CN104049055B - Power equipment oil dissolved gas chromatographic peak area computing method - Google Patents

Abstract

A kind of power equipment oil dissolved gas chromatographic peak area computing method, relate to electric device maintenance technical field, and what solve is the technical matters improving computational accuracy.The method first draws the chromatographic curve of Gas in Oil of Transformer, again according to chromatographic peak beginning and ending time point, the smoothingtime length of chromatographic curve, computer chromatography threshold value, cut-off point value and peak maximum height value, and then adopt peak process function to calculate the chromatographic peak area of object gas chromatographic curve.Method provided by the invention, is applicable to the content detecting Gas in Oil of Transformer.

Description

Power equipment oil dissolved gas chromatographic peak area computing method

Technical field

The present invention relates to electric device maintenance technology, particularly relate to a kind of technology of power equipment oil dissolved gas chromatographic peak area computing method.

Background technology

In electric system, insulating material in the oil-filled pipeline of power equipment of normal operation and Electric Power Equipment Insulation oil, can be aging gradually under the effect such as hot, electric, produce multiple inflammable gas, constantly accumulation, convection current, diffusion, dissolving in the fluid of these gases in the oil-filled pipeline of power equipment, until saturated and bubble, gas content in power equipment oil is analyzed, insulation status and the internal electric equipment discharge scenario of power equipment can be identified, effectively can reduce the generation of power equipment accident.

One of power equipment oil dissolved gas detection method of content uses chromatogram, the method that existing employing chromatogram calculates power equipment oil dissolved gas content is: the chromatographic peak area size first being calculated power equipment oil dissolved gas chromatographic curve by the mode of correlation calibration value, then the gas concentration corresponding according to chromatographic peak area draws power equipment oil dissolved gas content.But because initial peak and end peak easily change by the impact of environmental change, thus have influence on the size of peak area, therefore the method for existing computer chromatography peak area also exists the low defect of computational accuracy.

Summary of the invention

For the defect existed in above-mentioned prior art, technical matters to be solved by this invention is to provide the high power equipment oil dissolved gas chromatographic peak area computing method of a kind of computational accuracy.

In order to solve the problems of the technologies described above, a kind of power equipment oil dissolved gas chromatographic peak area computing method provided by the present invention, it is characterized in that, concrete steps are as follows:

1) utilizing chromatograph, take time shaft as abscissa axis, with chromatogram value axle for axis of ordinates, draws the chromatographic curve of each component gas in power equipment oil;

2) choose and need the gas composition of computer chromatography peak area to be object gas, the chromatographic peak start time point of target setting gas chromatogram curve, chromatographic peak stop time point and chromatographic peak smoothingtime length, chromatographic peak start time point is wherein designated as T0, chromatographic peak stop time point is designated as T1, and chromatographic peak smoothingtime length is for being designated as Δ Tc;

3) calculate Chromatogram Baseline starting point chromatogram value and the Chromatogram Baseline cut off chromatogram value of object gas, its computing formula is:

$\mathrm{Vs}=\left(\underset{i=T0}{\overset{T0+\mathrm{\ΔTc}}{\mathrm{\Σ}}}{V}_i\right)/\mathrm{\ΔTc};$

$\mathrm{Vt}=\left(\underset{i=T1}{\overset{T1+\mathrm{\ΔTc}}{\mathrm{\Σ}}}{V}_i\right)/\mathrm{\ΔTc};$

In formula, Vs is the Chromatogram Baseline starting point chromatogram value of object gas, and Vt is the Chromatogram Baseline cut off chromatogram value of object gas, V _ifor object gas chromatographic curve is in the chromatogram value of time point i;

4) in coordinate system belonging to object gas chromatographic curve, draw straight line L, make this straight line L through coordinate points (T0+ Δ Tc/2, Vs), and coordinate points (T1+ Δ Tc/2, Vt);

5) on the segment of curve of object gas chromatographic curve from T0 to T1, choosing the data point maximum with straight line L spacing, is the peak maximum height value of object gas chromatographic curve by the spacing setting between this data point and straight line L;

