Correction method and system for concentration detection of dissolved gas in transformer oil

Abstract

The invention discloses a correction method and system for concentration detection of dissolved gas in transformer oil, and the method comprises the steps: respectively obtaining and storing second harmonics of the dissolved gas in the transformer oil with different preset concentrations at different temperatures, and selecting a calibration temperature, determining an inversion relation between the second harmonic peak valley value of the calibration temperature and the concentration of the dissolved gas in the transformer oil, and respectively calculating correction coefficients of other temperatures relative to the calibration temperature according to the second harmonics of the dissolved gas in the transformer oil with different preset concentrations at different temperatures; the actually measured temperature and actually measured second harmonics of the dissolved gas in the transformer oil are obtained, the peak-valley value of the actually measured second harmonics is multiplied by the correction coefficient corresponding to the actually measured temperature to obtain the corrected peak-valley value, then concentration inversion is conducted on the corrected peak-valley value according to the inversion relation, and the corrected concentration of the dissolved gas in the transformer oil is obtained. According to the invention, the influence of temperature on the TDLAS measurement result can be effectively avoided.

Description

Technical Field

[0001] The invention relates to a transformer oil spectrum online monitoring technology, and in particular to a correction method and system for detecting dissolved gas concentration in transformer oil. Background Art

[0002] The transformer oil spectrum online monitoring system heats the oil in the transformer, separates the gas dissolved in the oil, and then measures the gas concentration through tunable semiconductor laser absorption spectroscopy (TDLAS) technology, and infers the possible hidden faults of the transformer through the gas concentration. The main gases dissolved in transformer oil are carbon monoxide, carbon dioxide, methane, ethane, ethylene, and acetylene. TDLAS technology is a technology that applies a tuning signal to a diode laser to achieve wavelength scanning, obtains the absorption spectrum of gaseous substances, and thus infers its composition and state information. It is widely used in gas detection in industrial and environmental fields.

[0003] TDLAS technology is based on the infrared absorption spectrum of gas molecules. The rotation and vibration states of gas molecules will change due to the influence of ambient temperature. Therefore, temperature changes in the measurement environment will cause the gas absorption line to drift, and the amplitude of the absorption peak will also change, thus affecting the gas concentration detection. The same concentration measured at different temperatures will produce different results. Summary of the invention

[0004] The technical problem to be solved by the present invention is as follows: In view of the above-mentioned problems in the prior art, a correction method and system for detecting dissolved gas concentration in transformer oil are provided, which can effectively avoid the influence of temperature on TDLAS measurement results.

[0005] In order to solve the above technical problems, the technical solution adopted by the present invention is:

[0006] A method for correcting dissolved gas concentration detection in transformer oil comprises the following steps:

[0007] The second harmonics of the dissolved gas in the transformer oil with different preset concentrations at different temperatures are obtained and saved respectively, a calibration temperature is selected, an inversion relationship between the peak and valley values ​​of the second harmonics at the calibration temperature and the concentration of the dissolved gas in the transformer oil is determined, and correction coefficients of the remaining temperatures relative to the calibration temperature are calculated respectively according to the second harmonics of the dissolved gas in the transformer oil with different preset concentrations at different temperatures;

[0008] The measured temperature and the measured second harmonic of the dissolved gas in the transformer oil are obtained, the peak-to-valley value of the measured second harmonic is multiplied by the correction coefficient corresponding to the measured temperature to obtain the corrected peak-to-valley value, and then the concentration of the corrected peak-to-valley value is inverted according to the inversion relationship to obtain the corrected concentration of the dissolved gas in the transformer oil.

[0009] Furthermore, when the correction coefficients of the remaining temperatures relative to the calibration temperature are calculated respectively according to the second harmonics of the dissolved gas in the transformer oil with different preset concentrations at different temperatures, it includes:

[0010] The second harmonics of the dissolved gas in the transformer oil of the current preset concentration at different temperatures are selected, and the ratios of the second harmonic peak-to-valley values ​​at the temperatures other than the calibration temperature to the second harmonic peak-to-valley values ​​at the calibration temperature are calculated in turn to obtain the correction coefficients of all other temperatures of the dissolved gas in the transformer oil of the current preset concentration relative to the calibration temperature.

