The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
The general structure of the electric traction system highlights the complexity and diversity of electrical equipment from the power supply. The return circuit, part of electric traction railway, consists of the running rails, the joint coils and the return feeder to the traction substation. Monitoring of the electrical equipment, existent in the electric traction railway, is a newest concept. The...
The paper describes how different parameters from vacuum circuit breaker influence the closing and opening time. Operational voltage, ambient temperature or hydraulic pressure can introduce delays in opening and closing the circuit breaker. These parameters are motorized through sensors that send all the data to a control unit. The control unit calculates the decision/(time) when to make controlled...
This paper refers to the magnetic actuator from vacuum circuit breaker. The actuator is one of the main component with functions for switching, latching and release. Due to the low quality of power supply of actuator, undesirable effects such as the delay during the operation of connecting or disconnecting the circuit breaker can result. As case of study to observe this delay was used a monopolar...
This paper aims to presents an overview of electrical contact resistance. The electrical contacts are important elements which can be found on all of the electrical installations from the power source to the consumer. The presence of an electrical contact on a current path always introduces an additional electrical resistance, named contact resistance. After an overview of the role of the contacts...
The traction current is returning to the supply source crossing the return circuit to the 25 kV single-phase AC power source. The return circuit consists of the running rails, which are connected by conductors to the joint coils terminals, and the return feeder to the traction substation. The connecting conductors (connection ropes) are subjected to thermal stresses due to the intense currents which...
The paper presents an impact analysis of the thermal stresses of electrical equipment impact on the environment temperature. To accomplish this were determined the steady-state overtemperatures and thermal time constants for three different sections of a busbar system, from a low voltage electric switchboard, in order to determine the thermal stresses for each case. To see how much the value of thermal...
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.
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...
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...
The paper focuses on controlled switching for the circuit breaker of a shunt reactor. Controlled switching is a modern technique used for the adjustments of the transient stress witch appear at the switching process. This paper presents the controlled switching and perspectives according to recent theoretical and technological aspects. Also, it is presented the contributions of controlled switching...
This paper presents the supply system used in electric traction of single-phase with 25 kV, 50 Hz which was modeled in Electromagnetic Transients program (EMTP). It simulates the influence of contact resistances in return circuit for different loads of locomotive on three circulation sectors. Also, it is presented the influence of inductances in return circuit for different loads.
Considering the current tendency for efficiency of electrical equipment operation from an electricity company the paper aims to present an asset management system at the power substation level. Also, paper describe the software application of asset management that allows among others: the calculation of technical condition and importance of electrical equipment; estimate the maintenance order of them;...
Monitoring and diagnosis of power circuit breakers represent an important activity for increase the reliability and safety in power system. In order to deal with the uncertain information in the process of diagnosis, the paper presents a diagnosis system based on fuzzy logic which has the role to acquire information about the monitored equipment for faults detection. Also, the paper describe the LabVIEW...
In the last years it was found that the most of the electricity transport networks in the world are more and more loaded. This is due to increased electricity consumption and economic, political and ecological difficulties encountered in the construction of new transmission lines and/or power plants. A possible solution to solve these problems is provided by the use of FACTS (Flexible Alternating...
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...
Recent concerns about environmental issues led to global energy policies oriented to new energy sources less polluting and cheaper. Energy produced by photovoltaic technology is clean and renewable. The actual problem is that currently the price of photovoltaic systems is relatively high. Research in this field is now focused on improving the efficiency of electricity production using photovoltaic...
On-line monitoring of electrical equipment and their diagnosis is a field which has special attention because it can detect some faults in their incipient phase and thus prevent serious failure of the equipment and also prevent financial and materials related losses. This paper presents a system for monitoring and diagnosis of electrical equipment of medium voltage installations. Also are presented...
High voltage circuit breakers are essential elements in the power system. This is due to their capability to make, carry and break both normal operating currents and also overload and short circuit currents. Failure of this component of the power system can cause undesirable consequences, both technical and economic. Introduction of monitoring and diagnosis of high voltage circuit breakers is intended...
The paper presents the software application for offline monitoring and diagnostic for determining of technical state of electrical equipment from a power substations.
Circuit breakers have a very important role in generation and transmission of electricity and represent a vital part of the power system. Monitoring the high voltage circuit breakers represent an important challenge when this activity must be acquired online. The paper presents the architecture of an online monitoring and diagnosis system of electrical equipment which has the role to acquire, to transfer...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.