6) calculate the chromatographic peak area of object gas chromatographic curve, its computing formula is:

$S=2\×\underset{i=T0}{\overset{T1}{\mathrm{\Σ}}}f\left(V_i\right);$

In formula:

If V _i≤ (Vs+Vt+Hmax)/2, then f (V _i)=0;

If V _i> (Vs+Vt+Hmax)/2, then f (V _i)=V _i-(Vs+Vt+Hmax)/2;

In formula, S is the chromatographic peak area of object gas chromatographic curve, V _ifor object gas chromatographic curve is in the chromatogram value of time point i, Hmax is the peak maximum height value of object gas chromatographic curve.

Further, the value of the chromatographic peak start time point T0 of object gas chromatographic curve is set as: T0=r × Ts;

In formula, Ts is chromatographic object gas chromatographic peak initial time minimum range, and r is safety factor, and the value of r is 0.9.

Further, the value of the chromatographic peak stop time point T1 of object gas chromatographic curve is set as: T1=k × Tm;

In formula, Tm is chromatographic object gas chromatographic peak end time maximum range, and k is safety factor, and the value of k is 0.95.

Further, the value of the chromatographic peak smoothingtime length Δ Tc of object gas chromatographic curve is set as:

ΔTc＝(T1-T0)×(k－1)/2。

Power equipment oil dissolved gas chromatographic peak area computing method provided by the invention, baseline threshold value and cut-off point value is calculated according to the chromatographic peak beginning and ending time of the chromatographic curve of oil dissolved gas, and calculate maximum peak height value, finally calculate the chromatographic peak area of oil dissolved gas, the method adopts peak process function, automatically gives up low value point, reduces the calculation level at initial peak and cut-off peak, the impact of environmental change on chromatogram calculated by peak area can be reduced, thus can improve the computational accuracy of chromatographic peak area.

Accompanying drawing explanation

Fig. 1 is the calculation flow chart of embodiment of the present invention power equipment oil dissolved gas chromatographic peak area computing method.

Embodiment

Illustrate below in conjunction with accompanying drawing and be described in further detail embodiments of the invention, but the present embodiment is not limited to the present invention, every employing analog structure of the present invention and similar change thereof, all should list protection scope of the present invention in.

As shown in Figure 1, a kind of power equipment oil dissolved gas chromatographic peak area computing method that the embodiment of the present invention provides, it is characterized in that, concrete steps are as follows:

1) utilizing chromatograph, take time shaft as abscissa axis, with chromatogram value axle for axis of ordinates, draws the chromatographic curve of each component gas in power equipment oil;

2) choose and need the gas composition of computer chromatography peak area to be object gas, the chromatographic peak start time point of target setting gas chromatogram curve, chromatographic peak stop time point and chromatographic peak smoothingtime length, chromatographic peak start time point is wherein designated as T0, chromatographic peak stop time point is designated as T1, and chromatographic peak smoothingtime length is for being designated as Δ Tc;

Wherein, T0=r × Ts, Ts are chromatographic chromatographic peak initial time minimum range, and r is safety factor, and the value of r is generally 0.9;

Wherein, T1=k × Tm, Tm are chromatographic chromatographic peak end time maximum range, and k is safety factor, and the value of k is generally 0.95;

Wherein, Δ Tc=(T1-T0) × (k-1)/2;

3) calculate Chromatogram Baseline starting point chromatogram value and the Chromatogram Baseline cut off chromatogram value of object gas, its computing formula is:

$\mathrm{Vs}=\left(\underset{i=T0}{\overset{T0+\mathrm{\ΔTc}}{\mathrm{\Σ}}}{V}_i\right)/\mathrm{\ΔTc};$

$\mathrm{Vt}=\left(\underset{i=T1}{\overset{T1+\mathrm{\ΔTc}}{\mathrm{\Σ}}}{V}_i\right)/\mathrm{\ΔTc};$

