Operation and correlation of VSC-based technologies in city center power grids

With the development of urbanization, the power consumption in cities is increased, and the distribution of power equipment and power load is also more concentrated. However, the city power grids normally suffer from uneven power flow distribution and high short-circuit current level. In cases of peak load periods, some substation transformers may encounter overload conditions while some nearby transformers are only lightly loaded. Such a dilemma may be solved by the use of power electronics devices based on voltage source converters (VSC) technologies. VSC technologies are capable of optimizing the system power flow and provide fast and flexible control capability. The paper studies the viability of applying VSC in urban grid transmission systems, and further considers the correlations of VSC based HVDC links and FACTS devices.