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.
Circuit breaker (CB) installed for capacitor bank is the CB which commonly experiences the switching process due to the capacitor bank function as a voltage regulator. In closing switching process, CB encounter transient condition due to inrush current. In this paper, the simulation for studying the inrush current characteristic of capacitor bank switching in Indonesia has been performed. Simulation...
Considering the dielectric and mechanical characters of controlled switching (CS) in a compensation line, an EMTP-ATP model of a substation is established to analyze inrush current and reignition in the switching operation, and the optimum switching strategy is proposed. The results confirm the effect of CS on reducing series reactor in the line. The influence of reactance and chopping current on...
This paper presents mainly on the basis of open loop L-Z source inverter. By using the power electronics converter the distributed generating system is connected to the grid. In that by adding inductance and diode to the input side of power electronic converter the input voltage to be boosted and eliminates the ripples in the input current and reduce the inrush current. In the distributed generating...
The modern methods of insulation coordination make use of probabilistic concepts and statistical procedures especially for very high voltage systems. This paper presents, a proper approach to calculate the switching surge flashover rate (SSFOR) using Adaptive Neuro Fuzzy Interface System (ANFIS). The switching overvoltages distribution along the power transmission line under different conditions are...
This paper proposes on-chip soft-start method with minimum extra components and turbulence free start up of dc-dc converter. During the soft start, the output voltage is slowly increased to the steady state value so that the inrush current and overshoots are prevented. The proposed topology is implemented in buck converter designed to give 3.3V output for wide supply range of 4.5V to 18V and load...
This paper proposes analysis of boost converter with super-twisting algorithm under sliding mode operation in continuous conduction mode. The super-twisting algorithm reduces the chattering effect which is inherent in conventional sliding mode control. This control minimizes the initial current peak and provides output voltage regulation irrespective of input voltage perturbation and load changes...
In recent years, the demand for testing of inductive load current switching duties has significantly increased. Parallel to this, a range of changes to the IEC standard 62271-110 have become effective. This contribution is intended to give an overview on some recent test experiences in inductive load switching with circuit breakers in a voltage range 12–550 kV, showing practical examples, changes...
This paper proposes a novel non-isolated high step-up converter suitable for miniaturization by high frequency design. High step-up converters with voltage multipliers are promising for high frequency design because many of them can be free from coupled inductors or transformers, which may lower the voltage gain due to the leakage inductance or may cause significant AC conduction loss in the primary...
A charge equalizer system is suggested for use in the future battery-packs employed in plug-in vehicles or house used in UPS-based supply systems deriving energy for supplementing the grid-connected main supply. Such applications are becoming common in Distributed Generation on spot from sources of solar (or wind), especially when grid connected power-supply is interrupted for some reason. The charge...
When operating in island mode, DC-based microgrid mainly starts up through batteries and bidirectional DC-DC converters. In conventional way, an extra start-up circuit is required to limit the surge current, which not only decreases the efficiency but also increases the cost. In this paper, the generation mechanism of the surge current is analyzed, through which the duty cycle control scheme is proposed...
In three-phase applications, the six-switch boost PFC rectifier is the most widely employed topology because of its good performance and cost effectiveness. A vast amount of literature that deals with this circuit is exclusively focused on various control schemes aimed at optimizing different aspects of its steady-state and/or transient performance. However, no literature is available on its start-up...
In this paper, a novel high step-up converter is presented, containing a multi-winding coupled inductor and a charge pump capacitor. Since the charge pump capacitor is connected in series with a coupled inductor, the surge current caused by the capacitor charging can be reduced, thereby causing the life of the capacitor to be prolonged. Above all, the energy stored in the leakage inductance of the...
Soft-start is very important for Boost converters to keep output voltage stable. However, previous methods may cause large initial inrush current, big voltage drop, overshoots and long start-up time. In this paper, the conventional resistor capacitor (RC) soft-start scheme is firstly analyzed, and then a novel soft-start strategy by using a variable ramp-slope with predefined voltage (VRSPV) is proposed...
In this paper, the energy transient response during circuit breaker operation for shunt reactor is simulated. To recreate the energy transient phenomenon which occurs during reactive power switching, modeling for Electro Magnetic Transients Program (EMTP) are well established and analyzed. Following this, methods for improving transient recovery voltage (TRV) during switching of reactive power supply...
In this paper, switching overvoltages are studied on part of 380 kV interconnected network of Central Anatolia of Turkey, which contains six busbars that are interconnected with five different transmission lines of different lengths and geometries. The studies are carried out by an electromagnetic transient software program called PSCAD/EMTDC. Overvoltages that take place due to energizing a line...
A multi-output auxiliary power supply realized by a flyback converter is presented for providing the needed low power supplied for the control circuits and driving circuits in power processing systems. In the proposed circuit topology, lossless snubbers are introduced into the flyback converter to recover energy trapped in leakage inductor of transformer, to smooth out voltage across drain-source...
One of the switching overvoltage reduction methods of ultra high voltage (UHV) transmission line is to use a pre-insertion resistor in the circuit breaker. There are no comprehensive and specific references concerning the pre-insertion resistor. In this paper, utilizing the closing resistor for switching overvoltage reduction is completely studied. In addition, the installation of inductor and capacitor...
Distribution transformers operating in modern system grids or in industrial networks are subjected to many switching transients. They may occur due to routine operations, network reconfigurations or reaction on protection signals. Depending on the network configuration and parameters such events my lead to external overvoltages and result in additional stresses on the insulation system. The paper...
This paper presents a fully protected low side switch design from the thermal behavior perspective. The power dissipation is evaluated both for normal operation and for the main high power operation conditions: short circuit and overload, inductive clamping and turn on/off process. Electro-thermal simulations are used to evaluate the surface temperature, that is taken into account in designing the...
this paper is a general discussion of the methods of switching employed for reactive power compensation, the problems encountered with conventional devices, and the improvements made by the latest advancements in technology. Switching reactive power produces voltage transients, chops currents, and stresses equipment. The switching can be harmful to the reactor, the capacitor, the switching device,...
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.