| With the increasing destruction of the earth's ecological environment and the gradual depletion of fossil fuel energy,people urgently need new energy sources to support the operation of human society.The vast ocean that occupies 70% of the earth's area has attracted the attention of a large number of relevant researchers.Among them,tidal flow can become the focus of development and utilization in the world because of its high energy density and strong predictability,but at present,a lot of low-speed tidal energy has not been well utilized.As an energy harvesting device of power flow power generation system,the turbine drives the generator to run after absorbing the fluid,and finally converts the energy in the power flow into electric energy.In order to ulteriorly reduce the mechanical loss of the system and improve the operating efficiency of the system,the traditional gearbox structure can be abandoned in the design of power flow power generation system,and the direct drive mode can be changed.But this method also has certain defects: the power flow energy received by the energy capture device fluctuates significantly,and the mechanical output energy of the turbine also has a large range of variation.Therefore,special requirements are put forward for generators used in power flow power generation system.For the special requirements of direct drive power generation system,and combined with the current situation in the waters near the central fishing port of Rizhao Yellow Sea(The average velocity was 0.7 ? 0.9m/s,and the maximum velocity was about 1.3m/s),this paper selects the permanent magnet synchronous generator as the design object.The motor is required to run efficiently at low speed and rated speed is designed at 100r/min.The generating set can generate more than 1kW of electricity,it can be used as a supplementary power generation method for fishing boats operating in the ocean.Firstly,this paper introduces the basic components of the power generation system and the related theories of energy capture firstly,then carries on the overall design to the 1kW tidal power generation system.A horizontal shaft generator with a diversion hood is selected in this case,and driving mode is direct drive.Secondly,the structure requirements of permanent magnet synchronous generator are put forward,the stator and rotor structures of the generator are designed respectively,and the permanent magnet synchronous generator model is established in ANSYS;taking the maximum output voltage and minimum loss of generator as the optimization goal,the design of permanent magnet and rotor core is optimized;the electric parameters of the permanent magnet synchronous generator are calculated,and the voltage equation of the generator is establishedwith the parameter calculation method in the finite element method.Finally,it is verified that the efficiency of the permanent magnet synchronous generator designed in this paper reaches86.4% when the operating speed is around 100r/min.Finally,the three permanent magnet synchronous generators designed in this paper are used for electric energy conversion to adapt to the energy fluctuation of power flow energy in actual operation.The running speed of both the turbine and the generator is stable at about 100r/min,and the generator is in an efficient operation state.A power flow energy conversion system is established,which takes the output of generator as input and outputs a three-phase alternating current with amplitude,frequency,phase and phase sequence that can be directly used for load or connected to power grid through a series of electrical energy conversion. |
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