Design And Control Of Direct Drive System For Single Axis Centrifugal Compressor

In recent years,with the emergence of new materials,the continuous improvement of frequency conversion control methods,the diversification of electromagnetic design methods and the emergence of high-temperature resistant high-temperature and high-temperature bearings,the development of high-speed motors has shown a diversified trend.High-speed motors are used in a wide range of modern industrial applications,including high-speed machine tool spindles,air-conditioning compressors,and high-speed centrifugal compressors.With the development of high-speed motors,the possibility of high-speed direct drive is greatly improved.Compared with conventional motors with speed-increasing devices,high-speed direct drive reduces the size of the equipment system,while reducing the number of transmission poles from the perspective of energy consumption.,reducing energy loss and improving mechanical operation efficiency.At the same time,it also greatly reduces the working noise,which can be said to be a green,environmentally friendly and energy-saving driving method.Considering the difficulty and economy of the control method,this paper uses the high-speed induction motor to drive the single-axis centrifugal compressor as the equipment system to carry out the following research.Select a model of single-shaft centrifugal compressor to explain the basic technical parameters.The force analysis of the impeller of the main force component of the centrifugal compressor is carried out,the load distribution is determined,the axial force is calculated,and the shaft power is calculated.A direct-drive high-speed shaft structure model was established.Through the simplification of mechanics,a high-speed shaft mechanical model was established.The transfer matrix method was used to calculate and analyze the first four-step critical speed of the high-speed shaft.The results show that the critical speed is within the safety margin.The design process of high-speed induction motor is clarified,and the main problems in the design process of high-speed induction motor are analyzed,that is,the influence of cogging on the asynchronous additional torque and how to improve the power factor.For the previous motor design process,the main dimensions and electromagnetic parameters of the motor were estimated and roughly calculated.This paper proposes to construct a maximum optimization condition considering the motor loss and realize the optimization model of volume power maximization.The model is solved to obtain the optimal structure size and electromagnetic parameters of the motor at the working speed.In the process,the eddy current field,electromagnetic characteristics and starting characteristics of the motor are analyzed in detail.The magnetic field line and magnetic induction intensity distribution,motor three-phase starting current,starting torque and air gap flux density are analyzed.The results are in line with the actual design.It is required that the motor air gap has less harmonics and the design is reasonable.At the same time,the temperature field simulation model of high-speed induction motor is established.After calculating the core loss and winding loss,the temperature field simulation of the motor is carried out,the temperature distribution of each part of the motor is analyzed,and the design of the cooling water channel is guided.Finally,the structure of different stator slots is analyzed.The influence of the stator stator temperature field distribution.A high-speed induction motor IFOC control based on MRAS is proposed.By constructing a reactive power model,the rotor time constant is reduced.Compared with the traditional indirect magnetic field oriented control,the speed control performance is better.The paper has 65 pictures,9 tables,and 70 references.