CN204945325U - A kind of relevant 126kV synthesis loop arc voltage on-line detecting system - Google Patents

Abstract

The utility model relates to the technical field of the high-current on-off test of primary cut-out, a kind of relevant 126kV synthesis loop arc voltage on-line detecting system specifically, comprise housing and circuit board, host computer and power supply, this system circuit board is provided with preposition measuring voltage voltage divider, signal condition limit filtration circuit, isolating amplifier circuit, data acquisition unit, trigger pip circuit, data acquisition unit connects the display of host computer waveform signal and data signal processing unit by digital optical fiber, the input end of data acquisition unit is provided with trigger pip circuit, carry out the conversion of AD Sampling Machine, the signal input part of preposition measurement voltage divider is provided with left and right sensor.The method that the utility model adopts separate unit voltage divider floating potential to measure, reduce the hardware requirement to voltage divider common-mode rejection ratio, propose a kind of new software compensation method of inner wire pressure drop simultaneously, eliminate the galvanic circle parasitic pressure drop in arc voltage measuring process, make the arc voltage of measurement more accurate.

Description

A kind of relevant 126kV synthesis loop arc voltage on-line detecting system

[technical field]

The utility model relates to the technical field of the high-current on-off test of primary cut-out, specifically a kind of relevant 126kV synthesis loop arc voltage on-line detecting system.

[background technology]

Arc voltage is the important parameter characterizing arc-chutes arc extinction performance, when dropout current is certain, in the big current stage, the size of arc voltage is relevant with the free degree of the state of electric arc, air gap, at interaction stage, the change of arc voltage can judge that the energy of injection arc gap and arc gap are conducted to the relation of the energy of surrounding medium, and the relation between medium recovery strength and voltage resume intensity, the selection of this design to arc-chutes, material, the Defect Search of assembly quality, the adjustment etc. of mechanical travel characteristic are highly profitable.

In arc voltage measuring process, the impedance voltage drop on the inner conductive loop between the turnover line end of isolating switch and arc-chutes inevitably superposition on tested arc voltage.In high-current on-off test, even if less impedance also can produce larger pressure drop, the arc voltage that inner wire impedance voltage drop makes measurement obtain is inaccurate.

At present, the method for conventional elimination external common-mode voltage is hardware compensating method, and when testing electric current and be comparatively large and system wiring being longer, common mode voltage can cause larger measuring error.To meet the requirement that measuring error is less than 2%, the difference of two voltage divider ratios can not more than 5.4 × 10 ^-6, obviously technically difficulty is very large.And this method also cannot eliminate the impedance voltage drop of test product circuit breaker internal.

[summary of the invention]

The purpose of this utility model develops the arc voltage measuring system on-line equipment of a set of synthetic test high-voltage switch equipment, arc voltage is detected by voltage divider, solve test product inner conductor problem of pressure drop in measuring process, this device antijamming capability is strong, highly sensitive, thus ensures validity and the success ratio of detection.

To achieve these goals, a kind of relevant 126kV synthesis loop arc voltage on-line detecting system of design, comprise housing and circuit board, host computer and power supply, this system circuit board is provided with preposition measuring voltage voltage divider, signal condition limit filtration circuit, isolating amplifier circuit, data acquisition unit, trigger pip circuit, described data acquisition unit connects the display of host computer waveform signal and data signal processing unit by digital optical fiber, the input end of described data acquisition unit is provided with trigger pip circuit, carry out the conversion of AD Sampling Machine, the signal input part of described preposition measurement voltage divider is provided with left and right sensor, this system adopts voltage divider floating potential measuring technique, reduce the requirement of voltage divider common-mode rejection ratio, improve sensitivity.

Voltage divider circuit adopts resistance-type high-voltage bleeder, and model is SEC or FRC voltage divider.

Signal condition limit filtration circuit adopts high-pressure filter circuit, and model is FC mode filter.

Isolating amplifier circuit adopts high-voltage amplifier, and model is WMA-02 or HA-405 amplifier.

Data acquisition unit adopts Single-chip Controlling, and single-chip microcomputer model is C80151F.

Trigger pip circuit adopts AD conversion digital integrating circuit, and model is AJ65SBT-64 or AD7705 module.

Compared with the existing technology, advantage is the utility model:

Detect the electrical discharge arc of high-voltage switch gear by bleeder circuit, there is actuation time fast, the advantage such as highly sensitive, anti-interference, effectively prevent by electric arc cause beyond accident occur; Adopt the method that separate unit voltage divider floating potential is measured, reduce the hardware requirement to voltage divider common-mode rejection ratio, propose a kind of new software compensation method of inner wire pressure drop simultaneously, eliminate the galvanic circle parasitic pressure drop in arc voltage measuring process, make the arc voltage of measurement more accurate.

[accompanying drawing explanation]

Fig. 1 is the formation schematic diagram of the utility model measuring system.

[embodiment]

Below in conjunction with accompanying drawing, the utility model is described in further detail, and the structure of this device and principle are very clearly concerning the people of this specialty.Should be appreciated that specific embodiment described herein only in order to explain the utility model, and be not used in restriction the utility model.

