FPGA implementation of digital controller for active power line conditioner using SRF theory

A large variety of electronic circuits such as inverter, chopper, cyclo-converters, SMPS used by industrial and domestic purpose, the characteristics of such equipments are non-linear in nature. Due to non-linear characteristics the load current gets distorted which causes undesirable effects like heating, equipment damages, EMI effects etc. in power network. The active power filter (APF) is the best solution for eliminating the harmonics caused by the non-linear loads. This paper presents the implementation of a digitally controlled APF. Designed in Hardware Description Language (VHDL or Verilog) the controller becomes independent of process technology. Synchronous reference frame is used for generation of reference current. PI currents algorithm is written in VHDL code and hysteresis current controller (HCC) together is implemented using FPGA platform.