In this thesis, after a survey on harmonics problems and different mitigation techniques, Hybrid Active Power Filters (HAPF) are studied. HAPFs are a newer kind of filters used to control harmonics in power systems. These filters are made by combining passive and active filters to prevent resonance of passive filter while obtaining better filtering quality with a small rated inverter. An introduction to passive and active filters is given and some methods used to combine these filters are studied. There are two commonly-used types of HAPFs…Using TMS320F2812 DSP unit, the direct current control approach with finite states predictive current controller and the finite states unified control approach are implemented. The implementation results are compared with simulation results to verify viability of proposed method. Different practical and software optimization techniques are discussed in details. In the end, there is a summary of thesis and suggestions for further studies. Keywords: Dissertation format, keyword, keyword, keyword (4 to 8 keywords are necessary)