| With the rapid development of society, the social for energy demand continues to grow, anincreasingly serious problem of environmental pollution, energy shortages, the developmentefforts in solar, wind and other renewable energy imminent. China is rich in wind resources forsolving China’s environmental problems and energy issues; the development of wind powertechnology has a very important significance. Wind power technology development since the unitcapacity of wind turbines is increasing, the wind farm from the land gradually extended to the sea,control theory and control continue to be used in wind turbine control system, gradually increasethe stability of wind power technology. But compared with Europe and the United States, China inthe pitch control, Low Voltage Ride Through (LVRT) control technology, there is some distancethese technologies are still based on the introduction of learning-based. At present, the technologyis still the main of introduction to learning. Especially in the pitch variable control of windturbines with Direct-Drive Permanent Magnet Synchronous Generator (DPMSG) and LVRTtechnology, there is less research. Therefore, based on the Heilongjiang Provincial Department ofEducation2012annual scientific and technological research project (Project Number:12521039,Project Name: Research on variable speed and variable pitch intelligent control about windpower generation system), Mainly researched pitch control technology of DPMSG wind turbines,design intelligent combination of BP neural network and fuzzy control variable pitch controllermodel and simulation, has some theoretical and practical significance.This paper first introduces the overview of wind power at home and abroad, analyzes andcompares the most commonly used doubly fed induction wind turbines and the advantages anddisadvantages of the DPMSG wind turbines. Direct drive wind turbines with PMSG, from theanalysis of the aerodynamic characteristics of the wind turbine and pitch control theory, studies thepermanent magnet wind turbines system, transmission variable pitch controller mode（lsimple PIDcontroller） as well as the mathematical model of the PMSG, a7.5kW wind turbine permanentmagnet synchronous simulation matlab/simulink intuitive draw dynamic characteristic curves ofthe DPMSG wind system in the course of their work, laid a theoretical foundation for furtherstudy of the permanent magnet synchronous wind turbine intelligent pitch controller.The next analysis of BP neural network and fuzzy control theory, proposed BP neural networkcontroller for DPMSG wind turbine in below rated wind speed (low wind speed) and the second modes of operation above rated wind speed (high wind speed) different, and fuzzy controller. BPneural network controller with LM quick count of the data in the appendix learning training,arrived at a different pitch angle, the tip speed ratio about the most maximum wind energy capturecoefficient, create a query table for the control of small wind speed (in this case the paddle anglewill remain the same angle of0°), speed control, to achieve the purpose of the capture maximumwind energy; To fuzzy controller error change rate of the input power error and power, the pitchangle of the output, will allow the power range of the error and its rate of change blur draw thecorresponding domain of fuzzy control rules derived, calculated the fuzzy control lookup table,using a velocity-type two-dimensional controller, to achieve a large wind speed, the powercontrol, and stable so as to the output power of the wind speed in the vicinity of the rated power.In order to verify the reliability of the two fuzzy controllers based on matlab/simulinkenvironment to establish a2MW direct drive permanent magnet wind turbine, small wind speedand wind speed simulation, The operation results prove that the two controllers is feasible, betterreflect the dynamic characteristics of the wind turbines in two wind speeds, with a certain degreeof anti-interference and control accuracy. |
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