Ocean current generation speed-changing constant frequency method and apparatus base on hydrostatic transmission

Abstract

The present invention discloses a hydraulic transmission-based variable-speed constant-frequency method for power generation by ocean currents, and a device thereof. The main shaft of an impeller is connected with a variable displacement pump; the high-pressure oil transmitted from the variable displacement pump is connected into an energy storing device and a variable motor; a permanent magnet synchronous generator is connected with the variable motor and is then connected with a power grid; the main shaft of the impeller and the main shaft of the generator are respectively provided with a revolution speed transducer; a controller is used for calculating and transmitting the displacement signals of the variable displacement pump according to the rotational speed of the impeller and the flow velocity of the ocean current; the displacement of the variable displacement pump can be regulated to change the reverse torque of the main shaft of the variable displacement pump, so as to change the rotational speed of the impeller and to realize the variable-speed operation. The controller can calculate and transmit the displacement signals of the variable motor according to the rotational speed and the rated speed of the motor; the displacement of the motor can be regulated to maintain the constant rotational speed of the variable motor; then the generator can generate electric energy of rated frequency, thus maintaining the constant-frequency operation. The device can stabilize the variable-speed operation and the energy output of the power generating device of ocean currents, is more slightly influenced by the impact of the ocean current, and has no AC equipment but higher efficiency.

Description

technical field [0001] The invention relates to a speed-variable and constant-frequency method of a power generation system and a device thereof, in particular to a hydraulic transmission-based ocean current power generation variable-speed and constant-frequency method and a device thereof. Background technique [0002] The horizontal axis ocean current power generation device is a new type of ocean current energy development and utilization device that entered the research field at the beginning of the 21st century. It is based on Bezier's energy capture theory, which captures the kinetic energy of water through the impeller and converts it into electrical energy. Similar to wind power, when the speed of the impeller changes with the speed of the water flow, it can make the impeller capture more energy of the ocean current. When the generator in the ocean current power generation device is connected in parallel with the power grid, the generator is required to generate elec...

AI Technical Summary

Problems solved by technology

Both of the above two methods of variable speed and constant frequency are based on electrical methods, and both require expensive inverter equipment, which will cause more than 15% energy loss in the process of energy transmission

In the horizontal axis type ocean current power generation device, if the electric variable speed and constant frequency method is adopted, since the generator is driven by the impeller to generate electricity after the gear box speeds up, the generator is greatly affected by the impact of the ocean current, and the variable speed of the impeller The operation and energy output of ocean current generators are more erratic

In addition, its expensive generators have to be placed underwater, which makes maintenance inconvenient. The use of converter equipment not only causes energy loss, but also makes the structure of the power generation system huge and complicated, especially the electrical system.

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