CN102253291B - Testing station for automatic tracking compensation arc complete-set equipment - Google Patents

Abstract

The invention discloses a testing station for a thyristor controlled neutralizer, and relates to the field of electric power test facilities. The testing station comprises an experimental object serving as the thyristor controlled neutralizer (TCN) and a power grid power supply, and is provided with a bus of 10.5 KV, an isolation power supply, a three-phase voltage transformer, a fixed capacitor bank, a fling-cut capacitor bank, a fault point ground state operation switch, an instrument panel and an interface terminal board, wherein the power grid power supply, the isolation power supply and the power supply bus are connected sequentially; the TCN, the three-phase voltage transformer, the fixed capacitor bank, the fling-cut capacitor bank and the fault point ground state operation switch are connected with the power supply bus respectively to obtain an isolated experimental power supply respectively; and the instrument panel and a terminal block of the interface terminal board are in butt joint with terminal blocks corresponding to other functional blocks respectively to measure related parameters. The testing station is convenient to use, safe and reliable; a commissioning test program of the TCN after using points are installed is simplified, the continuous innovation in the TCN is promoted technically, and the quality of the TCN is improved continuously.

Description

Testing station for thyristor controlled neutralizer

Technical field

The present invention relates to power test facility field, relate in particular to a kind of testing station for thyristor controlled neutralizer.

Background technology

Automatic Following-up Compensation Arc-decreasing Wires complete equipment (Thyristor Controlled neutralizer is called for short TCN) are a kind of power products that integrates a plurality of high voltage electric equipments and computer controller.Its major function is to eliminate distribution system single phase earthing instantaneity earth fault, and restriction arc light grounding surge promotes the electric power netting safe running level.All to test by " national standard ", " industry standard " or contract engagement before consisting of integral body in its each unit.But this not enough, after forming a whole, also must its repertoire be examined by simulating under the actual motion condition, whether reaches the level of " national standard ", " industry standard " or contract engagement to verify its allomeric function.

Up to the present, domesticly go back the testing station that neither one can be born check " automatic Following-up Compensation Arc-decreasing Wires complete equipment ", therefore it is imperative to build our station, complied with the needs of building intelligent grid.

Summary of the invention

Purpose of the present invention is exactly to overcome the shortcoming and defect that existing product exists, and a kind of testing station for thyristor controlled neutralizer is provided.

The object of the present invention is achieved like this:

In order to promote TCN to constantly bring forth new ideas technically, constantly promoting qualitatively, need it to be in operation and have validity and stability preferably.The present invention has simplified in the commissioning test program of using after point is installed, to the TCN that examines by global function, only need do neutral point of electric network asymmetrical voltage and electric network capacitance and current measurement under different running method in the handing-over debugging, and this test is to rely on the controller of TCN is completed, without any risk.

Specifically, this testing station comprises experimental subjects---the automatic Following-up Compensation Arc-decreasing Wires complete equipment and the electric network source that are formed by Z-type grounding transformer, utility appliance, TCN arc suppression coil and controller;

Be provided with 10.5KV bus, insulating power supply, threephase potential transformer, fixed condenser group, opening-closing capacitor bank, the running of trouble spot ground state switch, panel board and interface end daughter board;

Its annexation is:

Electric network source, insulating power supply are connected with power source bus and are connected, automatic Following-up Compensation Arc-decreasing Wires complete equipment, threephase potential transformer, fixed condenser group, opening-closing capacitor bank and trouble spot ground state are connected switch and are connected with power source bus respectively, obtain respectively the experimental power supply of isolating;

The connection terminal corresponding with other functional blocks docking respectively of the connection terminal of panel board and interface end daughter board realizes the measurement of relevant parameters.

The principle of work of this testing station is:

This testing station designs by the entity simulation theory, called entity emulation theory is that the TCN that order is examined is in the electromagnetic environment acceptance examination property test identical with its actual motion, the voltage that namely bears, the electric current that passes through connect with electrical network, the wiring of controller, first and second wiring of voltage transformer (VT), current transformer is all the same with the TCN actual motion.Having the electrical network three-phase ground capacitance only is that the size of each phase condenser capacity is by the testing requirements combination with the high-voltage capacitor simulation.The switch working procedure is according to the examination project settings, it is true to nature in virtual condition that the switch operational process causes the transient state of line voltage, electric current, arc suppression coil voltage, electric current, the phenomenon of steady-state process, and recorded by the transient state registering instrument, controller is not only hunted these information that recorded, and judge the execution control strategy according to the quantity of information of hunting, complete every test mission.

