Design And Research Of2.935MW Permanent Magnet Synchronous Generator For Wind Turbine

In recent years, environmental pollution has become more serious, moreattention has been paid to the research and utilization of new energy. Because ofwide distribution area and large volume, wind energy has become a research hotspotof renewable energy; wind power generation has become the fourth generation inaddition to thermal power, hydropower, and nuclear power. Several typical windgenerators are analyzed in this dissertation. According to the requirements ofmanufacturers, the performance characteristics for permanent magnet synchronousgenerator is analyzed and studied. The electromagnetic scheme of2.935MW highspeed permanent magnet synchronous generator is calculated.Firstly, the differences on the rotor structure of interior and surface permanentmagnet synchronous generator were analyzed and a comparison which severaltypical rotors structure can provide the maximal area of magnetic flux was made inthis dissertation. On this basis, the generator rotor structure was selected. Theequivalent magnetic circuit model of permanent magnet synchronous generator wasimproved, and then the calculation formula for main magnetic flux with differentrotor structure of permanent magnet synchronous generator was presented. Then thebasis of selection parameters of permanent magnet synchronous generator wasdiscussed, the project of the generator was determined, and the key problem ofpermanent magnet synchronous generator design was studied.Secondly, the iron loss and synchronous reactance of generator was calculatedwith the finite element method. A new method of computation inductance in transientfield was proposed. After calculation the three-phase self-inductance and mutual-inductance, using Park transformation, the d-q axis synchronous inductor wasobtained. This method not only considered the magnetic-cross effect, also was moreconvenient. The factors affecting the voltage regulation rate was focused on. Theinfluences of the permanent magnet size and d-q axis reactance on the voltageregulation rate were researched. The method to reduce the voltage regulation ratewas put forward. Finally, based on the electromagnetic scheme, simulation of the generator wasmade through the soft of Ansoft Maxwell. The generator no-load, load, short circuitcharacteristics were analyzed. The voltage total harmonic distortion, cogging torque,no-load flux leakage coefficient, power factor, electromagnetic torque was calculated.The permanent magnet demagnetization risk of short circuit conditions was checked.After verification, the performance met the design requirements.