JP2006229130A - Method of estimating and managing lifetime of power unit - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of accurately estimating an optimal lifetime, longer than a maker recommended lifetime, of an electrolytic capacitor in a power unit. <P>SOLUTION: In step S2, a peak temperature on the surface of the electrolytic capacitor is specified, and a cordless memory type small-sized temperature measure (temperature memory button) is directly attached to the peak temperature part to start measuring a surface temperature. If the thermometry is performed for a predetermined time, the small-sized temperature measure is taken out and work is shifted to "optimal lifetime estimation due to Arrhenius' lifetime computation" of step S4. Measured temperature data are fetched into a computer and substituted to an Arrhenius' lifetime computation formula to calculate the optimal lifetime. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method for estimating an optimum life of a power supply device used in various electric facilities and a life management method for examining measures for extending the life of the power supply device.

なお、式（１）において、Ｌは寿命時間（Ｈ）、Ｌｓは規定寿命（Ｈ）、Ｋは定数、Ｔは使用時の環境温度である使用温度（℃）、Ｔｓは使用時の環境温度の最高値である規定寿命温度（℃）である。定数Ｋは、通過リップル電流による発熱分に関連する寿命の補正係数である。
特開平０８−３２２１４１号公報（第０００３段） Various control panels (such as switchboards) are provided with power supply devices such as power conversion devices. The electrolytic capacitor used in this power supply device smoothes, for example, an AC 100V input power supply voltage to a DC24V output power supply voltage. Normally, the life of the power supply device greatly depends on the life of the electrolytic capacitor. In the case of an aluminum electrolytic capacitor, an electrolytic solution is sealed in a bottomed case, and the opening of the case is sealed with a packing (rubber elastic body). In this electrolytic capacitor, the electrolyte solution is vaporized by the ambient temperature, the gas pressure rises, diffuses in the packing and increases the gas escape equivalent series resistance. The capacity decreases. The diffusion of the electrolyte greatly depends on the ambient temperature, and the relationship between the change over time in the electrical characteristics of the electrolytic capacitor and the ambient temperature approximates the Arrhenius chemical reaction kinetics. From this, the lifetime of the electrolytic capacitor is estimated by the Arrhenius lifetime calculation formula of the following formula (1) (see, for example, Patent Document 1).

In equation (1), L is the life time (H), Ls is the specified life (H), K is a constant, T is the operating temperature (° C.) which is the environmental temperature during use, and Ts is the environmental temperature during use. It is the specified life temperature (° C) which is the maximum value of. The constant K is a life correction coefficient related to the amount of heat generated by the passing ripple current.
Japanese Patent Laid-Open No. 08-322141 (stage 0003)

  There are various usage environments and operating conditions of the power supply device including the electrolytic capacitor, and there are also various life estimation values of the power supply device. The estimated lifetime of the electrolytic capacitor is obtained by the above formula (1). The measured value of the use temperature T changes depending on how the temperature of the use temperature T is measured and how it is measured. Life expectancy varies. Since a general power supply device is incorporated in a heat sink and the inside of the power supply device is densely packed in a non-insulated part, it is practically difficult to measure the actual temperature of the electrolytic capacitor. Therefore, in the current situation, the life estimation of the power supply device depends on the manufacturer's recommendation of the power supply device.

  However, the estimated life expectancy recommended by the manufacturer is actually short-lived (than the actual optimum life) for safety reasons. For example, the manufacturer's recommended life expectancy for aluminum electrolytic capacitors for 24V power supply equipment is 7-8 years. Replace the electrolytic capacitors with new ones based on this estimated life of 7-8 years, and perform maintenance, inspection and repair of cooling equipment for power supply equipment. Like to do. Such a manufacturer-suggested life estimation is convenient and convenient for the user because it is easy to manage the life, but parts replacement that is repeated early and early places a great economic burden on the user.

  The present invention has been made in view of such circumstances, and a method for accurately estimating an optimum life that is longer than the manufacturer's recommended life of an electrolytic capacitor in a power supply device, and a life extension using this life estimation method. It is an object to provide a life management method suitable for study.

  In order to achieve the above object, the present invention measures the surface temperature of an electrolytic capacitor of a power supply apparatus having an electrolytic capacitor for smoothing an input power supply voltage with a cordless memory type small temperature measuring device directly attached to the electrolytic capacitor. This is characterized by substituting the temperature measurement data memorized in the vessel into the Arrhenius lifetime calculation formula to estimate the optimum lifetime of the electrolytic capacitor.

