| With the fast development of information technology, digital CVCF-PWM inverters become possible. The capability of the on-line UPS is the best among all kinds of UPS. This dissertation focuses on the study of the digital SPWM inverters. It can provide the steady and pure sine wave power with little distortion. This dissertation introduces a design method of a digital control SPWM inverter. The core control chip is TMS320LF2406.First of all, the developing state of UPS, the advantage of the DSP technology applied in the UPS,the characteristics of modern technology are summarized. The continuous and discrete state-space model of the system are analyzed and established. The influencing factors on the fundamental wave are discussed. How to produce SPWM through TMS320LF2406 is also introduced in the thesis.To control the inverter in UPS, several kinds of repetitive control projects are discussed step by step, at last the thesis uses the plug-in repetitive control with the proportional and integral control. The simulation model of the 50Hz inverter is designed according to the project and the parameter of the system, and the results are provided. The theory analysis and the simulation results both prove the correction and the feasibility of the project.In the part of hardware design, the operating principle of on-line UPS is introduced, and the hardware implementation block diagram of the inverter system is provided. Furthermore, the dissertation analyzes and designs the power circuit and the control circuit in details, detection circuit of voltage and correlative circuit and so on are also introduced.The software design of the inverter system is described. The sequence, the interruption and some important flowcharts are analyzed and their block diagrams are provided in details At the end of this dissertation, the experiment results of the system are provided, The results show that the proposed control scheme can stabilize the output 50Hz sine wave wel1,is a cost—effective wave for UPS invert control system. |
