Design Of Control System Of Grid-connected Inverter For Switched Reluctance Wind Power Generator Based On FPGA

As a kind of renewable energy, wind power is clean and available in plentiful supply. Therefore, the usage of wind is gained great popularity and wind power technology has become an increasingly hot topic. In a large number of wind generators, SRG is one of the most promising variable speed generators directly driven by wind generators due to its large range of speed changing, excellent low speed performance, reduced motor loss, constant voltage DC output, simple grid connected and needless of gearbox, etc. However, the usage of SRG has been seriously hindered for lack of thorough and systematical study in grid-connected inverter for switched reluctance wind power generator.Based on the application of SRG in wind power field, this paper mainly focuses on the digital control technologies of grid-connected inverter for wind power, and makes all-round study, from simulation to experiment test.Started with SRG’s advantage in the field of wind power, this paper analyzes the study status of SRG in the field of wind power and control technologies of grid-connected inverter for wind power. And then, the main contents and meanings of this research are conformed. On the basis of analyzing the architecture and principle of Switched Reluctance Generator System, an exhaustive study about control problem of grid-connected inverter’s current output and phase-lock problem of3-phase circuit’s voltage. With these analysis and research this paper sets a control scheme of grid-connected inverter’s current output based on variable frequency based hysteretic SVPWM and a design approach of network phase-lock based on d-q transformation. For a better study of the control scheme, a simulation model of its grid-connected inverter is also built in Matlab. Through the simulation waveform of3-phase current output, influence of hysteresis width is analyzed to test the availability of the control scheme presented. What’s more, system parameter is presumptively determined by the simulation waveform of three phase phase-locked loop.With a clear control scheme and system requirements, EP3C10E144, a sort of FPGA chip, is selected as the main control chip to design the hardware control system of grid-connected inverter for switched reluctance wind power generator in this paper. By design philosophy of signal sampling circuit, FPGA operating circuit, communication circuit, driver circuit and power source circuit detailed introduced in this paper, hardware circuit interference problem encountered during the design of hardware circuit is analyzed and then some effective anti-interference measures are adopted to satisfy electromagnetic capability requirements and a hardware platform is therefore has been accomplished.On the basis of detailed research on control scheme and in relation to the design of hardware circuit, this paper realizes some function blocks of grid-connected inverter control system on FPGA with VHDL. Meanwhile, optimized sequential logic and multiplier time sharing method are adopted in the realization of those function blocks to ensure the reliability and high speed of the control algorithm.Finally, functional simulations about those gird-connected inverter control system function blocks designed in this paper are made. Performance test based on the experiment platform built in this paper show that in voltage balance3-phase network, with a low aberration rate, the frequency and phase of the gird-connection inverter can flow the network voltage quickly, so it can totally meets the system requirements of grid-connected inverter for switched reluctance wind power generator.