JP2009195044A - Power supply apparatus and method of notifying remaining life of electrolytic capacitor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a power supply apparatus easily and accurately detecting the remaining life of an electrolytic capacitor without increasing a cost. <P>SOLUTION: The power supply apparatus 50 includes the electrolytic capacitor 7, a temperature sensor 24 which measures the temperature of the electrolytic capacitor 7 or the ambient temperature thereof, a load rate calculating means which calculates a load rate, a memory 26, a remaining life calculating means which calculates the remaining life of the electrolytic capacitor 7 based on the measured temperature and the calculated load rate, and a warning circuit 28 which issues a warning about the remaining life when the calculated remaining life reaches a warning time. A CPU 20 actuates the load rate calculating means and the life calculating means. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a power supply device including a power conversion unit such as a converter circuit, an inverter circuit, a chopper circuit, and the like, and in particular, has a function for detecting the life of an electrolytic capacitor in order to prevent the power supply device from being stopped due to the electrolytic capacitor reaching its life. The present invention relates to a power supply apparatus and an electrolytic capacitor life warning method.

  In a power supply device, for example, a switching power supply device, an AC power supply voltage is rectified to a pulsating voltage by a rectifying element, and the pulsating voltage is smoothed by a large-capacity electrolytic capacitor to be a DC input voltage. Is supplied to the switching unit to output an arbitrary voltage.

  In such a power supply device, the improvement in reliability may be hindered by the problem of the life of the electrolytic capacitor. This is because the life of the electrolytic capacitor is extremely short compared to the life of other electrical components, and the life of the electrolytic capacitor determines the life of the power supply device.

  When estimating the life of an electrolytic capacitor, detect the degree of pulsating current flowing in a circuit in parallel with the electrolytic capacitor, or install a capacitor that is substantially the same as the electrolytic capacitor whose life is to be estimated. In the past, it has been proposed to indirectly estimate by examining the above. Also, in the proposal in Patent Document 1 below, the conductors connected to the two terminals 3 and 4 of the electrolytic capacitor (the reference numerals are the reference numerals in the drawings) are plate-like conductor plates 5 and 10, respectively, which are insulated. The sheet 7 and the pressure sensor 1 are stacked to form a composite capacitor. When the capacity of the electrolytic capacitor is reduced due to aging, the accumulated charge is reduced and the Coulomb force acting between the conductor plates 5 and 10 is reduced. Since (attraction force) decreases, a proposal has been made that the decrease in attraction force is detected by the pressure-sensitive sensor 1 sandwiched between the conductor plates 5 and 10 to estimate the lifetime of the electrolytic capacitor.

JP-A-11-190754

  However, the proposals of the above prior art including the above-mentioned Patent Document 1 have problems such as an increase in the cost of the apparatus and an increase in installation space.

  Moreover, the load on the apparatus was not taken into account, and the life estimation of the electrolytic capacitor was not accurate. Here, the load factor is the ratio of the output current to the rated current of the power supply device. The life of the electrolytic capacitor of the power supply device that operates with a large load factor is shorter than that of the power supply device that operates with a small load factor.

  The present invention has been made in view of the above, and can be realized by adding a few components and software without increasing the cost, and easily and accurately detect the life of the electrolytic capacitor. An object of the present invention is to provide a power supply device and an electrolytic capacitor lifetime warning method that can be used.

  In order to solve the above-described problems and achieve the object, the power supply device of the present invention includes an electrolytic capacitor, temperature measuring means for measuring the temperature of the electrolytic capacitor or the surrounding of the electrolytic capacitor, and load factor calculation for calculating the load factor. A lifetime calculating means for calculating the remaining lifetime of the electrolytic capacitor based on the measured temperature and the calculated load factor, and a lifetime warning when the calculated remaining lifetime reaches the warning time. And an informing means for informing the above.

  The electrolytic capacitor life warning method according to the present invention is a method for warning the life of an electrolytic capacitor of a power supply device having an electrolytic capacitor for voltage smoothing and having a power conversion unit that converts input power into power. The subtraction time data table in which the subtraction time for is stored is stored in the storage means, the temperature around the electrolytic capacitor or the electrolytic capacitor is measured, and the load factor of the power supply device is calculated. From the measured temperature and the calculated load factor The subtraction time is calculated based on the subtraction time data table, and the remaining life time is calculated by subtracting the subtraction time from the predetermined life time corresponding to the electrolytic capacitor, and the calculated remaining life time reaches the warning time. It is characterized by notifying the life warning when

  According to the present invention, the subtraction time is obtained from the measured temperature and the calculated load factor based on the subtraction time data table, and the life remaining is obtained by subtracting the subtraction time from the life time predetermined for the electrolytic capacitor. Calculate time. That is, a temperature measuring means, a subtraction time data table in which a subtraction time for the temperature and the load factor is stored, and a life calculation means for calculating the remaining lifetime of the electrolytic capacitor from the subtraction time data table are provided, in addition to the temperature. Since the life detection is performed in consideration of the load factor, it can be realized by adding a few components and software, and there is an effect that the life detection of the electrolytic capacitor can be easily and accurately performed.