  The present invention also includes a step of specifying the highest temperature portion of the surface of the electrolytic capacitor with a surface thermometer, a step of measuring the surface temperature of the highest temperature portion of the specified electrolytic capacitor with a cordless memory type small temperature measuring instrument, The optimum life of the electrolytic capacitor can be estimated by the process of taking out the temperature measuring device from the power supply device and processing the stored temperature measurement data by a computer to calculate the optimum life of the electrolytic capacitor.

  Here, the power supply device is a 24V power supply device provided with an aluminum electrolytic capacitor that smoothes AC100V to DC24V, and is provided together with a cooling device on various control panels. As the cordless memory type small temperature measuring device, a small temperature measuring device marketed under the name of the temperature memory button can be applied. The temperature memory button has a circular thin button shape that is slightly larger than a one-yen coin, and can be directly attached to the surface of the electrolytic capacitor of the power supply device. A cordless temperature memory button is attached to the power supply unit installed in the control panel, so the temperature can be measured with the control panel door closed, and there is no risk of a short circuit accident in the panel. By attaching a temperature memory button directly to the surface of the electrolytic capacitor of the power supply, the actual temperature of the electrolytic capacitor can be accurately measured. In this case, it is possible to identify the maximum temperature part of the electrolytic capacitor surface with a surface thermometer, measure the temperature of this maximum temperature part with the temperature memory button, and make the actual temperature of the electrolytic capacitor stable the life of the electrolytic capacitor It is desirable for accurate estimation.

  By taking out the temperature memory button from the power supply, reading the temperature measurement data stored in the temperature memory button with a computer, and substituting the read data into the Arrhenius life formula, the optimum life of the electrolytic capacitor can be estimated. Since the optimum lifetime that can be estimated is based on the directly measured value of the surface temperature of the electrolytic capacitor, the lifetime is surely longer than the manufacturer's recommended lifetime, and can be effectively used as a measure for extending the lifetime of the electrolytic capacitor.

  In the present invention, the surface temperature of the electrolytic capacitor in the power supply device cooled by the cooling device is measured with a small cordless memory type temperature measuring device directly attached to the electrolytic capacitor. Thus, a load temperature test and a load current measurement test of the power supply device can be performed, and the cooling effect of the cooling device can be determined from the test results, and measures for extending the life of the power supply device can be studied.

  The life of the electrolytic capacitor in the power supply device greatly depends on the ambient temperature. According to the Arrhenius lifetime calculation formula, the estimated lifetime is halved or doubled when the ambient temperature fluctuates by 10 ° C. Therefore, a cooling device that constantly cools the power supply device is provided in the control panel including the power supply device. This cooling device adjusts the internal temperature of the control panel, and the cooling effect fluctuates due to factors such as clogging of the filter at the air intake outside the panel and deterioration of the cooling fan performance. affect. If the cooling effect of this cooling device is judged from the actual temperature measurement value of the electrolytic capacitor and the results of the load temperature test and load current measurement test of the power supply device, how can the life of the electrolytic capacitor be extended? It can be seen that this can be done, and the life of the power supply device can be extended.

  According to the present invention, the surface temperature of the electrolytic capacitor that determines the life of the power supply device is measured with a small cordless memory type temperature measuring device, and the measured temperature data is substituted into the Arrhenius life calculation formula by a computer. Since the optimum lifetime is estimated, the estimated lifetime is surely longer than the manufacturer's recommended lifetime and can be estimated with higher accuracy. For this reason, it is possible to extend the period of parts replacement along with the life of the power supply device, and to achieve an excellent effect that the economic burden on the user side of the power supply device is reduced.

  Moreover, if the cooling effect of the electrolytic capacitor by the cooling device is judged from the actual measured temperature value of the electrolytic capacitor and the results of the load temperature test and load current measurement test of the power supply device, how can the life of the electrolytic capacitor be extended? It can be seen that it is possible to extend the life of an appropriate and more economical power supply.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS.

  FIG. 1 is a flowchart for explaining the method of the present invention. FIG. 2 shows an overview of the control panel 1 that is the target of life estimation. The control panel 1 includes a vertically long box-shaped main body 2. A filter 3 is installed at the lower front of the main body 2, and outside air is introduced into the main body 2 as cooling air through the filter 3. A cooling fan 4 is installed on the upper back of the main body 2. The power supply device 10 is arranged at the uppermost stage inside the main body 2, the control modules 12 and 12 and the input / output card 13 are arranged at the lower stage, and the cooling device 30 is arranged around these modules. The cooling device 30 includes a filter 3, cooling fans 4, 5 and the like, and cools the power supply device 10 and the control modules 12 and 12 to an appropriate temperature.

