Loss And Heat Calculation Of The Direct-driven Wind Permanent Magnet Synchronous Generator

The permanent magnet synchronous generator(PMSG) is directly driven by the wind turbine, the gearbox is not needed, and it has the advantages such as simple structure, high reliability, and so on. It has wide application in the area of wind generation. However, PMSG is connected with the grid through the full scale converter. The converter produces more harmonics, which result in the increase of loss and heat. The analysis and calculation of the loss and heat of PMSG become very complicated. Therefore, it is very important to analyze and calculate the loss and heat of PMSG in detail. This thesis, supported by Natural Science Foundation Project of Chongqing, mainly studies the effect of types and control parameters of the converter on the distribution of losses and temperature of PMSG. And a 1.5 MW PMSG is calculated as an example.Firstly, from the theory of electromagnetic field, the 2D time-stepping finite element model coupled with the circuit was built up. Secondly, the feature of converter was analyzed, and the influences of converter on the harmonics were stated. Thirdly, the calculation methods of the stator harmonic iron loss, copper loss and eddy current loss of rotor permanent magnet were presented. The losses of PMSG were calculated at the RL load, uncontrollable rectifier load and PWM converter load respectively. The characteristics of change are discussed in detail by the comparison. Fourthly, the 2D thermal network model and 2D temperature field finite element model were built up respectively. Furthermore, the temperature distribution of PMSG was got. Finally, the influences of converter types and control parameters on the loss and temperature distribution were discussed.The results show that, when the direct-driven PMSG operated at the rated speed is connected with uncontrollable converter load, the stator copper loss is biggest, the eddy current loss of permanent magnet is bigger, and the stator iron loss is least. However, when the direct-driven PMSG operated at the rated speed is connected with RL load or PWM converter load, the stator copper loss is biggest, the stator iron loss is bigger, and the eddy current loss of permanent magnet is least. The converter type and control parameters have the significant influence on the loss and heat of PMSG. The maximum temperature appears on the stator upper layer winding at all the conditions.The results of the thesis are valuable for the design and control of the direct-driven wind PMSG.