Compact magnetic self-compensation in DC systems

Abstract

The invention relates to a compact fuse unit (1) for magnetic self-compensation in direct current systems, comprising a first conductor (2), a second conductor (3) and a first fuse conductor (4) arranged in parallel to one another, wherein the first fuse conductor (4) is arranged symmetrically between the first conductor (2) and the second conductor (3), further comprising and arranged in parallel to one another, a third conductor (5), a fourth conductor (6) and a second fuse conductor (7), wherein the second fuse conductor (7) is arranged symmetrically between the third conductor (5) and the fourth conductor (6), wherein the first conductor (2) and the second conductor (3) are electrically connected to the second fuse conductor (7) and the first fuse conductor (4) is electrically connected to the third conductor (5) and the fourth conductor (6), wherein a first fuse (8) is arranged in the first fuse conductor (4) and a second fuse (9) is arranged in the second fuse conductor (7).The invention further relates to a system (14) with several compact security units (1).

Description

TECHNICAL FIELD

[0001] The invention relates to a compact fuse unit for magnetic self-compensation in direct current systems and to a system with several compact fuse units. BACKGROUND

[0002] It is known that strict magnetic limits are established for certain areas of the navy. In this context, particular emphasis is placed on the special routing of connecting cables. For example, electrical conductors are arranged in such a way that they form a quadrupole pattern in cross-section.

[0003] A quadrupole in electrical engineering refers to the arrangement of typically four conductors or cables. When cables are laid out as a quadrupole, it means they are arranged in a specific four-conductor configuration. A quadrupole is created by arranging two opposite-equal electric or magnetic dipoles. This arrangement offers several advantages. One advantage is that it improves shielding against external electromagnetic interference. This is because the opposing pairs of conductors in a quadrupole have the same magnetic and electric field strength, causing external interference affecting either pair to cancel each other out.

[0004] Similar requirements regarding magnetic limits can also be applied to switchgear. The problem here is that the cables require protection, and, due to the requirement for easy replacement, for example, fuses must be easily accessible. This means that low-leakage cable routings are opened and placed next to each other in the switchgear cabinet, resulting in less magnetic interaction.

[0005] Fig. Figure 1 shows a highly simplified representation of a typical arrangement of three fuse pairs in a control cabinet, with the fuses for the positive and negative poles positioned side by side. While such a configuration is optimized for space, it is not magnetically advantageous.

[0006] Improving the magnetic properties depends on the number and type of loads. One possibility, for example, could be reversing the polarities. Fig. Figure 2 illustrates an improved polarity arrangement with regard to magnetic properties. Optimal results are achieved when the current intensities are roughly equivalent.

[0007] It is the responsibility of the operator or an automation system to monitor and control relevant loads and energy sources. This system generally offers the operator two optimization strategies. The first strategy allows for free configuration of loads, which provides maximum flexibility, but at the cost of suboptimal magnetics due to unbalanced loads. The second strategy, on the other hand, relies on an identical load to achieve optimized magnetics, but does not allow for flexibility in the configuration of loads.

[0008] With a large number of consumers, such as those found in a ship's electrical system, many fuse outlets are required. This could lead to interference and thus cause peaks in the magnetic properties.

[0009] Previous approaches to solving the problem have employed the following strategies: In the past, the specified limit values ​​were generally set higher. Control panels were measured under specific operating conditions, and compensation magnets were installed. However, this approach has the disadvantage that the compensation magnets represent additional magnetizable mass in a non-magnetically designed control panel and, in the worst case, can even cause an increased static magnetic field. Attempts have also been made to use higher voltages to reduce currents, based on the principle that power is the product of voltage and current (P=U*I). However, using higher voltages to reduce currents can have several potential disadvantages, which may be purely technical in nature but may also affect compliance with applicable standards. SUMMARY OF THE INVENTION

[0010] The object of the invention is to provide a compact fuse unit for improved magnetic self-compensation in DC systems and a system with several compact fuse units.

