Studies On Multi Physics Field Of MW Level Permanent Magnet Synchronous Wind Power Generator

With the continuous development of wind power industry, the capacity of awind generator is increasing, and the permanent magnet wind generator hasgradually become the main development trend of wind power market. Therequirements for safety and reliability of wind generator are higher especially inthe offshore wind power system, and now the permanent magnet wind generatorshows the advantages. Because of the large size and heavy quality of permanentmagnet wind generator, the installation of generator is very difficult. So thepermanent magnet wind generator is expected owning low failure rate to reducethe maintenance cost. In this situation, the design and temperature fieldcalculation of permanent magnet wind generator are very important. And theaccurate calculation of losses in the generator is the premise condition ofanalyzing the wind generator temperature distribution. Due to the temperaturedistribution of generator is implicated by the calculation method of losses, thepermanent magnet eddy current loss could not be ignored for the large capacitypermanent magnet wind generator.First of all, the permanent magnet eddy current loss is calculated andanalyzed when the1.5MW permanent magnet wind generator running underrated load. In consideration of the effect of coating on the permanent magneteddy current loss, the permanent magnet eddy current losses are calculated whenthe surface of permanent magnet plating zinc and nickel phosphorus alloy. Inorder to comparative analysis the influence degree of surface coating onpermanent magnet eddy current loss, the permanent magnet eddy current losswith no surface coating is calculated, and the calculation results are compared and analyzed.The three-dimensional transient temperature field of the1.5MW permanentmagnet wind generator is calculated by the finite element method. Then thetemperature distribution of the permanent magnet wind generator running in therated wind speed is analyzed. And the temperature values of the generatordifferent sections are picked up for drawing temperature-time curve diagram,which may be helpful for the design of cooling system of large-capacitypermanent magnet wind generator.At last, based on improving the permanent magnet on the rotor surfacestructure of1.5MW permanent magnet wind generator, another rotor structure ofpermanent magnet wind generator is designed. And the electromagnetic field ofimproved rotor structure of permanent magnet wind generator is analyzed. At thesame time, the eddy current loss in one permanent magnet is calculated when thepermanent magnet wind generator running in the rated load through the two-dimensional transient electromagnetic field of generator. Based on the aboveconditions, the two-dimensional steady temperature field distribution ofimproved rotor structure of permanent magnet wind generator running in therated wind speed is calculated, and the temperature trend of generator is analyzed,which may provide some basis for the design of large-capacity permanent magnetwind generator.