Shell protection integrated bus duct for low-voltage power transformation and distribution

Abstract

The utility model discloses a shell protection integrated bus duct for low-voltage power transformation and distribution, which comprises a plurality of bus duct sections and a plurality of connectors, a shell of the bus duct is connected with a PE (Poly Ethylene) grounding busbar arranged in the center, and an N phase of a busbar conductor in the bus duct is in conduction connection with the PE grounding busbar arranged in the center; the connector is used for conducting connection of busbars of two adjacent bus ducts, conducting connection of a PE grounding busbar and an N phase, and insulating isolation between the adjacent busbars and the PE grounding busbar and between the adjacent busbars and the N phase; the middle of the connector is provided with three aluminum connecting sheets and copper connecting sheets which are located between the adjacent insulating phase-isolating films on the two sides, wherein two of the aluminum connecting sheets and the copper connecting sheets are used for conducting connection of the PE grounding busbars inserted into the two sides, and a copper-aluminum composite sheet which is used for conducting an N-phase busbar inserted into the two sides with the PE grounding busbars synchronously through the aluminum connecting sheets and the copper connecting sheets. Accident current of the bus duct shell can be quickly evacuated from the PEN line when the transformer is in single-phase grounding, superior protection is quickly driven to cut off a power supply, and accidents are prevented from being expanded.

Description

TECHNICAL FIELD

[0001] The utility model relates to the ground protection technology of bus duct, especially to a shell protection integrated bus duct for low-voltage transformation and distribution. BACKGROUND

[0002] In the existing building electrical engineering, due to the bus duct design and installation of low-voltage transformer room and distribution room are different in different places, three-phase four-wire, three-phase five-wire, five-core, four-core, 5P, 4P and other connection modes are adopted respectively. In the construction in the project, most of them are made into 3L+N+flat iron grounding or 3L+N+PE (PE connection flat iron grounding) construction methods. The above two connection modes have the following problems at present: 1. When single-phase grounding occurs, the accident cannot be quickly dispersed because the small accident current cannot drive the upper protection electric appliance to act and cut off the power supply accident point. The arc of the accident point continues, which burns the other phase wire insulation layer close to the accident point, eventually causing inter-phase short circuit. If someone touches the bus duct shell between single-phase to inter-phase short circuit, it will endanger personal safety; 2. Because the N line is made into an insulator in the two kinds of construction cases at present, the resistance of the grounding flat iron and grounding bolt is greater than that of the transformer PEN. Most of the loop current returns to the transformer. The current cannot return to the power grid but only dissipates on the transformer shell and metal parts, causing the temperature of the transformer to rise.

[0003] In the existing building electrical engineering in low-voltage strong electric system, mainly using TN-C-S system, or TN-C system and TN-S system combination, in low-voltage transformer substation, the best is to use TN-C system. In 3L+PEN, the feeder line of low-voltage transformer substation outlet is preferably TN-S system, 3L+N+PE. In low-voltage transformer substation distribution line protection grounding and working grounding, and the current engineering application, there are the following problems: (1) the loop current is several single-phase load and three-phase voltage unevenly generated loop current, these loops will exist current when using electricity, and because the transformer substation has a more perfect grounding network, therefore, these loop currents are backflow to the substation end dissipation; (2) due to the limited current of loop current, and the transformer and working grounding connection, resulting in very low voltage, to the substation end, basically with the grounding network is zero potential, at most only 1Ⅴ voltage difference; (3) working grounding is mainly to disperse the loop current to the conductor of grounding network, collectively referred to as working grounding; (4) protection grounding is mainly used for single-phase grounding accident current dispersion to ensure personal safety in case of accident; (5) accident current is phase voltage, if single-phase grounding, if not quickly dispersed, the voltage generated will be relatively high, the live metal shell will endanger personal safety; (6) if single-phase grounding accident cannot be quickly dispersed, because the accident current is small and cannot drive the upper protection electric appliance to act to cut off the power supply, the arc of the accident point continues to burn the other phase line insulation layer close to the accident point, eventually causing inter-phase short circuit; and if the time between single-phase to inter-phase short circuit, someone touches the bus duct shell will endanger personal safety; (7) at present, most of the low-voltage transformer substation is made into 3L+N+flat iron grounding and 3L+N+PE (PE connects flat iron grounding network), because the N line of the two schemes is made into an insulator, the resistance of the grounding flat iron and grounding bolt is greater than that of the transformer PEN, resulting in most of the loop current returning to the transformer, which cannot return to the power grid, but only dissipates on the transformer shell and metal parts, causing the temperature of the transformer to rise; in many projects, the transformer load is not fully utilized, but the temperature of the transformer is very high, the main reason is that most of the loop current returns to the transformer to dissipate; (8) whether using cable or bus duct, using independent N line with insulation, when single-phase grounding occurs, as long as the phase insulation is damaged, the phase current will be transmitted to the metal shell of the bus duct or cable bridge; the metal shell of the existing bus duct or cable bridge is normally insulated with a surface treatment of 200-500 megaohm, the N line in three-phase four-wire 3L+N is an insulator, which is impossible to return the accident current to the N line.Therefore, the accident current cannot be quickly transmitted to the PEN line; (9), the independent PE line of the three-phase five-wire is originally transmitted to the PE line from the attachment end of the bus duct, and the attachment side plate of the bus duct end is separated from the body by a sealing strip, thereby cutting off the path of the accident current transmitted to the PE line; (10), in addition, the flat iron round steel grounding transmission, the resistance of the flat iron round steel is 7.63 times that of the copper conductor, and the normal configuration is 4x40 or 5x50 flat iron, and according to the 5x50 flat iron, only the dispersion capacity of 35 square copper conductor is reached. According to the standard, the PE / PEN standard configuration can only reach 300A or less; the existing bus duct of the power transformation and distribution room is 1000A or more, and the flat iron cannot meet the speed of the accident current dispersion of the bus duct of 1000A or more.

