CN205488606U - Overcome earthing cable of SVC high -intensity magnetic field to influence of secondary cable - Google Patents

Abstract

The utility model discloses an overcome earthing cable of SVC high -intensity magnetic field to influence of secondary cable, including main ground net, ground copper bars and secondary cable, three ground wires tops of each unit square of main ground net, each parallel ground copper bars that arranges, every ground copper bars both ends is connected with the ground wire electricity of below, and the shielding layer both ends connection of secondary cable is on relative ground copper bars, and still including earthing cable, its both ends are connected by the shielding layer both ends of secondary cable with relative ground copper bars is electric respectively to earthing cable sets up or parallel arrangement with the secondary cable side by side. The utilization copper core earthing cable on the secondary cable shield layer of main ground net that connects in parallel, according to the electrical circuitry, its shielding layer to the secondary cable can play fine shunting action, through the aforesaid setting, realize that earthing cable is minimum with the closed loop area of secondary cable constitution to prevent to increase newly the closed loop and introduce new big induced -current under the SVC high -intensity magnetic field, and then arouse a series of problems of generating heat.

Description

A kind of earth cable overcoming SVC high-intensity magnetic field that secondary cable is affected

Technical field

This utility model relates to the safety protection field of power equipment, is specifically related to overcome reactive power compensator The earth cable that secondary cable is affected by high-intensity magnetic field.

Background technology

At present, a lot of power stations SVC dynamic reactive compensation device improves the voltage stability of power system, Wherein air reactor is as effectively regulating power, is to ensure that the capital equipment of device stable operation.Hollow The space magnetic field of reactor compares and dissipates, for powerful strong power system, and space magnetic field energy about Bigger, it is possible to surrounding to be produced intense electromagnetic and pollutes.

In actual transformer station, the buried earthed system in underground is as easy as rolling off a log couples generation sense with space magnetic field Induced current, but because of the disguise of its riding position, faradic current therein and solution lack always Weary enough concerns.Main Underground grounded screen lays the Manual earth network based on horizontal grounding objects.

Analysis through web frame over the ground is learnt, at SVC subterranean zone by ground connection bronze medal and main grounding grid structure The large-scale closed loop become, has induced huge electric current under strong magnetic field action, and its electric current is the most thousands of Peace, owing to secondary cable shielding layer resistance ratio secondary cable core resistance is big, secondary cable shielding layer divides The electric current obtained is less, but be enough to cause secondary cable shielding layer heating to affect it and normally work, by reality Test emulation and its electric current of in-site measurement all more than ten peaces.

Utility model content

The purpose of this utility model is to overcome above-mentioned deficiency, it is provided that one overcomes SVC high-intensity magnetic field to two The earth cable of secondary cable impact, reduces the electric current flowing through secondary cable, thus effectively prevents its screen layer Generate heat and affect it and normally work.

For reaching the purpose of above-mentioned utility model, this utility model is achieved through the following technical solutions:

A kind of earth cable overcoming SVC high-intensity magnetic field to affect secondary cable of the present utility model, including main Grounded screen, grounding copper bar and secondary cable, above three ground wires of each unit grid of described main grounding grid, Piece grounding copper bar of each parallel arrangement, each grounding copper bar two ends are electrically connected to ground with lower section, secondary electricity The screen layer two ends of cable are connected on relative grounding copper bar, it is characterised in that also include earth cable, By its two ends are connected electrically in the screen layer two ends of secondary cable with relative grounding copper bar respectively, and ground connection Cable is arranged side by side with secondary cable or be arranged in parallel.By above-mentioned setting, it is achieved earth cable and secondary The enclosed loop area that cable is constituted is minimum, thus prevents newly-increased closed loop from introducing new big sense under SVC high-intensity magnetic field Induced current.

Further, the cable core at described earth cable two ends crimps a copper lug respectively, and copper lug passes through spiral shell Stricture of vagina securing member is fixed with grounding copper bar, is arranged by copper lug and threaded fastener, it is simple to earth cable with Dismounting between grounding copper bar or connection.

Further, the cable core at described earth cable two ends welds with the screen layer two ends of secondary cable respectively Connect, it is ensured that the screen layer of secondary cable and the good contact of earth cable.

Accompanying drawing explanation

Fig. 1 is of the present utility model to overcome the connection on the earth cable that secondary cable affects of the SVC high-intensity magnetic field Structural representation.

Fig. 2 is the equivalent circuit diagram of earth cable attachment structure shown in Fig. 1.

Fig. 3 is the attachment structure schematic diagram of earth cable of the present utility model and grounding copper bar.

Detailed description of the invention

Technical scheme in this utility model embodiment is carried out clear, complete with embodiment below in conjunction with the accompanying drawings Describe wholely, it is clear that described embodiment be only a part of embodiment of this utility model rather than All embodiments.