  The power supply device 10 is a block body in which components such as a transformer and an electrolytic capacitor are assembled on a heat sink, and for example, an electrolytic capacitor 11 is provided in an upper portion. The life of the power supply device 10 is determined by the life of the electrolytic capacitor 11. When the power supply device 10 is a 24V power supply device, the life of the electrolytic capacitor recommended by the manufacturer is about 7 years. The life estimation of the electrolytic capacitor 11 according to the method of the present invention is performed as shown in the optimum life estimation flow F1 in the upper part of FIG.

  The optimum life estimation starts at the repair arrival time of the control panel 1 including the power supply device 10 (start) as shown in step S1 of the flow F1. Prior to this start, the door of the control panel 1 is opened in step S2, and the power supply of the power supply apparatus 10 is opened. The power supply device 10 is removed, the electrolytic capacitor 11 is exposed in the test room, and temporary power is supplied to the power supply device 10. Next, a surface thermometer (not shown) identifies a plurality of electrolytic capacitors 11 having a high surface temperature inside the power supply device 10 (2 to 3 are identified). As shown in the schematic diagram of FIG. 2, a cordless memory type small temperature measuring device 20 is directly attached to the specified maximum temperature portion of the electrolytic capacitor 11 with a strong double-sided tape or the like. If the power supply device 10 is attached to the control panel 1, the power is restored, and the door of the control panel 1 is closed, the preparation for the actual temperature test in Step 3 is completed. The actual measurement by the small temperature measuring device 20 can be started and stopped by setting the small temperature measuring device 20 in advance with a computer. When this temperature measurement is performed for a predetermined time, the door of the control panel 1 is opened, the small temperature measuring device 20 is taken out from the power supply device 10, and the process proceeds to the operation of “optimum life estimation by Arrhenius life calculation” in step S4.

  When the maximum value of the temperature measurement data stored in the small temperature measuring device 20 is 52 ° C., this temperature is the maximum temperature of the surface of the electrolytic capacitor 11 and can be used as an actual measurement value when the capacitor is actually operated. When the temperature data of 52 ° C. is taken into a computer and substituted into the use temperature T of the above-mentioned Arrhenius life calculation formula (1), the calculated optimum life is 9.0 years. Therefore, the lifetime of 7 years as the repair period recommended by the manufacturer is extended by 2 years. This is the result of measuring the temperature of the electrolytic capacitor 11 as close as possible to the actual measured value, and what was repaired or replaced in 7 years can be postponed for 2 years, greatly reducing the user's economic burden. it can.

  In the above work for estimating the optimum life, it is advantageous to measure the surface temperature of the electrolytic capacitor 11 with the cordless memory type small temperature measuring device 20 in the following points. That is, temperature measurement using a surface thermometer or a small resistance thermometer is also possible, but these require preparations and are expensive. On the other hand, the cordless memory type small temperature measuring device 20 known as a temperature memory button can be used as it is, and is generally low in cost. Further, since the small temperature measuring device 20 is cordless, it can be used without worrying about a short circuit inside the power supply device, and the actual temperature of the electrolytic capacitor 11 that is actually operated by closing the door of the control panel 1 can be measured.

  The optimum life of the electrolytic capacitor 11 estimated by the method of the present invention can be studied for extending the life based on the life extension study flow F2 in the lower part of FIG. This life extension is performed by determining the cooling effect of the cooling device 30 in the control panel 1 of FIG.

  In the load temperature test in step S5 of FIG. 1, after the power supply 10 is opened, the power supply 10 is removed and a simulated load (not shown) is connected in the test room. By this test, a temperature test value for the load of the power supply device 10 is obtained. Next, the power supply device 10 is attached to the control panel 1, and the actual load current is measured with an ammeter. The actual load current value and the maximum temperature of the electrolytic capacitor 11 obtained in step S3 clarify the temperature of the electrolytic capacitor 11 with respect to the actual load current. If this data is compared with the load temperature test value of the power supply device 10, the cooling effect of the power supply device 10 can be determined. The cooling effect of step S6 in FIG. 1 is determined from the obtained data. For example, if the load temperature test value is within + 10 ° C., it is determined that the cooling effect is “good”.