The present invention has following advantages and good effect:

1. this testing station provides a platform that is used for examining the full merit of TCN, and is easy to use, safe and reliable;

2. simplified TCN in the commissioning test program of using after point is installed, to the TCN that examines by global function, only need make neutral point asymmetrical voltage and the capacitance current measurement of electrical network under the method for operation in the handing-over debugging, be complete by controller and measure, without any risk;

3. enabling of this testing station can promote TCN constantly bringing forth new ideas technically, and in qualitative continuous lifting, its useful effect will embody a concentrated reflection of the raising of safe operation of electric network level.

Description of drawings

Fig. 1 is block diagram of the present invention;

Fig. 2 is fundamental diagram of the present invention;

Fig. 3 .1 is the enlarged drawing (left one side of something) of Fig. 2;

Fig. 3 .2 is the enlarged drawing (right one side of something) of Fig. 2.

Wherein:

00-automatic Following-up Compensation Arc-decreasing Wires complete equipment (TCN),

01-Z type grounding transformer, 02-utility appliance, 03-TCN arc suppression coil, 04-controller;

The 10-electric network source;

The 20-power source bus;

The 30-insulating power supply,

The 31-step-down transformer, the 32-step-up transformer;

The 40-threephase potential transformer;

50-fixed condenser group;

The 60-opening-closing capacitor bank;

70-trouble spot ground state running switch;

The 80-panel board;

90-interface end daughter board.

Embodiment

Describe in detail below in conjunction with drawings and Examples:

One, overall

As Fig. 1, Fig. 2, Fig. 3 .1, Fig. 3 .2, this testing station comprises experimental subjects---the automatic Following-up Compensation Arc-decreasing Wires complete equipment 00 and the electric network source 20 that are formed by Z-type grounding transformer 01, utility appliance 02, TCN arc suppression coil 03 and controller 04;

Be provided with 10.5KV bus 10, insulating power supply 30, threephase potential transformer 40, fixed condenser group 50, opening-closing capacitor bank 60, the running of trouble spot ground state switch 70, panel board 80 and interface end daughter board 90;

Its annexation is:

Electric network source 20, insulating power supply 30 are connected with power source bus successively and are connected, automatic Following-up Compensation Arc-decreasing Wires complete equipment 00, threephase potential transformer 40, fixed condenser group 50, opening-closing capacitor bank 60 and trouble spot ground state are connected switch 70 and are connected with power source bus 10 respectively, obtain respectively the experimental power supply of isolating;

The connection terminal corresponding with other functional blocks docking respectively of the connection terminal of panel board 80 and interface end daughter board 90 realizes the measurement of relevant parameters.

Two, functional block

0, automatic Following-up Compensation Arc-decreasing Wires complete equipment (TCN) 00

01, the Z-type grounding transformer 01

Z-type grounding transformer 01 is that TCN carries inductance current to the bridge of trouble spot; Its neutral point and TCN arc suppression coil 03 join, and HV Terminal A, B, C are connected to 10.5KV bus 10 by the 2#FN3-10 on-load switch.

02, utility appliance 02

Utility appliance 02 comprises No. 3,5 double-tuned filters parallel with one another and voltage transformer (VT);

3, No. 5 double-tuned filters are used for 3,5 order harmonic components in filtering TCN output current.

JDZJ-10,10000/100,0.5 step voltage mutual inductor are used for measuring neutral point voltage Un, and the Un quantity of information passes to transient state note instrument the corresponding interface of controller 04.

03, the TCN arc suppression coil 03

TCN arc suppression coil 03 is to compose in parallel controlled admittance by low power-factor transformer and bidirectional triode thyristor, by regulating silicon controlled conduction angle regulation output electric current;

LFS-10,0.5 grade, 100/5 current transformer measure output current, and the current information of output is sent to the corresponding interface of transient state registering instrument and the corresponding reometer terminal of panel board 80 of controller 04;

Silicon controlled K ₁, G ₁, K ₂, G ₂Dock with the corresponding interface of controller 04;

Controllable silicon is Subharmonic Resonance damper in parallel also.

