Study Of A Universal Medium And Small Variable Frequency Power Supply

Since the exhaustion of the traditional energy, the high opinion of the environment and a variety of defeats of the current power system, distributed generation would bring into play more and more significant action. Recent years, some new distributed generation technology, such as fuel cell, micro gas turbine, solar cell and wind power generation, developed rapidly. But electricity generated by them can not merge into the electrified wire netting or supply the loads directly. It should be converted to the electricity with the phase to ground voltage is 220V, and the frequency is 50Hz to merge into the electrified wire netting or supply the neighboring loads.This paper introduces a medium and small variable frequency power supply for a distributed generation, which including a permanent magnetism dynamo pulled by a diesel engine, to converts the medium frequency electricity generated by the dynamo into the electricity which the ground voltage is 220V, the frequency is 50Hz. Based on surveying the development of variable frequency power supply and analyzing its development tendency, and considering the practical features of the assignment, the conversion system is designed as follows: it selects the 3-phase Pulse Width Modulation Engine SA4828 as the PWM control signals generator; it chooses the single-chip-computer PIC16F877 as the microcontroller, which integrated the A/D modulation, which cuts down the complexity of the hardware system and strengthens the dependability of the system..The paper introduces the design process of the hardware and the software, the simulation results and the tests results. The simulation results and tests results show that the conversion system introduced in this paper works well, and meets the design demands. The job of this paper worked for deep research and established the foundation.