CN201697998U - Partial discharge on-line monitoring and locating device of gas insulated switchgear - Google Patents

Abstract

The utility model relates to a partial discharge on-line monitoring and locating device of a gas insulated switchgear, which comprises a signal conditioning circuit used for signal amplification and filtering, and is characterized by further comprising a sensor, an intelligent selector switch, a high-speed digital collector and a processor, wherein the sensor consists of antennae arranged at the positions of box-type insulators of an SF6 gas insulated substation; the intelligent selector switch is connected with the antennae of the sensor for alternately gating the antennae, and is connected with the signal conditioning circuit by a high-frequency shielding coaxial cable; a data acquisition channel of the high-speed digital collector is connected with an output end of the signal conditioning circuit; and the processor is connected with the high-speed digital collector by a bus, and is connected with the intelligent selector switch by the bus. The partial discharge on-line monitoring and locating device of the gas insulated switchgear has the characteristics of high locating accuracy and interference resistance.

Description

A kind of on-line monitoring locating device of local discharge of gas-insulator switchgear

Technical field

The utility model belongs to insulation of electrical installation monitoring positioning device, particularly SF ₆Gas insulated transformer substation partial discharge monitoring and source of leakage location device.

Background technology

SF ₆Gas is a kind of good insulating medium and arc-extinguishing medium, it have nontoxic, not flammable, dielectric strength is high and the arc extinguishing ability considerably beyond general dielectric characteristics.Therefore, SF ₆The gas insulated combined electrical equipment size is little, floor area is little, in light weight, no fire hazard, thereby has greatly improved the reliability of electric system.SF ₆The appearance of gas insulated transformer substation (GIS) and use and to have broken the notion of traditional transformer station is for the development of compact high voltage, the new-type transformer station of high capacity provides wide space.Yet,, cause having brought difficulty for the monitoring of GIS just because of the closure of gas insulated combined electrical equipment.Particularly, the defective that is produced because of insulation among the GIS can cause shelf depreciation (PD) under the effect of highfield, and the shelf depreciation sustainable development meeting of GIS inside causes insulation breakdown, the stability of crisis electric system and security.In addition, because major accidents such as the GIS shell burns, blow-out disc action can cause a large amount of SF ₆Gas is overflowed, thus severe contamination GIS air outside quality.Particularly because the GIS shell that the internal arc fault causes burns the SF that escapes ₆Gas contains a large amount of gaseous state electric arc analytes, also is accompanied by the injection of solid metallic fluoride dust simultaneously.

In all kinds of faults of GIS, insulation fault occupies larger proportion.Practical operation situation shows: insulation breakdown mostly occurs on the solid insulation surface, and soon following period of time after often occurring in GIS and putting into operation, and there was not superpotential in usually not generation systems operation when fault took place.Causing this class insulation fault mainly is some little insulation defects, dirty etc. as inner impurity, burr, loose contact and solid insulation surface.These defectives are more small and hidden usually, be not enough to cause when power frequency withstand test, puncture immediately, but shelf depreciation can take place in the back of putting into operation under normal working voltage effect, make defective develop expansion gradually, the electric charge that discharge is produced accumulates gradually on the solid insulation surface, causes Electric Field Distribution seriously to distort.Therefore, GIS is as the substantial equipment in the electric system, and its state-detection obviously is very necessary.And shelf depreciation is one of important parameter of reflection GIS insulating property, and it is the sign and the form of expression of GIS insulation degradation, is again the reason of the further deterioration of insulation, so detect the GIS local discharge signal and the location of shelf depreciation is had great importance.

Among the GIS there be substantially the partial discharge monitoring method: coupling capacitance method, ultrahigh frequency method, monitoring ultrasonic method, chemical monitoring method, optical monitoring method.Ultrahigh frequency method, monitoring ultrasonic method are the partial discharge monitoring methods of two kinds of present comparative maturities.In recent years, the detection method for local discharge of many novelties more and more causes people's attention.For example the phase place gate pole control method that proposes of Japan Nagoya university, the physical-chemical diagnostic method that Russian scientist proposes, the wavelet method that is used for the monitoring of wideband electromagnetic ripple that Osaka, Japan university proposes, finite time-domain difference (FDTD) method that the Britain scientist proposes.