04, controller 04

Controller 04 is the core component of TCN.

1, the 10.5KV bus 10

10.5KV bus 10 is a kind of power supplys through isolation.

2, electric network source 20

Electric network source 20 is 10.5KV power supplys of introducing from electrical network 10.5KV system.

3, insulating power supply 30

Insulating power supply 30 is comprised of interconnective step-down transformer 31 and step-up transformer 32.

Step-down transformer 31 is 1 * 3 φ, 630KVA, 10KV ± 2 * 2.5%/0.4KV transformer, and adapted D200, D210-6003300 switch are down to 400V with voltage by 10.5KV.

Step-up transformer 32 is 1 * 3 φ, 630KVA, 10KV ± 2 * 2.5%/0.4KV transformer, and adapted D200, D210-6003300 switch are raised to 10.5KV with voltage by 400KV.

10.5KV connect 10.5KV bus 10 by the 1#FN3-10 on-load switch, be furnished with 3 * LFS, 200/5,0.5 grade of current transformer, the quantity of information of its secondary is connected to the corresponding reometer terminal of panel board 80.

4, threephase potential transformer 40

Threephase potential transformer 40 is 3 * JDZJ-10,10000/100,0.5 step voltage mutual inductor, is used for measuring three phase voltage Ua, Ub, Uc and residual voltage U ₀The interface that the transient state registering instrument of these information of voltage amount input control devices 04 is corresponding and the corresponding voltage table terminal of panel board 80.

5, the fixed condenser group 50

Use C _a1, C _b1, C _c1Represent respectively A, the B of fixed condenser group 50, the ground capacitance value of C three-phase;

During for adequacy test, the requirement of neutral point asymmetrical voltage value value, make C _b1=C _c1, C _a1≤ 0.9C _b1

Fixed condenser group 50 3#FN-10 switch on-off.

6, opening-closing capacitor bank 60

Use C _a2, C _b2, C _c2Represent respectively A, the B of opening-closing capacitor bank 60, the ground capacitance value of C three-phase switching capacitance;

During for adequacy test, the requirement of neutral point asymmetrical voltage value value, make C _b2=C _c2, C _a2≤ 0.9C _b2

Opening-closing capacitor bank 60 use 4#FN-10,5#FN-10,6#FN-10 switch on-off.

7, trouble spot ground state running switch 70

Trouble spot ground state running switch 70 7#FN-10 switch on-off.

8, panel board 80

Panel board 80 comprises the 1st multifunctional meter 81, the 2nd multifunctional meter 82, the 3rd multifunctional meter 83,1MA reometer 84,2MA reometer 854,3MA reometer 86,1MV voltage table 87 and 2MV voltage table 88;

1) the 1st multifunctional meter 81

The voltage wiring terminal U of the 1st multifunctional meter 81 _a, U _b, U _cRespectively with the voltage wiring terminal U of threephase potential transformer 40 _a, U _b, U _cDocking;

The current wiring terminal I of the 1st multifunctional meter 81 _abcDock with three secondary terminals of current transformer of step-up transformer 32 respectively.

The 1st multifunctional meter 81 is line voltage U of measuring 10.5KV bus 10 _ab, U _bc, U _ca, phase voltage U _a, U _b, U _c, supply frequency, source current I _a, I _b, I _c, power factor (PF), active power and applied power.

2) the 2nd multifunctional meter 82

The voltage wiring terminal U of the 2nd multifunctional meter 82 _a, U _b, U _cRespectively with the voltage wiring terminal U of threephase potential transformer 40 _a, U _b, U _cThe terminal docking;

The current wiring terminal I of the 2nd multifunctional meter 82 _abcDock with three secondary terminals of current transformer of fixed condenser group 50 respectively.

The 2nd multifunctional meter 82 is line voltage U of measuring 10.5KV bus 10 _ab, U _bc, U _ca, phase voltage U _a, U _b, U _c, supply frequency, the three-phase current I of fixed condenser group 50 _a, I _b, I _c, active power, reactive power and power factor (PF).

