CN2129995Y - Automatic current limiter for high voltage electric net earthing capacity - Google Patents
Automatic current limiter for high voltage electric net earthing capacity Download PDFInfo
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- CN2129995Y CN2129995Y CN 92230747 CN92230747U CN2129995Y CN 2129995 Y CN2129995 Y CN 2129995Y CN 92230747 CN92230747 CN 92230747 CN 92230747 U CN92230747 U CN 92230747U CN 2129995 Y CN2129995 Y CN 2129995Y
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Abstract
The utility model relates to an automatic current limiting device of a grounding capacitor of a high voltage network, and is characterized in that the electric capacity of a network and the inductance capacity are kept balance by a grounding transformer, an arc-suppressing reactor, a stabilizing resistor, a detecting transformer and an electronic controller. So continuous and adjustable inductive current is realized. When the grounding of some phase is generated, the condenser current flowing over grounding point is automatically limited to be under 6A. The utility model is especially suitable for the network of 3.6KV or 10KV of a coal mine, a metal mine, a metallurgical industry and a power industry, can effectively restrict capacitance current and the arc over-voltage caused by the capacitance current of single phase grounding, can decrease phase fault of multipoint grounding caused by single phase grounding, can decrease the blasting of cables, the burnout of motors and other accidents, can enhance the continuity of the energy supply of the mine networks, can limit the area of power failure and the affected production time to a minimum range.
Description
The utility model relates to a kind of high-voltage fence earthing capacitance current volitional check (compensation) device, belongs to the electronic control technology field, is specially adapted to colliery, metallic ore, metallurgy, chemical industry, electric power system 3-10KV, the application of 50HZ electrical network.
Current China's coal-mine high-voltage fence; the transformer neutral point insulation modes that adopt more;, reconstruction scale newly-built along with mine increases gradually; cable line reaches tens kilometers; equipment such as synchronous motor, transformer and motor lightning protection capacitor are housed in addition, reach each between each phase and all be distributed with very big electric capacity along the lead total length relatively, when neutral point of electric network is earth-free; each phase-to-ground voltage of three-phase system is symmetrical when normal operation, and the current potential of neutral point is zero.Because the vector of three-phase ground capacitance electric current and equalling zero is not so there is electric current to pass through in the ground.When electrical network generation single-phase earthing, as shown in Figure 1, variation has taken place in each phase-to-ground voltage, and the voltage to earth of ground connection phase is zero, and the neutral point voltage to earth is a phase voltage, and non-fault phase-to-ground voltage value raises
Doubly, polar plot as shown in Figure 2, the change of each phase-to-ground voltage of electrical network can think and ground connection phase voltage equal and opposite in direction that the residual voltage that direction is opposite is added on each phase voltage, among the figure
C'=
+
CO=0,
A'=
A'+
AO,
B'=
B+
BO, its angle is 60 °, its size
A'=
B'=
AOUnder the single-phase earthing situation, the line voltage swing of three-way electrical network and phase place do not change, and influence (ground installation can be handled in 2 hours) to do not had by electric user.Though non-fault phase-to-ground voltage raises
Doubly, because its electric equipment class of insulation is by the design of line voltage, so also there is not big danger, harm is maximum is that capacitive earth current has increased 3 times during than normal operation, i.e. I
CA=I
CB=
I
CO, I
CC=0, the electric current of the earth point of flowing through
CA+
CBAs shown in Figure 3, its big or small I
C=
I
CA=3I
COInterrelated data is introduced, when earthing capacitance current during greater than 10A, very easily cause intermittently flashing, produce vibration, cause to produce 2.5-3.5 times of phase voltage or higher overvoltage between the phase and ground, burn out electrical equipment and electrical or cause two-phase strange land ground short circuit, or cause three-phase shortcircuit in the cable core, and causing frequent outage, the portable blower master fans blowing-out, gas accumulates, even the peril of gas and dust explosion takes place.Ore deposit, Pingxiang office Anyuan once took place to dodge the road because of the porcelain vase crackle, caused arcing ground over-voltage, caused the cable short circuit accident, main fan blowing-out 2 hours.Blow out and just have 50-80 time every year because of single-phase earthing causes cable in ore deposit, the color village of Shenyang office, Ma Kuang also once took place to cause two-phase strange land short circuit accident because of single-phase earthing.For this reason, new " safety regulations in coal mine " the 423rd regulation of promulgation in 86 years: " unbalanced earth fault capacitance current of mine high-voltage fence must not surpass 20 amperes, otherwise must take restriction.Yet "; owing to reasons such as technology, the overwhelming majority mine that transfinites is not taken measures, and has only several mines to test the arc suppression coil static compensating device of artificial neutral point through inductance discontinuous manual adjustment; as shown in Figure 4; when normally moving, grounding transformer TME bears the symmetrical voltage of electrical network, only flows through very little exciting curent; be in Light Condition; its neutral point differential earth potential is zero, and (neutral point displacement voltage of ignoring arc suppression coil), do not have electric current to pass through in the arc suppression coil this moment.When C phase ground connection, the line voltage that grounding transformer bears is just asymmetric, and when the positive sequence component voltage that the three-phase asymmetrical voltage decomposes out was symmetry, it only caused very big positive sequence exciting curent in grounding transformer.Decompose the zero-sequence component voltage that comes out and will produce the identical zero-sequence current of equal and opposite in direction phase place in the grounding transformer three-phase coil, the three-phase zero-sequence current converges after arc suppression coil flows to earth point.The zero sequence impedance of every phase coil of grounding transformer is Z
O, then every phase zero-sequence current I
O=(U
0)/(Z
0), the three-phase zero-sequence current synthesizes 3I
O, flowing through arc suppression coil is inductive current, hysteresis U
O90 ° at phase angle, as shown in Figure 5.By Fig. 4, Fig. 5 as can be known electrical network by grounding transformer behind grounding through arc, when single phase ground fault, grounding transformer can produce one close with the earthing capacitance current size, inductance current and earthing capacitance current that phase place is opposite offset, and make the electrorheological of earth point get very little.Though this static compensating device has certain effect than neutral point insulation mode, but the cable line and the equipment of mine often change, cause electric capacity also to change thereupon, original by not changing the arc suppression coil tap that circuit is adjusted, just improper, get because of compensating improper thing that it is anti-sometimes, produce vibration and unallowed overvoltage occurs.Want to make compensation to be in optimum state, also conversion arc suppression coil tap thereupon in the time of must changing according to capacitance current, complicated and dangerous like this work is difficult to accomplish when the mine main actual motion.Therefore, static compensation is promoted and is limited to.Automatically during the external minority of compensation way developed country is also testing and constantly improving, maintain the leading position.
The purpose of this utility model is to overcome above-mentioned weak point of the prior art, and provide a kind of employing electronic controller from motion tracking electrical network capacitance variations, the realization inductive current is regulated automatically, when in case single-phase earthing takes place, the capacitance current that earth point flows through is limited in below the 6A, electric arc is very fast from putting out, and suppresses overvoltage between 2.5-2.6 times of phase voltage.
The purpose of this utility model is achieved in that this device is made up of main transformer, isolating switch, fuse, grounding transformer, arc-suppression reactor, reactor voltage table, stabilizing resistor, neutral point voltage instrument transformer, neutral point voltage table, the electronic controller that detects transformer, current transformer, reactor current table and have detection, contrast, discriminating, a computing.
By main transformer 35/6-10kv(or 110/6-10KV, or 6-10/3KV) three phase network circuit A, B, C connect isolating switch, fuse, grounding transformer, arc-suppression reactor, stabilizing resistor, detection transformer respectively successively, through current transformer ground connection, simultaneously between grounding transformer mid point and ground, be connected to neutral point of electric network displacement voltage instrument transformer, form the major loop of artificial neutral point and capacitance current restriction.
By the grounding transformer that fuse inserts, its secondary voltage inserts electronic controller, detects primary, and control loop.
The secondary winding of neutral point voltage instrument transformer meets neutral displacement voltmeter V
1, introduce simultaneously on the electronic controller, make mid point offset voltage of electronic controller input.
The secondary winding of arc-suppression reactor also connects reactance voltage Table V 2, introduces simultaneously on the electronic controller, makes inductive drop of input on the electronic controller.
The secondary winding of current transformer also connects the reactive current table, inserts simultaneously on the electronic controller, makes inductive current of electronic controller input.