The main research work of on-line monitoring localization method of existing local discharge of gas-insulator switchgear concentrates in the development of sensor.As application number is " a kind of local discharge of electrical equipment ultrahigh frequency locating and detecting device and method " patent of 200910104428.X, disclosed partial discharge positioning method is for directly asking for the mistiming from the high sampling rate oscillograph, and then realizes the shelf depreciation location.And for example application number is " online detection and location device of local discharge of gas-insulator switchgear and localization method " patent of 200610054229.9, and disclosed shelf depreciation also is to utilize the mistiming of two detection signal rising edges to realize the shelf depreciation location.Above-mentioned two kinds of methods are asked for the mistiming, and precision is not high, the influence that is subject to disturb.

The utility model content

The purpose of this utility model is at the weak point of the localization method of existing GIS local discharge on-line monitoring device, and a kind of on-line monitoring locating device that bearing accuracy height, method of operating simply reach a kind of local discharge of gas-insulator switchgear of characteristics such as calculated amount is little that has is provided.

The purpose of this utility model is achieved in that a kind of on-line monitoring locating device of local discharge of gas-insulator switchgear, comprises the signal conditioning circuit that is used for signal amplification and filtering, also have,

Sensor: the antenna by each boxlike insulator place that is placed in the SF6 gas insulated transformer substation is formed;

Intelligence Selection switch: be connected with each antenna of sensor,, and be connected with described signal conditioning circuit by the radioshielding concentric cable with gating antenna in turn;

The high-speed figure collector: its data acquisition channel is connected with the output terminal of signal conditioning circuit;

Processor: be connected with the high-speed figure collector by bus, and be connected with the Intelligence Selection switch by bus.

Above-mentioned Intelligence Selection switch is a single pole multiple throw.

The online detection and location device of the utility model shelf depreciation (hardware components) mainly by: sensor antenna (the also sensor that can say so and be made up of antenna), Intelligence Selection switch, signal conditioning circuit, high-speed figure collector, processor and control module are formed.Sensor antenna of the present utility model is installed in each disc insulator place of GIS, and each sensor antenna is connected with the Intelligence Selection switch; After the Intelligence Selection switch passes through the radioshielding concentric cable and signal conditioning circuit is connected, data acquisition channel with the high-speed figure collector is connected again, the high-speed figure collector is connected with processor by bus, processor is connected with control module by bus, and control module is connected with the Intelligence Selection switch by bus.

Compared with prior art, the beneficial effects of the utility model are:

1, bearing accuracy height, anti-interference are good

Owing to adopt specific wave head fitting process, by data fitting, reflect the trend of original function overall variation like function by finding the solution a simple road, through facts have proved that this method is effective, can determine the shelf depreciation source point exactly.

2, method of operating is simple, calculated amount is little.

3, apparatus structure is simple, cost of manufacture is not high.

After the utility model adopts technique scheme, have effective detection GIS shelf depreciation, can improve the characteristics such as antijamming capability of detection system.

Characteristics of the present utility model and advantage will further be set forth in conjunction with embodiment.

Description of drawings

Fig. 1 is a theory diagram of the present utility model;

Fig. 2 is the program flow diagram of the utility model method;

Fig. 3-the 1st, the sensor antenna of an embodiment of the present utility model local discharge signal oscillogram at the scene;

Fig. 3-the 2nd, the wave head portion waveshape figure of the shelf depreciation that the employing of local discharge signal waveform shown in Fig. 3-1 wave head fitting process draws.

Embodiment

Among Fig. 1,1, sensor antenna (can select existing microstrip antenna for use); 2, Intelligence Selection switch (radio-frequency (RF) switch, talent board single pole multiple throw CH2); 3, signal conditioning circuit; 4, high-speed figure collector (Tyke TDS5104B oscillograph, the highest employing speed is 5GS/s, record length can reach 16m, the bandwidth of 1GHz); 5, processor (AT89C2051 single-chip microcomputer); 6, control module.

