Multi objectives operation of cascade inverter-based voltage quality disturbance generator

This paper proposes a series multi-objective VQDG which can generate typical voltage disturbance, such as flicker, sag or swell, harmonics, unbalance and their superimposition applied to testing load. In the application, the cascade H-bridges inverter is seriesly connected between the gird source and the testing load. The device has two advantages: the output disturbance voltage level is low and the power absorbed by load is mostly provided by grid. Compared with those devices with high power rating, the size of the capacitor of VQDG will be decreased remarkably. The device is manufactured and physical tests are performed to demonstrate the variety of functions.