According to the electrical network capacitance variations that the power network line switching causes, by electronic controller detection, contrast, discriminating, computing, the control servomotor is adjusted reactor magnetic air gap step-less adjustment inductance and is made inductance value and three-phase ground capacitance amount relative equilibrium.When certain phase ground connection is taken place when; the reactor predetermined amounts flows through inductive current; offset capacitance current, flow through capacitance current below 6A, to adapt to the needs of the sensitivity of a large amount of zero sequence direction type earth leakage protective current signals that use of each mine at present thereby be limited in earth point.
Grounding transformer seals in stabilizing resistor through arc-suppression reactor, and the condition of resonance when having eliminated full the compensation can limit effectively because the arcing ground over-voltage amplitude that single-phase earthing produces provides a resistive load for simultaneously the detection resonant tank.
The grounding transformer of interconnected star connection is all insulation mode of the little high permeability of loss, and oil is as artificial neutral point.
The utility model has the advantages that: be used for colliery, metallic ore system 3,6,10KV electrical network, capacitance current in the time of limiting single-phase earthing effectively, and the electric arc overvoltage that causes, significantly reduce because single-phase earthing brings out into multipoint earthing phase fault accident, blow out to reducing cable, burn motor, to improving the safety utilization of electric power condition, the continuity that improves the power system in mines power supply plays significant role.
The utility model is not limited to colliery, metallic ore, and can be applicable to other large and medium-sized enterprise's electrical networks such as metallurgy, chemical industry, building materials electric power system as the single-phase earthing arc-extinction device.
The drawing of accompanying drawing of the present utility model is described as follows:
Fig. 1 is the single-phase earthing line map.
The diverse vector figure of voltage to earth when Fig. 2 is single-phase earthing.
Capacitive earth current diverse vector figure when Fig. 3 is single-phase earthing.
Fig. 4 is that electrical network is through grounding transformer and arc-suppression reactor winding diagram.
Fig. 5 three is combined to the zero-sequence current phase diagram.
Fig. 6 is the utility model system construction drawing: main transformer 35/6,10kv(or 110/6,10KV) (1), isolating switch (2), fuse (3) grounding transformer (4), arc-suppression reactor (5), detect transformer (6), stabilizing resistor (7), arc-suppression reactor induction regulator (8), neutral point excursion voltage transformer (9), neutral point excursion voltage transformer secondary winding (10), servomotor control loop (11), current transformer (12), secondary winding in current transformer (13), grounding transformer secondary winding (14), electronic controller (15).
Fig. 7 is a block diagram of the present utility model.
The utility model is described in further detail below in conjunction with (accompanying drawing) embodiment:
This device draws from main transformer (1) to be allotted on 6-10kv electrical network A, B, the C three-phase, by isolating switch (2), fuse (3), grounding transformer (4), arc-suppression reactor (5), detection transformer (6), stabilizing resistor (7), arc-suppression reactor induction regulator (8), through current transformer (12) ground connection, form high-voltage fence unbalanced earth fault capacitance current volitional check device.
Insert three-phase grounding transformer (4) by fuse, the secondary voltage of its winding (14) is sent on the electronic controller (15), gives detection elementary winding of transformer (6) and control loop as power supply simultaneously.
Insert neutral point displacement voltage instrument transformer (9) between grounding transformer neutral point and ground, its secondary winding (10) meets voltmeter V
1, an end ground connection, the other end is introduced on the electronic controller (15) simultaneously.
In the arc-suppression reactor secondary winding and meet voltmeter V2, one end ground connection, the other end is introduced on the electronic controller (15).
Go up and meet ammeter A in secondary winding in current transformer (13), one end ground connection, the other end inserts on the electronic controller (15).
Electronic controller (15) according to detected various signals through comprehensive, relatively, differentiate that s operation control arc-suppression reactor induction regulator makes its inductance value and three-phase ground capacitance amount maintenance relative equilibrium, when single-phase earthing takes place when, inductive current that reactor flows through is offset capacitance current, thereby earth point flows through capacitance current less than 6A when having limited single-phase earthing.