[0011] Furthermore, when obtaining the measured temperature, it includes:

[0012] The measured second harmonic is cross-correlated with the second harmonic of dissolved gas in transformer oil with different preset concentrations at different temperatures, and the temperature of the second harmonic corresponding to the maximum correlation coefficient is selected as the estimated value of the measured temperature.

[0013] Furthermore, the correction coefficient corresponding to the measured temperature specifically refers to the correction coefficient of the temperature of the second harmonic corresponding to the maximum correlation coefficient.

[0014] Furthermore, obtaining the measured temperature specifically refers to obtaining the temperature measured by a temperature sensor pre-installed in the White Pool.

[0015] Furthermore, after obtaining the measured temperature and the measured second harmonic of the dissolved gas in the transformer oil, a step of matching a correction coefficient of the measured temperature is also included, including:

[0016] Performing concentration inversion on the peak and valley values ​​of the measured second harmonic according to the inversion relationship to obtain the concentration of dissolved gas in the transformer oil before correction;

[0017] A preset concentration closest to the concentration before correction is selected, and then a temperature closest to the measured temperature is selected from all temperatures of the gas dissolved in the transformer oil of the preset concentration, and the correction coefficient of the selected temperature is used as the correction coefficient of the measured temperature.

[0018] Further, the different preset concentrations include at least three levels of preset concentrations, and the different temperatures include at least five levels of temperatures.

[0019] The present invention also proposes a correction system for detecting dissolved gas concentration in transformer oil, comprising a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of any one of the correction methods for detecting dissolved gas concentration in transformer oil.

[0020] The present invention also provides a computer-readable storage medium having a computer program / instruction stored thereon. When the computer program / instruction is executed by a processor, the steps of any one of the methods for correcting the concentration of dissolved gas in transformer oil are implemented.

[0021] The present invention also provides a computer program product, comprising a computer program / instruction, which, when executed by a processor, implements the steps of any one of the methods for correcting dissolved gas concentration detection in transformer oil.

[0022] Compared with the prior art, the advantages of the present invention are:

[0023] The present invention obtains and saves the second harmonics of dissolved gas in transformer oil of different concentrations at different temperatures in the calibration stage, then selects the calibration temperature, and calculates the correction coefficients relative to the calibration temperature for the remaining temperatures, obtains the measured temperature and the measured second harmonic in actual measurement, multiplies the peak-to-valley value of the measured second harmonic by the correction coefficient corresponding to the measured temperature, and then performs concentration inversion, thereby realizing the correction of the detection of dissolved gas concentration in transformer oil, overcoming the influence of temperature on TDLAS measurement, improving the stability of dissolved gas measurement in transformer oil, and increasing the adaptability to the environment.

[0024] When obtaining the measured temperature, the present invention performs cross-correlation calculation on the measured second harmonic and all the stored second harmonics, and then takes the temperature of the second harmonic corresponding to the maximum correlation coefficient as the measured temperature, thereby realizing automatic recognition of temperature, without the need to install a temperature sensor, and effectively reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 Schematic diagram of methane second harmonic intercept signal.

[0026] Figure 2 Schematic diagram of the value range of cross-correlation of finite-length sequences.

[0027] Figure 3 The figure is a flow chart of a method according to an embodiment of the present invention. DETAILED DESCRIPTION

[0028] The present invention is further described below in conjunction with the accompanying drawings and specific preferred embodiments, but the protection scope of the present invention is not limited thereby.

[0029] Before introducing the specific embodiments of the present invention, the related concepts are explained first.

[0030] (1)TDLAS

[0031] Lambert-Beer theorem is the core theory of TDLAS, that is, a monochromatic laser with intensity I0 and frequency v has an intensity of I after passing through an absorbing medium with a length of L. The basic form is:

[0032] I(v)=I0 exp(-α(v)CL)

[0033] Where C is the concentration of the gas being measured, that is, the number of molecules per unit volume; α(v) is the absorption cross section of the medium at frequency v, which is related to the temperature and pressure during the test. The absorbance A of the gas at frequency v can be expressed by the incident light intensity and the initial light intensity:

[0034] A=In(I / I0)

[0035] It can be seen from the formula that when monochromatic light passes vertically through a uniform non-scattering light-absorbing medium, its absorbance A is proportional to the concentration C of the light-absorbing substance and the thickness L of the absorption layer. When the thickness of the absorption layer is known, the gas concentration can be calculated by the output light intensity.

