诺德NORDAC PRO SK 500P变频器配备了集成的多协议以太网接口,以及可用于多轴操作的多编码器接口和用于无电压参数设置的USB.接口,可满足不同的应用需求。这款新的控制柜变频器覆盖的电机额定功率范围为0.25-5.5kW,具有高水平的连接性...诺德NORDAC PRO SK 500P变频器配备了集成的多协议以太网接口,以及可用于多轴操作的多编码器接口和用于无电压参数设置的USB.接口,可满足不同的应用需求。这款新的控制柜变频器覆盖的电机额定功率范围为0.25-5.5kW,具有高水平的连接性、功能性和适配性。因此各种设备版本可以根据不同的应用需求进行优化配置。其插入式控制、安全和选配模块可确保较大的灵活性,而书本大小的紧凑型设计形式可节省控制柜的安装空间。展开更多
In the early development of the wind energy, the majority of the wind turbines have been operated at constant speed. Subsequently, the number of variable-speed wind turbines installed in wind farms has increased. In t...In the early development of the wind energy, the majority of the wind turbines have been operated at constant speed. Subsequently, the number of variable-speed wind turbines installed in wind farms has increased. In this paper, a comparative performance of fixed and variable speed wind generators with Pitch angle control has been presented. The first is based on a squirrel cage Induction Generator （IG） of 315 kW rated power, connected directly to the grid. The second incorporated a Permanent Magnet Synchronous Generator （PMSG） of 750 kW rated power. The performances of each studied wind generator are evaluated by simulation works and variable speed operation is highlighted as preferred mode of operation.展开更多
Hydro generators installed in Itaipu Binacional power plant with 824/737 MVA rated output power （50/60 Hz） belong to the largest ones in the world. Among many unique features, the generators are equipped with the la...Hydro generators installed in Itaipu Binacional power plant with 824/737 MVA rated output power （50/60 Hz） belong to the largest ones in the world. Among many unique features, the generators are equipped with the largest hydrodynamic thrust bearings ever built （external diameter 5,200 mm, axial load equals approximately 3,600 t）. This paper is an attempt to propose a new thrust bearing design with the use of the state-of-the-art technologies and simulation techniques that demonstrate a reduction of friction power losses generated by the thrust bearing. This paper is divided into two parts. Within the first one, the original thrust bearing design which was implemented in the generators is described. Related calculation results based on a TEHD （thermo-elasto-hydrodynamic） calculation software used by Alstom will be presented. A comparison between measurement results gathered in the 1980s is given. In the second part, a potential solution of a more beneficial bearing design is described. The proposed thrust bearing design modification is an implementation of Alstom＇s PolypadTM coating. This modern polymer （PEEK） coating material has already been used by Alstom in projects around the world for many years. This coating allows pushing the operating parameters limits toward higher temperatures and lower oil film thicknesses far beyond the limits known for the conventional bearing materials.展开更多
文摘诺德NORDAC PRO SK 500P变频器配备了集成的多协议以太网接口,以及可用于多轴操作的多编码器接口和用于无电压参数设置的USB.接口,可满足不同的应用需求。这款新的控制柜变频器覆盖的电机额定功率范围为0.25-5.5kW,具有高水平的连接性、功能性和适配性。因此各种设备版本可以根据不同的应用需求进行优化配置。其插入式控制、安全和选配模块可确保较大的灵活性,而书本大小的紧凑型设计形式可节省控制柜的安装空间。
文摘In the early development of the wind energy, the majority of the wind turbines have been operated at constant speed. Subsequently, the number of variable-speed wind turbines installed in wind farms has increased. In this paper, a comparative performance of fixed and variable speed wind generators with Pitch angle control has been presented. The first is based on a squirrel cage Induction Generator （IG） of 315 kW rated power, connected directly to the grid. The second incorporated a Permanent Magnet Synchronous Generator （PMSG） of 750 kW rated power. The performances of each studied wind generator are evaluated by simulation works and variable speed operation is highlighted as preferred mode of operation.
文摘Hydro generators installed in Itaipu Binacional power plant with 824/737 MVA rated output power （50/60 Hz） belong to the largest ones in the world. Among many unique features, the generators are equipped with the largest hydrodynamic thrust bearings ever built （external diameter 5,200 mm, axial load equals approximately 3,600 t）. This paper is an attempt to propose a new thrust bearing design with the use of the state-of-the-art technologies and simulation techniques that demonstrate a reduction of friction power losses generated by the thrust bearing. This paper is divided into two parts. Within the first one, the original thrust bearing design which was implemented in the generators is described. Related calculation results based on a TEHD （thermo-elasto-hydrodynamic） calculation software used by Alstom will be presented. A comparison between measurement results gathered in the 1980s is given. In the second part, a potential solution of a more beneficial bearing design is described. The proposed thrust bearing design modification is an implementation of Alstom＇s PolypadTM coating. This modern polymer （PEEK） coating material has already been used by Alstom in projects around the world for many years. This coating allows pushing the operating parameters limits toward higher temperatures and lower oil film thicknesses far beyond the limits known for the conventional bearing materials.