In formula, Vs is the Chromatogram Baseline starting point chromatogram value of object gas, and Vt is the Chromatogram Baseline cut off chromatogram value of object gas, V _ifor object gas chromatographic curve is in the chromatogram value of time point i;

4) in coordinate system belonging to object gas chromatographic curve, draw straight line L, make this straight line L through coordinate points (T0+ Δ Tc/2, Vs), and coordinate points (T1+ Δ Tc/2, Vt);

5) on the segment of curve of object gas chromatographic curve from T0 to T1, choosing the data point maximum with straight line L spacing, is the peak maximum height value of object gas chromatographic curve by the spacing setting between this data point and straight line L;

6) calculate the chromatographic peak area of object gas chromatographic curve, its computing formula is:

$S=2\×\underset{i=T0}{\overset{T1}{\mathrm{\Σ}}}f\left(V_i\right);$

In formula:

If V _i≤ (Vs+Vt+Hmax)/2, then f (V _i)=0;

If V _i> (Vs+Vt+Hmax)/2, then f (V _i)=V _i-(Vs+Vt+Hmax)/2;

In formula, S is the chromatographic peak area of object gas chromatographic curve, V _ifor object gas chromatographic curve is in the chromatogram value of time point i, Hmax is the peak maximum height value of object gas chromatographic curve.

Claims (3)

1. power equipment oil dissolved gas chromatographic peak area computing method, it is characterized in that, concrete steps are as follows:

1) utilizing chromatograph, take time shaft as abscissa axis, with chromatogram value axle for axis of ordinates, draws the chromatographic curve of each component gas in power equipment oil;

2) choose and need the gas composition of computer chromatography peak area to be object gas, the chromatographic peak start time point of target setting gas chromatogram curve, chromatographic peak stop time point and chromatographic peak smoothingtime length, chromatographic peak start time point is wherein designated as T0, chromatographic peak stop time point is designated as T1, and chromatographic peak smoothingtime length is for being designated as Δ Tc;

The value of time span Δ Tc is set as:

Tc＝（T1-T0）×（k－1）/2；

In formula, k is safety factor, and the value of k is 0.95;

3) calculate Chromatogram Baseline starting point chromatogram value and the Chromatogram Baseline cut off chromatogram value of object gas, its computing formula is:

；

；

In formula, Vs is the Chromatogram Baseline starting point chromatogram value of object gas, and Vt is the Chromatogram Baseline cut off chromatogram value of object gas, for object gas chromatographic curve is in the chromatogram value of time point i;

4) in coordinate system belonging to object gas chromatographic curve, draw straight line L, make this straight line L through coordinate points (T0+ Δ Tc/2, Vs), and coordinate points (T1+ Δ Tc/2, Vt);

5) on the segment of curve of object gas chromatographic curve from T0 to T1, choosing the data point maximum with straight line L spacing, is the peak maximum height value of object gas chromatographic curve by the spacing setting between this data point and straight line L;

6) calculate the chromatographic peak area of object gas chromatographic curve, its computing formula is:

；

In formula:

If , then ;

If , then ;

In formula, S is the chromatographic peak area of object gas chromatographic curve, for object gas chromatographic curve is in the chromatogram value of time point i, Hmax is the peak maximum height value of object gas chromatographic curve.

2. power equipment oil dissolved gas chromatographic peak area computing method according to claim 1, is characterized in that, the value of the chromatographic peak start time point T0 of object gas chromatographic curve is set as: T0=r × Ts;

In formula, Ts is chromatographic object gas chromatographic peak initial time minimum range, and r is safety factor, and the value of r is 0.9.

3. power equipment oil dissolved gas chromatographic peak area computing method according to claim 1, it is characterized in that, the value of the chromatographic peak stop time point T1 of object gas chromatographic curve is set as: T1=k × Tm;

In formula, Tm is chromatographic object gas chromatographic peak end time maximum range, and k is safety factor, and the value of k is 0.95.