[0036] Another basis of TDLAS is the harmonic detection theory, which uses a high-frequency cosine signal to add to the current and modulate the output of the semiconductor laser by controlling the current.

[0037] i ic (t) = i c +i a cosωt

[0038] Where i c and i a Represent the center current value and the modulation amplitude of the injected current respectively, and ω is the modulation frequency. It can be concluded that the instantaneous output frequency of the semiconductor laser is

[0039] v=v c +v a cosωt

[0040] v c and v a They refer to the center frequency of laser emission and the frequency modulation amplitude respectively. The intensity of the laser after absorption by the White cell is expanded into the Fourier series of I(v):

[0041]

[0042] Each harmonic component A n It can be measured by the lock-in amplifier:

[0043]

[0044] Where θ = ωt. When the light intensity absorption of trace gas in the White cell α(v)CL << 1, the above formula can be simplified as

[0045]

[0046] Therefore, each harmonic component A n (v c ) is proportional to the trace gas. a When it is much smaller than the absorption line width, Taylor expansion is performed on the above formula:

[0047]

[0048] It can be seen that the nth harmonic component is proportional to the nth derivative of α(v). Since there is a factorial in the denominator of the above formula, the amplitude of the absorption spectrum will drop rapidly as the harmonic order increases. Therefore, when selecting harmonics to calculate concentration, you cannot choose harmonics with too high an order. At the same time, odd harmonics are oddly symmetrical about the central absorption position, and the amplitude is 0 at the absorption center position, but if there is baseline interference, it will be difficult to find the central absorption position. Figure 1 As shown in the figure, the even harmonics are even symmetrical about the central absorption position, and the amplitude is the largest at the central absorption position, which is more conducive to searching the central absorption position. Usually, the second harmonic is selected for concentration calculation based on factors such as anti-interference ability and amplitude.

[0049] In actual operation, the peak-to-valley value of the gas absorption peak in the second harmonic is usually used as the basis for concentration calculation. By introducing a known concentration of gas into the White cell in advance, the linear relationship between the peak-to-valley value of the second harmonic gas absorption peak and the concentration is calculated. When it is necessary to measure a gas of unknown concentration, the peak-to-valley value of the second harmonic is calculated with this relationship to reversely infer the concentration.

[0050] (2) Signal correlation theory

[0051] The larger the cross-correlation value, the more similar the two signals are. When the correlation value of signal A and signal B is 1, it means that the two signals are completely consistent; when the correlation value is 0, it means that there is no relationship between the two signals and there is no correlation.

[0052] like Figure 2 As shown, assuming that the two real signals are x(n) and y(n), the cross-correlation function of the two sequences is

[0053]

[0054] The value range of the signal x(n) is N x1 ≤n≤N x2 , the range of values ​​of y(n) is N y1 ≤n≤N y2 From the above formula, we can see that the calculation of the cross-correlation function includes three steps: shift, multiplication and addition. The signal y(n) is shifted left or right by |m| positions and multiplied by the signal x(n). The product and accumulation can obtain the cross-correlation function value r under a certain shift value m.xy (m).

[0055] -(N y2 -N x1 )≤m≤(N x2 -N y1 )

[0056] Therefore, for finite length signals x(n) and y(n), if N y2 ≤N x1 , then r xy (m) is only valid when m ≥ 0; if N y1 ≥N x2 , then r xy (m) has a value only when m≤0. If x(n) and y(n) are both causal finite length sequences that have values ​​starting from n=0 and have the same length, then the value range of m is -N y2 <m<N y2 .

[0057] Embodiment 1

[0058] In order to avoid the influence of ambient temperature, this embodiment proposes a correction method for detecting the concentration of dissolved gas in transformer oil. From the perspective of software and signal processing, the cross-correlation theory is used to identify the measured ambient temperature (if a temperature detector is installed in the gas chamber, it may affect the optical path, affect gas absorption, or cause the cavity in the gas chamber to be too large, reducing the concentration of the gas released from the transformer). In the gas calibration stage, the conversion coefficients of various gases (carbon monoxide, carbon dioxide, methane, ethane, ethylene, acetylene) dissolved in the transformer oil are stored between different temperatures and the calibration temperature. During actual measurement, the measurement environment is corrected by identifying the measurement temperature and using the linear interpolation method. By observation, the shape and position of the absorption peak of the gas are slightly different at different temperatures. Therefore, the similarity between the measured absorption peak and the stored peak type can be used to judge the temperature in the gas chamber.

