Active Power Compensation of Voltage Source Converters with Energy Storage Capacitors

The voltage at the point of common coupling (PCC) in a weak network is very sensitive to load changes. A sudden change in active load will cause both a phase jump and a magnitude fluctuation in the bus voltage, whereas reactive load changes mainly affect the voltage magnitude. With the addition of energy storage to a static synchronous compensator (StatCom), it is possible to compensate for the active power change as well as providing reactive power support. In this paper some effective active power compensation schemes are proposed. Simulation and experimental results verify the compensation schemes by showing that a StatCom with energy storage can significantly reduce phase jumps and magnitude deviations of the bus voltage. Simulation results are also presented showing the benefits of active power compensation to certain applications with phase sensitive load