Research On Digital Control Technology For2kW Single-Phase Power Inverter System

With the development of railway electrification and the maturity promotion of DC600V powersystem on passenger trains, research on vehicle-based inverter is becoming more and moreemphasized. And how to ensure that the vehicle-based inverter can work high stability, high reliability,fault emergency response capability during high-speed train running is the main research directions.Meanwhiles, with the continuous perfection of digital signal processors, it has been used more widelyin power electronics applications. In vehicle-based inverter applications, digital control is graduallyreplacing the traditional analog control. And digital control also provides the prerequisite andfoundation for the realization of intelligent monitoring and management in train power system.The digital control technique for single-phase power inverter system is studied on the thesis. Thissystem tepology include pre-stage push-pull DC-DC boost converter and post-stage single-phasefull-bridge inverter.Based on the state-space averaging, the average model of the control object isderived for the two-stage inverter system. Then, in order to obtain more rational and more precisecontrol parameters, this paper expounds the design idea and design process of the digital controller indetail. The digital controller design of pre-stage converter is studied by different instantaneous valuefeedback control schemes, which are used for inhibiting the low-frequency input current ripple ofpre-stage and are verified by the reverse current gain model and MATLAB simulation. The work alsoinvestigates the digital controller design of single-phase full-bridge inverter.And the compoundcontrol strategy with mixing repetitive control and dual-loop control is studied because of thedrawback of traditional instantaneous value feedback control.Finally, the paper presents the integrated design of single-phase power inverter system, includingthe design of general structure, the selection of main power device, the design of filter circuit,assignment of the control resource and the design of software structure flow chart. At last, a2Kwexperimental prototype is built, and the experiments for validating the above theory are carried out.The resulet indicates the feasibility of the digital controllers designed in this paper.