Fig. 1 is that the system that implements the utility model hardware constitutes synoptic diagram.System comprises that be arranged on the GIS outside a plurality of are used to detect sensor, Intelligence Selection switch 2, signal conditioning circuit 3, high-speed figure collector 4, processor 5 and control module 6 that the antenna 1 of local discharge signal constitutes.

A kind of on-line monitoring locating device of local discharge of gas-insulator switchgear comprises the signal conditioning circuit that is used for signal amplification and filtering, also has,

Sensor: the antenna by each boxlike insulator place that is placed in the SF6 gas insulated transformer substation is formed;

Intelligence Selection switch: be connected with each antenna of sensor,, and be connected with described signal conditioning circuit by the radioshielding concentric cable with gating antenna in turn;

The high-speed figure collector: its data acquisition channel is connected with the output terminal of signal conditioning circuit;

Processor: be connected with the high-speed figure collector by bus, and be connected with the Intelligence Selection switch by bus.

Fig. 2 is a process flow diagram of the present utility model.When the inner generation of GIS shelf depreciation produces discharge steep-sided pulse signal, can excite to produce the above uhf electromagnetic wave of hundreds of megahertz.GIS exterior antenna 1 receives the electromagnetic wave of local discharge generation, processor 5 sends instruction and makes control module 6 gating Intelligence Selection switches 2, adopt screened coaxial cable to make Intelligence Selection switch 2 be connected to antenna, 3 pairs of detection signals of signal conditioning circuit carry out filtering, eliminate and disturb and noise signal, after high-speed figure collector 4 becomes signal into digital signal, carry out calculation process by processor 5 again.

Fig. 3-1, Fig. 3-2 is respectively the typical shelf depreciation waveform that detects at the scene of the sensor antenna of an embodiment of the utility model and the wave head part that draws with the wave head fitting process thereof, as can be seen from the figure local discharge signal clearly, its signal amplitude is approximately 4.9mV, can satisfy the needs of Partial Discharge Detection, have higher sensitivity.From the waveform that the wave head fitting process draws, this match waveform can characterize actual shelf depreciation waveform generally, also obtains the distance that Partial Discharge Sources arrives this antenna from algorithm simultaneously.

Intelligence Selection switch of the present utility model is a single pole multiple throw, by the corresponding antenna of control module control backgating.Signal conditioning circuit comprises amplifying circuit and filter segment.High-speed figure collector of the present utility model, processor and control module are market and purchase part.Processor sends instructions to control module by bus, choose sensor collection by control module control Intelligence Selection switch, the signal that collects is behind signal conditioning circuit, is digital signal by high-speed figure collector (being analog to digital converter) with conversion of signals, processor is analyzed and is handled the digital signal of high-speed figure collector collection, thereby GIS inside Partial Discharge Sources is positioned.

Data fitting is a kind of method that a simple approximate function that is suitable for reflects original function overall variation trend of finding the solution.A host of facts prove that the matched curve method is a kind of efficient ways.

Waveform to a large amount of shelf depreciations is furtherd investigate, and the wave head part that can draw the shelf depreciation waveform can be described by double-exponential function.Suppose that the local discharge of gas-insulator switchgear signal is u (t), defining the zero hour of discharging was zero moment, and then the wave head partial function form of u (t) is:

$u\left(t\right)=a\×(e^{-s_{1}t}-e^{-s_{2}t})$

A, s in the formula ₁, s ₂Be undetermined parameter.

If sensor to local discharge signal be u ₁(t), then the wave head partial function form of this signal is:

$u_1\left(t\right)=u(t-t_1)=a\×(e^{-s_1(t-t_1)}-e^{-s_2(t-t_1)})=b\×e^{-s_{1}t}-c\×e^{-s_{2}t}$

In the formula

t ₁For local discharge signal from the shelf depreciation source point to the used time of this sensor.

Local discharge signal u ₁(t) through being sampled as burst u ₁(n), find out u ₁(n) maximal value is carried out normalization then.

$\stackrel{\‾}{u_1\left(n\right)}=\frac{u_1\left(n\right)}{{\left(u_1\left(n\right)\right)}_{\max }}$ n＝1，2，...，N

N is sampled signal u ₁(n) sampling number, (u ₁(n)) _MaxBe burst u ₁(n) maximal value.

