| Energy and environment are two hot issues every country is facing nowadays.Developing new and renewable energies which do no harm to the environment is themain development trend. With the proposal of smart grid concept and low-carboneconomic development model, we are paying more and more attention to thedevelopment and utilization of renewable resource, especially the wind power whichhas the largest developing scale. As the most mature renewable energy technology inrecent days, wind power not only has important social benefits but also environmentalbenefits. For our country with a shortage of energy, wind power generation can fill theenergy vacancy and ease the energy shortage in some cities. And at the same time, itcan ease the environmental issue of China as a clean resource. Therefore, the researchof wind power is catching more and more attention and it has been in p reliminaryapplication with a bright future.Although it is real and concrete to conduct experiments in wind powergeneration filed, it is not easy for field study due to the poor environment andintermittent issues, as well as the increased time and study cost. As a result, it will betimely, convenient and comprehensive to build a wind power generation simulationsystem under laboratory conditions and carry out studies based on this system. Thissystem can simulate a variety of circumstances in wind field and it is easy forresearchers and students to participate in the simulation test. It is of great importancefor the development of wind power generation technology to build a simulationsystem.This paper conducts research on separately excited direct currentmotor(DCM)-brushed double-fed induction generator（DFIG）power wind generatingsimulation system. After analyzing the necessity of the wind power generationdevelopment and the current status and future trends of wind power generationtechnology in details, this paper carries out analysis and study of DCM-DFIG windpower generating simulation system in depth. From a universal perspective, we analyze the structure and operation characteristics of wind power generatingsimulation system, the principle of DCM simulation wind turbine, the principle andcontrol strategies of DFIG, the scanning platform design of wind power generatingsystem, etc. For the whole DCM-DFIG wind power generating simulation system, westudy from control principle, simulation analysis, circuit design, experiment analysis,etc.The main research work is as bellows:(1) Every part of the wind power generating simulation system is analyzed indetail. The types and characteristics of prime mover and generator are introduced. Thecontrol method, operation characteristics, advantages and disadvantages of differentprime movers and generators are determined. Based on those, the DCM-DFIG windpower generating simulation system with variable speed and constant frequency isproposed and the main parts as well as their functions are described.(2) The principles of separately excited DCM and DCM wind turbine simulatorare analyzed in detail. On this basis, the armature and excitation voltage phase-controlmethods of separately excited DCM are analyzed based on Siemens DC speedregulator6RA70256GV62.Besides, the dual close-loop control strategy of speed andcurrent is theoretically analyzed.(3) The working principle of DFIG, the application of DFIG in wind powergeneration, the types of DFIG rotor circuit back-to-back converter and the operationprinciple and mechanism of converter at main and rotor side are analyzed. At thesame time, various PWM modulation algorithms and application principles areanalyzed to achieve effective control of DFIG.(4) The essential characteristics of switching function algorithm and space vectormodulation algorithm, especially the mechanism of8vectors are analyzed. A SPWMmodulation algorithm and a SVPWM modulation algorithm with minimum lossare proposed, which can reduce the minimum switching frequency and stress of VSIto the maximum extent and have been verified and employed in the floor waterheating system. Put forward an idea to apply the SPWM and SVPWM modulationalgorithms with the minimum loss for converter to the voltage source rectifier. Thisalgorithm is applied to voltage source rectifier and we have found the similaritiesand differences between the algorithms for rectifier and converter.(5) After analyzing the principle of DCM-DFIG wind power generatingsimulation system, MATLAB/SIMLINK simulation analysis of power circuit inDCM-DFIG wind power generating simulation system is built. And after giving the simulation analysis of each part, a comprehensive and detailed simulation andanalysis of the whole wind power generation system is conducted, which can achievethe entire process from the variation of wind force to the paralleling in the grid(6) On the basis of above work, a DCM-DFIG wind power generating simulationsystem experimental platform is designed and built under laboratory conditions andrelying on actual R&D project. This system includes host computer wind powergeneration system SCADA monitoring platform， DCM wind turbine simulator andDFIG generating operation parts. This paper analyzes the block diagram, circuittopology and control processes of this wind power generation system, gives parts ofthe experimental results in the initial test and verifies the feasibility and practicality ofDCM-DFIG wind power generating simulation system proposed in this paper. |
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