A Brief Comparison Between Conventional HVDC and VSC-HVDC Transmission System
摘要
The advantages of AC transmission system are mainly reflected in power generation and distribution. Due to the use of AC system, the transformation, transmission, distribution and use of the electricity in different voltages are easy to achieve. However, whether it is an AC overhead line or a cable line, its transmission capacity and transmission distance are limited. At the same time, the stability of the system and the level of short-circuit current are two limitations of AC power supply. In recent years, the conventional DC transmission technology has gradually developed and become the most mature technology in power electronics in the field of power system transmission, which is mainly used in long-distance and large-capacity transmission. HVDC transmission system is composed of rectifier bridge and inverse bridge connected through the direct current line. VSC-HVDC transmission is recently emerged, which is a DC transmission technology based on pulse width modulation technology and power electronic devices that can be turned off. This paper mainly compares the VSC-HVDC and conventional HVDC from the structure, the way of connecting to AC power system, the stability and short-circuit current influence, and also give a brief introduction of their application in practical engineering.