CN104833940A - Method and device for detecting error of multi-transformation ratio voltage transformer - Google Patents

Abstract

Provided are a method and a device for detecting errors of a multi-transformation ratio voltage transformer. The method detects the multi-transformation ratio voltage transformer according to the multi-transformation ratio voltage transformer error detection device. A multi-transformation ratio voltage transformer error detection circuit is formed by an error measuring device, a self-boost standard voltage transformer TV0, a test voltage transformer TVX, a wire-wound non-inductive resistor with a tap, and a relay. The customized standard voltage transformer is used in the device, so as to solve a problem of a detection standard of the multi-transformation ratio voltage transformer. A voltage transformer load error curve extrapolation method is used, and the four-range wire-wound non-inductive resistor with a tap is made. A ratio-voltage substitution method is used, so that a problem of adaptability of voltage range of the transformer error detection device is solved. Existing voltage booster, the transformer error detection device, and other voltage transformer calibration devices are used, and the device realizes detection of multi-transformation ratio voltage transformer errors. The method and the device are advantaged by simple, economical, scientific, and practical use, and good operationality, and low in cost.

Description

A kind of polytropic ratio voltage transformer error detection method and device

Technical field

The present invention relates to a kind of polytropic ratio voltage transformer error detection method and device, belong to Electric Measurement Technology field.

Background technology

Polytropic ratio electromagnetic potential transformer, be widely used in distribution network automated equipment, relate to the safety of electrical network, stable operation, for certain model, each winding major parameter and effect: (1a-1n) winding, class of accuracy is 3 grades, and rated secondary voltage is 220V, and rated sencondaryload is generally 350VA; (2a-2n) winding, class of accuracy is 1 grade, and rated secondary voltage is 100V, and rated sencondaryload is generally 80VA.Must detect according to JJG1021-2007 " electric power mutual-inductor vertification regulation " the carrying out to above-mentioned two Secondary Winding when full performance quality detects, according to GB1207-2006 " electromagnetic potential transformer " § 6.1.2 rated secondary voltage: " rated secondary voltage selects by the actual conditions of mutual inductor use occasion, receives monophase system or the standard value of the single-phase potential transformer received between three-phase system line and threephase potential transformer is 100V; " therefore, the standard device of conventional voltage transformer calibrating device all by rated secondary voltage be 100V or carry out Design and manufacture.(2a-2n) winding rated secondary voltage is 100V, can examine and determine circuit (see Fig. 1) routinely and detect.(1a-1n) winding rated secondary voltage is 220V, belong to unconventional secondary voltage, high precision inductive voltage divider and the cascade of test specimen voltage transformer secondary voltage then to be adopted to carry out proportion divider, can carry out consistent with the rated secondary voltage of standard potential transformer of the output voltage after proportion divider is detected (see Fig. 2).Range due to conventional voltage Burden box is 2.5, 5, 10, 20, 40, 80 (VA), whole parallel connection drops into and adds up to 157.5VA, and rated voltage is only 100V, needing is the trial voltage that the series connection of 100V voltage load box can tolerate 220V by 3 rated voltages, after series connection, the corresponding range of voltage load box under 220V changes into 4.03, 8.07, 16.1, 32.3, 64.5, 129.1 (VA), whole input adds up to 254.1VA, obviously 100% rated load requirement can not be met, for this reason, one group of 3 rated voltage is also wanted to be the series connection of 100V voltage load box, again above-mentioned two groups of series load casees are carried out parallel connection (see Fig. 2) can meet rated sencondaryload be less than 508.2VA detect requirement, at least need 7 voltage load boxes to carry out connection in series-parallel use just may realize, and often organize when each Burden box range switches and must use identical range, otherwise the damage of Burden box can be caused due to intrinsic standoff ratio difference.Operating process is complicated, and labour intensity is large, and efficiency is low.Therefore, study a kind of polytropic ratio voltage transformer error detection method to the above-mentioned situation of change, there is realistic meaning.

Summary of the invention

The object of the invention is, will examine and determine to solve the voltage transformer (VT) mutual inductor that rated secondary voltage is 220V at present, there is operating process complexity, labour intensity is large, inefficient problem, the invention provides a kind of polytropic ratio voltage transformer error detection method and device.

Realize technical scheme of the present invention to comprise:

Set up polytropic ratio voltage transformer error pick-up unit, and by the detecting step of described pick-up unit, polytropic ratio voltage transformer (VT) is detected.

