Critical issues in space charge estimation using PEA system

Space charge accumulation in dielectrics is an important phenomenon that needs to be fully understood for effective utilization of dielectric materials. Pulsed electro-acoustic method is one of the well-known techniques used to measure these space charges. However due to limited frequency bandwidth of sensor attached at ground electrode, the method requires signal processing technique like deconvolution to get actual charge profile inside dielectric material. If there is no noise in experimental charge signal deconvolution turns out to be simple and requires only spectral division. However in practical cases noise is present in experimental charge signal and deconvolution turns out to be complex and various factors like resolution and noise are affected in restored charge profile during deconvolution process. This paper addresses such critical issues encountered during estimation of space charge signal. Experimental signal obtained in the authors' laboratory has been used for original charge estimation using a PEA system, which is developed in the authors' lab.