Design of innovated structure of wind energy system with reduced manufacturing cost and optimized efficiency

DC generators have the major drawback of the large number of sliding brush-collar contacts, making this motor structure expensive and requiring a non-negligible maintenance cost. To avoid this problem, an excitation system allowing the excitation current to be reversed after the electromotive force changes polarity is added. The structure of the generator is found by equivalence to a permanent magnet direct current generator structure by changing the magnets by equivalent concentrated coils. A control technique of this type of generator, used in a wind energy production system, is developed to show the efficiency of this type of generator in the field of wind energy production. Related to permanent magnets generators, the studied structure is with reduced production cost since the magnets are replaced by coils. The innovation aspects of the studied generator are the modularity (use of several modules to increase the power delivered by the generator), the elevated efficiency due to the limited number of power chain components, the elevated power to weight ratio, the simplicity of the control and the reduced manufacturing cost. In conclusion, the use of the studied generator in the wind energy system, makes the power chain simple, inexpensive and robust.