The utility model as shown in Figure 1, voltage divider is measured primarily of prime, signal condition and Isolation Amplifier Module, sampling unit and host computer waveform show and data processing four part is formed, this system is also provided with preposition measuring voltage voltage divider, signal condition limit filtration circuit, isolating amplifier circuit, data acquisition unit, trigger pip circuit, data acquisition unit connects the display of host computer waveform signal and data signal processing unit by digital optical fiber, the input end of data acquisition unit is provided with trigger pip circuit, carry out the conversion of AD Sampling Machine, the signal input part of preposition measurement voltage divider is provided with left and right sensor, this system adopts voltage divider floating potential measuring technique, reduce the requirement of voltage divider common-mode rejection ratio, improve sensitivity.Voltage divider circuit adopts resistance-type high-voltage bleeder, and model is SEC or FRC voltage divider.Signal condition limit filtration circuit adopts high-pressure filter circuit, and model is FC mode filter.Isolating amplifier circuit adopts high-voltage amplifier, and model is WMA-02 or HA-405 amplifier.Data acquisition unit adopts Single-chip Controlling, and single-chip microcomputer model is C80151F.Host computer adopts the instrument of LabVIEW programming, is provided with waveform display and data processing.Trigger pip circuit adopts AD conversion digital integrating circuit, and model is AJ65SBT-64 or AD7705 module.

Basic parameter and basic mechanical design feature index:

Resitstance voltage divider:

(1) intrinsic standoff ratio 480:1; High-voltage arm resistance 1.2M Ω, low-voltage arm resistance 2.5k Ω

(2) voltage withstand class: 126kV

(3) response speed :≤5 μ s

(4) output violent change protection voltage: ± 8v

Transient state registering instrument (main frame, digital fiber shielding system and software systems):

(1) passage: 2 road single-ended analog amount inputs

(2) channel input impedance: >=1M Ω

(3) measurement range: ± 5V

(4) frequency band (-3dB): 1MHz

(5) resolution: 12

(6) the highest sampling rate: 10MS/s

(7) common-mode isolation voltage: >=2000V

(8) powered battery, >=8h

126kV synthesis loop arc voltage on-line detecting system of the present utility model adopts voltage divider floating potential measuring technique, effectively work in strong-electromagnetic field interference environment, and in arcing process quantitative measurment arc voltage waveform, in arc voltage measuring process, the pressure drop that bearing great current bus produces is superimposed upon on arc voltage, by taking software compensation method, the busbar voltage drop of high-voltage switch gear is suppressed, to minimum, make the arc voltage of measurement more accurate.

Software compensation method comprises the following steps:

If in official test, the stray currents sequence recorded is I (k), and discrete voltage sequence is U (k), wherein: k=1, and 2 ... N.

Intercepted the voltage and current waveform that forearc is in short-circuit stage, its waveform known all meets Asin (ω t+B)+Ce ^-Dtform, the expression of voltage and current waveform can be obtained by curve, be designated as: i (t)=Asin (ω t+B)+Ce ^-Dt

u(t)＝A ₁sin(ωt+B ₁)+C ₁e ^-Dt

In above formula, ω=2 π f, f gets 50Hz.A, B, C, D and A1, B1, C1 are the constant that matching obtains, and calculate inner wire parameter L and R,

By can obtain:

$\begin{array}{c}\frac{A_1}{A}=\sqrt{R^2+{\left(\mathrm{\ω}L\right)}^2}\\ \frac{C_1}{C}=R-LD\end{array}$

Solve: $L=\frac{-cD+\sqrt{((D^2+{\mathrm{\ω}}^2)a^2-c^2{\mathrm{\ω}}^2)}}{D^2+{\mathrm{\ω}}^2}$

R＝LD+c；

Wherein: $a=\frac{A_1}{A},$ $c=\frac{C_1}{C}$

Obtain the arc voltage after cancellation impedance voltage drop:

$U_{arc}\left(k\right)=U\left(k\right)-(I\left(k\right)R+L\frac{I(k+1)-I\left(k\right)}{\mathrm{\Δ}t}).$

Claims (6)

1. a relevant 126kV synthesis loop arc voltage on-line detecting system, comprise housing and circuit board, host computer and power supply, it is characterized in that this system circuit board is provided with preposition measuring voltage voltage divider, signal condition limit filtration circuit, isolating amplifier circuit, data acquisition unit, trigger pip circuit, described data acquisition unit connects the display of host computer waveform signal and data signal processing unit by digital chemical fibre, the input end of described data acquisition unit is provided with trigger pip circuit, carry out the conversion of AD Sampling Machine, the signal input part of described preposition measurement voltage divider is provided with left and right sensor.

2. a kind of relevant 126kV synthesis loop arc voltage on-line detecting system as claimed in claim 1, it is characterized in that voltage divider circuit adopts resistance-type high-voltage bleeder, model is SEC or FRC voltage divider.

3. a kind of relevant 126kV synthesis loop arc voltage on-line detecting system as claimed in claim 1, it is characterized in that signal condition limit filtration circuit adopts high-pressure filter circuit, model is FC mode filter.

4. a kind of relevant 126kV synthesis loop arc voltage on-line detecting system as claimed in claim 1, it is characterized in that isolating amplifier circuit adopts high-voltage amplifier, model is WMA-02 or HA-405 amplifier.

5. a kind of relevant 126kV synthesis loop arc voltage on-line detecting system as claimed in claim 1, it is characterized in that data acquisition unit adopts Single-chip Controlling, single-chip microcomputer model is C80151F.

6. a kind of relevant 126kV synthesis loop arc voltage on-line detecting system as claimed in claim 1, it is characterized in that trigger pip circuit adopts AD conversion digital integrating circuit, model is AJ65SBT-64 or AD7705 module.