3) the 3rd multifunctional meter 83

The voltage wiring terminal U of the 3rd multifunctional meter 83 _a, U _b, U _cRespectively with the connection terminal U of threephase potential transformer 40 _a, U _b, U _cDocking;

The current terminal I of the 3rd multifunctional meter 83 _abcDock with three secondary terminals of current transformer of opening-closing capacitor bank 60.

The 3rd multifunctional meter 83 is line voltage U of measuring 10.5KV bus 10 _ab, U _bc, U _ca, phase voltage U _a, U _b, U _c, supply frequency, the three-phase current I of opening-closing capacitor bank 60 _a, I _b, I _c, active power, applied power and power factor (PF).

4) 1MA reometer 84

The secondary terminals I of the current transformer of the secondary terminals of 1MA reometer 84 and trouble spot ground state running switch 70 _jJoin;

1MA reometer 84 is to measure fault residual current.

5) 2MA reometer 85

The terminal of 2MA reometer 85 and TCN arc suppression coil 03 low power-factor transformer ground end Current Transformer Secondary terminal I _n1Join;

2MA reometer 85 is electric currents of measuring TCN arc suppression coil 03 low power-factor transformer.

6) 3MA reometer 86

The terminal of the connection terminal of 3MA reometer 86 and TCN arc suppression coil 03 low power-factor transformer secondary side current mutual inductor joins;

3MA reometer 86 is to measure TCN arc suppression coil 03 low power-factor transformer secondary side current.

7) 1MV voltage table 87

The terminal of 1MV voltage table 87 is the open delta voltage U with threephase potential transformer 40 ₀Docking;

1MV voltage table 87 is to measure residual voltage.

8) 2MV voltage table 88

The terminal of 2MV voltage table 88 be with utility appliance 02 in voltage transformer (VT) time terminal U _n1Join;

2MV voltage table 88 is to measure neutral point of electric network voltage.

9, the interface end daughter board 90

Interface end daughter board 90 is interface end daughter boards of controller 04 measuring-signal, SCR control signal, power supply terminal three.

Interface U _a, U _b, U _cU with voltage transformer (VT) in threephase potential transformer 40 _a, U _b, U _cDocking;

Interface U _nWith voltage transformer (VT) U in utility appliance 02 _n1Terminal joins;

Interface I _n1I with current transformer that low power-factor transformer connects in TCN arc suppression coil 03 _n1Join;

Interface L ₁, n and power supply L, n join;

Interface G1, K1, G2, K2 respectively with TCN arc suppression coil 03 in controllable silicon G1, K1, G2, K2 join.

Two, test method

Configure high voltage electric equipment, power electronic equipment and realize that for the specific apparatus instrument of testing it is to the objectives of examination of TCN according to Fig. 2.

For adapting to whole group of switching, single-phase wire break and the test of two-phase broken string switching, adopt 3 FN3-10 on-load switches.Wherein 4#FN3-10 is as whole group of capacitor switching, and 5#FN3-10 is as A phase capacitor switching, and 6#FN3-10 is as B, C phase capacitor switching.Before whole group of capacitor switching, must first throw 5#FN3-10 and 6#FN3-10.

The 7#FN3-10 switch is as the running of trouble spot ground state.The A of this switch, B phase moving contact are connected to respectively a 10KV disconnecting link S ₁, S ₂

When being used as " A break mutually and with ground connection " test, S ₁Close, S ₂Disconnect, when being used as " B, C break mutually and with B phase ground connection " test, S ₁Disconnect S ₂Close.

LFS-10,25/5 current transformer are used for measuring residual flow, it is to be contained on the exhausted son of porcelain of a 10kV, and when being used as the metallic earthing test, its primary side directly connects with ground wire, when being used as the resistor-type earth test, its ground end once connects with ground wire through resistance; When being used as the current interruption test, its ground end once should join with the head end wiry that is wrapped in insulator surface.