  If it is determined in step S6 of FIG. 1 that the cooling effect is poor and the “life” is affected, the cooling measures in step S8 are examined. First, as shown in the description in the ellipse of FIG. 3, it is necessary to specify the cause of the rise in the capacitor temperature. Investigate and verify the causes of "high load", "high air conditioning set temperature", "cooling fan performance degradation", and "filter clogging".

  It is verified whether or not the power supply device 10 is in an overload state by the “load is high” verification, the load temperature test in step S5 of FIG. 1 and the actual load current measurement value.

  The verification that “the air conditioning set temperature is high” and the relationship between the air conditioning temperature in the room where the control panel 1 is installed and the temperature of the electrolytic capacitor 11 are investigated. It is verified whether or not the temperature of the electrolytic capacitor 11 is lowered due to the temperature set change of the air conditioning.

  “Cooling fan performance degradation” verification, the internal temperature distribution of the control panel 1 and the relationship between the temperature of the electrolytic capacitor 11 and the performance of the cooling fan are investigated. The temperature distribution is measured by the small temperature measuring instrument 20 used for measuring the temperature of the electrolytic capacitor 11. It is verified whether or not the temperature of the electrolytic capacitor 11 is lowered by improving the performance of the cooling fan and adding the fan.

The “filter clogging” verification and the relationship with the temperature of the electrolytic capacitor 11 due to the influence of the filter 3 on the front surface of the control panel 1 are investigated. It is verified whether the temperature of the electrolytic capacitor 11 decreases due to the performance recovery of the filter and the specification change.

  Based on the above four verification results, the process proceeds to step S8 of “Cooling countermeasure review and repair cost determination” in FIG. An effective cooling effect measure is selected from the verification result. If the repair cost of the cooling device 30 is lower than the power device repair cost, it is determined as “Yes” and the process returns to Step S3. If it is determined as “No”, the process returns to Step S7. Return.

  In step S7, “consider extending the life of electrolytic capacitors” is performed. During the period of 7 to 8 years, which is the estimated lifetime from the past, the development technology of electrolytic capacitors has progressed, and many electrolytic capacitors with high performance and long life have been developed. Consider whether it is possible to replace electrolytic capacitors from several generations before with high performance and long life electrolytic capacitors. Here, if it is determined that the performance improvement measure for the electrolytic capacitor is cheaper than the repair cost of the power supply device, it is determined as “possible”, the process proceeds to step S9, and “life extension work” is performed. If it is determined as “No” in step S7, the process proceeds to step S10, and “Construction with optimum life cycle” is performed.

  It should be noted that the present invention is not limited to the above-described embodiment, and it is needless to say that various modifications can be made without departing from the gist of the present invention.

It is a lifetime estimation flowchart for demonstrating this invention. It is a front view which shows the outline | summary of the control panel which has a power supply device. It is a figure which shows the example of a lifetime deterioration factor of an electrolytic capacitor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Control board 3 Filter 4 Cooling fan 10 Power supply device 11 Electrolytic capacitor 12 Control module 13 Input / output card 20 Cordless memory type small temperature measuring instrument, temperature memory button 30 Cooling device

Claims (3)

  The surface temperature of the electrolytic capacitor of a power supply device having an electrolytic capacitor for smoothing the input power supply voltage is measured with a cordless memory type small temperature measuring device directly attached to the electrolytic capacitor, and the temperature measurement data stored in the small temperature measuring device Is substituted into the Arrhenius lifetime calculation formula to estimate the optimum lifetime of the electrolytic capacitor.   The step of specifying the maximum temperature portion of the electrolytic capacitor surface of the power supply device having an electrolytic capacitor for smoothing the input power supply voltage with a surface thermometer, and the surface temperature of the maximum temperature portion of the electrolytic capacitor with a cordless memory type small temperature measuring device The method includes: a step of measuring; and a step of calculating the optimum lifetime of the electrolytic capacitor by processing the temperature measurement data stored in the memory by taking out the small temperature measuring device from the power supply device by a computer. The life estimation method of the power supply device according to 1.   A power supply device having an electrolytic capacitor for smoothing an input power supply voltage, and measuring a surface temperature of the electrolytic capacitor in a power supply device cooled by a cooling device with a cordless memory type small temperature measuring device directly attached to the electrolytic capacitor A power supply device life management method, comprising: performing a load temperature test and a load current measurement test, determining a cooling effect of the cooling device from the test results, and examining measures for extending the life of the power supply device.

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