An Overview of HVDC Power Transmission System with Voltage Source Converter

A general platform is introduced to study thedynamics of power systems with high voltage dc (HVDC) transmission links. Small-signal stability, voltage stability, and interaction phenomena of power systems with both line-commutated-converter HVDC (LCC-HVDC) and voltage-source- converter HVDC (VSC-HVDC) are addressed using the proposed platform. In quest of high efficiency, power density and problems of bulk power transmission over long distance, requirement of full control over power transmission and growing interest to incorporate renewable energy source into the grid has led to develop a new era of high voltage direct current (HVDC) transmission system. The researchers have developed many new HVDC configurations and voltage source converter (VSC) based HVDC transmission is one of them. Their high efficiency, compact size, high reliability, short installation and commissioning period and low operating and maintenance cost make it suitable choice for HVDC transmission. The HVDC system with power converter acts as a backbone and provides high reliability with a long useful life to support the AC electrical system. The power conversion i.e. AC to DC or vice versa is achieved by controllable electronic switches in a 3-phase bridge configuration.The wide spread use of AC-DC converters for various applications has resulted in power quality pollution leading to failure of sensitive equipments, reduced efficiency, etc