Study On Three-phase Six-switch High Power Factor Rectifier Based On DSP

Improve the power factor is an effective solution to decrease the harmonic pollution which comes from power electronic devices, especially the harmonic pollution comes from AC/DC converter, It is the effective way to improve power quality and reliability. To this end, High power factor and low current harmonic distortion of PWM rectifier technology turn into the application of power electronics technology research focus. Three-phase six-switch rectifier with the advantages of less switching devices, the network side of the current unity power factor, low current harmonics, control high degree of freedom and two-way flow energy. Widely used in high power applications. Typical control way of three-phase six-switch rectifier mostly using vector control technology. This control skill design procedure cumbersome, required more components and more complex control circuit, high cost. One Cycle Control technology is one of novel nonlinear control technology. There are modulation and control dual function, automatically eliminate the steady-state and transient errors, not sensitive to noise, fast dynamic response, robustness, low current harmonic distortion etc. So it’s important theoretical significance and engineering value to explore One Cycle Control technology in three-phase six-switch rectifier.Firstly, This dissertation analyzes the purpose and significance of the power factor correction (PFC). Analysed the active power factor correction technology development status of various topologies and control strategies. Analysised the pros and cons as well as their respective applications.Secondly, Analysed the basic principle of One Cycle Control technology. Introduced the details working principle of a three-phase six-switch rectifier. Analysised of the rectifier work under different working modes in section six. Derived the mathematical model of the three-phase six-switch rectifier under One Cycle Control. Got key control equation.Then, according to the design specifications and parameters, Designed the hardware and software of three-phase six-switch rectifier. Introduced boost inductor, power switches, output capacitor of the main circuit, the DSP minimum system, voltage and current sampling conditioning circuit, driver circuit of control circuit, and auxiliary power supply. Designed the software control program. Including system initialization, PWM, ADC, interrupt service, current inner loop and voltage outer loop PID control program.Finally, a 1Okw rectifier prototype is realized. Conducted experiments with different output power levels. Measured the experimental results with different output power levels. Experimental results show that, Three-phase six-switch rectifier used One Cycle Control there are theoretical feasibility and practical engineering significance.