[0004] Due to the above reasons, the loop current is returned to the shell of the transformer and the metal part connected with the PEN, which causes the transformer to heat; and when single-phase grounding occurs, the upper protection electric appliance cannot be quickly driven to act to cut off the power supply, which causes the shell voltage of the bus duct to be high, and endangers personal safety and expands to phase-to-phase short circuit. Practical new type content

[0005] The shell and protection integrated bus duct for low-voltage power transformation and distribution directly communicates with the PEN line of the bus duct through the connector, realizes the same current-carrying capacity of the conductor and the PEN, ensures that the accident current of the shell is quickly dispersed from the PEN line when single-phase grounding occurs, quickly drives the upper protection electric appliance to act to cut off the power supply, and prevents the expansion of the accident.

[0006] The technical scheme adopted by the shell and protection integrated bus duct for low-voltage power transformation and distribution to solve the technical problems is:

[0007] A shell and protection integrated bus duct for low-voltage power transformation and distribution is used for a bus coupler in low-voltage power transformation and distribution, and comprises multiple bus ducts and multiple connectors.

[0008] The shell of each bus duct is directly connected with the PE grounding bus bar arranged at the center, and the N phase of the bus bar conductor in each bus duct is in conductive connection with the PE grounding bus bar at the center; the connector is used for conductive connection of the bus bars of two adjacent bus ducts, synchronous conductive connection of the PE grounding bus bar and the N phase, and mutual insulation isolation between the adjacent bus bars and the PE grounding bus bar and the N phase.

[0009] The outer shell of each busbar is connected to the PE grounding busbar arranged in the center, and the N-phase busbar of each busbar is arranged adjacent to the PE grounding busbar. There are three aluminum connecting pieces and copper connecting pieces in the middle of the corresponding connector, which are located between two adjacent insulating phase separation membranes on both sides and are used for conducting and connecting the PE grounding busbars inserted on both sides, and a copper-aluminum composite sheet is used for synchronously conducting the N-phase busbars inserted on both sides with the PE grounding busbar through the aluminum connecting pieces and copper connecting pieces.

[0010] Preferably, the aluminum connecting piece and the copper connecting piece are symmetrically arranged. The aluminum connecting piece is directly conductively connected to the inserted aluminum alloy PE grounding busbar, and the copper connecting piece is directly conductively connected to the N-phase busbar of the copper alloy through the copper-aluminum composite sheet.