[0059] The idea of ​​the method in this embodiment is to store the second harmonics of various gases dissolved in transformer oil at different temperatures at different concentrations. In actual measurement, the stored second harmonics can be used to perform cross-correlation calculations with the second harmonic signals, and the stored curve with the strongest correlation can be selected to obtain the temperature of the curve and the corresponding correction coefficient. Figure 3 As shown, the following steps are included:

[0060] S1) calibration stage: obtaining and saving the second harmonics of the dissolved gas in the transformer oil at different temperatures with different preset concentrations, selecting the calibration temperature, determining the inverse relationship between the second harmonic peak-to-valley value of the calibration temperature and the concentration of the dissolved gas in the transformer oil, and calculating the correction coefficients of the remaining temperatures relative to the calibration temperature according to the second harmonics of the dissolved gas in the transformer oil at different temperatures with different preset concentrations;

[0061] S2) Measurement stage: obtaining the measured temperature and the measured second harmonic of the dissolved gas in the transformer oil, multiplying the peak-to-valley value of the measured second harmonic by the correction coefficient corresponding to the measured temperature to obtain the corrected peak-to-valley value, and then performing concentration inversion on the corrected peak-to-valley value according to the inversion relationship to obtain the corrected concentration of the dissolved gas in the transformer oil.

[0062] In this embodiment, the dissolved gas in the transformer oil includes various gases such as carbon monoxide, carbon dioxide, methane, ethane, ethylene, and acetylene. The following takes methane as an example to specifically describe each step.

[0063] In step S1 of this embodiment, the different preset concentrations include at least three levels of preset concentrations of high, medium and low, and the different temperatures include at least five levels of temperature, specifically including: storing 10ppm methane at the second harmonics of -20 degrees, 0 degrees, 20 degrees, 40 degrees and 60 degrees; storing 50ppm methane at the second harmonics of -20 degrees, 0 degrees, 20 degrees, 40 degrees and 60 degrees; storing 100ppm methane at the second harmonics of -20 degrees, 0 degrees, 20 degrees, 40 degrees and 60 degrees. These second harmonics are all measured by TDLAS technology.

[0064] In step S1 of this embodiment, when respectively calculating the correction coefficients of the remaining temperatures relative to the calibration temperature according to the second harmonics of the dissolved gas in the transformer oil at different preset concentrations at different temperatures, it includes:

[0065] The second harmonics of the dissolved gas in the transformer oil of the current preset concentration at different temperatures are selected, and the ratios of the second harmonic peak-to-valley values ​​at the temperatures other than the calibration temperature to the second harmonic peak-to-valley values ​​at the calibration temperature are calculated in turn to obtain the correction coefficients of all other temperatures of the dissolved gas in the transformer oil of the current preset concentration relative to the calibration temperature.

[0066] For example, for the same concentration of methane, such as 100ppm, calculate the peak-to-valley values ​​at -20 degrees, 0 degrees, 20 degrees, 40 degrees, and 60 degrees respectively. Then select the calibration temperature. For example, if you select 20 degrees, then take 100ppm methane at 20 degrees as the standard, and calculate the coefficients of the peak-to-valley values ​​of the remaining temperatures relative to the calibration temperature. For example, at 20 degrees, the peak-to-valley value is 10000, and at -20 degrees the peak-to-valley value is 12000, then the peak-to-valley value temperature correction coefficient of -20 degrees relative to the calibration temperature is 1.2. By analogy, the correction coefficients of 0 degrees, 40 degrees, and 60 degrees relative to the calibration temperature (20 degrees) can be calculated, so that the correction coefficients of 10ppm and 50ppm methane at -20 degrees, 0 degrees, 40 degrees, and 60 degrees relative to the calibration temperature (20 degrees) can be further calculated.

