This paper presents a block diagram representation of double-sided LC compensated wireless capacitive power transfer (CPT) systems, with particular relevance to electric vehicle (EV) charging applications. The proposed representation greatly reduces the algebraic complexity in the steady-state analysis of CPT systems. It also opens up the possibility of open-loop stability analysis, which has been carried out through Nyquist plots. Additionally, an explicit expression for the optimal capacitive coupling coefficient (k_opt) is derived, corresponding to the condition that maximizes the power transfer across the CPT power train. This analytical insight enables precise estimation of the maximum power that can be delivered across the capacitive link under given operating conditions. The proposed k_opt is experimentally validated using a 1 MHz laboratory prototype, tested across a range of coupling coefficient k values. The analytical and experimental results are in close agreement, with a maximum relative error of 3%.
