Conductance based fryze algorithm for improving power quality for non-linear loads

In the present scenario, non-linear loads are increasing day by day, due to which harmonics are being injected in the power system. This affects a number of sensitive loads connected to the system and affects their performance. This paper discusses the simulation as well as hardware implementation results with a Distribution STATic COMpensator (DSTATCOM) for compensation of unbalanced loads and harmonic currents produced by non-linear loads. The control scheme used for the compensation is conductance-based on the generalized Fryze currents minimization theory. A proportional-integral (PI) controller is used for maintaining the dc bus voltage of the capacitor used in voltage source converter (VSC). The switching of VSC is done using Hysteresis Current Controller (HCC) based on indirect current control scheme. The hardware implementation of DSTATCOM is implemented with the help of dSPACE DS1104 R&D controller having TMS320F240 as a slave DSP. Both MATLAB-based and hardware implementation results are presented for demonstrating the steady state as well as dynamic load conditions. The conductance based Fryze control scheme is found to be very effective in reducing the THD of supply current to IEEE-519 standards.