A Vector Control based Shunt Current Compensation Scheme for Power Quality Improvement in High Power Radiology Applications

The following paper proposes a Space-Vector based active filter for 3-phase systems, in order to improve the source end power quality. A shunt converter topology has been considered, which is vector controlled in order to ensure a fundamental sinusoidal current drawn from the mains supply. The control scheme senses the supply side voltage and the load current to generate the three phase reference signals. Control action is achieved in the fundamental rotating (d-q) reference frame. The converter connected in parallel to inject a compensating current at the PCC so that the harmonics present in the line are cancelled out and the sinusoidal nature of current is restored. A three phase system supplying a rectifier load is considered here since it closely emulates the HV generators used in Fixed Room Radiology applications. The system has been simulated using MATLAB and the results are presented.