Research On Shunt Hybrid Active Power Filter Without Harmonic Dectection

Non-linear load, inductive load of the utility grid inject substantial harmonic and reactive power to grid, causing serious pollution to the quality of grid, not only affecting power system normal operation, but also having serious interference on surrounding communication systems and electronic devices. Thus the elimination of harmonics has real practical significance.This paper studies the hybrid power filter which is composed of shunt Active Power Filter and Passive Filter in parallel. After discussing the structure and development of hybrid power filter, it analyses the working principle of Active Power Filter. The paper sets up a Shunt Hybrid Power Filter mathematical model and circuit model. Also the analysis of process during the transmission between AC-side and DC-side in Active Power Filter is done.Based on the above analysis, the paper studies the control mode without harmonic detection based on the grid current, which realizes the control through dq transformation. Analysis of the equivalence of new control scheme and traditional ones is done. Afterwards Phase Lock Loop is studied Its math model is established and simulation has been completed by Matlab. Passive Filter is designed. The systems with passive filter and with hybrid power filter are compared by simulation studies.In order to verify the effectiveness of proposed control scheme, an experimental system is set up. The system includes three-phase inverter, control circuit which uses DSP TMS320LF2407A as the core, drive circuit, and so on. Software programming and debugging is completed, as well as the Phase Lock Loop experiment, connecting to grid experiment and compensation experiment.Simulation and experimental results show that the proposed Shunt Active Power Filter without harmonic detection can compensate harmonic current.