Destructive consequences of trapped space charges within HVDC coaxial cable insulation, such as accelerated aging, degradation, and breakdown, are some of the most significant challenges that manufacturers and users usually come up with. Pulsed Electro-Acoustic (PEA) method is a widely-used method for space charge detection and measurement, in which the space charge profile is mapped through acoustic waves that are excited by applied pulsed-voltage. There are a few practices for pulse application into PEA circuit. Pros and cons of the different injection practices have been remained unknown due to limited accessibility to the critical points like the core conductor. Modeling of the pulse injection setups can help us with simulating the essential parameters, like voltage and current, at the unreachable spots. The way how the circuit can be modeled, selecting adequate software and transmission line model, strengths and weaknesses of the injection practices and the changes required for possible optimization in the practices are challenging questions that need to be answered. This thesis develops frequency-dependent models for all the PEA injection setups that are usually deployed for Medium Voltage (MV) mini-cables geometry. It shows, through a validation
process, that PSCAD/EMTDC phase model can yield sufficiently accurate results with reference to the lab measurements. In the next stage, the questioned strengths and weaknesses of each original design setup are determined through a series of lab tests and computer-aided simulations by utilizing of which the best setup is recognized. Seeking some approaches for further optimization of the setups is also another aim of this research. This thesis proves that the PSCAD/EMTDC phase model is capable to present an acceptably exact model for the circuits, despite having some limitations that will be explained. Operational
versions of all setups, in which the fundamental problems are cleared up, will also be proposed in this thesis. Among all the setups, Core Pulse Injection (CPI) and Table Pulse Injection (TPI) practices offer the best non-optimized (original design) and optimized results, in terms of quality of the delivered voltage across the target dielectric respectively, while the original design of Double Side Pulse Injection (DSPI) and Single Side Pulse Injection (SSPI) seem to be unreliable due to severe oscillatory behaviors. Nevertheless, two modified versions for DSPI and SSPI show quality results.