[0011] The object directed to a compact fuse unit is achieved by a fuse unit for magnetic self-compensation in direct current systems, comprising a first conductor, a second conductor and a first fuse conductor arranged parallel to one another, wherein the first fuse conductor is arranged symmetrically between the first conductor and the second conductor, further comprising and arranged parallel to one another, a third conductor, a fourth conductor and a second fuse conductor, wherein the second fuse conductor is arranged symmetrically between the third conductor and the fourth conductor, wherein the first conductor and the second conductor are electrically connected to the second fuse conductor and the first fuse conductor is electrically connected to the third conductor and the fourth conductor, wherein a first fuse is arranged in the first fuse conductor and a second fuse is arranged in the second fuse conductor.

[0012] One advantage of this compact fuse unit is that each load receives individual compensation, as the corresponding lines in switchgear are laid as three-wire systems. This structure, consisting of a line, a fuse, and a second line, enables independent compensation that is independent of the load of neighboring lines / fuses, thus avoiding external compensation. This offers the operator the advantage of not being forced to monitor the loads and currents or ensure symmetrical operation.

[0013] In an advantageous embodiment of the compact fuse unit, insulating separating plates are arranged between the first conductor and the first fuse conductor, between the second conductor and the first fuse conductor, between the third conductor and the second fuse conductor, and between the fourth conductor and the second fuse conductor. These plates form a physical barrier between the various conductors within the fuse unit. They not only serve as protection against direct contact between the conductors, which could lead to short circuits, but they also reduce the installation space required for the fuse unit by reducing air and creepage distances.

[0014] In addition, they could also serve as protective barriers against physical damage. For example, if a foreign object enters the fuse unit while changing fuses, the insulating plates could prevent it from coming into contact with the conductors and potentially causing damage. Furthermore, the insulating plates could help ensure the structural integrity of the fuse unit, making it more stable and resistant to physical stress.

[0015] It is advantageous if the first and second fuses each have a cover. Covering fuses in switchgear has several reasons. The cover prevents people from accidentally coming into contact with live parts when changing fuses and suffering an electric shock. The cover can also help ensure safer maintenance work by preventing tools or other objects from accidentally falling into the switchgear and causing a short circuit.

[0016] In an advantageous embodiment of the compact fuse unit, the first conductor and the second conductor are connected to the second fuse conductor via a first connection such that at least a portion of this first connection protrudes beyond a plane spanned by the first and second conductors. Furthermore, in this advantageous embodiment, the third conductor and the fourth conductor are connected to the first fuse conductor via a second connection such that at least a portion of the second connection protrudes beyond a plane spanned by the third and fourth conductors. This type of cable routing guarantees optimal symmetry at the transition from conductors to the associated fuse conductors and vice versa.With a purely space-based routing, it would be sufficient at the intersection point if only lines in a specific current direction protruded from the plane, while lines in the opposite current direction remained in the plane. However, this could then negatively affect the magnetic properties.

[0017] Typically, the first through fourth conductors are loaded at 50% of their rated current during operation, and the fuse conductors are loaded at 100% of their rated current, so they generate the same magnetic flux density. This helps maintain symmetry and can help minimize unwanted magnetic effects.

[0018] The problem, which is addressed to a system with multiple compact fuse units, is solved by a system in which the fuse units are arranged side by side in such a way that the first and second current directions of adjacent conductors of two adjacent fuse units are opposite to each other during operation. When the current directions in adjacent conductors are opposite to each other, their magnetic fields neutralize each other in close proximity. This reduces the overall magnetic field and reduces the occurrence of resulting outward magnetic fields and associated interference with neighboring loads. This can improve the overall performance and efficiency of the system.

[0019] It is advantageous if the system comprises a consumer line, i.e. a line leading from a fuse unit in a switch cabinet to a consumer, with four quadrupole conductors arranged in the quadrupole, wherein the first and the second quadrupole conductor are provided for a first current direction of an electric current and the third and the fourth quadrupole conductor are provided for a second, opposite current direction of the electric current, wherein the first quadrupole conductor is electrically connected to the first conductor, the second quadrupole conductor is electrically connected to the second conductor and the third quadrupole conductor and the fourth quadrupole conductor are electrically connected to the first fuse conductor.