[0011] Preferably, when the connector is connected to the busbars arranged in a single row on both sides, the busbar includes a top cover plate, a bottom sealing plate, a front-side busbar plate, a rear-side busbar plate and multi-phase busbar conductors. The top cover plate and the bottom sealing plate are respectively arranged on the top side and the bottom side of the multi-phase busbar conductors for sealing the upper and lower sides, and the front-side busbar plate and the rear-side busbar plate are respectively arranged on the front side and the rear side of the multi-phase busbar conductors for sealing the front and rear sides;

[0012] An inner partition is provided in the middle of the inner sides of the top cover plate and the bottom sealing plate, extending along the height direction between the top cover plate and the bottom sealing plate. The inner partition and the top cover plate or the bottom sealing plate form a "T" shape structure respectively. The top cover plate and the bottom sealing plate are formed by docking a pair of symmetrically arranged "T" shape structures up and down to form an "I" shape structure that divides the multi-phase busbar conductors into two by two front and back. The inner partition is used as an internal PE line for independently evacuating the accident current inside the entire busbar housing when a single phase is grounded. The N-phase busbar in the multi-phase busbar conductors is arranged closely against the inner partition, and the contact surface is directly conductively connected to the inner partition;

[0013] The top cover plate, the bottom sealing plate, the front-side busbar plate and the rear-side busbar plate together form an outer shell PE line for evacuating the accident current of the outer shell when a single phase is grounded. The outer shell PE line and the internal PE line jointly form a double-busbar PE shell protection joint structure in the shape of an inverted "曰".

[0014] The beneficial effects of the present utility model are:

[0015] In this invention, each set of connecting conductors on the connector is connected to the busbars (excluding the N-phase) between the two connecting conductors inserted into the busbar slots on both sides; the connector is provided with three aluminum and copper connecting pieces located between the insulating phase-isolating films on both sides, two of which are used for the conductive connection of the PE grounding busbars inserted on both sides, and one copper-aluminum composite piece for the N-phase busbars inserted on both sides to be synchronously connected to the PE grounding busbar through the aluminum and copper connecting pieces; thus realizing the working grounding of the transformer in the low-voltage power distribution room.

[0016] Through the above methods, the PEN lines of two adjacent busbar units are directly connected via connectors. The outer shell of the busbar and the PE are made of aluminum alloy and are assembled as a whole. The N-phase conductor in the busbar conductor is made of copper and is connected to the PE busbar by a copper-aluminum composite sheet at the connector, with copper side connected to copper side and aluminum side connected to aluminum side, effectively solving the problem of electrochemical oxidation. At the same time, aluminum or copper busbars are connected to the steel grounding grid under the concrete as the working ground at the PEN end of the transformer, effectively ensuring that the current carrying capacity of the conductor is the same as that of the PEN. This ensures that when a single phase of the transformer and busbar is grounded, the fault current of the outer shell is quickly dissipated from the PEN line, which quickly triggers the upper-level protection device to cut off the power supply and prevent the accident from escalating. Attached Figure Description

[0017] Figure 1 This is an exploded structural diagram of a single-row busbar trunking connected to some connectors in this utility model;

[0018] Figure 2 This is an enlarged three-dimensional structural diagram of the busbar connection end of the single-row busbar trunking in this utility model;

[0019] Figure 3 This is an exploded structural diagram of the single-row busbar trunking connected to the connector in this utility model;

[0020] Figure 4 This is an enlarged schematic diagram of the "I"-shaped structure corresponding to the PE line of the single-row busbar trunking in this utility model;

[0021] Figure 5 This is a top view schematic diagram of the connection structure of a single-row busbar trunking and some connectors in this utility model;

[0022] Figure 6 This is an enlarged schematic diagram of the structure of the double-row busbar PE line in this utility model. Detailed Implementation

[0023] Clearly, the described embodiments are merely a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative efforts under the premise that no creative efforts are made, belong to the scope of protection of the present application.

[0024] It should be noted that similar reference numbers and letters represent similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0025] A shell-integrated bus duct system for low-voltage power distribution, as shown in Figures 1 to 5 for busbars in low-voltage power distribution, comprising a plurality of bus ducts (a, b) and a plurality of connectors c, the plurality of bus ducts (a, b) and the plurality of connectors c are sequentially connected to form a distribution busbar in low-voltage power distribution; the shell of each bus duct is directly connected with a centrally arranged PE grounding busbar 4, and the N phase of the busbar conductor in each bus duct is in conductive connection with the centrally arranged PE grounding busbar 4; the connector is used for conductive connection of the busbar of two adjacent bus ducts, synchronous conductive connection of the PE grounding busbar 4 and the N phase, and mutual insulation isolation between the adjacent busbar and the PE grounding busbar 4 and the N phase.