Polytropic ratio voltage transformer error pick-up unit of the present invention is by error measuring means, from boosting standard potential transformer TV ₀, test product voltage transformer (VT) TV _x, band tap winding non-induetive resistor and relay form.From boosting standard potential transformer TV ₀with test product voltage transformer (VT) TV _xa high voltage winding group meet 10kV respectively; The 1a end of test product voltage transformer secondary (1a-1n) 220V winding connects relay 4 contact, and 1n end connects relay 2 contact; The 2a end of test product voltage transformer secondary (2a-2n) 100V winding connects relay 3 contact, and 2n end connects relay 1 contact; From boosting standard potential transformer Secondary Winding 220V range output terminal 1a ₀error measuring means is connected, standard potential transformer Secondary Winding 100V range output terminal 2a by relay J 4 ₀direct connection error measuring means.

Relay J 1 and relay J 2 chain, relay J 3 and relay J 4 chain; Relay J 1 can switch between 1n and 2n; Relay J 2 can switch between 1a and 2a; Relay J 3 can switch between 1a and 2a; Relay J 4 can at 1a ₀and 2a ₀between switch;

Error measuring means operating voltage shelves U _pconnection standard secondary windings of PT 100V range output terminal 2a respectively ₀terminal n nonpolar with standard potential transformer secondary ₀; End thrown by the cutter that error measuring means difference voltage shelves Δ U connects relay J 3 and J4 respectively.

End thrown by the cutter connecting relay J 1 by relay J 5 with one end of tap winding non-induetive resistor R; End thrown by the cutter that the other end with tap winding non-induetive resistor R connects relay J 2.

Relay in circuit of the present invention adopts interlock dpdt relay.

Band tap winding non-induetive resistor of the present invention is divided into four sections:

First paragraph: resistance is 100 Ω, and electric current is not less than 2.2A, and power is not less than 484W; Second segment: resistance is 100 Ω, and electric current is not less than 1.1A, and power is not less than 242W; 3rd section: resistance is 200 Ω, and electric current is not less than 0.55A, and power is not less than 121W; 4th section: resistance is 600 Ω, and electric current is not less than 0.22A, and power is not less than 48.4W.

The step of a kind of polytropic ratio of the present invention voltage transformer error detection method is as follows:

1, this method adopts the polytropic ratio voltage transformer error pick-up unit be made up of the winding non-induetive resistor of the standard potential transformer that certainly boosts, band tap, error measuring means and interlock dpdt relay.

2, wiring is carried out by polytropic ratio detection device for voltage mutual inductor wiring diagram;

3, error measuring means is set to voltage transformer (VT) detecting pattern, voltage range is set to 100V; Relay J ₃, J ₄switch to contact " 4 "; Relay J ₅disconnect, S ₁=0VA; S ₂=0VA;

4, voltage is slowly risen to the U of measurement point rated voltage _t%;

5, the ratio difference f of also recording error measurement mechanism display is read ₀; Phase differential δ ₀;

6, relay J ₃, J ₄switch to contact " 3 ";

7, the ratio difference f of also recording error measurement mechanism display is read ₄; Phase differential δ ₄;

8, voltage is slowly down to 0;

9, relay J ₅closed; Relay J ₁, J ₂switch to contact " 2 ", S ₂=OVA; According to (1a-1n) winding rated load S _1nand table 1 is selected corresponding resistance range and switches winding non-induetive resistor; Relay J ₃, J ₄switch to contact " 4 ";

10, voltage is slowly risen to the U of measurement point rated voltage _t%;

11, the ratio difference f of also recording error measurement mechanism display is read ₁; Phase differential δ ₁;

12, relay J ₃, J ₄switch to contact " 3 ";

13, the ratio difference f of also recording error measurement mechanism display is read ₆; Phase differential δ ₆;

14, voltage is slowly down to 0;

15, relay J ₅closed; Relay J ₁, J ₂switch to contact " 1 ", S ₁=OVA; According to (2a-2n) winding rated load S _2nand table 1 is selected corresponding resistance range and switches winding non-induetive resistor; Relay J ₃, J ₄switch to contact " 4 ";

16, voltage is slowly risen to the U of measurement point rated voltage _t%;

17, also recording error measurement mechanism ratio difference f is read ₂; Phase differential δ ₂;

18, relay J ₃, J ₄switch to contact " 3 ";

19, also recording error measurement mechanism ratio difference f is read ₅; Phase differential δ ₅;

20, voltage is slowly down to 0;

21, by measuring error data f ₀, f ₁, f ₂, δ ₀, δ ₁, δ ₂and rated sencondaryload value S _1n, S _2nand the corresponding load value S of the winding noninductive resistance of testing process access ₁, S ₂bring following formula into respectively, calculate the U of measurement point rated voltage under rated load _tthe ratio difference f of % (1a-1n) winding ₃; Phase differential δ ₃;

