Design Research On Stability Of Wind-Solar Complementary Power Supply System For Marine Cage Culture

Offshore net cage aquaculture is an important fish farming technology in China’s marine aquaculture industry.As an offshore facility,the conventional commercial electricity supply is not suitable for the energy supply of net cage aquaculture systems.To ensure the uninterrupted operation of lighting,monitoring,and data transmission systems of the aquaculture net cage,a continuous,reliable,and cost-effective offshore power supply technology is needed to meet the electricity demand.This article selects a wind-solar complementary power supply system suitable for offshore net cage aquaculture as a solution to the high electricity cost and poor power supply stability of the offshore net cage aquaculture system in Dalian.Through the investigation of a large amount of literature and climate data,the relevant parameters of the working environment of the offshore net cage farming wind-solar complementary power supply system have been determined.Based on the energy supply demand of 12 k W·h of daily electricity consumption for a certain company’s net cage farming system,it is planned to deploy 4 sets of offshore net cage wind-solar complementary power supply equipment with daily power generation of no less than 3k W·h.According to the calculation results,a 12 V 0.3k W vertical axis small wind turbine and a 12 V 0.2k W monocrystalline silicon solar panel are selected as the main equipment in the power supply system.A small ocean buoy with a basic shape of a hemisphere and a diameter of 1.8m is designed as the main floating body.Based on the three-dimensional potential flow theory,the hydrodynamic simulation analysis of the buoy model is carried out through ANSYS Workbench.The simulation results show that the first-order wave force mainly affects the buoy in the heave direction and has a large magnitude.After being affected by the first-order wave force,the curve trend is continuous and smooth.Within the wave main frequency range(0.2rad/s～2.5rad/s),there is no resonance phenomenon in the six degrees of freedom directions of the buoy;the buoy is almost unaffected by the second-order wave force,and there may be a small resonance at4.5rad/s,but it has avoided the wave main frequency.The buoy has good motion performance under wave action and can meet the design requirements for continuous operation.Based on the results of structural design and simulation analysis,a prototype of offshore wind and solar complementary power supply floating buoy was manufactured and relevant performance tests were carried out.The experimental results show that the sealing performance of the power cabin of the prototype is good;the actual draft height of the prototype is 0.78 m,which is very close to the design draft height of 0.75 m,and meets the technical requirements;the inclination and oscillation period of the prototype in each wave direction are all less than 5s,which meets the relevant design requirements.The experimental results prove that the floating buoy prototype has good swinging response ability and overall stability in the offshore environment,and meets the design requirements.