[0026] Continuing as shown in Figures 1 to 5 for the single-row structure bus duct, the connector comprises a front side plate 1, four groups of two-by-two arranged connection conductors 2, and a rear side plate 3, the four groups of connection conductors 2 are arranged in front of and behind the front side plate 1 and the rear side plate 3, and each group is in conductive connection with the busbar of the two-side bus duct inserted between the two connection conductors 2; the four groups of two-by-two adjacent connection conductors 2 are symmetrically arranged and each group is in conductive connection with each other, and form four groups of two-by-two conductive connection with the busbar of the two-side bus duct, which are waterproof and high-temperature resistant; since the shell of each bus duct is connected with the centrally arranged PE grounding busbar 4, and the N phase busbar 5 of each bus duct is in close conductive connection with the PE grounding busbar 4, the corresponding connector is provided with three insulating phase isolation films 6 located between the two adjacent sides, and two aluminum connecting pieces 7 and copper connecting pieces 8 for conductive connection of the two inserted PE grounding busbars 4, and a copper-aluminum clad piece 9 for synchronous conductive connection of the N phase busbar 5 inserted on both sides with the PE grounding busbar 4 through the aluminum connecting piece 7 and the copper connecting piece 8. Among them, the aluminum connecting piece 7 and the copper connecting piece 8 are symmetrically arranged, the aluminum connecting piece 7 is in direct conductive connection with the inserted aluminum alloy PE grounding busbar 4, and the copper connecting piece 8 is in direct conductive connection with the copper alloy N phase busbar 5 through the copper-aluminum clad piece 9.

[0027] For the single-row bus duct, as shown in Figure 4 and Figure 5As shown, a single row of connectors directly connects the PEN lines of two adjacent busbars. Since the outer shell of the busbar and the PE are made of aluminum alloy and are assembled as a whole, the N phase in the busbar conductor is made of copper conductor and is connected to the PE grounding busbar by a copper-aluminum composite sheet 9 at the connector to achieve copper-to-copper and aluminum-to-aluminum connection, effectively solving the problem of electrochemical oxidation.

[0028] like Figures 1 to 5 As shown, for a single-row busbar trunking, the busbar trunking includes a top cover plate 10, a bottom sealing plate 11, a front busbar plate 12, a rear busbar plate 13, and four-phase busbar conductors 14. The top cover plate 10 and the bottom sealing plate 11 are respectively placed on the top and bottom sides of the four-phase busbar conductors 14 for sealing the upper and lower sides. The front busbar plate 12 and the rear busbar plate 13 are respectively placed on the front and rear sides of the four-phase busbar conductors for sealing the front and rear sides. An inner partition plate 15 is provided in the middle of the inner side of both the top cover plate 10 and the bottom sealing plate 11, extending along the height direction between the top cover plate 10 and the bottom sealing plate 11. The inner partition plate 15 is respectively connected to the top cover plate 10 and the bottom sealing plate 11. The top cover plate 10 or the bottom sealing plate 11 form a "T" shaped structure. The top cover plate 10 and the bottom sealing plate 11 are connected by a pair of symmetrical "T" shaped structures to form an "I" shaped structure that separates the four-phase busbar conductors in pairs. The inner partition plate 15 is used as an internal PE line for independent evacuation of the internal fault current of the entire busbar trunking when a single phase is grounded. The top cover plate 10, the bottom sealing plate 11, the front busbar plate 12 and the rear busbar plate 13 together form the outer casing PE line for evacuation of the outer casing fault current when a single phase is grounded. The outer casing PE line and the inner PE line together form a "Y" shaped inverted double busbar PE shell protection structure.

[0029] like Figure 6 As shown, for the busbar trunking with a double-row structure, when the connector is connected to the double-row busbar trunking on both sides, the corresponding method is adopted. Figure 1 , Figure 4 The single-row busbar trunking shown is arranged in a double-row structure by stacking the trunking from top to bottom.

