Impedance-Based Modelling Method for Length-Scalable Long Transmission Cable for Stability Analysis of Grid-Connected Inverter

Abstract

This paper presents an impedance-based modelling method for length-scalable long transmission cable (LTC), which is able to assess influence of LTC on stability of grid-connected inverter (GCI). Electrical parameters of power cable in per-unit-length (p.u.l.) are first extracted from the measured terminal short-circuited and open-circuited admittances. Then, the terminal admittance of power cable in different length can be derived on the basis of the obtained p.u.l. parameters. Finally, a decoupled two-port circuit model is established for the LTC using the derived terminal admittance. Simulation results are given to validate effectiveness of the proposed impedance-based modelling method for LTC. The proposed impedance-based modelling method is able to avoid repetitive terminal impedance measurement. Also, the proposed model is able to support impedance-based stability criterion for GCI with length-scalable LTC.