基于MATLAB/Simulink的变频电机系统能耗实用模型

摘要

变频电机系统能耗分析需要对系统各环节建立准确的损耗计算模型.针对目前有限元模型建模繁琐、计算量大的现状,在考虑了变频电源谐波对铁耗电阻影响的基础上,建立了计及铁耗等效电阻的异步电机数学模型及PWM变频器主电路损耗模型,提出一种基于MATLAB/Simulink的变频电机系统实用模型,实现了变频电机系统各环节损耗准确分析.通过对不同工况下变频器、电机和系统总效率的仿真分析,揭示了传统忽略变频器能耗的损耗分析方法对系统最佳运行点估算存在一定误差.为了验证模型正确性,对一组5.5 kW变频电机系统进行了试验对比,验证了文中模型能够正确有效地模拟变频电机系统运行.研究成果为进一步研究系统能耗最优控制策略提供了重要理论支撑.%A reliable and reasonably accurate loss model of variable speed motor systems is important for its performance prediction and energy consumption analysis.Most of the existing methods are based on the finite element analysis,but the disadvantage lies in the computational difficulty,which is not suitable for practical application.A practical simulation model of variable speed motor systems based on MATLAB/Simulink was estabcished.The converter losses were calculated by analytical model of IGBT and Diode,and the iron lossed in variable-frequency motor was considered as variable iron loss equivalent resistance.The efficiency of the motor system under different conditions was analyzed,and it showed that traditional models of motor systems may cause errors when determining the optimal system operating point,with the converter losses neglected.The experimental validation was also performed on a 5.5 kW motor.The achievement coucd provide technique support for the optimal control strategy for motor systems.