[0030] In the above embodiments, the integrated protective distribution busbar allows the circuit current to return to the transformer and distribution room and be directly dissipated from the outer shell of the busbar trunking. In the TN-C system, this helps most of the circuit current to be delivered to the grounding grid under the concrete, while some is also dissipated from the outer shell of the busbar trunking, effectively reducing the operating temperature of the transformer.

[0031] Meanwhile, when a single-phase line insulation is damaged, since the PEN and the casing form an integrated structure in the integrated structure of the busbar trunking, when a single phase is grounded, there is no issue of whether the fault current can be dispersed to the PEN line. That is, the N-phase line directly short-circuits with the PEN line, and the upstream protection device will quickly cut off the power supply. There is no need to worry about the fault current in the casing endangering personal safety or expanding to a phase-to-phase short circuit, which effectively improves electrical safety.

[0032] The above-described embodiments are only preferred embodiments of the present application, and do not limit the implementation scope of the present application. Equivalent changes made according to the shape, structure and principle of the present application should be covered in the protection scope of the present application.

Claims

1. A housing-protected integrated busbar trunking for low-voltage power distribution, used in bus couplers in low-voltage power distribution, characterized in that, It includes multiple sections of busbar trunking and multiple connectors. The multiple sections of busbar trunking and the multiple connectors are connected in sequence to form a distribution busbar in low-voltage power transformation and distribution. The outer shell of each section of busbar trunking is directly connected to the PE grounding busbar arranged in the center, and the N phase of the busbar conductor in each section of busbar trunking is conductively connected to the PE grounding busbar in the center; the connector is used for the conductive connection of the busbars of two adjacent sections of busbar trunking, as well as the synchronous conductive connection of the PE grounding busbar and the N phase, and the mutual insulation isolation between the adjacent busbars, the PE grounding busbar and the N phase. The outer shell of each section of busbar trunking is connected to the PE grounding busbar arranged in the center, and the N-phase busbar of each section of busbar trunking is arranged adjacent to the PE grounding busbar. There are three aluminum connecting pieces and copper connecting pieces located between two adjacent insulating phase separation membranes on both sides in the middle of the corresponding connector, and two of them are used for the conductive connection of the PE grounding busbars inserted on both sides, and a copper-aluminum clad sheet is used for the synchronous conductive connection of the N-phase busbars inserted on both sides to the PE grounding busbar through the aluminum connecting pieces and copper connecting pieces.

2. The integrated enclosure busbar trunking for low-voltage power distribution according to claim 1, characterized in that: The aluminum connecting piece and the copper connecting piece are symmetrically arranged. The aluminum connecting piece is directly conductively connected to the aluminum alloy PE grounding busbar inserted, and the copper connecting piece is directly conductively connected to the N-phase busbar of copper alloy through the copper-aluminum clad sheet.

3. The integrated enclosure busbar trunking for low-voltage power distribution according to claim 1, characterized in that: When the connector is connected to the busbar trunking arranged in a single row on both sides, the busbar trunking includes a top cover plate, a bottom sealing plate, a front-side busbar plate, a rear-side busbar plate and a multi-phase busbar conductor. The top cover plate and the bottom sealing plate are respectively placed on the top side and the bottom side of the multi-phase busbar conductor for sealing the upper and lower sides, and the front-side busbar plate and the rear-side busbar plate are respectively placed on the front side and the rear side of the multi-phase busbar conductor for sealing the front and rear sides. There is an inner partition extending along the height direction between the top cover plate and the bottom sealing plate in the middle of the inner sides of the top cover plate and the bottom sealing plate. The inner partition and the top cover plate or the bottom sealing plate form a "T" shape structure respectively. The top cover plate and the bottom sealing plate are formed by docking a pair of symmetric "T" shape structures up and down to form an "I" shape structure that separates the multi-phase busbar conductors in pairs front and back. The inner partition is used as an internal PE line for independent evacuation of the accident current inside the entire busbar trunking shell when a single phase is grounded. The N-phase busbar in the multi-phase busbar conductor is closely arranged against the inner partition, and the contact surface is directly conductively connected to the inner partition. The top cover plate, the bottom sealing plate, the front-side busbar plate and the rear-side busbar plate jointly form an outer shell PE line for evacuating the accident current of the outer shell when a single phase is grounded. The outer shell PE line and the internal PE line jointly form a double-busbar PE shell protection联体 structure in the shape of an inverted "曰".

Images