  Embodiments of a power supply apparatus and electrolytic capacitor life warning method according to the present invention will be described below in detail with reference to the drawings. Note that the present invention is not limited to the embodiments.

Embodiment 1 FIG.
FIG. 1 is a schematic functional block diagram of a first embodiment of a power supply device according to the present invention. In FIG. 1, the input of the power supply device 50 of the present embodiment is connected to a commercial AC power supply 3. The output of the power supply device 50 is connected to the load 60. The power supply device 50 is a switching power supply that generates a stable DC power supply from the AC commercial power supply 3 and supplies it to the load 60. That is, the power supply device 50 converts the commercial AC power supply 3 into a predetermined DC power supply and applies it to the load 60 connected to the output terminal.

  As shown in FIG. 1, an input rectifier circuit 5, an input smoothing electrolytic capacitor 7, and a switching circuit 9 are provided in this order from the AC commercial power supply 3 side on the primary side of the transformer 11. On the other hand, on the secondary side of the transformer 11, from the transformer 11 to the load 60 side, an output rectifier circuit 13, an output smoothing electrolytic capacitor 15, an output voltage detection circuit (output voltage detection means) 17, an output current detection circuit. (Output current detection means) 19 is provided in this order. Among these, the input rectifier circuit 5, the input smoothing capacitor 7, the switching circuit 9, the transformer 11, the output rectifier circuit 13, and the output smoothing capacitor 15 serve as power conversion means for converting the commercial AC power source 3 into a predetermined DC power source. A converter unit (power conversion unit) 40 is configured.

  The power supply device 50 further includes a CPU device 20, a PWM control unit (voltage control unit) 21, a temperature sensor (temperature measurement unit) 24, a memory (storage unit) 26, and an alarm circuit (notification unit). ing. The CPU device 20 gives a target voltage value to the PWM control unit 21. The PWM control unit 21 captures the target voltage value from the CPU device 20, captures the output voltage value detected by the output voltage detection circuit 17, and controls the switching circuit 9 so that the output voltage of the power supply device 50 becomes the target voltage value. Feedback control. The feedback control of the switching circuit 9 performed by the PWM control unit 21 is a well-known technique in which the switching operation of the switching circuit 9 is controlled by PWM (Pulse Wide Modulation) and the output voltage becomes variable. The output voltage of the switching circuit 9 is detected by the output voltage detection circuit 19, and the detection signal is input to the PWM control unit 21.

  The temperature sensor 24 is, for example, a CMOS temperature sensor, and measures the air supply temperature of the fan on the control board to obtain the ambient temperature. Note that the ambient temperature may be measured by measuring the temperature of the electrolytic capacitor itself, or indirectly by measuring the ambient temperature of the electrolytic capacitor in the present embodiment, and may be unified as appropriate. .

  The memory 26 constituting the storage means stores a load factor calculation means, a life calculation means, and a subtraction time data table that are configured by software. The lifetime calculation means calculates the remaining lifetime of the electrolytic capacitor from the measured temperature and the calculated load factor based on the subtraction time data table. The subtraction time data table used for calculating the remaining life time is obtained in advance from the following electrolytic capacitor life years data table and stored in the memory 26.

  FIG. 2 is a diagram showing an electrolytic capacitor life years data table according to the present embodiment. The electrolytic capacitor life years data table is a table showing the life years with respect to the load factor and the ambient temperature in a predetermined electrolytic capacitor. According to the life years data table of the present embodiment, in a certain type of electrolytic capacitor, for example, when the load factor is 60% and the ambient temperature is 40 ° C., the life years are 10.62 years. When the load factor is 80% and the ambient temperature is 50 ° C., the lifetime is 3.97 years.

  Next, the subtraction time data table will be described. The calculation of the remaining life time performed by the life calculation means is performed at predetermined time intervals. In accordance with this, the temperature around the electrolytic capacitor is measured and the load factor is calculated at predetermined time intervals. That is, for example, temperature measurement and load factor calculation are performed every hour, and the remaining lifetime of the electrolytic capacitor is calculated based on the measured temperature and the calculated load factor. The subtraction time data table stores the subtraction time for the temperature and load factor used in the calculation at this time, and the life calculation means subtracts the subtraction time from the life time determined in advance corresponding to the electrolytic capacitor. Thus, the remaining life time is calculated.

