Modelling and Control of an Inverter for VSC-HVDC Transmission System with Passive Load

This paper is about a study on inverter control of a voltage source converter based high voltage direct current (VSC-HVDC) transmission system. An inverter model has been developed for the purpose of system control and stability analysis. The VSC-HVDC system is the exclusive power supply to a passive load in this study, and the control objective is to obtain a constant sinusoidal output voltage under load variations. State space equations are derived to obtain the root loci, and to analyze the system stability. The influence of the circuit parameters on the system stability is investigated using the root loci. Results obtained from the simulation studies using EMTDC/PSCAD have verified the theoretical model and the proposed control method.