电工技术学报2024,Vol.39Issue(14):4341-4352,12.DOI:10.19595/j.cnki.1000-6753.tces.230717
基于动态磁网络法大型感应电机阻抗参数及起动特性计算
Calculation of Impedance Parameters and Starting Characteristics of Large Induction Motor Based on Dynamic Magnetic Network
摘要
Abstract
Large induction motors are widely used in traction and drive applications.The accurate calculation of impedance parameters is crucial for predicting motor performance,determining the driving load,and optimizing motor design.The large induction motor has a long starting time and large current,experiencing apparent time-varying core saturation and skin effect.Current approaches,such as the magnetic network method,often neglect the nonlinearity in the magnetic permeance of the motor during the starting process,leading to inaccuracies in considering the saturation deviation caused by variable starting currents.Accordingly,the dynamic magnetic network method is proposed to analyze the electromagnetic performance of large induction motors in the transient process.Considering the influence of the saturation effect and skin effect on the motor impedance,the calculation method for motor starting characteristics is proposed,thereby improving the accuracy and efficiency of calculating dynamic impedance parameters and starting characteristics. The proposed nonlinear dynamic magnetic network model considers the air gap's magnetic permeance variation caused by the rotor's speed changes.The effect of the starting current characteristic on the saturation degree inside the motor is discussed.According to the magnetic field line and the saturation degree,the calculation method for nonlinear permeability in the dynamic magnetic network model is determined.Based on the dynamic magnetic network model and the rotor skin effect model,the dynamic impedance parameters are calculated by considering leakage flux,rotor speed variation,and saturation phenomena.The dynamic mathematical model of large induction motors is derived from the rotor multi-circuit method.According to the electromagnetic coupling relationship in the transient process,a dynamic coupling solution is determined to obtain dynamic impedance parameters and starting characteristics,considering variations in current,speed,saturation,and skin depth.Calculation accuracy at a lower computational cost is improved. Calculation results show that when the motor starts to reach the stable running state,the resistance increase coefficient gradually decreases from 5.517 to 1.025,and the reactance decrease coefficient increases from 0.36 to 1.Using dynamic parameters for calculating the starting characteristics of large motors improves accuracy.Compared with the traditional calculation method,the relative errors of starting torque,starting current,and maximum torque are reduced by 2.54%,0.68%,and 5.39%,respectively.Compared with the finite element method(FEM),the solution time is reduced by about 90%. The following conclusions can be drawn.The proposed method ensures accurate calculation by coupling dynamic impedance parameters and starting characteristics for large induction motors,considering the nonlinearities in the magnetic permeance during the starting process and the saturation deviation caused by the time-varying starting current.Compared to the traditional calculation method and FEM,it improves accuracy and computational efficiency,facilitating calculations for related motor types.关键词
大型感应电机/动态磁网络/动态阻抗/转子多回路法/起动特性Key words
Large induction motors/dynamic magnetic network/dynamic impedance/rotor multi-loop method/starting characteristic分类
信息技术与安全科学引用本文复制引用
夏云彦,周洲,邵远亮,连如博..基于动态磁网络法大型感应电机阻抗参数及起动特性计算[J].电工技术学报,2024,39(14):4341-4352,12.基金项目
国家自然科学基金资助项目(52077047). (52077047)