$f_3=\frac{1}{2.2}\{f_0-\frac{S_{1n}}{S_1}[0.8(f_0-f_1)+\frac{\mathrm{\π}}{108}({\mathrm{\δ}}_0-{\mathrm{\δ}}_1)]-\frac{S_{2n}}{S_2}[0.8(f_0-f_2)+\frac{\mathrm{\π}}{108}({\mathrm{\δ}}_0-{\mathrm{\δ}}_2)\left]\right\}(\%)$

${\mathrm{\δ}}_3=\frac{1}{2.2}\{{\mathrm{\δ}}_0+\frac{S_{1n}}{S_1}[\frac{64.8}{\mathrm{\π}}(f_0-f_1)-0.8({\mathrm{\δ}}_0-{\mathrm{\δ}}_1)]+\frac{S_{2n}}{S_2}[\frac{64.8}{\mathrm{\π}}(f_0-f_2)-0.8({\mathrm{\δ}}_0-{\mathrm{\δ}}_2)\left]\right\}(\′)$

22, by measuring error data f ₄, f ₅, f ₆, δ ₄, δ ₅, δ ₆and rated sencondaryload value S _1n, S _2nand the corresponding load value S of the winding noninductive resistance of testing process access ₁, S ₂bring following formula into respectively, calculate the U of measurement point rated voltage under rated load _tthe ratio difference f of % (2a-2n) winding ₇; Phase differential δ ₇;

$f_7=\{f_4-\frac{S_{1n}}{S_1}[0.8(f_4-f_5)+\frac{\mathrm{\π}}{108}({\mathrm{\δ}}_4-{\mathrm{\δ}}_5)]-\frac{S_{2n}}{S_2}[0.8(f_4-f_6)+\frac{\mathrm{\π}}{108}({\mathrm{\δ}}_4-{\mathrm{\δ}}_6)\left]\right\}(\%)$

${\mathrm{\δ}}_7=\{{\mathrm{\δ}}_4+\frac{S_{1n}}{S_1}[\frac{64.8}{\mathrm{\π}}(f_4-f_5)-0.8({\mathrm{\δ}}_4-{\mathrm{\δ}}_5)]+\frac{S_{2n}}{S_2}[\frac{64.8}{\mathrm{\π}}(f_4-f_6)-0.8({\mathrm{\δ}}_4-{\mathrm{\δ}}_6)\left]\right\}(\′)$

23, data processing: result of calculation ratio difference remains into 0.01%, and phase differential remains into 0.1 '.

The invention has the beneficial effects as follows, the present invention, when detecting polytropic ratio voltage transformer error, adopts the standard potential transformer of customization, solves the problem of polytropic ratio voltage transformer (VT) examination criteria device; On voltage transformer (VT) vertification regulation calibrating line tower foundation, adopt voltage transformer (VT) load error extra curvature pushing manipulation and make the four-range winding non-induetive resistor that is with tap by oneself, solving the problem lacking off-standard voltage Burden box; Adoption rate voltage method of substitution, solves the adaptive problem of transformer error pick-up unit voltage range; Utilize the voltage transformer (VT) calibration equipment such as existing stepup transformer, transformer error pick-up unit, the detection to polytropic ratio voltage transformer error can be realized.Have that method is succinct, economy, science, practicality, workable, low cost and other advantages.

The present invention is applicable to Electric Measurement Technology field.

Accompanying drawing explanation

Fig. 1 is that conventional voltage mutual inductor detects wiring diagram;

Fig. 2 is cascade inductive voltage divider unconventional no-load voltage ratio voltage transformer (VT) calibrating wiring diagram;

Fig. 3 is polytropic ratio detection device for voltage mutual inductor schematic diagram;

Fig. 4 is band tap winding non-induetive resistor schematic diagram;

Symbol in figure:

TV ₀, TV _x----be respectively standard potential transformer, test product voltage transformer (VT);

A ₀, X ₀----be respectively standard potential transformer winding is high-end, low side;

A, X----are respectively that test product voltage transformer (VT) winding is high-end, low side;

1a ₀----be standard potential transformer Secondary Winding 220V range output terminal;

2a ₀----be standard potential transformer Secondary Winding 100V range output terminal;

N ₀----the be nonpolar terminal of standard potential transformer secondary;

1a, 1n----are respectively that test product voltage transformer secondary (1a-1n) winding is high-end, low side;

2a, 2n----are respectively that test product voltage transformer secondary (2a-2n) winding is high-end, low side;

Y ₁, Y ₂, Y ₃, Y ₄, Y ₅, Y ₆, Y ₇----be respectively voltage load box;

R----winding non-induetive resistor device;

U _p----error measuring means operating voltage;

U _n----rated primary voltage;

Δ U----error measuring means difference voltage;

~ U----stepup transformer output voltage;

J ₁, J ₂----be interlock dpdt relay contact;

J ₃, J ₄----be interlock dpdt relay contact;

J ₆, J ₇----be interlock dpdt relay contact;

J ₈, J ₉----be interlock dpdt relay contact;

J ₁₀, J ₁₁----be interlock dpdt relay contact;

J ₅----be relay tip;

1,2,3,4----is respectively relay tip position.

