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Bin Bai,Junyi Zhang,Yanchao Cui,Han Li 대한기계학회 2020 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.34 No.7
To improve the simulation efficiency of mistuned blisk, a method called receptance substructure component modal synthesis method (RSCMSM) is proposed to reduce its degrees of freedom (DOFs). The advantage of this method is that only the interface DOFs need to be solved, which observably enhances the computational efficiency. The modal frequencies, maximum modal shape and frequency response function are calculated via RSCMSM. It is seen that the smooth frequency band is governed by blade vibration and the steep frequency band is governed by disk or bladed-disk coupling vibration. In addition, a peak is observed for the tuned blisk but many peaks appear for the mistuned blisk and many small wave crests are observed near the peak. To verify validity of this method, the computational time of RSCMSM is compared with high fidelity finite element method (HFFEM) and classical substructure component modal synthesis method (CSCMSM), which manifests that the computational efficiency increases by 32.19 %-80.82 % than that of HFFEM when the mistuned level is 0 %~5 %. Moreover, computational efficiency of RSCMSM is increased by 0.85 %-7.56 % than that of CSCMSM. The validity of RSCMSM is verified for calculating the complex mechanical structure.
Yiqi Liu,Wenlong Song,Ningning Li,Linquan Bai,Yanchao Ji 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6
This paper discusses the elimination of DC voltage deviation and the enhancement of load current sharing accuracy in multi-terminal high voltage direct current (MT-HVDC) systems. In order to minimize the power line losses in different parallel network topologies and to insure the stable operation of systems, a decentralized control method based on a modified droop control is presented in this paper. Averaging the DC output voltage and averaging the output current of two neighboring converters are employed to reduce the congestion of the communication network in a control system, and the decentralized control method is implemented. By minimizing the power loss of the cable, the optimal load current sharing proportion is derived in order to achieve rational current sharing among different converters. The validity of the proposed method using a low bandwidth communication (LBC) network for different topologies is verified. The influence of the parameters of the power cable on the control system stability is analyzed in detail. Finally, transient response simulations and experiments are performed to demonstrate the feasibility of the proposed control strategy for a MT-HVDC system.
Liu, Yiqi,Song, Wenlong,Li, Ningning,Bai, Linquan,Ji, Yanchao The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.6
This paper discusses the elimination of DC voltage deviation and the enhancement of load current sharing accuracy in multi-terminal high voltage direct current (MT-HVDC) systems. In order to minimize the power line losses in different parallel network topologies and to insure the stable operation of systems, a decentralized control method based on a modified droop control is presented in this paper. Averaging the DC output voltage and averaging the output current of two neighboring converters are employed to reduce the congestion of the communication network in a control system, and the decentralized control method is implemented. By minimizing the power loss of the cable, the optimal load current sharing proportion is derived in order to achieve rational current sharing among different converters. The validity of the proposed method using a low bandwidth communication (LBC) network for different topologies is verified. The influence of the parameters of the power cable on the control system stability is analyzed in detail. Finally, transient response simulations and experiments are performed to demonstrate the feasibility of the proposed control strategy for a MT-HVDC system.