摘  要：热保护是确保电动机安全正常工作的一个重要措施。分析了电动机热保护技术的研究现状和发展趋势。主要介绍基于电流反时限特性的热保护方法和基于电阻法测温的热保护方法以及基于热模型的热保护方法。随着对电机热模型的深入研究，基于热模型的电机热保护将成为电机热保护的主要方法。
关键词：异步电动机；热保护；热模型；概述

Abstract: Thermal protection,the main content of motor protection is an important measure to ensure the normal work of the motor.Analyzed research and development trends of on-line thermal protections of induction motors:Introduced the thermal protections based on time-current curve,winding resistance and thermal model.Along with the in-depth study of the thermal model of motor,protections based on thermal model would become main methods of on-line thermal protections of induction motors.
Key Words: Asynchronous motor;Thermal protection;Thermal model;Summary