Embodiment

The specific embodiment of the present invention is as follows:

Customize one from boosting standard potential transformer, rated primary voltage is 10kV, and Secondary Winding rated voltage is 220V, and centre tap rated voltage is 100V.Certainly the boosting standard potential transformer of customization should be not less than 0.2 grade, take into account the dirigibility of equipment use, operability and manufacturing cost, by from boosting standard potential transformer class of accuracy be decided to be 0.05 grade, its electrical principle as shown in Figure 3, the standard potential transformer TV in figure ₀.Customize the winding non-induetive resistor (see Fig. 4) of band tap as Secondary Load of Voltage Transformer, its basic parameter: class of accuracy is 0.5 grade, and resistance value is respectively: 100 Ω, 200 Ω, 400 Ω, 1000 Ω.The measurement and calculation of test specimen voltage transformer error is carried out according to " the D1 equation " in JJG1021-2007 " electric power mutual-inductor vertification regulation " § Appendix D " voltage transformer (VT) load error extra curvature pushing manipulation ".

When calculating with equation, need respectively at load S ₁the error amount of voltage transformer (VT) is obtained with measurement under zero load.Voltage transformer (VT) is at S ₂under error be calculated as follows:

In formula: f ₀, f ₁, f ₂-be respectively load zero load, S ₁and S ₂under ratio difference;

δ ₀, δ ₁, δ ₂-be respectively load zero load, S ₁and S ₂under phase differential;

-be respectively load S ₁, S ₂power-factor angle.

Voltage error and phase differential limit value according to GB 1207-2006 " electromagnetic potential transformer " § 14.2 measuring voltage mutual inductor: " the arbitrary load between rated frequency and 80% ~ 120% rated voltage and its power factor is under the condition of 0.8 (delayed), voltage error and the phase differential limit value of voltage transformer (VT) should not exceed table 12 values listed." namely voltage transformer (VT) should examine and determine under power factor is the condition of 0.8 (delayed).The present invention uses winding non-induetive resistor for secondary load, and its power factor is 1.0, therefore, in formula (1) and (2) wherein coefficient $0.0291\≈\frac{2\mathrm{\π}\×100}{360\×60}=\frac{\mathrm{\π}}{108},$ $34.38\≈\frac{360\×60}{2\mathrm{\π}\×100}=\frac{108}{\mathrm{\π}},$ Bring in formula (1) and (2) and obtain:

$f_2=\{f_0-\frac{S_2}{S_1}[0.8(f_0-f_1)+\frac{\mathrm{\π}}{108}({\mathrm{\δ}}_0-{\mathrm{\δ}}_1)\left]\right\}(\%)...\left(3\right)$

${\mathrm{\δ}}_2=\{{\mathrm{\δ}}_0-\frac{S_2}{S_1}[0.8({\mathrm{\δ}}_0-{\mathrm{\δ}}_1)-\frac{64.8}{\mathrm{\π}}(f_0-f_1)\left]\right\}(\′)...\left(4\right)$

Formula (3) and (4) are Secondary Winding ultimate principle voltage transformer (VT) load error extra curvature pushing manipulation computing formula, the present invention needs solution two Secondary Winding voltage transformer errors to measure problem, according in JJG1021-2007 " electric power mutual-inductor vertification regulation " § Appendix D " voltage transformer (VT) load error extra curvature pushing manipulation " " if voltage transformer (VT) has two or more Secondary Winding, can affecting linear superposition on measure winding error after each winding strap load.Obtain measure winding whole winding strap separately load time error." then two Secondary Winding ultimate principle voltage transformer (VT) load error extra curvature pushing manipulation computing formula be:

$f_3=\{f_0-\frac{S_2}{S_1}[0.8(f_0-f_1)+\frac{\mathrm{\π}}{108}({\mathrm{\δ}}_0-{\mathrm{\δ}}_1)]-\frac{S_4}{S_3}[0.8(f_0-f_2)+\frac{\mathrm{\π}}{108}({\mathrm{\δ}}_0-{\mathrm{\δ}}_2)\left]\right\}(\%)...\left(5\right)$