Find out then after the normalization

The sampled point of sampled point amplitude between 0.3～0.9, i.e. intercepting

One section.

To intercept then

Parameter b, c, s are obtained in matched curve ₁, s ₂Because

$\frac{b}{c}=\frac{a\&times;e^{-s_{1}t}}{a\&times;e^{-s_{2}t}}=e^{(s_2-s_1){\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="HSA00000117674000021.png"\; state="\{\{state\}\}">t</figure-callout>}}_1}$

Thereby obtain:

${\mathrm{<figure-callout\; id="1"\; label="t"\; filenames="HSA00000117674000021.png"\; state="\{\{state\}\}">t</figure-callout>}}_1=\frac{\ln (b/c)}{s_2-{\mathrm{<figure-callout\; id="1"\; label="s"\; filenames="HSA00000117674000021.png"\; state="\{\{state\}\}">s</figure-callout>}}_1}$

Determine true origin, set up the three-dimensional cartesian coordinate system in space.The volume coordinate of supposing this sensor is (x ₁, y ₁, z ₁), the Partial Discharge Sources coordinate is that (z), local discharge signal is at SF for x, y ₆Velocity of propagation in the gas is v, so have:

(x-x ₁) ²+(y-y ₁) ²+(z-z ₁) ²＝(vt ₁) ² (1)

In like manner, the volume coordinate of supposing two other sensor is respectively (x ₂, y ₂, z ₂), (x ₃, y ₃, z ₃), the time that draws with the wave head fitting process is respectively t ₂, t ₃So, draw following two equations:

(x-x ₂) ²+(y-y ₂) ²+(z-z ₂) ²＝(vt ₂) ² (2)

(x-x ₃) ²+(y-y ₃) ²+(z-z ₃) ²＝(vt ₃) ² (3)

With (1), (2), (3) three equations simultaneousnesses, just can obtain the position (X, Y, Z) of Partial Discharge Sources.

A kind of local discharge of gas-insulator switchgear on-line monitoring locating device, this device utilizes sensor antenna (to can be described as, the sensor of forming by antenna), Intelligence Selection switch, signal conditioning circuit, high-speed figure collector, processor and control module, position by processor, its method step is as follows:

(1) initialization: at three dimensions, promptly the location storage in rectangular coordinate system in space and is set timing acquisition time at interval in processor with each antenna sensor;

(2) sampling local discharge signal: the sampling time, then processor at first took turns antenna in the gating sensor by total line traffic control Intelligence Selection switch, then data is sent in the processor;

(3) shelf depreciation is judged: according to the amplitude of signal, be criterion with the noise signal amplitude of the no shelf depreciation at the detection scene measured in advance, judge whether to take place shelf depreciation;

(4) mistiming location: according to the accurate mistiming of determining the local discharge signal of any three sensor measurements of wave head fitting algorithm of the present utility model, according to the sulfur hexafluoride (SF of GIS ₆) electromagnetic wave propagation speed in the medium, can calculate the particular location of Partial Discharge Sources;

(5) show: when shelf depreciation takes place when, position and with judgment result displays at the processor screen; When shelf depreciation not taking place, got back to for (2) step and wait for timing sampling local discharge signal next time.

Claims (2)

1. the on-line monitoring locating device of a local discharge of gas-insulator switchgear comprises, is used for the signal conditioning circuit of signal amplification and filtering, it is characterized in that: also have,

Sensor: the antenna by each boxlike insulator place that is placed in the SF6 gas insulated transformer substation is formed;

Intelligence Selection switch: be connected with each antenna of sensor,, and be connected with described signal conditioning circuit by the radioshielding concentric cable with gating antenna in turn;

The high-speed figure collector: its data acquisition channel is connected with the output terminal of signal conditioning circuit;

Processor: be connected with the high-speed figure collector by bus, and be connected with the Intelligence Selection switch by bus.

2. according to the on-line monitoring locating device of the described a kind of local discharge of gas-insulator switchgear of claim 1, it is characterized in that: described Intelligence Selection switch is a single pole multiple throw.

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