[0020] On the generator side, the fuse units are connected to a busbar. A busbar, also known as a busbar, offers several advantages in electrical systems. Busbars enable effective and efficient distribution of electrical energy within a system or building. They serve as common connection points for multiple circuits, enabling simple and orderly power distribution. They are capable of safely handling high amperages, making them ideal for industrial applications and high-current systems. Busbars offer a high degree of flexibility in the installation and expansion of electrical systems. They allow for easy addition or removal of circuits without major reconstruction. Busbars contribute to safety by reducing the risk of short circuits and electrical fires.They are often equipped with protective devices such as fuses and circuit breakers that trip in the event of an overload or short circuit. Compared to cables, busbars take up less space and ensure a neat and tidy installation. Because busbars have a lower impedance than cables, they result in lower energy losses. This increases the efficiency of the entire system. Therefore, it is advantageous if the third and fourth conductors, as well as the second fuse conductors, of different fuse units are connected to a busbar.

[0021] This is particularly advantageous when the busbar is designed with poles arranged to form a quadrupole. A quadrupole can also be formed by two conductors and a symmetrically spaced inner conductor. It is a common configuration in electrical engineering, particularly in coaxial cable technology and radio frequency technology. This configuration offers advantages such as good shielding against external electromagnetic interference and constant impedance, which is important for signal transmission.

[0022] It is advisable to arrange fuse units in pairs with their backs facing each other so that the current directions toward the backs of adjacent conductors and toward the backs of adjacent fuse conductors are opposite to each other during operation. In mirrored switchboards, such a back-to-back arrangement is possible, forming quadrupoles (when viewed from above), which is theoretically the best form of magnetic compensation. BRIEF DESCRIPTION OF THE DRAWINGS Fig. Figure 1 shows schematically a typical arrangement of three pairs of fuses in a prior art switch cabinet design, in which the fuses for the positive pole and the negative pole are arranged side by side, Fig. Figure 2 shows schematically a typical arrangement of three fuse pairs in a control cabinet design according to the state of the art with respect to the Fig. 1 shown arrangement reversed polarities, Fig. 3 shows a compact fuse unit according to the invention, Fig. 4 shows two compact security units arranged side by side in a system according to the invention, Fig. 5 shows a transition area for conductors according to the inventive fuse unit, Fig. 6 shows a schematic diagram of the distribution of polarities in a compact fuse unit for a consumer, Fig. Figure 7 shows a schematic diagram of the distribution of polarities in compact fuse units arranged side by side for three consumers and Fig. Figure 8 shows a schematic diagram of the distribution of polarities in compact fuse units arranged side by side and one behind the other for a total of six consumers. DESCRIPTION OF THE EMBODIMENTS

[0023] Fig. Figure 1 shows a schematic and highly simplified typical arrangement of three fuse pairs 23 in a prior art switch cabinet design, in which a first fuse 8 for the positive pole 24 of a load and a second fuse 9 for the negative pole 25 of the load are arranged side by side. The design with alternating polarities is compact and optimized for space, but offers no magnetic advantage.

[0024] Fig. Figure 2 shows how an improvement could be achieved in a state-of-the-art setup by swapping the polarities (see dashed circle) in such a way that the corresponding magnetic fields cancel each other out as much as possible. A magnetic advantage only arises at equivalent current strengths.

[0025] Fig. 3 shows a compact fuse unit 1 for magnetic self-compensation in DC systems according to the invention. The fuse unit 1 comprises, arranged parallel to one another, a first conductor 2, a second conductor 3 and a first fuse conductor 4, wherein the first fuse conductor 4 is arranged symmetrically between the first conductor 2 and the second conductor 3, further comprising and arranged parallel to one another, a third conductor 5, a fourth conductor 6 and a second fuse conductor 7, wherein the second fuse conductor 7 is arranged symmetrically between the third conductor 5 and the fourth conductor 6. According to the invention, the first conductor 2 and the second conductor 3 are electrically connected to the second fuse conductor 7 and the first fuse conductor 4 is electrically connected to the third conductor 5 and the fourth conductor 6, wherein a first fuse 8 is arranged in the first fuse conductor 4 and a second fuse 9 is arranged in the second fuse conductor 7.