${\mathrm{\δ}}_3=\{{\mathrm{\δ}}_0+\frac{S_2}{S_1}[\frac{64.8}{\mathrm{\π}}(f_0-f_1)-0.8({\mathrm{\δ}}_0-{\mathrm{\δ}}_1)]+\frac{S_4}{S_3}[\frac{64.8}{\mathrm{\π}}(f_0-f_2)-0.8({\mathrm{\δ}}_0-{\mathrm{\δ}}_2)\left]\right\}(\′)...\left(6\right)$

In formula: f ₀, δ ₀-be ratio difference, the phase differential under measure winding and other windings all zero load;

F ₁, δ ₁-be measure winding load S ₁with ratio difference, the phase differential under other winding zero loads;

F ₂, δ ₂-for measure winding is unloaded and other winding loads S ₃under ratio difference, phase differential;

F ₃, δ ₃-be measure winding load S ₂with other winding loads S ₄under ratio difference, phase differential;

According to voltage transformer (VT) calibrating wiring diagram, when calibrating rated secondary voltage is the voltage transformer (VT) of 220V, conventional error measuring means does not all design 220V voltage range, adoption rate voltage method of substitution of the present invention, namely when pressing voltage transformer (VT) calibrating wiring diagram, error measuring means operating voltage loop is connected to the 100V output terminal (see Fig. 3) of standard potential transformer, during error calculation, carries out ratio conversion in coefficient again.

Concrete grammar is as follows:

According to mutual inductor principle and theory of errors, the error of voltage transformer (VT) can represent with plural error ε:

$\mathrm{\ϵ}=\frac{K_U{U}_X-U_1}{U_1}\×100(\%)...\left(7\right)$

In formula (7): K _ufor voltage transformer (VT) no-load voltage ratio;

U _xfor voltage transformer secondary voltage;

U ₁for voltage transformer (VT) primary voltage;

Plural number error packet contains ratio difference f and phase differential δ:

ε＝f+jδ……(8)

In code calibrating circuit, when the error of standard potential transformer is negligible, U ₁=K _uu ₂₀, U ₂₀for standard potential transformer secondary voltage, for the formula of bringing into (8) obtains:

$\mathrm{\ϵ}=\frac{U_X-U_{20}}{U_{20}}\×100(\%)...\left(9\right)$

In code calibrating circuit, error measuring means adopts error of measurement principle, U _x-U ₂₀=Δ U, Δ U is difference voltage, brings formula (9) into and obtains:

$\mathrm{\ϵ}=\frac{\mathrm{\ΔU}}{U_{20}}\×100(\%)...\left(10\right)$

In formula (10), U ₂₀=220V, because conventional error measuring means does not have the voltage range of 220V, adoption rate voltage method of substitution during detection, U' ₂₀=100V, then: U ₂₀=2.2U' ₂₀, bring formula (10) into and obtain:

$\mathrm{\ϵ}=\frac{1}{2.2}\×\frac{\mathrm{\ΔU}}{U_{20}^{\′}}\×100(\%)...\left(11\right)$

Known according to formula (11), the data that adoption rate voltage method of substitution detects are testing result divided by 2.2.For adapting to requirement of the present invention, to be the computing formula of the load error extra curvature pushing manipulation of 220V winding be rated secondary voltage:

$f_3=\frac{1}{2.2}\{f_0-\frac{S_{1n}}{S_1}[0.8(f_0-f_1)+\frac{\mathrm{\π}}{108}({\mathrm{\δ}}_0-{\mathrm{\δ}}_1)]-\frac{S_{2n}}{S_2}[0.8(f_0-f_2)+\frac{\mathrm{\π}}{108}({\mathrm{\δ}}_0-{\mathrm{\δ}}_2)\left]\right\}(\%)...\left(12\right)$

${\mathrm{\δ}}_3=\frac{1}{2.2}\{{\mathrm{\δ}}_0+\frac{S_{1n}}{S_1}[\frac{64.8}{\mathrm{\π}}(f_0-f_1)-0.8({\mathrm{\δ}}_0-{\mathrm{\δ}}_1)]+\frac{S_{2n}}{S_2}[\frac{64.8}{\mathrm{\π}}(f_0-f_2)-0.8({\mathrm{\δ}}_0-{\mathrm{\δ}}_2)\left]\right\}(\′)...\left(13\right)$

For the ease of identifying, be that the computing formula of the load error extra curvature pushing manipulation of 100V winding changes to by rated secondary voltage:

