Development of a Low-cost Thermal Camera for Electrical Condition Monitoring

Abstract

Abnormal rises in temperature of electrical equipment could be a sign of electric fault. By measuring the temperature of the equipment, it is possible to detect the early sign of electrical failure. Therefore, preventive maintenance based on thermal inspection is important to ensure the safety operation of the electrical system. Thermal inspection is normally done by using a handheld thermal camera. However, professional thermal camera is expensive and not suitable to be installed at a fixed location for continuous temperature monitoring. In this paper, a low-cost embedded system is proposed for measuring the temperature of electrical equipment based on thermal imaging. The system can be permanently installed to continuously monitor the thermal condition of an electrical installation. The proposed system consists of a Raspberry Pi 3 controller board connected to a MLX90640 32x24 pixels thermal sensor and a Pi NoIR camera. The temperatures measured by the thermal array sensor are converted into a heat map to form a thermal image. The thermal image is then overlaid on the visual image and displayed on the LCD screen. The system can be programmed to generate warning signal when the measured temperature is above a certain threshold value. Experiments carried out on the developed system showed that it is able to locate the hotspot regions of an electrical installation.