Research And Development Of Digital On-line UPS

Digital control of UPS becomes a trend and direction in its development with the appearance of high performance DSP controller. The application of DSP technology can upgrade the stability and the purity of the UPS`s output voltage, improve the performance of the dynamic and the steady response, also make the products easily standardized and upgraded. The dissertation focused on the research of the digital online UPS in which TMS320LF2407A was considered as the core chip. The completed work are:Based on the point of the topology of the main circuit, the dissertation analyzed the characteristics of the respective power circuit of UPS. Performance and mathematical models of the three chief parts of UPS system including APFC, DC/DC boost circuit and invert segment are analyzed in the dissertation. The servo simulation models of the system main circuit were constructed in MATLAB and SaberDesigner according to various research demands. Generation and lock of PWM signal and the deadband control were considered when system model was constructed in SaberDesigner.The dissertation represented the design methods of several important device parameters. In order to provide a solution for designing the input inductor on the electric network side which is a bottleneck of system, a new design proposal was presented in the dissertation based on the preset power amount and the depression of the current ripples. The dissertation discussed the design method of the internal current loop and external voltage loop with conventional PI algorithm as foundation. To improve the dynamic and the steady response of the system, several intelligent control algorithms were applied in the system, such as the varying speed PID with deadbeat in the voltage loop control of APFC, the predictive algorithm in the current loop control of DC/DC boost, the Parameters self-adjusting fuzzy PI control with repetitive control in inverter.A total UPS simulation platform was built in the dissertation according to the UPS control system and the main circuit model constructed above. Then the dissertation verified the conventional control arithmetic and the optimal control arithmetic of the UPS from the local parts and overall system. The detailed analysis and comparation of the input/output simulation experiment waveforms and spectrums have been done according to the input /output character of the system. In order to realize the digital and discrete simulation just as the DSP program and experimentation, all the control modules of the UPS simulation system were programmed as discrete by using MAST language first, then to be packed as modules respecticely.A new model reconstruction based on the control scheme was presented in the dissertation in the case of without the input current and the output DC voltage detection The control scheme simplified the control system design with no modification of the main circuit topology, the methematics was easy to bo implemented without any integrating and differential calculations. The system obtained fine dynamic and steady response under the new controller, so it has both of the theoretical and practical value.According to the main circuit topological structure of system and the character of TMS320LF2407A, the dissertation portrayed the design of the main control hardware circuit, the software time sequence arrangement and the software flowchart, also the deadbeat control and compensation of the system were discussed in detail.In order to improve the control performance of the digital UPS, the dissertation analysised several important design details which influenced on the holistic performance of the digital UPS from the point of appliedview and the corresponding ways and means were presented. Among these, the input voltage state detection and throw-over was the precondition and the key for the UPS to realize proper non-stop running. Based on the existed methods, the dissertation presented a new detection circuit of the input source which can quickly detect and judge the realtime state of the input source quickly.The dissertation constructed the UPS physical experiment platform and completed corresponding experiments including the half bridge rectification experiment, the batteries DC/DC boost voltage control experiment and the half bridge inverter control experiment. Through the analyses of the experiment waveforms and data, the dissertation verified the correctness of above-mentioned theories.