(1) this testing station is to TCN00 examination project implementation program

1, electric capacity is settled

(1) electrical network total capacitance value

C _A, C _B, C _CBe the microfarad number of three-phase ground capacitance, X _eq1For high reactance becomes Under equivalent short-circuit reactance value (Ω), C _A, C _B, C _CValue: C _B=C _C, C _A=0.9C _B

(2) fixing group electric capacity value

$\frac{{10}^6}{\mathrm{\&omega;}(C_{a1}+{\mathrm{<figure-callout\; id="1"\; label="C\; b"\; filenames="HDA0000057555320000021.png"\; state="\{\{state\}\}">C</figure-callout>}}_b+C_{c1})}=(0.85~0.9)\frac{{10}^6}{\mathrm{\&omega;}(C_A+C_B+C_C)}$

C _a1, C _b1, C _c1Value: Cb1=C _c1Ca1=0.9C _c1

(3) switching group electric capacity value

$\frac{{10}^6}{\mathrm{\&omega;}(C_{a2}+{\mathrm{<figure-callout\; id="2"\; label="C\; b"\; filenames="HDA0000057555320000021.png,HDA0000057555320000041.png"\; state="\{\{state\}\}">C</figure-callout>}}_b+C_{c2})}=(0.15~0.1)\frac{{10}^6}{\mathrm{\&omega;}(C_A+C_B+C_C)}$

C _a2, C _b2, C _c2Value: C _b2=C _c2C _a2=0.9C _b2

2, under normal circumstances, the tracking and monitoring of electrical network electric capacity and tuning test

Throw 1#FN3-10 → throwing 2#FN3-10 → throwing 3#FN3-10, controller is 1 " in measure capacitor value and take off humorous degree and set up δ ° of thyristor operating angle → throw 5#FN3-10 by predetermined; measure the electrical network capacitor value in 6#FN3-10 → throwings 4#FN-3 switch; controller is 1 " in measure the electrical network capacitor value and predeterminedly take off humorous degree and set up δ ° of thyristor operating angle → disconnect the 4#FN5-10 switch by predetermined, controller is 1 " and by predetermined δ ° of the humorous degree setting thyristor operating angle that take off.

3, Single Phase Metal ground connection and tuning test

7#FN3-10 ground connection running switch is placed in metallic earthing state (but this moment, switch was in off-state) → close 5#FN3-10,6#FN3-10 → close 4#FN3-10 → close 3#FN3-10 → close 7#FN3, TCN should be 0.02 " in carry offset current to the trouble spot; fault residual current is not more than 10A; residual flow hour 100ms stabilization time → disconnections 7#FN3-10; the earth fault disappearance, power system restoration is normal.Controller redeterminated out the electrical network capacitor value in 2 seconds, and by predetermined δ ° of the humorous degree setting thyristor operating angle that take off.It is singlephase earth fault that controller can be identified this.

4, single-phase electricity resistance type ground connection and tuning test.

Only need 7#FN3-10 ground connection running switch is rearranged to resistance eutral grounding state (but this moment, 7#FN3-10 was in off-state), other operation procedures are tested with metallic earthing.

5, current interruption test

The 7#FN3-10 switch is placed in the 7#FN3-10 through fine wire ground state (but this moment switch still be in off-state) → close 5#FN3-10,6#FN3-10 → close 4#FN3-10 → close 3#FN3-10 → close, tinsel fusing this moment, power system restoration is normal, but electrical network is in neutral point footpath 6000 Ω resistance eutral grounding states.Controller is 2 " in again measure the electrical network capacitor value and take off humorous degree and set up δ ° of thyristor operating angle by predetermined.

6, single-phase wire break and ground connection and tuning test

7#FN3-10 ground connection running switch is placed in A phase resistance grounded state (but this moment, switch still was in off-state) → close 3#FN3-10 → close 5#FN3-10, 6#FN3-10 → close 4#FN3-10 → disconnection 5#FN3-10, this moment, A broke (be equivalent to wire fracture do not land the period) mutually, this Time Controller is 2 " with interior after measuring broken string the electrical network capacitor value and take off humorous degree and set up that δ ° of silicon controlled conduction angle → 7#FN3-10 closes by predetermined, be the A ground connection of breaking mutually this moment, TCN carries offset current to the trouble spot in a cycle, fault residual current is less than 10A, residual flow stabilization time is less than 100ms → disconnection 7#FN3-10, this moment, electrical network was got back to the running status that A breaks mutually, controller is 2 " with the interior electrical network capacitor value and take off humorous degree and set up δ ° of thyristor operating angle by predetermined resurveyed.It is A phase the complex grounding fault with interruption that controller can be identified this.