$f_7=\{f_4-\frac{S_{1n}}{S_1}[0.8(f_4-f_5)+\frac{\mathrm{\π}}{108}({\mathrm{\δ}}_4-{\mathrm{\δ}}_5)]-\frac{S_{2n}}{S_2}[0.8(f_4-f_6)+\frac{\mathrm{\π}}{108}({\mathrm{\δ}}_4-{\mathrm{\δ}}_6)\left]\right\}(\%)...\left(14\right)$

${\mathrm{\δ}}_7=\{{\mathrm{\δ}}_4+\frac{S_{1n}}{S_1}[\frac{64.8}{\mathrm{\π}}(f_4-f_5)-0.8({\mathrm{\δ}}_4-{\mathrm{\δ}}_5)]+\frac{S_{2n}}{S_2}[\frac{64.8}{\mathrm{\π}}(f_4-f_6)-0.8({\mathrm{\δ}}_4-{\mathrm{\δ}}_6)\left]\right\}(\′)...\left(15\right)$

In formula: S ₁, S ₂-be respectively (1a-1n) and (2a-2n) winding to detect time institute's on-load;

S _1n, S _2n-be respectively (1a-1n) and (2a-2n) winding rated sencondaryload to detect time institute's on-load;

Be the Secondary Winding of 100V according to GB 1207-2006 " electromagnetic potential transformer " to rated voltage, its specified outputting standard value: to be the specified outputting standard value of 0.8 (delayed) be power factor: 10VA, 15VA, 25VA, 30VA, 50VA, 75VA, 100VA.And State Grid Corporation of China's " modular design of power distribution automation equipment " requirement to polytropic ratio voltage transformer (VT), rated voltage 220V Secondary Winding specifies:

(1) built-in: rated capacity is not less than 150VA, capacity is not less than 300VA/10s in short-term;

(2) external: rated capacity is not less than 75VA;

(3) group screen formula: rated capacity is not less than 250VA, and capacity is not less than 500VA/10s in short-term;

According to above-mentioned restrictive condition, the noninductive resistance value that the present invention uses is calculated.

Enter state of saturation for avoiding voltage transformer (VT) and introduce measuring error, during error-tested, institute's on-load should be not more than rated sencondaryload.Meanwhile, for reducing the uncertainty introduced in extrapolation process, during error-tested, institute's on-load should be not less than 50% of rated sencondaryload.Then:

$\frac{1}{2}{S}_n\≤S\≤S_n...\left(14\right)$

$R=\frac{U^2}{S}...\left(15\right)$

In formula: S _nfor voltage transformer (VT) rated sencondaryload, unit: VA;

S is with secondary load by during error-tested, unit: VA;

R is noninductive resistance, unit: Ω;

U voltage transformer (VT) rated secondary voltage, unit: V;

Table 1

As can be seen from (table 1), band tap winding non-induetive resistor is divided into four sections:

First paragraph: resistance=100 Ω, electric current is not less than 2.2A, and power is not less than 484W;

Second segment: resistance=200 Ω-100 Ω=100 Ω, electric current is not less than 1.1A, and power is not less than 242W;

3rd section: resistance=400 Ω-200 Ω=200 Ω, electric current is not less than 0.55A, and power is not less than 121W;

4th section: resistance=1000 Ω-400 Ω=600 Ω, electric current is not less than 0.22A, and power is not less than 48.4W;

Can find out in conjunction with (Fig. 4), winding non-induetive resistor is divided into four ranges:

(1) 100 Ω range: relay J ₆, J ₇, J ₈, J ₉, J ₁₀, J ₁₁closed; This range scope of application: rated secondary voltage 220V, 500VA ~ 800VA; Rated secondary voltage 100V, 100VA ~ 150VA;

(2) 200 Ω ranges: relay J ₈, J ₉, J ₁₀, J ₁₁closed; J ₆, J ₇disconnect; This range scope of application: rated secondary voltage 220V, 250VA ~ 300VA; Rated secondary voltage 100V, 50VA ~ 75VA;

(3) 400 Ω ranges: relay J ₁₀, J ₁₁closed; J ₆, J ₇, J ₈, J ₉disconnect; This range scope of application: rated secondary voltage 220V, 150VA; Rated secondary voltage 100V, 25VA ~ 30VA;

(4) 1000 Ω ranges: relay J ₆, J ₇, J ₈, J ₉, J ₁₀, J ₁₁disconnect; This range scope of application: rated secondary voltage 220V, 50VA ~ 75VA; Rated secondary voltage 100V, 10VA ~ 15VA;

Control about testing process: because the error of (1a-1n) and (2a-2n) two windings all will detect, necessary optimization can be carried out to the control of testing process, for switchable load under avoiding state with voltage is to the damage of relay contact, according to the metrical error table (table 2) that voltage transformer (VT) load error extra curvature pushing manipulation load condition is corresponding.

