Control Design And Implementation Of AC/DC Power Conversion Device

With the improvement of human living standards and industrial production levels, theelectrical equipments in power grid are increasing continually. Different equipments needdifferent kinds of electrical power. Power electronics technology converts one kind ofelectrical power to another kind of electrical power to meet different load requirements. Thepower conversion relies on the control of power electronic devices, so the research to itscontrol technology has important practical significance.The AC/DC power conversion control technology is researched in the background ofmarine power conversion device. According to the overall system design,12-pulse rectifiercircuit is chosen as the topology, using thyristor as power conversion devices. So the controlstrategy is designed based on the topology and the thyristor characteristics. There are twoaspects about the control of the AC/DC power conversion device, which are control strategydesign and control circuit design.In the control strategy design, firstly the work principle and mathematical model of12-pulse rectifier circuit are analyzed. And then the filter parameters are designed. At last,reasonable control strategies are designed. Due to its nonlinearity, when the load changeslargely,12-pulse rectifier with the PID controller can’t adapt to the changes of the systemparameters, which may lead to poor control performance. The fuzzy control can work underimprecise input and can handle nonlinear problems. So a fuzzy controller is designed for12-pulse rectifier to control the output voltage of the system. And the control performance iscompared with the one with PID controller. The simulation is under the environment ofMATLAB\Simulink.In the control circuit design, due to the integration and digitalization of the moderncircuit design, the TMS320F2812of TI Company is chosen as the main control chip, and theperipheral hardware design is based on the chip. The hardware circuit design includes ACsynchronization circuit, level conversion circuit, pulse amplification circuit, DC samplingcircuit, the serial communication circuit. And in the environment of Code Composer Studio3.3, aiming at hardware design, the software is designed, including AC synchronizationsubroutine, pulse generation and distribution subroutine, the voltage sampling subroutine,serial communication subroutine. In the communication subroutine design, the data transferwith upper computer is realized using the MODBUS protocol. Finally, the reasonableness ofthe hardware and software design is verified by the experimental waveforms.