7, two-phase broken string and a phase ground connection and tuning test

7#FN3-10 disconnecting ground state is placed in B phase resistance grounded (but this switch still is in off-state) → close 3#FN3-10 → close 5#FN3-10, 6#FN3-10, 4#FN3-10 → disconnection 6#FN3-10, this moment, electrical network was B, the C two lines vacant state that fractures, controller is 2 " in measure the electrical network capacitor value and predetermined take off humorous degree and set up that δ ° of thyristor operating angle → 7#FN3-10 closes, be equivalent to the B phase conductor and land this moment, TCN carries offset current to fault in a cycle, residual flow is in 10A, residual flow stabilization time is less than 100ms → disconnection #7FN3-10, be equivalent to the trouble spot current interruption or manually get rid of earth fault this moment, power system restoration is to B, C two-phase broken string state.Controller is 2 " measures electric network capacitance and current and set up δ ° of controller of silicon controlled conduction angle by the reservation tuning degree with interior that to identify this be B, C two-phase broken string one phase earth fault again.

8, complete equipment band ground connection operation test in 2 hours.

The thyristor operating angle of TCN is transferred to 180 °, 7#FN3-10 is placed in the metallic earthing state, make complete equipment be under rated current continuous service 2 hours, the examination low power-factor transformer, grounding transformer, temperature rise, the noise level of the assemblies such as the inductance of controllable silicon, wave filter and capacity cell, Subharmonic Resonance damper or have or not other abnormal conditions.

9, filter filtering effect examination

Manual adjustments thyristor operating angle (0-180 °), first-harmonic, the harmonic current of entrance, outlet and the wave filter of measurement wave filter itself.

10, voltage, the current measurement on filter inductance, capacity cell

Manual adjustments silicon controlled conduction angle is measured the voltage and current of each inductance, capacity cell under different conduction angle.

(2) startup of this testing station and applicable cases

This testing station builds up in by the end of August, 2010 in, is and then 10KV in September～November to a voltage, and capacity is 315KVA's

The automatic Following-up Compensation Arc-decreasing Wires complete equipment are tested.

1, the configuration of electrical network artificial capacitor

Electrical network electric capacity is divided into fixing group and switching group.Fixedly group is to simulate not by the total capacitance of switching circuit.But the switching group is the electric capacity of simulation switching circuit.Switching group electric capacity is controlled with three switches, and namely the A phase moving contact of 6#FN3-10 connects A phase electric capacity, and its rest energy head joins with the A phase moving contact of 4#FN3-10; The B of 7#FN3-10 switch, C phase moving contact connect B, C phase electric capacity, and its B, C phase static contact join with the moving contact of 4#FN3-10B, C phase.The purpose that connects like this is to do the rashly operation of circuit three phase capacitance with 4#FN3-10, can do again the operation of single-phase wire break and two-phase broken string.

	The A phase	The B phase	The C phase	∑ C A+ C B+ C C
					Fixing group	5.36 μ F	5.36 μ F	4.72 μ F	15.45 μ F
The switching group	2.5 μ F	2.372 μ F	1.97 μ F	6.842 μ F

When throwing fixing group not to voltage:

If the at this moment full conducting of controllable silicon (180 °),

$I_1=\frac{251}{j(\mathrm{Xeq}-\frac{{10}^6}{\mathrm{\&omega;cx}})}=\frac{251}{j(116.67-206.1)}=j2.8A$

(Xeq is low power-factor transformer primary side equivalence short-circuit reactance)

$I_2=j2.8\&times;\frac{6062}{600}=j28.3A$

High resistance primary side voltage: 2.8 * 116.67=330V.

Throw (fixing group+switching group) asymmetrical voltage:

Try to achieve from the oblique angle coordinate:

U′ _M＝404V

$I_1^{\&prime;}=\frac{404}{j(116.67-149.864)}=j15.423A$

$I_2^{\&prime;}=j15.432\&times;\frac{6062}{600}=115.9A$

The voltage of high resistance primary side:

15.423×116.67＝1779.4V

Computational data shows, fixedly each phase capacitance arrangement of group capacitor and switched capacitor is proper, can carry out the test of Listed Items in (2).

