The soft-switching solid-state transformer (S4T) employs only 12 main active devices and an auxiliary resonant circuit to implement a bidirectional solid-state transformer, with an attractive feature of achieving a full range of zero-voltage-switching conditions for all the main devices. This paper covers detailed design of the power stage, auxiliary resonant circuit, and control of the S4T. The high-frequency transformer is an essential element for the S4T, and it has a unique feature of dc-biased flux. Design of such a high-frequency transformer is also discussed in detail in this paper. Soft startup, shutdown, and fast dynamic response under load transients are also attractive behaviors because of the low inertia of the S4T. Experimental results from a 208-V/10-kV·A S4T unit are presented.

Design of a 10-kV·A Soft-Switching Solid-State Transformer (S4T)

Low profile, shielded magnetic components for circuit board applications include self centering core and coil assemblies with coil receptacle and centering projections formed in core pieces that are assembled around a preformed coil. Welding and plating techniques for forming termination structure for the preformed coil avoid thermal shock issues. External gapping elements and agents to form a gapped core structure are avoided, and gap size in the cores may be tightly controlled over large production lot sizes.

Miniature shielded magnetic component

A polyphase filtering choke arrangement of a power electronics appliance, more particularly of a frequency converter. which arrangement comprises two separate magnetic cores, around both of which a polyphase winding is arranged, particularly for filtering the harmonics of a network current and the common-mode noise currents, wherein both the magnetic cores ( 1, 2, 101 a - 101 c, 102 a - 102 c, 130 a - 130 d, 140 a - 140 d ) are shaped to form a closed magnetic circuit, the magnetic cores ( 1 and 2, 101 a - 101 c and 102 a - 102 c, 130 a - 130 d and 140 a - 140 d ) are arranged one on top of the other, the magnetic cores are connected to each other with connecting pieces ( 11 - 13, 11 a - 13 b, 111 - 113, 121 - 124 ), and the winding directions of the windings of the magnetic cores are opposing with respect to each other, in which case the fluxes produced in the magnetic cores of each current are of opposing directions, in which case the flux produced by the difference-mode current circulates via the connecting pieces from one magnetic core to another.

Filtering choke arrangement

A light pipe having substantially uniform brightness along a length thereof is disclosed. The light pipe includes a first end for receiving a plurality of light rays, a reflective portion for directing the received light rays in a pre-determined internal light pattern, wherein the reflective portion includes a plurality of reflective elements, and an emitting portion for emitting the light rays in a pre-determined light distribution pattern.

Light pipe with uniformly lit appearance

The invention relates to a reactor arrangement for alternating electrical current. The reactor arrangement comprises different coils (105, 107) for positive and negative half-cycles of the alternating electrical current. The negative and positive half-cycles of the alternating electrical current are directed to the different coils with the aid of unidirectional electrical components (106, 108) such as, for example, diodes. The both coils are arranged to magnetize a common magnetic core element (104) in a same direction. The reactor arrangement further comprises at least one permanent magnet (109) that generates, into the magnetic core element, a biasing magnetic flux component having an opposite direction than that of magnetic flux components generated with the coils. Therefore, the biasing magnetic flux component generated with the permanent magnet relieves magnetic saturation of the magnetic core element. Hence, the size and the weight of the magnetic core element can be reduced.

A reactor arrangement for alternating electrical current

A D.C. reactor comprising a core structure having two opposed cores separated by a magnetic gap, to form a closed magnetic circuit; a coil wound on one or both of the cores; a pair of permanent magnets for biasing, disposed on the core structure; magnetic flux generation means for causing the bias flux generated by the permanent magnets and the flux generated by the coils to flow in opposite directions; and bypass means for causing the bias flux generated by the permanent magnets to bypass the magnetic gap. The core structure comprises an E-shaped core and an I-shaped core, the magnetic gap is defined between a center leg of the E-shaped core and the I-shaped core, the coil is wound on the center leg of the E-shaped core, and each permanent magnet is shaped into a rectangle and disposed on both side surfaces of the center leg of the E-shaped core. The permanent magnet is a sheet-like permanent magnet magnetized so that each of its longitudinal direction and the direction of thickness forms two poles on each side, and the neutral line of this permanent magnet is brought into conformity with the center line of the magnetic gap and is disposed on both outer side surfaces of the core structure. Since the flux generated by the D.C. reactor does not pass inside the permanent magnet, an eddy current loss decreases, and even when a large current abruptly flows through the coil, the permanent magnet is not demagnetized.

Ryuichirou Kabushiki Kaisha Yaskawa Tominaga

Papers

D.C. reactor