Accurate derivation of switching dynamics for load compensation in non-stiff source distribution system

In this paper, an accurate derivation of switching dynamics of voltage source inverter (VSI) has been obtained for the load compensation application in a non-stiff source distribution system. The method of hysteresis current control has been used for tracking of the reference current for the shunt connected VSI. The feeder impedance and load dynamics are included in the derivation which otherwise have been neglected in the switching frequency formulation in all the results derived so far in the literature. Further, a modification in the switching dynamics has been obtained on the recently published result. It is shown that the derivative of the reference current has significant effect in determining the switching frequency. Its effect becomes more prominent when the VSI need to compensate nonlinear component of the load. The derived results are verified using PSCAD/EMTDC simulation studies for a single-phase distribution system drawing a fixed spectra harmonic load. The experimental validation of the proposed result is obtained for nonlinear load compensation in a distribution system using FPGA programming of the control algorithm.