Table 2

The concrete implementation step of detection method is as follows:

The first step: carry out wiring by (Fig. 3) mode of connection;

Second step: error measuring means is set to voltage transformer (VT) detecting pattern, voltage range is set to 100V; Relay J ₃, J ₄switch to contact " 4 "; Relay J ₅disconnect, put S ₁=0VA, S ₂=0VA;

3rd step: U voltage slowly being risen to measurement point rated voltage _t%;

4th step: read and the ratio difference f of recording error measurement mechanism display ₀; Phase differential δ ₀;

5th step: relay J ₃, J ₄switch to contact " 3 ";

6th step: read and the ratio difference f of recording error measurement mechanism display ₄; Phase differential δ ₄:

7th step: voltage is slowly down to 0;

8th step: relay J ₅closed; Relay J ₁, J ₂switch to contact " 2 ", put S ₂=0VA; According to (1a-1n) winding rated load S _1nand table 1 is selected corresponding resistance range and switches winding non-induetive resistor; Relay J ₃, J ₄switch to contact " 4 ";

9th step: U voltage slowly being risen to measurement point rated voltage _t%;

Tenth step: read and the ratio difference f of recording error measurement mechanism display ₁; Phase differential δ ₁;

11 step: relay J ₃, J ₄switch to contact " 3 ";

12 step: read and the ratio difference f of recording error measurement mechanism display ₆; Phase differential δ ₆;

13 step: voltage is slowly down to 0;

14 step: relay J ₅closed; Relay J ₁, J ₂switch to contact " 1 ", put S ₁=0VA; According to (2a-2n) winding rated load S _2nand table 1 is selected corresponding resistance range and switches winding non-induetive resistor; Relay J ₃, J ₄switch to contact " 4 ";

15 step: U voltage slowly being risen to measurement point rated voltage _t%;

16 step: read and recording error measurement mechanism ratio difference f ₂; Phase differential δ ₂;

17 step: relay J ₃, J ₄switch to contact " 3 ";

18 step: read and recording error measurement mechanism ratio difference f ₅; Phase differential δ ₅;

19 step: voltage is slowly down to 0;

20 step: by measuring error data f ₀, f ₁, f ₂, δ ₀, δ ₁, δ ₂and rated sencondaryload value S _1n, S _2nand the corresponding load value S of the winding noninductive resistance of testing process access ₁, S ₂bring formula (12), (13) respectively into, calculate the U of measurement point rated voltage under rated load _tthe ratio difference f of % (1a-1n) winding ₃; Phase differential δ ₃;

21 step: by measuring error data f ₄, f ₅, f ₆, δ ₄, δ ₅, δ ₆and rated sencondaryload value S _1n, S _2nand the corresponding load value S of the winding noninductive resistance of testing process access ₁, S ₂bring formula (14), (15) respectively into, calculate the U of measurement point rated voltage under rated load _tthe ratio difference f of % (2a-2n) winding ₇; Phase differential δ ₇; 22 step: data processing: result of calculation ratio difference remains into 0.01%, phase differential remains into 0.1 '.

Claims (5)

1. a polytropic ratio voltage transformer error pick-up unit, is characterized in that, described device is by error measuring means, from boosting standard potential transformer TV ₀, test product voltage transformer (VT) TV _x, band tap winding non-induetive resistor and relay form;

Described from boosting standard potential transformer TV ₀with test product voltage transformer (VT) TV _xa high voltage winding group meet 10kV respectively; The 1a end of test product voltage transformer secondary (1a-1n) 220V winding connects relay 4 contact, and 1n end connects relay 2 contact; The 2a end of test product voltage transformer secondary (2a-2n) 100V winding connects relay 3 contact, and 2n end connects relay 1 contact; From boosting standard potential transformer Secondary Winding 220V range output terminal 1a ₀error measuring means is connected, standard potential transformer Secondary Winding 100V range output terminal 2a by relay J 4 ₀direct connection error measuring means;

Described error measuring means operating voltage shelves U _pconnection standard secondary windings of PT 100V range output terminal 2a respectively ₀terminal n nonpolar with standard potential transformer secondary ₀; End thrown by the cutter that error measuring means difference voltage shelves Δ U connects relay J 3 and J4 respectively;

End thrown by the cutter that one end of described band tap winding non-induetive resistor R connects relay J 1 by relay J 5; End thrown by the cutter that the other end with tap winding non-induetive resistor R connects relay J 2;

Described relay J 1 and relay J 2 chain, relay J 3 and relay J 4 chain; Relay J 1 can switch between 1n and 2n; Relay J 2 can switch between 1a and 2a; Relay J 3 can switch between 1a and 2a; Relay J 4 can at 1a ₀and 2a ₀between switch.

