in this paper a new problem of three stage disassembly-assembly scheduling is introduced and reviewed. this problem, which was arisen from the aviation industry characteristics, is a generalization of the two stage assembly scheduling problem. products (helicopters) in the aviation industry return to assembler for annual overhaul repair services. in the first stage helicopters are disassembled ...

Optimal operation of a wind power generating system is featured by the variable-speed constant-frequency mode in which maximum-power-capturing from the wind turbine and constantfrequency-interfacing with the power system are the primary concerns. A slip power recovery system with a doubly excited wound rotor induction machine is attractive in this situation. In this paper, field orientation con...

Permanent magnet Vernier (PM-V) machines, at low power levels (few kWs), have shown a great potential to improve the torque density of existing direct-drive PM machines without much compromising on efficiency or making machine structure more complicated. An improved is very desirable for offshore wind applications where size an increasing concern. However, relatively poor factors PM-V will incr...

This paper focuses on the turbine-generator shaft models of double-cage Induction Generator (IG) based wind farm and its influence on the sub-synchronous resonance phenomenon. For this purpose, six different shaft models as 6-mass, 4-mass, 3-mass I, 3-mass II, 2-mass and 1-mass models are considered for double-cage IG wind-turbine. By using the linear modal analysis method, the effects of the d...

This paper presents Maximum Power Point Control for variable speed wind turbine driven permanentmagnet generator. The wind turbine generator is operated such that the rotor speed varies according to wind speed to adjust the duty cycle of power converter and maximizes Wind Energy Conversion System (WECS) efficiency. The maximum power point for each speed value is traced using Maximum Power Point...

1 Nameplate capacity is the maximum rated output of a generator under specific conditions designated by the manufacturer. Installed generator nameplate capacity is commonly expressed in MW. W ind energy has gained prominence as a means of generating electricity without emitting air pollutants or greenhouse gases. As the wind spins a wind turbine's blade assembly, known as a rotor, a generator c...

This paper presents a control strategy for a grid connected doubly fed induction generator (DFIG)-based wind energy conversion system (WECS).Control strategies for the grid side and rotor side placed in the rotor circuit of the Doubly Fed Induction Generator (DFIG) are presented along with the mathematical modeling of the Wind Energy Conversion System. In this control approach, wind generators ...

Abstract Despite the progress made in last decades field of machine condition monitoring, there are still cases where current state art is not enough and new technologies advanced analysis methods required to prevent unexpected failures. One example planetary gearboxes (PGs), which one main components mechanical transmission systems heavy-duty machines such as off-highway trucks, electric rope ...

Airflow hazards such as turbulence, vortices, or low-level wind shear can pose a threat to landing aircraft and are especially dangerous to helicopters. Because pilots usually cannot see airflow, they may be unaware of the extent of the hazard. We have developed a prototype airflow hazard visual display for use in helicopter cockpits to alleviate this problem. We report on the results of a prel...