Topology Optimization and Measurement Performance Evaluation for Space Charge Elliptical Polarization Detecting System

Abstract

The space charge elliptical polarization detecting technique with high spatiotemporal resolution provides a reliable means to assess the electronic equipment insulation under complex PWM, dc, and ac electrical stress conditions. In this article, the topological design of the transmission-based and reflection-based space charge elliptical polarization measurement methods is proposed. Furthermore, according to the Stokes vector and Muller matrix, the signal transformation characterization model from the charge perturbation elastic wave, laser polarization state to laser optical intensity is constructed. Meanwhile, measurement sensitivity of different topological methods is analyzed. It is pointed out that compared with transmission-based elliptical polarization detection, reflection-based elliptical polarization detection has a higher sensitivity. Then, the elliptical polarization measurement sensitivity analysis platform is built for detecting topology selection from experimental perspective. Finally, the pulse electric acoustic (PEA)-elliptical polarization testing platform and PEA charge testing platform are constructed, respectively. Then, charge measurement performance of the reflection-based elliptical polarization detecting method is evaluated. The experiment shows that the reflection-based elliptical polarization detecting topology could realize insulation charge perturbation elastic wave measurement. Meanwhile, the charge measurement spatial resolution (SR) could reach up to $12~\mu $ m, in accordance with the measurement resolution of PEA charge testing method, which has the potential to be used in more complex condition measurement.