JP2658477B2 - Transformer life prediction method - Google Patents

Description

The present invention relates to a system for predicting the life of a transformer.

B. Summary of the Invention The present invention relates to a method for predicting the life of a transformer by predicting the deterioration of the insulating paper of the transformer from the gas concentration in the insulating oil of the transformer. By predicting when it will be and issuing a prediction message, transformer maintenance and reliability will be improved.

C. Conventional technology Conventionally, in order to predict the life of a transformer, humans manually collect insulating oil from the transformer body, analyze the collected oil by gas chromatography, etc., and analyze the analysis results. Was determined.

D. Problems to be Solved by the Invention Conventionally, the life of a transformer has been predicted based on human feelings. Therefore, the transformer must be used until an abnormality (failure) occurs in the transformer. As a result, the inefficient way of replacing the transformer had to be taken. Therefore, the maintenance and reliability of the transformer were poor.

The present invention has been made in view of the above conventional problems,
The purpose is to predict and calculate when the gas concentration in the transformer insulating oil will reach the dangerous concentration by using an arithmetic processing unit such as a computer and issue a prediction message, thereby improving the maintenance and reliability of the transformer. It is to plan.

E. Means for Solving the Problems The present invention provides a life prediction method for predicting the life of a transformer from the gas concentration in transformer insulating oil in order to achieve the above-mentioned object. Measurement is performed a predetermined number of times, and among these measured values, an increase in the gas concentration with respect to the current measured value is calculated from the previous measured value, and a prediction start concentration of the gas concentration and the transformer are calculated in order to predict a danger of the transformer. A comparison operation is performed with the accumulated concentration in the insulating oil of the transformer, and a prediction operation is performed by predicting the time when the gas concentration reaches the dangerous concentration indicating the danger of the transformer from the time when the accumulated concentration becomes equal to or higher than the predicted start concentration. Give a message.

F. Embodiment An embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a method for predicting the life of a transformer according to an embodiment of the present invention. In the figure, 1a, 1b,..., 1n are transformer main bodies, 2a, 2
b, ..., 2n are oil-in-gas analyzers, 3a, 3b, ..., 3n are sequence controllers, 4 is a computer processing unit, 5
Is a printer that performs various printing based on the calculation results of the calculation processing unit 4.

Each of the gas-in-oil analyzers 2a to 2n receives a start signal from the sequence controller 3a to 3n, and receives a start signal from each of the transformer main bodies 1a.
Analyze the insulating oil gas (CO ₂ ) in 11n and transmit analog analysis data to the sequence controllers 3aa3n.
Sequence controllers 3a-3n are gas-in-oil analyzers 2a-2n
Is converted into a digital signal and sent to the arithmetic processing unit 4. The arithmetic processing unit 4 performs arithmetic processing on the digital analysis data from the sequence controllers 3a to 3n, and causes the printer 5 to print the result of the arithmetic processing. The printer 5 prints the predicted date, the predicted time, the caution required of the gas in the oil of the transformer of the corresponding number, and the prediction of aging.

The sequence controllers 3a to 3n send start signals to the gas-in-oil analyzers 2a to 2n to perform the analysis and measurement of the gas-in-oil concentration in accordance with a program to perform the gas concentration measurement in the oil a predetermined number of times at a predetermined time. Let the measurement take place. The arithmetic processing unit 4 performs arithmetic processing based on the analysis data sent from the in-oil gas analyzers 2a to 2n through the sequence controllers 3a to 3n.

The life prediction of the transformer is performed by predicting the deterioration of the insulating paper of the transformer from the gas concentration in oil. That is, as shown in FIG. 2, the arithmetic processing unit 4 calculates the CO ₂ cumulative value from the gas (CO ₂ ) concentration at the start of the use of the transformer and the gas concentration at a time α years after the start of the use of the transformer. Is stored.

As a condition for starting the prediction, if CO ₂ has reached the prediction start concentration n (ppm) after α years have elapsed from the start of use, the year and month at which the dangerous concentration m (ppm) is reached is predicted once a month. The result is output to the printer 5 for β years. Therefore, the prediction process keeps predicting the year and month that will be m (ppm) once a month during β. The prediction predicts the date and time when the gas concentration reaches m (ppm) from the increase rate in the past year from n to n ',
Forecast the date to reach m (ppm) from the current CO ₂ concentration and the annual increase rate. As the increase rate for one year, data for one year is stored as a measured value for one day or a measured value for one hour, and the increase rate for one year is calculated based on this data.

The date when the dangerous concentration of gas is reached is calculated by the following equation.

{M- (B2 + A2)} ÷ [{(B2 + A2) - ( B1 + A1)} ÷ 12 ] = C Here, A1 is the difference cumulative value of CO ₂ concentration from the time of oil change up to one year.

A2 is the difference cumulative value of CO ₂ concentration from the time of oil change to today.

B1 is the CO ₂ concentration one year ago.

B2 is today's CO ₂ concentration.

 m is the gas concentration determination value at the end of life.

 C is the number of months until today.

The arrival date is calculated by adding the month C up to the arrival obtained by the above equation to the current year and month.

In this way, the arithmetic processing unit 4 calculates the increment from the previous time, compares the cumulative density with the predicted start density, and does not issue a message if the cumulative density is lower than the predicted start density. When the cumulative concentration exceeds the predicted start concentration, the date and time when the dangerous concentration is reached is predicted (calculated), and the predicted start concentration n (ppm)
The forecast message is issued every month from the point where the number of times exceeds. When the insulating oil is replaced, the increment after the replacement is added to the accumulated concentration immediately before the replacement.

G. Effects of the Invention As described above, the present invention eliminates the need to judge the life of a transformer while taking and storing the status record of the transformer, etc. Can be predicted, and the maintenance and reliability of the transformer can be improved.

[Brief description of the drawings]

FIG. 1 is a block diagram of a system for predicting the life of a transformer according to an embodiment of the present invention, and FIG. 2 is an explanatory diagram of a prediction operation of the system of FIG. 1a ~ 1n ... Transformer body, 2a ~ 2n ... Gas analyzer, 3a ~ 3n
…… Sequence controller, 4 …… Calculation processing unit, 5…
... a printer.

Claims (1)

(57) [Claims] In a life prediction system for predicting the life of a transformer based on the gas concentration in a transformer insulating oil, the gas concentration is measured a predetermined number of times during a predetermined period. While calculating the increase of the gas concentration with respect to the current measured value, the prediction start concentration of the gas concentration is compared with the cumulative concentration in the transformer insulating oil in order to predict the danger of the transformer, and the cumulative concentration is calculated. A method for predicting the life of a transformer, wherein a prediction message is issued by predicting and calculating a timing when the gas concentration reaches a dangerous concentration indicating a danger of the transformer from a time point when the predicted starting concentration is exceeded.