Design Of Wind Power Switched Reluctance Generator

Under the background of these questions become more and more increasinglyacute with each other, such as energy shortage, environmental protection and climatechange, the development of clean energy, smart grid construction, development oflow carbon economy, realization of optimal dispose of energy, wind power have beenbecome the common choice all over the world. As the national strategic emergingindustries of our country, the importance of wind power is never change in China. In《2006-2020plan for national program for long-and medium-term scientific andtechnological development》, it has been Put forward clearly that the renewable energydevelopment and utilization with low-cost large-scale should be vigorously carry out,up to2010, the wind power capacity will be over150million kilowatts. On March19,2013, the new approved the "twelfth five-year" in the third batch of wind powerproject plan has been announced by the national energy bureau, The scope of windpower will be over28.72million kilowatts.In the case of wind power development at top speed presently, there are manyopportunities of the small wind generator,(1) At present, the type of wind generatorin China are large power mainly, there is an area to be developed for the type of smallpower direct driving wind generator;(2) There are some places near city withsufficient wind power, it is not suitable for large power wind generator, but the smallpower wind generator will have to show its mettle in these places;(3) There anmany wind energy resources among large power wind generator have been wasted,and the small power wind generator can be used as a supplement;(4) With highperformance and high reliability, the small power wind generator is suitable toProvide security power for live and production in remote areas.The switched reluctance generator (SRG) system with12/8pole motor isresearched in the paper. And the relationship of related parameters in switchedreluctance generator power is explored, such as the open angle, the turn-off Angle, theexcitation voltage, the excitation current, and the topology structure of its powerconverter, the control method; To increase the variable wind speed adaptability forswitched reluctance generator to the wind machine (with the simulation of a primemotor), a piecewise control strategy is proposed. In low speed, the control strategy isvarying step and the maximum wind power tracking control; In high speed, theconstant power control strategy is adopt. The simulation model for switchedreluctance generator system with12/8pole motor is on MATLAB/SINULINKplatform is built, and do the experiments on the experimental prototype, the simulation resultshas verified the feasibility and effective of the control strategy.First of all, under the support of projects in National energy bureau and Hunanprovince key, the large number of information literature of small power windgenerator and SRG in recent five years for domestic and foreign has been consulted,on the basis of the development situation for SRG, the existed problems about SRGhas been found. In accordance with the specific wind power application field (such asgreen building with DC micro-grid, the Communication power, et al), the small power low-speed direct-drive switched reluctance wind generator has been researched anddesigned.Secondly, several common structural characteristics of switched reluctancegenerator has been summarized, such as6/4pole,8/6pole,12/10pole, and12/8pole.To meet the requirement of low speed and small power switch magnetic resistance,the12/8pole SRG is suitable for small wind power to power for green building withDC micro-grid. By analyzing the interrelationship among the power mode in SRG, thenonlinear dynamic inductance, in and the switching loss, the linear control strategy ornonlinear control strategy is carried out on SRG; there are several working mode ofSRG is discusses (such as pulse width modulation, pulse frequency modulation, currentchopping control mode, angle position control mode, etc.), the reasonable choice isthe synthetic mode of current chopping control mode and angle position control modeto improve power generation efficiency of SRG.Thirdly, According to the actual situation of nonlinearity of SRG dynamicinductance, the nonlinear magnetic chain, and the nonlinear controller of SRG powerconverters, the nonlinear mathematical model of SRG system has been built, basedon the following four equation, the voltage equations, the flux linkage equations, themotion equations, and the torque equation. And the simulation model of SRG onMATLAB/SIMULINK software platform, the segmented control experiments hasbeen accomplished.(1) Under the current chopper control mode, the capture for themaximum wind power realization in low speed is realized.(2) Under the angleposition control mode, the constant power control of high speed period is realized, toprotect the wind turbines and SRG, the simulation experiments is carried out, such asthe opening control of SRG system, the closed-loop control of SRG system, theprocess of voltage building of SRG, the process of changing load, and the process ofvarying speed respectively.Fourth, based on the single-chip microcomputer control technology and thepower electronics technology, a set of switch magnetic resistance experiment systemis designed, where SRG hardware circuit is designed, such as the power converter, theprotection circuit, the position detection circuit, the current detection circuit, thevoltage detection circuit, and so on. The software is programmed, such as the mainprogram, the lock program of phase for SRG rotor, the control program of the openangle and the shutoff angle, the detection program, and the monitoring program, thedata processing program.Finally, the commissioning and integrated test for hardware and software iscarried on, the phase parameters (such as the bus-bar current, the bus-bar voltage, theinput torque, the speed of simulation wind turbine) is measured, the method toimprove SRG efficiency can be got. The data between the theoretical analysis andsimulation results were compared, the rationality and practicability of the proposedscheme is verified further, it will be provided a reference for new type SRG isdeveloped, and the process of industrialization will be promoted.