[0067] In step S1 of the present embodiment, determining the inversion relationship between the second harmonic peak-to-valley value of the calibration temperature and the concentration of dissolved gas in transformer oil specifically involves determining the inversion relationship between the second harmonic peak-to-valley value of the calibration temperature of dissolved gas in transformer oil of different preset concentrations and different preset concentrations, i.e. determining the functional relationship between the second harmonic peak-to-valley value of 20 degrees of 10ppm, 50ppm, and 100ppm methane and the corresponding concentration. The inversion relationship can be obtained by data fitting. Usually, the inversion relationship is a linear function relationship, i.e., the concentration and the peak-to-valley value are in a linear function relationship.

[0068] In step S2 of this embodiment, obtaining the measured temperature includes:

[0069] The measured second harmonic is cross-correlated with the second harmonic of the dissolved gas in the transformer oil with different preset concentrations at different temperatures, wherein the temperature of the second harmonic corresponding to the maximum correlation coefficient is the most correlated temperature, and the temperature of the second harmonic corresponding to the maximum correlation coefficient is selected as the estimated value of the measured temperature, so that the correction coefficient of the temperature of the second harmonic corresponding to the maximum correlation coefficient (obtained by step S1) is the correction coefficient corresponding to the measured temperature.

[0070] In step S2 of this embodiment, the concentration inversion is performed on the corrected peak-valley values ​​according to the inversion relationship, specifically by bringing the corrected peak-valley values ​​into the linear function relationship obtained by inversion in step S1 to obtain the corresponding concentration.

[0071] Embodiment 2

[0072] This embodiment also proposes a correction method for detecting dissolved gas concentration in transformer oil, which is basically the same as the method in Embodiment 1, except that this embodiment does not estimate the measured temperature by an algorithm, but obtains the measured temperature by installing a temperature sensor in the White pool.

[0073] Based on the above differences, in step S2 of this embodiment, obtaining the measured temperature specifically refers to obtaining the temperature measured by a temperature sensor pre-installed in the White pool.

[0074] When calculating the correction coefficients of different temperatures relative to the calibration temperature in step S1, for the same temperature, at different gas concentrations, the correction coefficients relative to the calibration temperature may be different, for example, the peak-to-valley temperature correction coefficient of 10ppm methane at -20 degrees relative to the calibration temperature is x1, the peak-to-valley temperature correction coefficient of 50ppm methane at -20 degrees relative to the calibration temperature is x2, and the peak-to-valley temperature correction coefficient of 100ppm methane at -20 degrees relative to the calibration temperature is x3. Therefore, in step S2 of this embodiment, after obtaining the measured temperature and the measured second harmonic of the dissolved gas in the transformer oil, a step of matching the correction coefficient of the measured temperature is also included, including:

[0075] Performing concentration inversion on the peak and valley values ​​of the measured second harmonic according to the inversion relationship to obtain the concentration of dissolved gas in the transformer oil before correction;

[0076] Select a preset concentration that is closest to the concentration before correction (specifically, select a preset concentration with the smallest difference from the concentration before correction, and the preset concentration corresponding to the smallest absolute value can be selected by calculating the absolute value of the difference between the preset concentration and the concentration before correction, as the preset concentration closest to the concentration before correction), and then select a temperature that is closest to the actual temperature from all temperatures of the gas dissolved in the transformer oil of the preset concentration (specifically, select a temperature with the smallest difference from the actual measurement, and the temperature corresponding to the smallest absolute value can be selected by calculating the absolute value of the difference between all temperatures and the actual measurement, as the temperature closest to the actual temperature), and use the correction coefficient of the selected temperature (obtained by step S1) as the correction coefficient of the actual temperature.

[0077] Embodiment 3

[0078] This embodiment proposes a correction system for detecting dissolved gas concentration in transformer oil, including a memory, a processor, and a computer program stored in the memory, and the processor executes the computer program to implement the steps of the correction method for detecting dissolved gas concentration in transformer oil described in Embodiment 1 or Embodiment 2.

[0079] This embodiment further provides a computer-readable storage medium on which a computer program / instruction is stored. When the computer program / instruction is executed by a processor, the steps of the correction method for detecting dissolved gas concentration in transformer oil described in Embodiment 1 or Embodiment 2 are implemented.

[0080] This embodiment further provides a computer program product, including a computer program / instruction, which, when executed by a processor, implements the steps of the correction method for detecting dissolved gas concentration in transformer oil described in Embodiment 1 or Embodiment 2.

