Study On Single Phase Three-level Power Factor Correction Converter With Digital Control

With the broad use of power electronic equipment, electromagnetic pollution becomes a more and more serious problem. All the countries make the strict standard for the power factor of electronic equipment. Thus the power factor correction (PFC) techniques have been a hot point in the field of power electronics in recent years. Meanwhile, with the continuous increase of the requirement for voltage level and power level of the power electronic equipment, multilevel converters, as an interesting solution according with the trend, have drawn tremendous interest.Digital signal processors (DSP) have been extensively used in areas of motor control and power switch supply control system. Compared to traditional analog control, DSP controllers have more advantage. With the rapidly improvement of DSP, more and more control schemas can be realize.This paper mainly study three-level Boost PFC control by digital method, present a modified predictive algorithm for three-level power factor correction.Based on analyzing operational principle and control strategy of three-level Boost PFC, we can obtain three-level Boost PFC possess more advantages in higher frequency smaller, volume of magnetic device and lower loss compared with one-level Boost PFC.The paper adopt a novel a modified predictive algorithm in digital control strategy. Base on researching tradition predictive algorithm, the method improve the capability of system in a way. It only can achieve higher switch frequency which normal digital control scheme can not reach, but also eliminate affection of output voltage ripple to control loop system. With this digital control scheme we can realize the higher power factor and output voltage cannot be change when load changed.Designed the digital signal processors and sideline circuits of three-level Boost PFC. Digital signal processors attach TMS320LS2407 of TI Company. The software system contained initialization module, PI algorithm module, digital accomplishment of voltage loop and current loop module, sampling algorithm module and program flow chart of whole system.According to the theory analysis, design the whole system of three-level Boost PFC controlled by modified predictive algorithm. The application efficiency is proved by the experiment results.