Development and Implementation of Bi-directional Voltage Source based Converter for HVDC Applications

Abstract

Nowadays, huge wind farms are built far out in the sea, which is beneficial from power generation point of view but not that lucrative when it comes to connection of the power source to the AC grid.

HVDC transmission based on Voltage Source Converter (VSC) technology which uses IGBTs and extruded DC cables is the most recent HVDC technology used for low power transmission which easily connects wind farms and solar farms to the grid. It operates with high frequency PWM in order to get high speed control of both active and reactive power. With PWM, it is possible to create any phase angle or amplitude (up to a certain limit) by changing the PWM pattern, which can be done almost instantaneously. Continuous and independent control of active and reactive powers is possible with VSCs used for power transmission (or voltage support combined with an energy storage source). Though LCC-HVDC can handle more power, it needs commutation voltage supplied by a synchronous compensator/STATCOM to the SCRs.

This project involves the simulation and analysis of the bidirectional operation of VSC under static as well as dynamic conditions of R and RL loading and its hardware modelling indicating the boost operation of such a converter with unity power factor at the input.