[0081] The above is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions under the concept of the present invention belong to the protection scope of the present invention. It should be pointed out that for ordinary technicians in this technical field, some improvements and modifications without departing from the principle of the present invention should also be regarded as the protection scope of the present invention.

Claims

1. A calibration method for detecting dissolved gas concentration in transformer oil, characterized in that: The following steps are involved: The second harmonics of the dissolved gas in the transformer oil with different preset concentrations at different temperatures are obtained and saved respectively, a calibration temperature is selected, an inversion relationship between the peak and valley values ​​of the second harmonics at the calibration temperature and the concentration of the dissolved gas in the transformer oil is determined, and correction coefficients of the remaining temperatures relative to the calibration temperature are calculated respectively according to the second harmonics of the dissolved gas in the transformer oil with different preset concentrations at different temperatures; The measured temperature and the measured second harmonic of the dissolved gas in the transformer oil are obtained, the peak-to-valley value of the measured second harmonic is multiplied by the correction coefficient corresponding to the measured temperature to obtain the corrected peak-to-valley value, and then the concentration of the corrected peak-to-valley value is inverted according to the inversion relationship to obtain the corrected concentration of the dissolved gas in the transformer oil.

2. The calibration method for detecting dissolved gas concentration in transformer oil according to claim 1, characterized in that: When calculating the correction coefficients of the remaining temperatures relative to the calibration temperature according to the second harmonics of the dissolved gas in the transformer oil at different preset concentrations at different temperatures, it includes: The second harmonics of the dissolved gas in the transformer oil of the current preset concentration at different temperatures are selected, and the ratios of the second harmonic peak-to-valley values ​​at the temperatures other than the calibration temperature to the second harmonic peak-to-valley values ​​at the calibration temperature are calculated in turn to obtain the correction coefficients of all other temperatures of the dissolved gas in the transformer oil of the current preset concentration relative to the calibration temperature.

3. The calibration method for detecting dissolved gas concentration in transformer oil according to claim 1, characterized in that: When obtaining the measured temperature, include: The measured second harmonic is cross-correlated with the second harmonic of dissolved gas in transformer oil with different preset concentrations at different temperatures, and the temperature of the second harmonic corresponding to the maximum correlation coefficient is selected as the estimated value of the measured temperature.

4. The calibration method for detecting dissolved gas concentration in transformer oil according to claim 3, characterized in that: The correction coefficient corresponding to the measured temperature specifically refers to the correction coefficient of the temperature of the second harmonic corresponding to the maximum correlation coefficient.

5. The calibration method for detecting dissolved gas concentration in transformer oil according to claim 1, characterized in that: Acquiring the measured temperature specifically refers to acquiring the temperature measured by a temperature sensor pre-installed in the White Pool.

6. The calibration method for detecting dissolved gas concentration in transformer oil according to claim 5, characterized in that: After obtaining the measured temperature and the measured second harmonic of the dissolved gas in the transformer oil, the step of matching the correction coefficient of the measured temperature includes: Performing concentration inversion on the peak and valley values ​​of the measured second harmonic according to the inversion relationship to obtain the concentration of dissolved gas in the transformer oil before correction; A preset concentration closest to the concentration before correction is selected, and then a temperature closest to the measured temperature is selected from all temperatures of the gas dissolved in the transformer oil of the preset concentration, and the correction coefficient of the selected temperature is used as the correction coefficient of the measured temperature.

7. The calibration method for detecting dissolved gas concentration in transformer oil according to claim 1, characterized in that: The different preset concentrations include at least three levels of preset concentrations, and the different temperatures include at least five levels of temperatures.

8. A calibration system for detecting dissolved gas concentration in transformer oil, comprising a memory, a processor and a computer program stored in the memory, characterized in that: The processor executes the computer program to implement the steps of the method for correcting the concentration of dissolved gas in transformer oil according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program / instruction stored thereon, characterized in that: When the computer program / instruction is executed by a processor, the steps of the method for correcting the concentration of dissolved gas in transformer oil as claimed in any one of claims 1 to 7 are implemented.

10. A computer program product comprising a computer program / instructions, characterized in that When the computer program / instruction is executed by a processor, the steps of the method for correcting the concentration of dissolved gas in transformer oil as claimed in any one of claims 1 to 7 are implemented.

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