Research Of The Speed Control Methods Of ESM Based On The Air Compressor

Along with the rapid development of chemisty、colliery petroleum and metallurgy industry,etc.The Centrifugal Compressor is one of the important components in large enterprise of these industry,while it is the largest energy consumption facility in the grid. So the research of energy-saving method of the Centrifugal Compressor is very important. The enterprises carry out major energy-saving technological renovation of The Centrifugal Compressor in succession in recent years.Quest for the energy-saving method in order to reduce costs.The aim of this thesis is mostly in The Centrifugal Compressor energy-saving,the demands on the pressure and flow of air vary with the actual situation.So departing form the operating condition points will be appeared. Then the operating conditing must be changed in order to achieve actual situation.This paper analyzes the method of adjust Centrifugal compressor, with reference to characteristic curve of Centrifugal Compressor itself and it cooperates with distribution system. At present, there are three means to adjust Centrifugal compressor:throttle adjustment, changing centrifugal element adjustmen and changing rotate speed adjustment. The third method is claimed economical of all adjustment method.The change in the speed of Centrifugal Compressor by changing the speed of drive motor.Big power electrical synchromotor motor (it called ESM for short) is reported in this paper. The variable frequency device is used for the ESM speed adjustment. The most widely-used variable frequency device in every industry are vector control (VC) and direct torque control (DTC). Analyzes the load performance of Centrifugal Compressor, compared with direct torque control the main advantage of vector control is that good stability, high control accuracy, large capacity of frequency converter etc..So the vector control is used for speed control of ESM.This paper adopts gap motor flux oriented vector control, which can make the control performance of A.C. ESM is similar to D.C. machine.The controlling difficulty is simplify to obtain better control results. In order to guarantee the consrant gap motor flux and current control accurately, a new voltage model is used for torque observation and feedforward supply voltage model is used for current control in control system. This makes good groundwork for vector control.The kye part of drive system is to establish the model of ESM accurately. The simulation model of ESM and other of nuclear module of vector control system are built using Matlab/Simulink toolbox and S-function. The accuracy in the simulation model and the vector control has been verified by the analysis of system steady simulation. The analysis of the simulation results shows that the speed control theory can compliy to Centrifugal Compressor requirements and can work stably at different loading.