Resistance value in the tuning test of single-phase earthing when 2, the trouble spot has stake resistance to exist

Neutral point displacement voltage when (1) the corrective network single-phase earthing has resistance to exist and resistance are determined

Derive according to the nodal method of analysis, when there is transition resistance R in earth point _ZThe time, the expression formula of neutral point displacement voltage is:

Wherein dz-is the composed of external damping rate, equals the trouble spot electricity and leads the ratio that holds with network, namely

From (1) or find out, synthetic neutral point displacement voltage

In fact can regard two voltage superpositions that have nothing to do mutually as forms.Component

Be after fault has been added to stake resistance Rz, produced by the intrinsic asymmetrical voltage of network; Component

That the fault phase voltage produces, irrelevant with the asymmetrical voltage of electrical network.

Be vector, undoubtedly synthesize

Also must be a vector.Since be a vector, their absolute value and on-Line Voltage leg-of-mutton position also must affect the size of three phase-to-ground voltages.Be not difficult to find out u from (1) formula ₀With d, a network is under a certain method of operation, its value is intrinsic: υ is that we adjust, and the σ angle that has controller follow the tracks of to regulate Th guarantees, it is random only having dz, because transition resistance Rz may be from large to small.Result of study points out, when

The time, be worst situation, wherein there is a phase voltage will reach the line magnitude of voltage or a little more than line voltage.The capacitance current I of modern simulation test network _C=43.432A, U _φ=6062V, given υ=-0.198 (over-compensation), at this moment resistance value is:

Under this resistance, when taking no account of

The time, draw with graphic analytic method:

A little less than U _φ, U ₁(fault phase) is about 0.2U _φ, U ₂The high outlet voltage of possibility, U ₃Slightly lower than line voltage.

The electric current of earth fault when (2) the corrective network single-phase earthing has resistance to exist

During singlephase earth fault, the transition resistance R of the electric current of the trouble spot of flowing through and trouble spot _ZRelevant.By kirchhoff Theorem deduction go out the to flow through current expression of trouble spot be:

(2)

Find out the electric current of trouble spot and fault phase voltage from (2) formula Phase place identical, it is comprised of three components:

1. scatter admittance component Ir, it and displacement voltage homophase.

2. reactive component j (Ic-I _L) lag behind (over-compensation) or leading (under-compensation) 90 ° than U φ.

3. asymmetric electric current

It is that the intrinsic asymmetric situation of network determines, with neutral point displacement voltage, take off humorous degree and excessively resistance R z is all irrelevant.Due to

Be negative sign in (2), and have capacity current character, therefore it is ahead of U _HC90 °.Due to being reduced by first-phase electric capacity as asymmetrical voltage, I _HCBe ahead of After clear and definite each component of Iz and displacement voltage direction relations, just can make the vector plot of Iz.In fact Be worth very littlely, can ignore, therefore neutral point displacement voltage

Can

Replace, therefore have:

$\left|\mathrm{Iz}\right|=\frac{\sqrt{{\mathrm{\&upsi;}}^2+{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HDA0000057555320000021.png,HDA0000057555320000041.png"\; state="\{\{state\}\}">d</figure-callout>}}^2}}{\sqrt{1+\frac{2d}{\mathrm{dz}}+\frac{{\mathrm{\&upsi;}}^2+{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="HDA0000057555320000021.png,HDA0000057555320000041.png"\; state="\{\{state\}\}">d</figure-callout>}}^2}{{\mathrm{<figure-callout\; id="2"\; label="dz"\; filenames="HDA0000057555320000021.png,HDA0000057555320000041.png"\; state="\{\{state\}\}">dz</figure-callout>}}^2}}}\&times;I_C$

Modern υ=-0.198,

=-0.375, I _C=43.432A gets d=0.05, substitution (3.3):

$\left|I_z\right|=\frac{\sqrt{{0.198}^2+{0.05}^2}\&times;43.432}{\sqrt{1+0.375\&times;2\&times;0.05+{0.375}^2({0.170}^2+{0.05}^2)}}=\frac{0.21\&times;43.432}{1.003865}\&ap;9^A$

Choose 5 series connection of roasting glaze wire-wound resistor of 10 Ω, 800W, its resistance and power have all satisfied the requirement of test condition.For safety reasons, select 5 series connection of resistance of 10 Ω, 1000W to use.

