基于改进型两次平衡对检法的感应分压器自校准方法

介绍了参考电势变压器和指零仪变压器设计原理,分析了屏蔽间泄漏对测量结果的影响;对常规两次平衡参考电势对检法进行了改进,使零平衡和段平衡测量过程中,参考电势和测差电路均可实现等电位保护;对自校准方法进行了推导,校准结果仅与段平衡和零平衡时锁相放大器测量的电压差值相关,与参考电势变压器、指零仪变压器、辅助变压器等的误差无关,屏蔽间泄漏的影响也得到消除。对1kV感应分压器进行了校准实验,并对校准结果进行了测量不确定度分析,其相对扩展不确定度的评估结果为5.4×10^-8(k=2)。

Self-calibration Method of Inductive Voltage Divider Based on Improved Incremental Buildup Method

The design method of reference voltage transformer and null detection transformer was introduced. The influence of leakage current between shielding of the transformers was analyzed. The classic incremental buildup calibration method was improved. Both the reference voltage and voltage difference measurement circuit got equipotential protection in zero balance and section voltage balance measurement procedures. The process of self-calibration method was derived. Calibration result was only related to the voltage difference measured by the lock-in amplifier during two balance procedures. The influences of reference voltage transformer, null detection transformer, auxiliary transformer and leakage current between shielding were removed. The calibration results of 1kV inductive voltage divider was presented, and the measurement uncertainty was evaluated, the relative expanded uncertainty was 5.4 × 10^-8(k=2).