Thermal response characteristics for elevators inverters based on infrared thermography
                                                ZHENG Bo1，XU Jinhai1，WANG Hong1，XU Lei1，TANG Bo2
(1.Hangzhou Special Equipment Inspection Institute, Hangzhou 310003, China; 2.College of Metrology and Measurement Engineering, China Jiliang University, Hangzhou 310018, China)

Abstract: Aiming at the problem of elevator stopped operation caused by the overheating of electronic components in the elevator inverter, the nondestructive testing system of infrared thermography and the cause of heating from elevator inverters were analyzed. On this basis, a noncontact measuring method by using infrared thermography was put forward to detect the surface temperature distribution of elevator inverters. Then, based on the thermodynamic theory and the fundamental law of infrared radiation, a mathematical expression of thermal radiance rate per unit area, surface emissivity and temperature was established. The elevator inverter was taken as the monitoring object and this transient thermal behavior during operation process was tested. The results indicate that the variation of the surface emissivity has little influence on the temperature amplitude of elevator inverters, and different heating areas can be clearly distinguished in the circuit board. Experimental results are consistent with the theoretical analysis, and the technology can realize noncontact measurement surface temperature of elevator inverters without stopping.

Key words: elevator; inverter; thermal response; infrared thermography; condition monitoring