In this paper,a dynamic equivalent method applicable to the direct-drive permanent magnet synchronous generator(PMSG)based wind farms under asymmetrical faults is proposed.Firstly,PMSGs are clustered based on their di...In this paper,a dynamic equivalent method applicable to the direct-drive permanent magnet synchronous generator(PMSG)based wind farms under asymmetrical faults is proposed.Firstly,PMSGs are clustered based on their different active power characteristics under asymmetrical faults.Further,single-machine equivalent models(SMEMs)are constructed for different clusters of PMSGs.In particular,an SMEM with multi-segmented slope recovery is introduced for PMSGs with ramp recovery characteristics.Further,a collector network equivalent method for wind farms applicable to both symmetrical and asymmetrical faults is presented.Moreover,an iterative simulation method is used to gain the required clustering indicators before the fault actually occurs.Eventually,the effectiveness of the proposed dynamic equivalent method is verified on a modified IEEE 39-bus system.展开更多
Using the active feedback control system on the elastic wave metamaterial,this research concentrates on the sound transmission with the dynamic effective model.The metamaterial is subjected to an incident pressure and...Using the active feedback control system on the elastic wave metamaterial,this research concentrates on the sound transmission with the dynamic effective model.The metamaterial is subjected to an incident pressure and immersed in the external mean flow.The elastic wave metamaterial consists of double plates and the upper and lower four-link mechanisms are attached inside.The vertical resonator is attached by the active feedback control system and connected with two four-link mechanisms.Based on the dynamic equivalent method,the metamaterial is equivalent as a single-layer plate by the dynamic effective parameter.With the coupling between the fluid and structure,the expression of the sound transmission loss(STL)is derived.This research shows the influence of effective mass density on sound transmission properties,and the STL in both modes can be tuned by the acceleration and displacement feedback constants.In addition,the dynamic response and the STL are also changed obviously by different values of structural damping,incident angle(i.e.,the elevation and azimuth angles)and Mach number of the external fluid with the mean flow property.The results for sound transmission by two methods are compared,i.e.,the virtual work principle for double plates and the dynamic equivalent method corresponding to a single one.This paper is expected to be helpful for understanding the sound transmission properties of both pure single-and double-plate models.展开更多
基金supported by the National Natural Science Foundation of China(No.U2166601).
文摘In this paper,a dynamic equivalent method applicable to the direct-drive permanent magnet synchronous generator(PMSG)based wind farms under asymmetrical faults is proposed.Firstly,PMSGs are clustered based on their different active power characteristics under asymmetrical faults.Further,single-machine equivalent models(SMEMs)are constructed for different clusters of PMSGs.In particular,an SMEM with multi-segmented slope recovery is introduced for PMSGs with ramp recovery characteristics.Further,a collector network equivalent method for wind farms applicable to both symmetrical and asymmetrical faults is presented.Moreover,an iterative simulation method is used to gain the required clustering indicators before the fault actually occurs.Eventually,the effectiveness of the proposed dynamic equivalent method is verified on a modified IEEE 39-bus system.
基金The authors wish to express gratitude for the support provided by the National Natural Science Foundation of China(Grant Nos.11922209,11991031 and 12021002).
文摘Using the active feedback control system on the elastic wave metamaterial,this research concentrates on the sound transmission with the dynamic effective model.The metamaterial is subjected to an incident pressure and immersed in the external mean flow.The elastic wave metamaterial consists of double plates and the upper and lower four-link mechanisms are attached inside.The vertical resonator is attached by the active feedback control system and connected with two four-link mechanisms.Based on the dynamic equivalent method,the metamaterial is equivalent as a single-layer plate by the dynamic effective parameter.With the coupling between the fluid and structure,the expression of the sound transmission loss(STL)is derived.This research shows the influence of effective mass density on sound transmission properties,and the STL in both modes can be tuned by the acceleration and displacement feedback constants.In addition,the dynamic response and the STL are also changed obviously by different values of structural damping,incident angle(i.e.,the elevation and azimuth angles)and Mach number of the external fluid with the mean flow property.The results for sound transmission by two methods are compared,i.e.,the virtual work principle for double plates and the dynamic equivalent method corresponding to a single one.This paper is expected to be helpful for understanding the sound transmission properties of both pure single-and double-plate models.
