附录一英文文献：Frequency Variation Speed Control1.1 The Popularity and Prospect of Frequency Variation Speed ControlThe electrical machinery exchange frequency conversion velocity modulation technology is the electricity saving, the improvement technical process improves the product quality and the improvement environment, the impetus technology advancement one main method now The frequency conversion velocity modulation by its outstanding velocity modulation and the braking quality, the high efficiency, the high power factor and the electricity saving effect, the widespread applicable scope and other many merits by the domestic grandfather was thought most has the development future velocity modulation way. The electrical transmission control system usually by the electric motor, the control device and the information installs 3 parts to be composed, the electrical transmission relates uses the electric motor by to save the electrical energy and to control the machinery reasonably the operating condition, the realization electrical energy - mechanical energy transformation, achieves, the high production, the low consumption goal high quality. The electrical transmission divides into does not modulate velocity and modulates velocity two big kinds, the velocity modulation is divided the exchange to modulate velocity and to direct current modulates velocity two ways. The variable speed motor directly does not supply power by the electrical network But the machinery which does not modulate velocity along with electric power electronic technology development this kind of original manuscript more and more many changes to the velocity modulation transmission by to save the electrical energy The improvement product quality, enhances the output Therefore the velocity modulation transmission is an important profession, already obtained the country to take, at present had certain scale.In recent years exchanged in the velocity modulation most to be active, to develop quickest is the frequency conversion velocity modulation technology, the frequency conversion velocity modulation is exchanges the velocity modulation foundation and the branch content. The last century transformer appearance causes the change voltage to become very much easy, thus has accomplished a huge electric power profession. Since long ago, the alternating current frequency always is fixed, the frequency conversion velocity modulation technology appearance causes the frequency to become may the full use resources.In this recent 10 years, the frequency conversion technology application has the very big development in our country, and obtained the good effect to be possible to say, the frequency conversion technology has accepted for the majority users, but had no alternative but to point out, our country in frequency conversion technology application aspect, with developed country level Shang You very big disparity. At present, the AC motors we are using now use frequency variation speed control only about 6%, but the developed country is 60%70%, Japan on air blower, water pump frequency conversion velocity modulation use rate is 10%, but our country is less than 0.01%, In Japan air-conditioner using frequency variation technique rate is 70%, but our countrys only then just started Embarks from this reality, frequency conversion technology remain have the very big development space, we should complete the promoted application work doggedly.And with the constant development of control technique and control avenue, frequency variation speed controlled has developed the vector controlled frequency variation velocity modulation, by controlling the AC motor inside act for shunt DC motor field copers flux, to enhance the permanent torque output scope and static and dynamic character, make the AC motor frequency variation speed controlled system superior to DC motor voltage variation speed controlled system. For simplifying the control system, reducing the fault rate, there has developed a vector controlled frequency variation speed control without speed sensor which based on the vector controlled frequency variation speed control. In some application which have low require , vector controlled frequency variation speed control without speed sensor could completely compare with the vector controlled frequency variation speed control that have speed sensor. The vector control has the epoch-making significance to the AC current motor velocity modulation.Frequency variation speed control is the best way in the motor speed modulation, it is the perfect gear in the companys technical reform and product renewal, it is the essential composition in the industrial automatic system, it is the assumption of realizing the automatic of product proceed and management, it is also the precondition in the development of informationization. In our countrys traditional estate, using the DC motor speed control actuation account about 85%90% in the speed controlle