Harmonic Elimination And Reactive Compensation Based On Digital Signal Processor

qA general description of the harmonic and reactive current, the development of harmonic elimination and reactive compensation technique around the world and theory of three-phase instantaneous reactive power is given in this thesis at first. The i_p - i_q imethod based on theory of instantaneous reactive power in detecting harmonic and reactive current is researched as emphases.Then the principle and structure of Active Power Filter is introduced. The simulation mode of Active Power Filter in harmonic elimination and reactive compensation based on i_p - i_q method is given in SIMULINK environments of MATLAB 6.5 software. Simulation research to the method of PWM control of generating compensative current is done. The purpose of simulation is discussed the structure and performance of the lowpass. The system control to the Active Power Filter is also researched. The results indicate that the simulation mode and the simulation means implemented are proper and efficient.At the basis of simulation, the experiment of integrated compensating harmonic and reactive currents shunt APF controlled by TMS320LF2407 is established. The hardware system and the software system of this device are designed. The hardware circuits include the current and voltage detecting, the PWM driving circuit based in 6SD321EI module, the main circuit and the protecting circuit of IGBT. The software system is written by DSP compile language. The main program includes the interrupt control, zero point detecting of voltage, harmonic and reactive currents detect, the DC bar voltage control, the PWM control and the protecting control.Finally this paper introduced wavelet theory and produced a new harmonic suppression algorism which high speed. The test results from CCS show that the proposed method is effective,which can be used to enhance the harmonic suppression function of the power system.