Rotary power machineries play an important role in the national economy field. Rotor shaft system is the core component of them and its torsional vibration can not be ignored because it’ll result in huge losses even disastrous consequences once the plant failed. Simulation analysis and experiment research based on extensive and in-depth investigation conduct useful probes for the torsional ...

Wind power is becoming more and more popular in the worldwide range, with its installation capacity 30% increasing annually. In China, the installation capacity of wind power generator has boosted from 1260MW in 2005, 2600MW in 2006, to over 5000MW in 2007. After a couple of years of development in the area of wind power technology, it has become mainstream to introduce variable pitch control...

In order to deal with the problem of battery shorter life and poor reliability of the solar powered streetlights， we created a new controlling method for battery discharging process according to State of Charge (SOC) of battery and developed a new type charge controller for solar powered streetlights. By this way, over-discharge of battery will no longer take place, which helps to improve ...

The harmonics question is the electric machine field important issue. Nowadays, because electric machine performance has been requested to enhance and electric machine\\\’s structure especially in permanent magnet electric machine is complicated, the problem of harmonics has been aroused people\\\’s interest generally. At the same time, with the electric machine\\\’s technol...

The performances of Asynchronized Turbogenerator(ASTG) are significantly better than those of conventional turbogenerator. Its appearance shows a new way to solve the problems of continuous over voltage on extra-high voltage transmission lines due to the surplus of reactive power and the stability of power systems with long distance transmission line.In this thesis, based on the basic operatio...

Mechanical motor such as pumping units used in the oil field or mine often works inthe state of low load,which makes induction motor in low efficiency and electric powerenergy greatly consumed and wasted. In order to solve the problem, this paperadvance using IGBT

With the development of computer and communication technology, Programming Logic Controller(PLC) is developed along the way of large-scale, network, specialization and so on. As a specialized PLC , the embedded PLC can be easily used by the end user and flexibly customized according to user’s requirements, so it is widely used in the fields of textile, printing, pharmacy and water conservan...

The research of energy-saving for three-phase Asynchronous Motors is always a hotspot in electric machinery area. Especially in recent years, the shortage of electric power supply in China makes it more urgent to research and popularize energy-saving devices for three-phase Asynchronous Motors. But at present, the cost of most energy-saving devices is too high. At a certain extent, this handic...

Sensorless vector control of induction motor is not only an important aspect but also a hotspot of investigation in modern AC drive. The key problem is how we can get the speed of motor accurately. The way of speed estimation is based on measurement of stator voltages and currents which are easy to measure. Induction machine is a controlled object that is non-linear, multi variables, strong co...

This thesis introduces a brief account of BLDCM and the development of fuzzy intelligent control first, then based on the analysis of the structure, the running principle, and the mathematical model of BLDCM, the simulation model of its timing system is established, and the transfer function is derived. A new intelligent control strategy is described according the programme of analysis and con...