Claims (4)

1. testing station for thyristor controlled neutralizer comprises experimental subjects---the automatic Following-up Compensation Arc-decreasing Wires complete equipment (00) and the electric network source (20) that are formed by Z-type grounding transformer (01), utility appliance (02), TCN arc suppression coil (03) and controller (04);

It is characterized in that:

Be provided with 10.5KV bus (10), insulating power supply (30), threephase potential transformer (40), fixed condenser group (50), opening-closing capacitor bank (60), the running of trouble spot ground state switch (70), panel board (80) and interface end daughter board (90);

Its annexation is:

Electric network source (20), insulating power supply (30) are connected 10 with power source bus) connect successively, automatic Following-up Compensation Arc-decreasing Wires complete equipment (00), threephase potential transformer (40), fixed condenser group (50), opening-closing capacitor bank (60) are connected switch (70) and are connected with power source bus (10) respectively with the trouble spot ground state, obtain respectively the experimental power supply of isolating;

The connection terminal corresponding with other functional blocks docking respectively of the connection terminal of panel board (80) and interface end daughter board (90) realizes the measurement of relevant parameters.

2. by testing station claimed in claim 1, it is characterized in that:

Described insulating power supply (30) is comprised of interconnective step-down transformer (31) and step-up transformer (32).

3. by testing station claimed in claim 1, it is characterized in that:

Described panel board (80) comprises the 1st multifunctional meter (81), the 2nd multifunctional meter (82), the 3rd multifunctional meter (83), 1MA reometer (84), 2MA reometer (85), 3MA reometer (86), 1MV voltage table (87) and 2MV voltage table (88);

The voltage wiring terminal of the 1st multifunctional meter (81) U _a, U _b, U _cRespectively with the voltage wiring terminal of threephase potential transformer (40) U _a, U _b, U _cDocking;

The current wiring terminal of the 1st multifunctional meter (81) I _abcDock with three secondary terminals of current transformer of step-up transformer (32) respectively;

The voltage wiring terminal of the 2nd multifunctional meter (82) U _a, U _b, U _cRespectively with the voltage wiring terminal of threephase potential transformer (40) U _a, U _b, U _cThe terminal docking;

The current wiring terminal of the 2nd multifunctional meter (82) I _abcDock with three secondary terminals of current transformer of fixed condenser group (50) respectively;

The voltage wiring terminal of the 3rd multifunctional meter (83) U _a, U _b, U _cRespectively with the connection terminal of threephase potential transformer (40) U _a, U _b, U _cDocking;

The current terminal of the 3rd multifunctional meter (83) I _abcDock with three secondary terminals of current transformer of opening-closing capacitor bank (60);

The secondary terminals of the current transformer of the secondary terminals of 1MA reometer (84) and trouble spot ground state running switch (70) I _jJoin;

The terminal of 2MA reometer (85) and TCN arc suppression coil (03) low power-factor transformer ground end Current Transformer Secondary terminal I _n1Join;

The terminal of the connection terminal of 3MA reometer (86) and TCN arc suppression coil (03) low power-factor transformer secondary side current mutual inductor joins;

The terminal of 1MV voltage table (87) is the open delta voltage U with threephase potential transformer (40) ₀Docking;

The terminal of 2MV voltage table (88) is and the middle voltage transformer (VT) time terminal U of utility appliance (02) _n1Join.

4. by testing station claimed in claim 1, it is characterized in that:

Described interface end daughter board (90) is controller (04) measuring-signal, SCR control signal, power supply terminal three's interface end daughter board;

Interface U _a, U _b, U _cWith voltage transformer (VT) in threephase potential transformer (40) U _a, U _b, U _cDocking;

Interface U _nWith voltage transformer (VT) in utility appliance (02) U _n1Terminal joins;

Interface I _n1With current transformer that low power-factor transformer connects in TCN arc suppression coil (03) I _n1Join;

Interface L ₁, n and power supply L, n join;

Interface G1, K1, G2, K2 join with TCN arc suppression coil (03) middle controllable silicon G1, K1, G2, K2 respectively.

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