The Research Of Distributed Generation Used Three Phase High Power Factor Rectifier

Because of the advantage such as making full use of new and clean energy, as well as be very efficient and flexible, distributed generation is to be the most important researches in the field of power system. But this useful technology needs high power factor, low harmonics pollution rectifiers and inverters to be its energy converters. In addition, traditional diode rectifiers and thyristor rectifiers are nonlinear load, they draw pulsed current from the ac main, causing significant current harmonics pollution and low power factor. Unity power factor rectifiers can improve the power factor, reduce the harmonic pollution. And because the international standards presented in IEC 1000-3-2 and IEEE 519 impose firm harmonic restrictions to modern rectifiers, a focused research effort on the topic of unity power factor rectifiers is intrigued.The project is a subproject of the nature science foundation project "The Research of Micro-gas Turbine-High Speed Generator Distributed Generation and Energy Converter System". Its aim is to convert the high frequency AC power produced by high speed generator into steady DC voltage with unity power factor rectifier, and supply the power to the later inverter to get reliable steady industrial frequency AC power. While three phase unity power factor rectifiers are applied in the high power field, it is more technical and complicated to control and costly in its researching period. Nowadays, low-cost, high-performance digital signal processing controllers, such as the Texas Instrument's TMS320LF240x, provide a better and cost-effective solution for a three phase rectifier's designing.This paper presents a digital controlled SPWM three phase bridge unity power factor rectifier which is based on a DSP controller. The core part of the main topology is an intelligent power module (IPM). Sampling from the DC output voltage and computing in the PI voltage loop, we get the reference of the current loop, then we make this reference multiply with each phase angle of each phase so that we get thereference current of each phase, and with three current PI loop computation, we get the control signal for switch components. With the great computing power of DSP controller and its peripherals specially designed for controlling field, we integrate all the function the system need such as the ADC sampling, computation of the control loops, PWM generation, fault protection into a single controller.This research focus on a 10KW SPWM three phase bridge rectifier, as a subproject, it offers a research basis to the mother project and it is meaningful for more intensive research in the field of high power factor rectifier in the future.