Voltage sag and swell generator with series injected inverter for the KCPP

This paper proposes a new SSG (sag and swell generator) with series injected inverter for the KCPP (Korea Custom Power Plaza), which is being constructed with the fund of the National Project in Korea. Main purpose of KCPP is to test and to evaluate several different kinds of high power CPD (custom power device) under the several power disturbance conditions before installing it in real site. We can generate typical power disturbances such as sag, swell, over voltage, under voltage and voltage flicker by using the proposed SSG composed of series inverter, energy storage DC capacitor, rectifier and voltage clamp circuit Also we can generate the distorted voltage waveforms and the phase jumping waveforms by controlling the series inverter In this paper, three kinds of control methods for the proposed 2 MVA SSG are given. Typical voltage sag and swell waveforms are implemented by adopting simple control method. Also the voltage flicker is generated by changing the amplitude of the injected voltage in random. Owing to the limited bandwidth of the proposed SSG, high frequency transient waveforms can be obtained by using the open loop control. The simulation and experimental results are given to verify the operation of the proposed SSG. Finally, conclusions will be given.