A hybrid system of a spar-type floating offshore wind turbine and a heaving annular wave energy converter(WEC)provides a promising solution for collocated ocean renewable energy exploitation.The performance of the hyb...A hybrid system of a spar-type floating offshore wind turbine and a heaving annular wave energy converter(WEC)provides a promising solution for collocated ocean renewable energy exploitation.The performance of the hybrid system depends on the dimensions of the WEC.Here an optimization method is proposed to determine the outer radius and the draft of the WEC under the wave condition in a randomly chosen operational site.First,three candidate models are selected based on three operational conditions of energy harvest:(1)The natural frequency of the system is matched with the peak wave frequency in the target site(referred to as synchronized mode),where the wind turbine and the WEC nearly heave together in a near-resonance condition,(2)The natural frequency of the WEC is matched with the peak wave frequency(ring mode),(3)The maximum wave power is harnessed under the peak wave frequency(target mode).Then the candidate modes are evaluated to obtain an optimum.Results show that the extracted wave power under the above operational conditions has an upper bound that can hardly be surpassed by enlarging the dimensions of the WEC only.The optimal annual wave energy production is achieved in the synchronized mode because of the superior performance of WEC over a wide bandwidth of effective energy conversion.展开更多
In this paper,a wind energy conversion system(WECS)is presented for the electrification of rural areas with wind energy availability.A three-phase AC-DC converter based on a bridgeless Cuk converter is used for power ...In this paper,a wind energy conversion system(WECS)is presented for the electrification of rural areas with wind energy availability.A three-phase AC-DC converter based on a bridgeless Cuk converter is used for power extraction from the permanent magnet synchronous generator(PMSG).The bridgeless topology enables the elimination of the front-end diode bridge rectifier(DBR).Moreover,the converter has fewer components,simple control,and high efficiency,making it suitable for a small-scale WECS.A squirrel cage induction motor(SCIM)is used to emulate a MOD-2 wind turbine to implement the PMSG-based WECS.A direct-drive eight-pole PMSG is used in this study;thus,a low-input-voltage system is designed.The converter is designed to operate in the discontinuous inductor current mode(DICM)for inherent power factor correction(PFC)and the maximum power point tracking(MPPT)is achieved through the tip-speed ratio(TSR)following.The performance of the developed system is analyzed through simulation,and a 500 W hardware prototype is developed and tested in different wind speed conditions.展开更多
基金This work was supported by the Guangdong Basic and Applied Basic Research Foundation(Grant No.2022B1515020036)the Natural Science Foundation of Guangzhou City(Grant No.202201010055)the Fundamental Research Funds for the Central Universities(Grant No.2022ZYGXZR014).
文摘A hybrid system of a spar-type floating offshore wind turbine and a heaving annular wave energy converter(WEC)provides a promising solution for collocated ocean renewable energy exploitation.The performance of the hybrid system depends on the dimensions of the WEC.Here an optimization method is proposed to determine the outer radius and the draft of the WEC under the wave condition in a randomly chosen operational site.First,three candidate models are selected based on three operational conditions of energy harvest:(1)The natural frequency of the system is matched with the peak wave frequency in the target site(referred to as synchronized mode),where the wind turbine and the WEC nearly heave together in a near-resonance condition,(2)The natural frequency of the WEC is matched with the peak wave frequency(ring mode),(3)The maximum wave power is harnessed under the peak wave frequency(target mode).Then the candidate modes are evaluated to obtain an optimum.Results show that the extracted wave power under the above operational conditions has an upper bound that can hardly be surpassed by enlarging the dimensions of the WEC only.The optimal annual wave energy production is achieved in the synchronized mode because of the superior performance of WEC over a wide bandwidth of effective energy conversion.
基金supported by Science and Engineering Research Board,India under SERB POWER FELLOWSHIP Grant (No.SPF/2021/000071)project Grant (No.EEQ/2021/000057)extended by SERB,India。
文摘In this paper,a wind energy conversion system(WECS)is presented for the electrification of rural areas with wind energy availability.A three-phase AC-DC converter based on a bridgeless Cuk converter is used for power extraction from the permanent magnet synchronous generator(PMSG).The bridgeless topology enables the elimination of the front-end diode bridge rectifier(DBR).Moreover,the converter has fewer components,simple control,and high efficiency,making it suitable for a small-scale WECS.A squirrel cage induction motor(SCIM)is used to emulate a MOD-2 wind turbine to implement the PMSG-based WECS.A direct-drive eight-pole PMSG is used in this study;thus,a low-input-voltage system is designed.The converter is designed to operate in the discontinuous inductor current mode(DICM)for inherent power factor correction(PFC)and the maximum power point tracking(MPPT)is achieved through the tip-speed ratio(TSR)following.The performance of the developed system is analyzed through simulation,and a 500 W hardware prototype is developed and tested in different wind speed conditions.
