Shunt active power filter as front end converter for DC loads

A shunt active power filter is used to draw reactive and harmonic components of the load power and allow only real component of the load power to be drawn from the source. Whereas a front end converter is used to control the active power flow exchange between the grid and the load. This paper presents a new approach for the shunt active power filter where it also acts as a front end converter. Firstly, it feed active power to the DC loads through the DC link and secondly, it serve as a reactive and harmonic power source for the AC load which is supplied real power from the main grid. A generalized p-q theory is applied for controlling the unified shunt active power filter and front end converter without any addition of extra components. The DC link voltage of the converter is controlled by comparing it with a reference value. Operating principle and working performance for different load perturbations are presented in detail for the converter. Control performance of the proposed shunt active power filter as front end converter is verified through the simulation studies on PSCAD/EMTDC programming platform.