[0026] Insulating separating plates 10 are arranged between the first conductor 2 and the first fuse conductor 4, between the second conductor 3 and the first fuse conductor 4, between the third conductor 5 and the second fuse conductor 7, and between the fourth conductor 6 and the second fuse conductor 7. The first and second fuses 8, 9 are each provided with a cover 11.

[0027] In addition, Fig. 3 first and second current directions 15, 16 during operation of the compact fuse unit 1. While the current in the upper half of Fig. 3 in the middle area, i.e. in the second fuse conductor 7 including the second fuse 9, flows from top to bottom, it does so in the lower half of Fig. 3 through the first and second conductors 2, 3. Conversely, the current flows in the lower half of the Fig. 3 in the middle, ie in the first fuse conductor 4 and in the first fuse 8, upwards and then branches out to flow further upwards via the third and fourth conductors 5, 6.

[0028] In Fig. Figure 4 shows a section of a system 14 according to the invention with two compact fuse units 1. The fuse units 1 are arranged side by side such that the first and second current directions 15, 16 of adjacent conductors 2, 3, 5, 6 are opposite to each other during operation.

[0029] Furthermore, Fig. 4 two consumer lines 17 connected to compact fuse units 1, each with four quadrupole conductors 18, 19, 20, 21 arranged in a quadrupole. In the case of the fuse unit 1 on the left, the first and second quadrupole conductors 18, 19 are provided for a first current direction 15 of an electric current and the third and fourth quadrupole conductors 20, 21 are provided for a second, opposite current direction 16 of the electric current, wherein the first quadrupole conductor 18 is electrically connected to the first conductor 2, the second quadrupole conductor 19 is electrically connected to the second conductor 3, and the third quadrupole conductor 20 and the fourth quadrupole conductor 21 are electrically connected to the first fuse conductor 4. The fuse unit 1, which in Fig. shown on the right-hand side, is linked to the quadrupole conductors 18, 19, 20, 21 of the consumer line 17 on the right-hand side in such a way that, in the operating state, opposite current directions 15, 16 are present on the adjacent conductors 2, 3, 5, 6 of the fuse units 1.

[0030] Fig. 5 shows the compact fuse unit 1 according to the invention in an oblique plan view. Here, it can be seen that the first conductor 2 and the second conductor 3 are connected to the second fuse conductor 7 via a first connection 12 such that at least a portion of this first connection 12 projects beyond a plane defined by the first and second conductors 2, 3, and wherein the third conductor 5 and the fourth conductor 6 are connected to the first fuse conductor 4 via a second connection 13 such that at least a portion of the second connection 13 projects beyond a plane defined by the third and fourth conductors 5, 6.

[0031] Fig. 6 shows in a plan view of a compact safety unit 1 the polarities of the conductors of the compact safety unit 1 from Fig. 3 for a single consumer using the example of the first conductor 2, the second conductor 3, and the first fuse conductor 4, or the third conductor 5, the fourth conductor 6, and the second fuse conductor 7, each with reversed polarity. Self-compensation of the magnetic fields occurs within the respective group of power lines assigned to a consumer.

[0032] Fig. Figure 7 shows the polarities of the lines of three compact fuse units 1 arranged side by side for three consumers. It has been shown that, unlike in the Fig. In the improved prior art arrangement shown in Figure 2, with two conductors per load, the polarities of adjacently arranged conductors of the inventive fuse units 1 of different loads should also be different with regard to magnetic compensation. The relevant areas are marked with dashed ovals.

