Control System Design Of Switched Reluctance Generator

As a new motor, Switched Reluctance Generator shows great potential in the field of windpower with its features such as low-cost, simple structure, easy interconnection with grid and high fault tolerance and its research has gradually deepened. Currently the output voltage optimization of SRG mainly relies on phase current control, yet angle control is few for its low accuracy and poor results. Therefore, this dissertation focuses on SRG control system, aimming at improving output voltage stability based on the angle and completting the design of the system, with an in-depth study in the control algorithm and expermental platform.Specific to the high copling and strong nonlinearity in SRG caused by its doubly salient structure, the dissertation analyzed the energy conversion relationships. Then based on the structural parameters, finite element analysis has been done to establish a two-dimensional table of flux, current and angle to determine the nonlinear model. The simulation of whole system model was built and the system performance under different parameters is analysed.To enhance the stability of dc-link voltage, this dissertation designed a strategy based on angle control. A control algorithm that turn-on angle based on regerence voltage value and turn-off angle based on the dc-link current ripple factor was determined, so that the output voltage can track the given voltage within a certain bisa. Then a new freewheeling operation was proposed, and its theory significance was analyzed and showed good effect in inhibitting the current fluctuations. Further, the freewheeling angle analytic fuction was designed based on switching angle, speed and dc-link voltage and the analytical characterization of each part is analysed. Then through a large number of simulation data and the way of parameters tuning, the function was determined. Simulation results showed that, through the progressive optimization of angle control, output voltage stability reached a consistent result compared with current control. Thus it shall lay a foundation for achieving multiple control objectives.For experimental prototype, software and hardware design of switched reluctance generator control system have been conpleted, and the experimental plotform has been built.The feasibility of the output voltage optimal strategy based on angle control is verified by experiments.