With the expansion of Power System scale, it becomes more and more important to keep Power System’s reliability and stability, as well as super performance and dynamic quality. Synchronous generator excitation control system is an important part in power system operation. It is designed to reduce voltage pulsation, balance the distribution of inactive power, increase anti-interference and st...

A lot of protection measures to asynchronous motor and many kinds of protection devices both home and abroad are investigated in this thesis, then the thesis designs an asynchronous motor protection device with simple structure. The device is credible with high ratio of performance with respect to the cost. The protection device is a kind of microcomputer motor protection device, which is base...

The railway signaling relay is a basic safety element of the railway traffic signaling control. It is widely used as the centralized control of the railway signaling equipment at the train station. The railway signaling relay being used now in China has some differences from that of the international standard. In order to improve the technical level and the liability of the relay, meet the req...

The plenty of harmonics produced by nonlinear, imbalance and impact load can make the waveform of current and voltage in power system produce serious distortion, which produce some power quality problems. The safety of power system and the quality of power supply has been threatened. The idea which restrain power quality from waveform of current and voltage become development tendency.Unified...

Capacitors are employed as main devices for reactive power compensation in distribution network, and the reasonable configuration of capacitors arrangement is of great significance for secure and economical operation of distribution network, since it may effectively improve the voltage level, reduce operation loss, enhance the utilization ratio of transmission equipment and strengthen the adj...

Mesoporous molecular sieves is a kind of porous inorganic materials, its pore size is in the range of 2-50 nm. It has large surface area, ordered pore array and good thermal stability, so it can be widely used in catalyst, seperator, nano-reactor, medicine release, photoelectric sensor, and so forth. Based on the investigation of literatures, in this thesis several typical mesoporous material...

The large-scale development of wind power is one of the most realistic strategies to solve the energy and power shortages in China. Wind rich and relatively rich areas in China account for just 26% of its territory. However, there needs to be a higher starting resistance of traditional wind generators. The wind speed for starting wind generators is 3.5m/s, and must be up to 4.2m/s for power g...

The performance of AC variable speed drive system has been improved greatly since field-oriented control is applie\\\’d, and the reliability of drive system composed of multiphase Permanent Magnet Synchronous Motor (PMSM) is enhanced. After the field-oriented control of three-phase PMSM drive system is introduced in brief, a mathematical model of multiphase PMSM, taking a six-phase PMSM ...

As an important control device in electric power system that plays an important role in the assurance of power supplying quality, excitation systems should be carefully tested both before leave-factory and after site installation.VI is an automatic test technique developed with the progress of electronics, bus and computer technology. This paper is about the development of the virtual tester t...

In the AC driving technique, Direct torque control (DTC) technology, which is characterized by the rapid response of torque and flux, has been widely attention. In recent years, aimed at the problem of DTC technology, many improved methods are proposed by scholar at Home and Abroad. In this thesis, a novel DTC scheme which not only remains the good performance but also eliminates the disadvan...