2. a polytropic ratio voltage transformer error detection method, is characterized in that, described method step is:

(1) a kind of polytropic ratio voltage transformer error pick-up unit be made up of the winding non-induetive resistor of the standard potential transformer that certainly boosts, band tap, error measuring means and interlock dpdt relay is adopted;

(2) wiring is carried out by polytropic ratio detection device for voltage mutual inductor wiring diagram;

(3) error measuring means is set to voltage transformer (VT) detecting pattern, voltage range is set to 100V; Relay J ₃, J ₄switch to contact " 4 "; Relay J ₅disconnect, S ₁=0VA; S ₂=0VA;

(4) voltage is slowly risen to the U of measurement point rated voltage _t%;

(5) the ratio difference f of also recording error measurement mechanism display is read ₀; Phase differential δ ₀;

(6) relay J ₃, J ₄switch to contact " 3 ";

(7) the ratio difference f of also recording error measurement mechanism display is read ₄; Phase differential δ ₄;

(8) voltage is slowly down to 0;

(9) relay J ₅closed; Relay J ₁, J ₂switch to contact " 2 ", S ₂=0VA; According to (1a-1n) winding rated load S _1nand table 1 is selected corresponding resistance range and switches winding non-induetive resistor; Relay J ₃, J ₄switch to contact " 4 ";

(10) voltage is slowly risen to the U of measurement point rated voltage _t%;

(11) the ratio difference f of also recording error measurement mechanism display is read ₁; Phase differential δ ₁;

(12) relay J ₃, J ₄switch to contact " 3 ";

(13) the ratio difference f of also recording error measurement mechanism display is read ₆; Phase differential δ ₆;

(14) voltage is slowly down to 0;

(15) relay J ₅closed; Relay J ₁, J ₂switch to contact " 1 ", S ₁=0VA; According to (2a-2n) winding rated load S _2nand table 1 is selected corresponding resistance range and switches winding non-induetive resistor; Relay J ₃, J ₄switch to contact " 4 ";

(16) voltage is slowly risen to the U of measurement point rated voltage _t%;

(17) also recording error measurement mechanism ratio difference f is read ₂; Phase differential δ ₂;

(18) relay J ₃, J ₄switch to contact " 3 ";

(19) also recording error measurement mechanism ratio difference f is read ₅; Phase differential δ ₅;

(20) voltage is slowly down to 0;

(21) by measuring error data f ₀, f ₁, f ₂, δ ₀, δ ₁, δ ₂and rated sencondaryload value S _1n, S _2nand the corresponding load value S of the winding noninductive resistance of testing process access ₁, S ₂bring following formula into respectively, calculate the U of measurement point rated voltage under rated load _tthe ratio difference f of % (1a-1n) winding ₃; Phase differential δ ₃;

(22) by measuring error data f ₄, f ₅, f ₆, δ ₄, δ ₅, δ ₆and rated sencondaryload value S _1n, S _2nand the corresponding load value S of the winding noninductive resistance of testing process access ₁, S ₂bring following formula into respectively, calculate the U of measurement point rated voltage under rated load _tthe ratio difference f of % (2a-2n) winding ₇; Phase differential δ ₇;

(23) data processing: result of calculation ratio difference remains into 0.01%, and phase differential remains into 0.1 '.

3. polytropic ratio voltage transformer error pick-up unit according to claim 1, is characterized in that, described from boosting standard potential transformer, rated primary voltage is 10kV, and Secondary Winding rated voltage is 220V, and centre tap rated voltage is 100V.

4. polytropic ratio voltage transformer error pick-up unit according to claim 1, is characterized in that,

Described band tap winding non-induetive resistor is divided into four sections: first paragraph: resistance is 100 Ω, and electric current is not less than 2.2A, and power is not less than 484W; Second segment: resistance is 100 Ω, and electric current is not less than 1.1A, and power is not less than 242W; 3rd section: resistance is 200 Ω, and electric current is not less than 0.55A, and power is not less than 121W; 4th section: resistance is 600 Ω, and electric current is not less than 0.22A, and power is not less than 48.4W.

5. polytropic ratio voltage transformer error pick-up unit according to claim 1, is characterized in that, described relay adopts interlock dpdt relay.