Claims (4)
1, a kind of high-voltage fence earthing capacitance current volitional check device, comprise grounding transformer, arc-suppression reactor, it is characterized in that this device realizes that by stabilizing resistor, arc-suppression reactor with by detection, contrast, discriminating, computing, adjustment reactor magnetic air gap the electronic controller of step-less adjustment inductance forms, its structure is:
A, by main transformer 35/6-10kv or 110/6-10KV, or the three phase network circuit A of 6-10/3KV, B, C connect isolating switch, fuse, grounding transformer, arc-suppression reactor, stabilizing resistor, detection transformer respectively successively, through current transformer ground connection, between grounding transformer mid point and ground, be connected to neutral point of electric network displacement voltage instrument transformer simultaneously;
B, by the grounding transformer that fuse inserts, its secondary voltage inserts on electronic controller, gives the control loop that detects primary power supply and servomotor simultaneously;
The secondary winding of C, neutral point voltage instrument transformer meets neutral displacement voltmeter V
1, introduce on the electronic controller simultaneously;
The secondary winding of D, arc-suppression reactor also connects the reactance voltage Table V
2, introduce on the electronic controller simultaneously;
The secondary winding of E, current transformer also connects the reactive current table, inserts on the electronic controller simultaneously.
2, high-voltage fence earthing capacitance current volitional check device according to claim 1 is characterized in that grounding transformer seals in stabilizing resistor through arc-suppression reactor.
3, high-voltage fence earthing capacitance current volitional check device according to claim 1 is characterized in that, the grounding transformer of interconnected star connection is all insulation mode of the little high permeability of loss, oil.
4, high-voltage fence earthing capacitance current volitional check device according to claim 1, it is characterized in that electronic controller regulates inductance value and the three phase network ground capacitance relative equilibrium that the arc-suppression reactor magnetic air gap is realized limit circuit automatically according to the power-to-ground capacitance amount, when mutually ground connection being taken place arbitrarily, the capacitance current of volitional check earth point is below 6A.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 92230747 CN2129995Y (en) | 1992-08-21 | 1992-08-21 | Automatic current limiter for high voltage electric net earthing capacity |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN 92230747 CN2129995Y (en) | 1992-08-21 | 1992-08-21 | Automatic current limiter for high voltage electric net earthing capacity |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN2129995Y true CN2129995Y (en) | 1993-04-14 |
Family
ID=33773791
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN 92230747 Expired - Fee Related CN2129995Y (en) | 1992-08-21 | 1992-08-21 | Automatic current limiter for high voltage electric net earthing capacity |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN2129995Y (en) |
Cited By (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1040821C (en) * | 1994-05-19 | 1998-11-18 | 株式会社日立制作所 | Apparatus and method for inhibiting earth current |
| CN102646973A (en) * | 2012-05-15 | 2012-08-22 | 宁夏电力公司电力科学研究院 | Distribution network electric shock protection method and device |
| CN102780215A (en) * | 2012-07-02 | 2012-11-14 | 太原理工大学 | Mine low voltage power network capacitative current automatic compensation device |
| CN102998582A (en) * | 2012-11-16 | 2013-03-27 | 宁海县供电局 | Detection method of distributing line phase short circuit fault and single phase grounding fault |
| CN105807137A (en) * | 2014-12-29 | 2016-07-27 | 国家电网公司 | Grounding transformer impedance determining method |
-
1992
- 1992-08-21 CN CN 92230747 patent/CN2129995Y/en not_active Expired - Fee Related
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN1040821C (en) * | 1994-05-19 | 1998-11-18 | 株式会社日立制作所 | Apparatus and method for inhibiting earth current |
| CN102646973A (en) * | 2012-05-15 | 2012-08-22 | 宁夏电力公司电力科学研究院 | Distribution network electric shock protection method and device |
| CN102780215A (en) * | 2012-07-02 | 2012-11-14 | 太原理工大学 | Mine low voltage power network capacitative current automatic compensation device |
| CN102780215B (en) * | 2012-07-02 | 2014-07-09 | 太原理工大学 | Mine low voltage power network capacitative current automatic compensation device |
| CN102998582A (en) * | 2012-11-16 | 2013-03-27 | 宁海县供电局 | Detection method of distributing line phase short circuit fault and single phase grounding fault |
| CN105807137A (en) * | 2014-12-29 | 2016-07-27 | 国家电网公司 | Grounding transformer impedance determining method |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C14 | Grant of patent or utility model | ||
| GR01 | Patent grant | ||
| C19 | Lapse of patent right due to non-payment of the annual fee | ||
| CF01 | Termination of patent right due to non-payment of annual fee |