This paper presents the influence of the environmental factors over the electrical equipment thermal stresses when it is monitored with infrared monitoring device. A good definition of the correction parameters for this monitoring device and the choice of the optimal conditions for monitor performing can lead to good results. In particular, the paper presents the influence of the dust layer from electrical equipment over the captured thermal image by the infrared monitoring device and further more to estimate its thermal stress. To achieve this, it was used an experimental stand where a copper bar was split in different areas and they were covered with different dust types and in the end the thermal stress of each area was estimated with the infrared monitoring device.

The electrical contacts are important elements which can be found on all of the electrical installations from the power source to the consumer. Also, the electrical contacts have an important role in the construction and operation of low voltage electrical equipment. The presence of an electrical contact on a current path always introduce an additional electrical resistance, named contact resistance. In this paper is studied the influence of the voltage drops to contact resistance, respectively to contact temperature of the low voltage electrical equipment.

This paper describes an innovative integrated solution for monitoring and protection of the power supply system of electric traction. The development of electronics devices, new possibilities to communicate (wireless), and new sensors makes it possible to design, develop and implement new hardware–software structures in various fields such as energy systems, transportation infrastructure, etc. This contributes to increasing developments in the monitoring and protection of railway infrastructure. A monitoring and protection system that uses sensors and devices to acquire electrical parameters from railway infrastructure has been developed and applied for fault detection and protection of power supply systems from electric traction. The solution of monitoring and protection presented are composed of a hardware–software structure with Global System for Mobile Communications (GSM) communication for monitoring of power supply installations from the electric traction and a central remote system composed of a device with GSM communication and a server that will allow, among others things, accurate detection of the block section (SC), in which an electrical fault (short circuit) has occurred, determination of the circuit breakers electro-erosion from the railway installations and an indication of the opportune moment for maintenance activity, respectively, as well as knowledge of the technical condition of some equipment from the return circuit. The proposed and developed method for monitoring devices has been validated in the railway laboratory to confirm its capability to detect defects and was tested in the field. Experimental results in the field and appropriate data analysis are included in this article.

Nowadays, sensors and condition monitoring systems are expanding rapidly and becoming cheaper. This contributes to increasing developments in condition monitoring in railway transport infrastructure. A condition monitoring system that uses an online device and sensors to acquire electrical parameters from railway infrastructure has been developed and applied for fault detection and diagnosis of impedance bonds. The impedance bond condition is monitored in real-time using current and temperature sensors, providing early warning if predefined thresholds are exceeded in terms of currents, imbalance currents, and temperatures. The proposed method and the developed monitoring device have been validated in the railway laboratory to confirm its capability to detect defects. The acquired parameters from impedance bonds are used to extract thermal stresses and technical conditions of this equipment. Experimental results and appropriate data analysis are included in the article.

This paper presents the parameters that are required in the monitoring and diagnostic of the circuit breakers and aspects concerning the dynamic contact resistance. Also, it is presented the experimental results obtained on two circuit breakers of medium voltage with SF6, at closing and opening, which are analyzed from the point of view of dynamic contact resistance.

The proper functioning of electrical equipment is strictly related to its technical condition and their exploitation is very important for the stability and reliability of the power system. Among the multitude of parameters monitored in the diagnosis of electrical equipment, the temperature is often used to find out the nature and the degree of the fault which can occur. The paper aims to present different temperature measuring devices that are currently used to identify faults in the power system and also a case study of thermal stress monitoring and diagnosis for a fault occurred on a circuit breaker being under exploitation.