Embodiment

Refer to Fig. 1, be the ground connection overcoming SVC high-intensity magnetic field that secondary cable is affected of the present utility model electricity The attachment structure schematic diagram of cable.The main grounding grid 4 of underground lays based on horizontal grounding objects (sign) Manual earth network, the depth of burying is 0.8 meter, and horizontal grounding objects is also referred to as ground wire, uses a plurality of 60 × 6mm2 The grid in zinc-coated flat steel sheet composition four directions, mesh spacing is designed as 10m, and down conductor plates with 70 × 8mm2 Zinc band steel.Being fixed with grounding copper bar 2 inside cable duct on main grounding grid 4, grounding copper bar 2 is with main Grounded screen 4 multiple spot is electrically connected with, and the screen layer two ends of the secondary cable 1 within cable duct are installed in respectively On the grounding copper bar 2 being oppositely arranged.

This utility model embodiment overcome the earth cable that secondary cable affects by SVC high-intensity magnetic field, including Main grounding grid 4, grounding copper bar 2 and secondary cable 1, three of each unit grid of described main grounding grid 4 Above ground wire, piece grounding copper bar 2 of each parallel arrangement, each grounding copper bar 2 two ends and the ground wire of lower section Electrical connection, secondary cable 1 two ends are connected on relative grounding copper bar 2, on the basis of said structure, Also including earth cable 3, its two ends are connected electrically in secondary cable 1 with relative grounding copper bar 2 respectively By screen layer two ends, and earth cable 3 is arranged side by side with secondary cable 1 or be arranged in parallel.

Refer to Fig. 2, for the equivalent circuit diagram of earth cable attachment structure shown in Fig. 1.Described ground connection electricity The sectional area of cable 3 is 1 × 120mm2, and equivalent resistance is less, and through-current capability is strong, it is possible to share secondary electricity A large amount of electric currents in cable 1 copper shield, can eliminate the high-intensity magnetic field impact on controlling cable.It is not added with again The electric current flowing through secondary cable shielding layer during earth cable 3 is I₁:

$I_1=\frac{R_2}{R_1+R_2}I$

I is the electric current in main grounding grid 4, and I1 is the electric current flowing through secondary cable 1 screen layer, and R1 is two The resistance of secondary cable 1 screen layer, R2 is the resistance of grounding copper bar 2, and in Fig. 2, R3 is earth cable 3 Resistance, when earth cable 3 in parallel connection, the electric current flowing through earth cable 3 is I_2,

$I_2=\frac{R_2{R}_3}{R_1{R}_2+R_2{R}_3+R_1{R}_3}I$

I is compared by mathematics₁/I₂It is known that flow through the electricity of secondary cable 1 screen layer after taking measure in parallel Before flow ratio less, if taking R2=R3,

$I_1/I_2=\frac{R_1+R_2}{2R_1+R_2}$

For practical situation secondary cable 1 screen layer resistance R1 much larger than grounding copper bar 2 resistance R2 with The resistance R3 of earth cable 3,After parallel shunt, secondary cable 1 shields Electric current on layer can be reduced to before half.

A progressive step, as an embodiment, the ground connection electricity of this utility model embodiment as shown in Figure 3 When the cable core two ends of cable 3 electrically connect with relative grounding copper bar 2, use copper lug 21 and earth cable The cable core crimping of 3 is fixing, and copper lug 21 at one end has the circular hole by screw, therefore uses screw thread Securing member 6 is fixed through copper lug 31 and grounding copper bar 2 also clamping.

It is further used as another embodiment, the cable core two of the earth cable 3 of this utility model embodiment End welds with the screen layer two ends of secondary cable 1.

Described earth cable 3 uses the copper core of high conductivity, if follow-on aluminum core electrical conductivity conforms to Ask, then this aluminum core also may be used.

The beneficial effects of the utility model are, using earth cable to shunt measure will not be to transformer station SVC runs and brings other negative issue, at the substation field that equipment has been fixed, can not change The simple electric current controlling cable shield that reduces under the conditions of other, which need not too much whole simultaneously Changing fund, effect is also very good.

Above-described embodiment is only in order to illustrate this utility model and and skill described by unrestricted this utility model Art scheme；Therefore, although this utility model is had been carried out by this specification with reference to each above-mentioned embodiment Detailed description, but, it will be understood by those within the art that, still can be new to this practicality Type is modified or equivalent；And all are without departing from the technical side of spirit and scope of the present utility model Case and improvement thereof, it all should be contained in the middle of right of the present utility model.

Claims (3)

1. overcome the earth cable that secondary cable is affected by SVC high-intensity magnetic field, including main grounding grid, Grounding copper bar and secondary cable, above three ground wires of each unit grid of described main grounding grid, each parallel Arranging a grounding copper bar, each grounding copper bar two ends are electrically connected to ground with lower section, the screen of secondary cable Cover layer two ends to be connected on relative grounding copper bar, it is characterised in that also including earth cable, they are two years old By end is connected electrically in the screen layer two ends of secondary cable with relative grounding copper bar respectively, and earth cable It is arranged side by side with secondary cable or be arranged in parallel.

The earth cable overcoming SVC high-intensity magnetic field that secondary cable is affected the most according to claim 1, It is characterized in that: the cable core at described earth cable two ends crimps a copper lug respectively, and copper lug passes through spiral shell Stricture of vagina securing member is fixed with grounding copper bar.

The earth cable overcoming SVC high-intensity magnetic field that secondary cable is affected the most according to claim 1, It is characterized in that: the cable core at described earth cable two ends welds with the screen layer two ends of secondary cable respectively.