Power transmission line analysis using exact, nominal π, and modified π models

An improvement in the simulation of the power lines is obtained by adding a negative capacitance in parallel with the series inductances in the π-equivalent circuit model.In electric lines and cables paraments are not lumped, but distributed all over the length of the circuit. Resistances, conductances, capacitances, and inductances are all expressed in Ω/m, /m, F/m, and H/m respectively. However, upon expanding 1/Z´ and Y´ in terms of the dimensionless variable (γL), where L is the length of the line, one more term leads to a more elaborate equivalent circuit, with an additional negative capacitance in parallel with the Z´.In this paper I will compare the Exact model, Nominal π, and the modified π model using 1. Input Impedance Study 2. Input to Output Voltage Ratio including two case studies 3. Output Voltage Transient Response.