Study of the reactive power and influence on AC grid in startup process of voltage source converter

摘要

DC distribution network is the basic supporting component of the future Energy Internet. A variety of power supplies, load, energy storage devices can be integrated to DC distribution network and it will act as energy management unit in Energy Internet. Due to of the large amount of DC capacitors contained in voltage source converters, the consumption of reactive power in the startup process needs to be calculated specifically. This paper introduces two basic charging strategies, and the numerical expressions of reactive power in different charging strategies are deduced. The current-limiting resistance will affect reactive power and completion time of charging significantly. Simulation results show that AC voltage will be affected seriously by the oscillation of reactive power, which leads to amplitude drop and waveform distortion during mode switching.