The Research Of Rectifier Control System For High-power On-line UPS

Uninterruptible-power-system (UPS) supply emergency power in case of utilitypower failures and are nowadays widely used as backup power in the Industrialproduction and social life, it includes three main control modules: AC/DC rectifier,DC/DC converter and DC/AC inverter. As the critical part of the UPS system, AC/DCrectifier should produce high reliable and high efficient output DC voltage for nextDC/AC inverter and battery whether the load is linear or not. The control strategy ofrectifier is widespread concerned by the control circle. This paper also focuses on theresearch of the AC/DC rectifier for UPS. On the bases of detailing the control strategyand the circuits of AC/DC rectifier, this paper introduces the T-S Fuzzy-PID logic theoryinto the control of rectifier. In order to realize the control strategy, TI high performancemicro controller TMS320F2808chip, the kernel of the intelligent controller was adopted.Both of the simulating and the experimental result prove that the study has its validity.The main research work and contributions of this paper are as follows.1．The current and the future developments of UPS and the main control strategies ofAC/DC rectifier are summarized and then the paper analyzes the overall structure ofrectifier, the regulator control technology of DC bus voltage and how to use the pawmodel of DSP to drive the SCR of12-pusle rectifier. Lay a foundation for the nextsystem analysis and programming.2．Present the realization methods of the hardware circuit and the software algorithm. Byconstructing the overall diagram of the rectifier system and the key circuit surroundingthe rectifier, the working principle of the rectifier’s major components is analyzed.Select T-S fuzzy PID control as the entire system control scheme, and thencommenced the programming based on the DSP chip.3．In order to know whether the proposed scheme is really feasible or not, the simulationin the MATLAB SIMULINK platform and the hardware emulator was carried out.The results show the feasibility of the scheme. Then test was launched on the actualprototype, test results have fully demonstrated that the control strategy can play a good role in the AC/DC output voltage control, and the output of the AC/DC rectifiersatisfies the practical requirement.