increasing the input impedance, increasing the exponential term time constant, data correction, and charge clearing are proposed, the final conclusion of the application of the capacitance divider surface potential detector is drawn through analysis and testing.