[0033] Fig. 8 finally shows polarities of conductors 2 - 7 of six compact fuse units 1 for six consumers, where three fuse units 1 each, as in Fig. 7, are arranged side by side and the two groups of three are arranged with their backs 22 to each other (back-to-back) in the control cabinet, in such a way that a positive pole 24 is always opposite or adjacent to a negative pole 25. Two dashed squares in Fig. 8 shows two groups of four conductors each forming a quadrupole. LIST OF REFERENCE SYMBOLS 1 compact fuse unit 2 first leader 3 second leader 4 first safety conductor 5 third leader 6 fourth leader 7 second fuse conductor 8 first backup 9 second fuse 10 Insulating partition plate 11 Cover 12 first connection 13 second connection 14 Systems 15 first current direction 16 second current direction 17 Consumer line 18 first quadrupole conductor 19 second quadrupole conductor 20 third quadrupole conductor 21 fourth quadrupole conductor 22 Back 23 fuse pairs 24 positive pole 25 Negative pole

Claims

[1] A compact fuse unit (1) for magnetic self-compensation in direct current systems, comprising a first conductor (2), a second conductor (3) and a first fuse conductor (4) arranged in parallel to one another, the first fuse conductor (4) being arranged symmetrically between the first conductor (2) and the second conductor (3), further comprising and arranged in parallel to one another, a third conductor (5), a fourth conductor (6) and a second fuse conductor (7), the second fuse conductor (7) being arranged symmetrically between the third conductor (5) and the fourth conductor (6), characterized by that the first conductor (2) and the second conductor (3) are electrically connected to the second fuse conductor (7) and the first fuse conductor (4) is electrically connected to the third conductor (5) and the fourth conductor (6), wherein a first fuse (8) is arranged in the first fuse conductor (4) and a second fuse (9) is arranged in the second fuse conductor (7). [2] The fuse unit (1) according to claim 1, wherein insulating separating plates (10) are arranged between the first conductor (2) and the first fuse conductor (4), between the second conductor (3) and the first fuse conductor (4), between the third conductor (5) and the second fuse conductor (7) and between the fourth conductor (6) and the second fuse conductor (7). [3] The fuse unit (1) according to one of the preceding claims, wherein the first and second fuses (8, 9) are each provided with a cover (11). [4] The fuse unit (1) according to one of the preceding claims, wherein the first conductor (2) and the second conductor (3) are connected to the second fuse conductor (7) via a first connection (12) such that at least a part of this first connection (12) projects beyond a plane spanned by the first and the second conductor (2, 3) and wherein the third conductor (5) and the fourth conductor (6) are connected to the first fuse conductor (4) via a second connection (13) such that at least a part of the second connection (13) projects beyond a plane spanned by the third and the fourth conductor (5, 6). [5] The fuse unit (1) according to one of the preceding claims, wherein the conductors (2, 3, 5, 6) are supplied with 50% of the rated current during operation and the fuse conductors (4, 7) are supplied with 100% of the rated current. [6] A system (14) comprising a plurality of compact fuse units (1) according to any one of the preceding claims, wherein the fuse units (1) are arranged next to one another such that first and second current directions (15, 16) of adjacent conductors (2, 3, 5, 6) of two adjacent fuse units (1) are opposite to one another during operation. [7] The system (14) according to claim 6, comprising a load line (17) with four quadrupole conductors (18, 19, 20, 21) arranged in the quadrupole, the first and the second quadrupole conductor (18, 19) for a first current direction (15) of an electric current and the third and the fourth quadrupole conductor (20, 21) for a second, opposite current direction (16) of the electric current, wherein the first quadrupole conductor (18) is electrically connected to the first conductor (2), the second quadrupole conductor (19) is electrically connected to the second conductor (3) and the third quadrupole conductor (20) and the fourth quadrupole conductor (21) is electrically connected to the first fuse conductor (4). [8] The system (14) according to any one of claims 6 or 7, wherein the third and fourth conductors (5, 6) and the second fuse conductors (7) of different fuse units (1) are connected to a busbar constructed such that poles are arranged to form a quadrupole. [9] The system (14) according to one of claims 6 to 8, wherein fuse units (1) are arranged in pairs with rear sides (22) relative to one another such that the current directions (7, 8) in the direction of the rear sides (22) of adjacent conductors (2, 3, 5, 6) and in the direction of the rear sides (22) of adjacent fuse conductors (4, 7) are opposite to one another during operation.

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