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.
This paper investigates methods for DC fault current interruption in high-power DC networks. It is shown that mechanical DC circuit breakers could only offer adequate protection if supplemented with fault current limiters. A simple electronic switch (IGBT or GTO) is suitable as a DC circuit breaker but the component sizing crucially depends on the speed of signal processing circuits. It is likely...
The failure of several transmission capacitor banks prompted The United Illuminating Company to perform an engineering study to evaluate the transient recovery voltage capabilities of existing 123-kV, oil-filled capacitor bank circuit breakers at the East Shore 115-kV substation. The study determined if the transient recovery voltage capability of existing bus and capacitor bank circuit breakers is...
Changes to the power system, especially the installation of new generation sources and new operating conditions, result in higher fault currents. Circuit breakers, which are previously designed and coordinated for the power systems before the appearances of new generation sources and new operating conditions, may have inadequate fault current interruption capability. This paper discusses those operating...
According to the distributed substation protection configuration and the principle of fault-clearance, a new model of fault diagnosis based on Petri net is proposed in this paper. In Petri net diagnosis model, all kinds of fault have a specific token which make it easily and clearly to find the fault location and understand the sequence of the fault events. The diagnostic is implemented by solving...
As electric power demand has constantly been increasing, more bulk power systems have been installed in a network. For environmental and technical reasons, the amount of distributed resources is increasing considerably in a distribution network. Therefore, distribution networks have become more complex mesh networks, which improve the reliability of distribution system and the flexibility of network...
This paper addresses the timely issues of modeling of, and defining selection criteria for, a solid state fault isolation device (FID) to be used in power electronic based distribution systems (PEDS). Circuit interruption requirements and FID location in power electronics based distribution system are discussed in this paper. The paper subsequently derives the FID parameters by mapping the characteristics...
Solid state fault interruption devices (FID) can interrupt fault currents much faster than the presently available circuit breakers. Due to their current inability to block system level voltages, presently available semiconductor devices are connected in series to increase blocking capability of the fault interrupting device. To verify the ability of the interruption device for use in a medium voltage...
For any type of shunt faults in power system, all parts of the network will experience voltage sag (voltage dip) for the duration at least equal to the fault clearing time. The percent of this voltage sag at a given point depends to its distance to the fault and fault resistance. If a bus bar supplying a group of induction motors is exposed to such voltage dip, which may be due to a fault at another...
FREEDM system is a computer-controlled distribution system with distributed generation, electronic loads and circuit breakers. The protection methods used in legacy distribution systems are too slow to protect the electronic loop. This paper determines the fault-produced short circuit current, which is a square shaped current wave with 2-3 times rated current amplitude. The fault will be identified...
The paper discusses a possible design for an electronic circuit breaker based on the IGCT as a switching device for the 12.47kV distribution system. Electronic Circuit Breakers are capable of faster switch off times, improved control and efficiency, greater reliability and enhanced safety than mechanical breakers. Based on the switching device and simulation results a new breaker with an improved...
Short circuit contributions from synchronous generators can persist for several seconds even after the field circuit breaker is opened. Delayed tripping of an AC field circuit breaker can allow faster reduction of generator field current in some circumstances. Faster reduction of generator field current will reduce the energy in a short circuit and consequently reduce the damage caused by the short...
The impact of distributed generation (DG) in a distribution network depends on the design of the protection system and the coordination between the different protective devices. This paper presents the main features of a library of protective devices implemented in an EMTP-type tool for power quality studies in distribution networks with distributed generation. The document discusses the present protection...
The technology comparison and analysis on the over-voltage and insulation coordination of UHV AC transmission system between China and Japan have been carried out in this study, which may include the level of the power frequency temporary over-voltage, switching overvoltage and secondary arc current and the measures to restrict them, the lightning protection methods for transmission line and substation,...
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.