Design Of Digital-Controller For The Three-Phase Variable-Frequency Power Supply

Technology of variable-frequency is a very important technology for energy-saving and environmental-protection. It's widely-used in industry production, traffic transportation and electrical appliance. Now, we are not only satisfied with the basic performance (such as stabilized frequency and stabilized voltage) of the variable-frequency supply. The direction of the development of the variable-frequency supply is digitization, high frequency, high power-density, high factor, low wastage, low harmonious etc..In this thesis, the method to set up math-model of supply is introduced and the model is given. Some important control methods are analyzed, and, the realization of two loops of current inside and voltage outside is introduced in detail. According to the requirement, the design of hardware and software of the power is given. And finally, the design is summarized objectively.The design of the power system can closely follow the direction of the development. At first, the supply has high factor because of the application of APFC. Secondly, in the control part, the double CPUs system of DSP (TMS320F2812) and MCU (PIC16F877) are used, so, the supply has high grade of digitization and has good characteristic of real time. Thirdly, the use of SVPWM makes the power has higher utilization ratio of DC voltage than SPWM. At last, the adoption of double loops control enables the supply has better characteristics of dynamic and static.