Topic
Magnetic core
About: Magnetic core is a research topic. Over the lifetime, 30011 publications have been published within this topic receiving 155247 citations.
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TL;DR: In this article, the T-Omega method is employed to calculate the three-dimensional transient eddy current field in large transformers, as well as the short-circuit electromagnetic forces acting on the transformer windings.
Abstract: The improved T- Omega method is employed to calculate the three-dimensional transient eddy current field in large transformers, as well as the short-circuit electromagnetic forces acting on the transformer windings. The effects of the magnetic shielding and initial angles of currents are studied, and the nonuniform distribution of ampere-turn along the height of the windings is taken into account. Thus, a common software package is developed. Two different transformers are analyzed, and the computed results show agreement with measured ones. >
30 citations
Patent•
12 Apr 2002TL;DR: In this paper, a magnetic core whose outer surface has been coated without handling brittle ribbon is presented, which is useful for efficiently producing the above-mentioned magnetic core without using any organic solvent and which per se is stable to heat and elapse of time.
Abstract: The present invention provides a magnetic core whose outer surface has been coated without handling brittle ribbon to thereby impart insulating properties and shape retention properties to the magnetic core after annealing heat treatment, and further provides an adhesive resin composition for a magnetic core, which is useful for efficiently producing the above-mentioned magnetic core without using any organic solvent and which per se is stable to heat and elapse of time. By forming a coating film having a certain thickness or more on an outer surface using a composition containing a resin of specific properties, there can be obtained a magnetic core whose outer surface has been coated without handling brittle ribbon to thereby impart insulating properties and shape retention properties to the magnetic core after annealing heat treatment. The adhesive resin composition containing particles of a resin having specific properties is useful for efficiently producing the above-mentioned excellent magnetic core without using any organic solvent, and this composition is stable to heat and elapse of time.
30 citations
TL;DR: In this article, the performance of a switched reluctance motor made of permendur was investigated, which has extremely high saturation flux density and very low core loss, and the motor torque, iron loss and efficiency were estimated by finite element method (FEM).
Abstract: A switched reluctance (SR) motor has a doubly salient pole structure. A stator has concentrated windings on each pole, while a rotor is only made of iron core. Therefore, the SR motor is expected as a low cost, extremely robust, variable speed motor. The performance of the SR motor greatly depends on magnetic properties of core material since it consists of only laminated-core and windings. This paper investigates the performance of an SR motor made of permendur which has extremely high saturation flux density and very low core loss. Motor torque, iron loss, and efficiency of the SR motor are estimated by finite element method (FEM). Furthermore, a suitable structure for the SR motor made of permendur is examined based on the design of experiments.
30 citations
TL;DR: In this paper, the authors proposed a coupled inductor cuk converter balancing method for lithium-based batteries, which uses N-channel metal-oxide field effect transistor (MOSFET) switches to achieve lower drain-source on-resistance and less voltage drop.
Abstract: In this paper, a cuk converter balancing method by using a coupled inductor for lithium based batteries is investigated. The proposed circuit is an active balancing circuit that will equalize eight battery cells in a series. In electrical vehicles (EV), a battery management system (BMS) is a vital task to achieve the best performance of the batteries and longer lifetime. The problem of voltage difference in a battery pack is an important issue to be improved. To overcome the voltage differences in battery string, an equalizing method is mandatory. The conventional cuk converter requires 2(n-1) switches to balance n cells, while the proposed circuit requires only n switches for n cells in series. In addition, the proposed developed topology uses coupled inductors instead of un-coupled inductors, unlike the traditional cuk converter balancing method. Since the cuk balancing transfers the energy among two adjacent cells, it requires a proportionately long equalization time particularly for long string battery packs, but the coupled inductor cuk converter type overcomes this problem. The switches are N-channel metal-oxide field-effect transistor (MOSFET) to achieve lower drain-source on-resistance, RDS(on), and less voltage drop as compared to the P-channels. The switches are triggered by complementary signals. The coupled inductor is made in such a way to hold the same magnetizing inductance. It can be done by using five wires in one hand. The circuit contains five inductors, one magnetic core, with five winding for eight cells, and one capacitor for two cells. Therefore, the overall circuitry and complexity of the circuit are reduced, resulting in a more cost-effective and easy to implement circuit. The system also does not demand complicated control for battery equalizing. The experimental circuit was implemented and simulation results were obtained to confirm the validity of the proposed system.
30 citations
TL;DR: In this article, a coupled inductor balancing method was developed to overcome cell voltage variation among cells in series, for Lithium Ion (Li-ion) batteries in Electrical Vehicles (EV), which is suitable for fast equalization due to the inductor-based balancing method.
Abstract: This article developed a coupled inductor balancing method to overcome cell voltage variation among cells in series, for Lithium Ion (Li-ion) batteries in Electrical Vehicles (EV). For an "eight cells in series" example, the developed balance circuit has four inductors, one magnetic circuit with one winding per two cells, and one control switch per cell, as compared to the traditional inductor-based equalizer that needs N-1 inductors and magnetic circuits for N number of cells and more switches. Therefore, ultimately, a more efficient, cost-effective circuit and low bill of materials (BOM) will be built up. All switches are logic-level N-Channel metal-oxide-semiconductor field-effect transistors (MOSFETs) and they are controlled by a pair of complementary signals in a synchronous trigger pattern. In the proposed topology, less components and fast equalization are achieved compared to the conventional battery management system (BMS) technique for electrical vehicles based on the inductor balancing method. This scheme is suitable for fast equalization due to the inductor-based balancing method. The inductors are made with a well-chosen winding ratio and all are coupled with one magnetic core with an air gap. Theoretical derivation of the proposed circuit was well-presented, and numerical simulation relevant to the electrochemical storage devices was conducted to show the validity of the proposed balance circuit. A complete balance circuit was built to verify that the proposed circuit could resolve imbalance problems which existed inside battery modules.
30 citations