Purpose
The pulsed electro-acoustic (PEA) method is widely applied for space charge measurement in solid dielectrics. The signals, however, can be seriously distorted during transmission, especially in non-planar specimens. The aim of this work is to find an efficient algorithm to correctly recover the space charge profile for different types of specimens.
Design/methodology/approach
The distortion can be associated with both geometry and material (attenuation and dispersion). Hence the recovery algorithm consists of two parts respectively. The influences of geometries, causing the divergences of electric force and acoustic waveform, can be corrected by sets of factors. The attenuation and dispersion of the material can be suppressed based on the transfer function matrix in frequency domain, which could be obtained from calibration.
Findings
A general algorithm applicable to three kinds of specimens (single-layer, multi-layer and coaxial-geometry dielectrics) has been proposed. Compared with the other two algorithms in literature, the present one offers the most accurate solution while taking relatively shorter time. In addition, this algorithm is applied on signals measured from a planar LDPE sample and the results show that the new algorithm is fairly effective with excellent stability in a real system.
Originality/value
As one of the most accurate algorithms, the present one is theoretically one third quicker than the others. This algorithm would be helpful in applications calling for large calculations, i.e. 3-D imaging of space charge distribution in XLPE cable.
A General Conductivity Expression for Space-Charge-Limited Conduction in Ferroelectrics and Other Solid Dielectrics