1. Field of the Invention
The present invention concerns a high-performance resistor having a plurality of resistor elements which are electrically connected in series.
2. Description of the Related Art
In the case of known high-performance resistors as are shown in simplified form in
As can be seen from
As adjacent resistor elements are connected together at the connections which are bent over at a right angle, the length of the bent-over portion determines the spacing of the adjacent resistor elements relative to each other. Here therefore the competing requirements are a structural configuration which is compact as possible (without having regard to thermal aspects) and an arrangement of the resistor elements, which is as assembly-friendly as possible. On the one hand, the spacing between adjacent resistor elements should be as small as possible in the interests of a compact design configuration, but on the other hand a greater spacing between adjacent resistor elements is more assembly-friendly than a smaller spacing.
U.S. Pat. No. 2,647,978 discloses a high-performance resistor having a plurality of resistor elements which are electrically connected in series. The resistor elements are connected together by way of bars. Provided at each of the two ends of the resistor elements is a respective element, the connection being at a right angle to the resistor element. A respective connecting portion is fixed to that connection, resistor elements being connected together by means of the connecting portions by way of the bars.
U.S. Pat. No. 2,662,958 also discloses a high-performance resistor with a plurality of resistor elements electrically connected in series. At their two ends the resistor elements have respective connections for connecting the resistor elements.
The object of the invention is to provide a compact and at the same time assembly-friendly high-performance resistor.
In one embodiment, a high-performance resistor includes a plurality of resistor elements which are electrically connected in series and each having a first and a second side and a first and a second end, wherein provided at the first end is a first connection and provided at the second end is a second connection for connection of resistor elements, characterized in that the first and second connections each have an inner portion and an outer portion, wherein the inner portion of the first connection is bent at a predetermined angle with respect to the first side of the resistor element and the outer portion of the first connection is in a plane which is substantially parallel to the plane of the resistor element, and wherein the inner portion of the second connection is bent at a predetermined angle with respect to the second side of the resistor element and the outer portion of the second connection is in a plane which is substantially parallel to the plane of the resistor element.
In that case the invention is based on the realization that, in the configuration according to the invention, the spacing of the connections at one side of the resistor elements and thus the space available in the assembly procedure between adjacent connections is doubled to twice the plate spacing. That provides that assembly is remarkably facilitated, while the spacing between the resistor elements remains the same and thus the high-performance resistor is of the same structural size.
In a preferred embodiment, the connections are displaced by a predetermined dimension on both sides with respect to the longitudinal axis of the resistor element. The fact therefore that one of the connections is a predetermined dimension above the longitudinal axis and the other is the same dimension below the longitudinal axis means that it is possible to construct a high-performance resistor according to the invention from similar standard resistor elements, by virtue of a suitable arrangement of the individual resistor elements.
In the above-described manner, there is provided a high-performance resistor which can be advantageously used as a load resistor (dump load) in the case of energy producers, in particular wind power installations. For that purpose a plurality of high-performance resistors can be arranged in cabinets or other suitable apparatus racks in order thus to achieve dimensioning for a sufficiently high permissible power dissipation.
The invention is described in greater detail hereinafter with reference to the Figures in which:
The electrical connection of the resistor elements 10, 11 to each other is effected by means of screw connecting means at the connections 16, in which respect other electrically conducting connection means are also possible. That can be clearly seen in relation to the foremost resistor element 10. A connection 16 is free in the view at the right-hand side. That serves for the electrical connection of the high-performance resistor. For example, cables or other suitable counterpart portions can be easily connected thereto. The left-hand connection 16 of that front resistor element 10 is connected by means of fasteners, such as the two screws 23, to the corresponding connection 16 of the subsequent resistor element 11. The connection of the individual resistor elements 10, 11 with each other to afford the high-performance resistor according to the invention can be clearly seen from
The first and second resistor elements 10, 11 in this case are of such a configuration that at their two ends they have a respective connection 16a, 16b, wherein one of the connections 16a is bent towards one side 10a and the other connection 16b is bent towards the other side 10b. Preferably the connections 16a, 16b have an inner and an outer portion. In that respect, the inner portion is respectively bent towards a first or a second side of the resistor element and the outer portion is then again of a configuration such as to be substantially parallel to the respective resistor element. The parallel configuration of the outer portions of the connections 16a, 16b substantially simplifies assembly of the respective resistor elements.
It can also be clearly seen from
The crucial difference in relation to the first embodiment is that here only one single resistor element 10 is also required to construct a resistor according to the invention. That derives from the displaced arrangement of the connections 16 with respect to the centre line of the resistor element 10. That displaced arrangement makes it possible for the resistor elements to be connected by a suitably oriented arrangement in accordance with the invention to provide a high-performance resistor.
As described hereinbefore, preferably flat resistor elements are provided in accordance with the invention. The resistor elements are preferably all of the same or identical structure. The above-described high-performance resistor can advantageously be used as a load resistor in the cabinets of the power electronics of a wind power installation or in a separate apparatus rack in a wind power installation in order to be used as a dump load. In that respect the dimensioning of the high-performance resistors is such that a sufficiently high level of permissible power dissipation can be achieved.
If the power generated by the electrical generator of the wind power installation cannot be delivered to a network or is not to be delivered, that electrical power is dissipated entirely or partially by way of the high-performance resistor. Rapid power regulation can thus be effected. As a power regulation of that kind involves electrical regulation, adjustment of the pitch angle of the rotor blades of the wind power installation is not absolutely necessary for the time being.
The high-performance resistor or a plurality of high-performance resistors is preferably arranged in the proximity of the inverter of the wind power installation.
All of the above U.S. patents, U.S. patent application publications, U.S. patent applications, foreign patents, foreign patent applications and non-patent publications referred to in this specification and/or listed in the Application Data Sheet, including but not limited to German Application No. 04 033 680 6, filed on Jul. 9, 2004, are incorporated herein by reference, in their entirety.
From the foregoing it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims.
Number | Date | Country | Kind |
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10 2004 033 680 | Jul 2004 | DE | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/EP2005/007419 | 7/8/2005 | WO | 00 | 11/29/2007 |
Publishing Document | Publishing Date | Country | Kind |
---|---|---|---|
WO2006/005542 | 1/19/2006 | WO | A |
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2725448 | Kintzing | Nov 1955 | A |
4654627 | Harkness | Mar 1987 | A |
5159310 | Cummins et al. | Oct 1992 | A |
5304978 | Cummins et al. | Apr 1994 | A |
5488334 | Wolk | Jan 1996 | A |
5917404 | Campbell | Jun 1999 | A |
Number | Date | Country |
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0 715 317 | Jun 1996 | EP |
770 317 | Sep 1934 | FR |
52165248 | Dec 1977 | JP |
09097701 | Apr 1997 | JP |
Number | Date | Country | |
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20080191836 A1 | Aug 2008 | US |