Hardware Design And Research Of Control Method About Power Electronic Filter

As the techniques of power electronics have been made great strides, electronics and electric devices are widely used, which do bring about convenience, efficiency and profits. However, with characteristics of non-linearity, impulsion and electric imbalance, these devices produce abundance of harmonic and reactive power in the power grid, which causes so distinct decline of power quality that the security and normal operation of power grid and electrical equipment might be endangered. This research aims at designing a device which can eliminate the harmonic in three-phase three-wire power grid.At first, the paper elaborated the harm of the harmonic for power grid and electric equipment, and points out that the most effective comprehensive treatment means of power grid pollution is the power electronic filter, which has a broad application prospect. Then the general situation and the present situation of the development of power electronic filter have been introduced. Then the power electronic filter has been classified from different aspects.Secondly, critical technology of power electronic filter, including real time detection technology of harmonic, control technology of converter and control technology of capacity in DC side of converter is recommended. The shunt power electronic filter has been chosen as the research object, which has been widely used. Put forward a no harmonic current detection scheme. No harmonic current detection scheme and harmonic current detection scheme are analyzed respectively.Thirdly, the option method of every component is presented, capacitance and its voltage value, inductance value, request of switching device is fixed. Simulation model, based on MATLAB/SIMULINK, is established, and run under given parameter and condition. Simulation results show that the overall system can fulfill filtered assignments. Then on the basis of correct simulation, hardware is designed according to the concept of modulization, which include signal detection module, control module, converter and its drive module, protection module. Signal detection module is in charge of detecting current and voltage signal, regulating the signal and giving to the A/D port of control module; TI company’s TMS320F2812is used as the control chip, the correct PWM waveform is generated by software algorithm; Control wave through the drive circuit so that it can drive the main circuit of IGBT, and at the same time driving circuit gives effective electrical isolation. Protection model let the overall hardware can run safely and reliably.Finally, a real-time data-detecting system has been designed, and experiment has been done with different load, and the results are analyzed. The real-time data-detecting system plays a very significant role in experiment. The paper laid the foundation for further power electronic filter system experiment.