FIG. 3 is a diagram illustrating a subtraction time data table according to the present embodiment. The subtraction time data table of FIG. 3 shows the subtraction time when the measurement interval is 1 hour. The subtraction time shown in FIG. 3 is based on the following formula because the lifetime of the electrolytic capacitor at an ambient temperature of 40 ° C. and a load factor of 80% is 7.94 years based on the data of FIG. Has been.
7.94 years (= 7.94 x 24 hours x 365 days) = 69,204 hours

  The CPU device 20 is configured to be able to make a complicated process determination based on a stored program. FIG. 4 is a diagram showing a flowchart of an operation related to the life detection of the electrolytic capacitor among the operations of the CPU device 20. The operation of the CPU device 20 will be described with reference to FIG. The CPU device 20 is configured to include a load factor calculating means and a life calculating means that are software. In particular, the operation of step S103 in the flowchart of FIG. 4 constitutes a load factor calculating means. The operation of step S105 constitutes a life calculation means.

  In FIG. 4, when the operation of the system is started, the CPU device 20 first identifies an electrolytic capacitor having the shortest service life as a capacitor to be measured among a plurality of electrolytic capacitors (step S101). In the present embodiment, it is assumed that the electrolytic capacitor 5 is an electrolytic capacitor to be measured. Returning to the flowchart, next, the temperature of the electrolytic capacitor 5 to be measured or the ambient temperature of the electrolytic capacitor 5 to be measured is measured by the temperature sensor 24 (step S102).

Then, the CPU device 20 calculates a load factor from the measured load current (step S103). Further, the CPU device 20 refers to the subtraction time in the subtraction time data table based on the measured temperature and the calculated load factor (step S104). Then, the CPU device 20 updates the value of the remaining life time by the following formula (step S105). The calculated remaining lifetime is stored in the memory 26 and becomes the remaining remaining lifetime when calculating the remaining lifetime for the next cycle.
(Life remaining time = Current life remaining time-Subtraction time)

  Further, the CPU device 20 determines whether or not the remaining life time obtained as a result of the calculation has reached the warning time (step S106). If not reached, the process returns to step S102. On the other hand, if reached, the process proceeds to step S107, and the warning circuit 28 displays a life warning.

  As described above, according to the power supply device of the present embodiment, the subtraction time is obtained based on the subtraction time data table from the measured temperature and the calculated load factor, and the life time determined in advance corresponding to the electrolytic capacitor is obtained. The remaining life time is calculated by subtracting the subtraction time from. Therefore, the temperature sensor 26 is provided, and a subtraction time data table in which the subtraction time with respect to the temperature and the load factor is stored, and a life calculation means for calculating the remaining life of the electrolytic capacitor from the subtraction time data table are prepared. The life detection can be realized, and the life detection is performed in consideration of the load factor in addition to the temperature. Therefore, the life detection of the electrolytic capacitor can be easily and accurately performed.

  Although this embodiment is applied to a power supply device that operates continuously for 24 hours, if a means for calculating the operation time is provided and the subtraction time is proportional to the operation time, The present invention can also be applied to a power supply device that does not operate continuously for 24 hours.

Embodiment 2. FIG.
FIG. 5 is a diagram showing an electrolytic capacitor lifetime years data table of the power supply device according to Embodiment 2 of the present invention. FIG. 6 is a diagram showing a subtraction time data table of the power supply device according to the second embodiment of the present invention. If the ambient temperature is low and the load factor is low, the number of years of service life will be very large in calculation (the shaded area in FIG. 5). In practice, however, the lifetime of electrolytic capacitors is up to 15 years, due to various other factors. Therefore, as shown in FIG. 6 of the present embodiment, the subtraction time is uniformly set as 0.5 hours in the range where the ambient temperature is 30 ° C. or less and the load factor is 90% or less, and at most 2 years shorter than the actual life. A warning is issued in 13 years.

  According to the power supply device of the present embodiment, the subtraction time stored in the subtraction time data table is set so as to be a constant value in a region below a predetermined temperature and below a predetermined load factor. Therefore, the life of the electrolytic capacitor can be detected more accurately in accordance with the actual operation. In connection with the present embodiment, it is preferable to operate the power device overhaul as the shorter of 15 years after shipment or the above warning.

  As described above, the power supply device according to the present invention is useful for a power supply device including an electrolytic capacitor, and particularly includes a power conversion unit such as a converter circuit, an inverter circuit, and a chopper circuit including a smoothing electrolytic capacitor. It is suitable for being applied to a power supply apparatus.

1 is a schematic functional block diagram of a first embodiment of a power supply device according to the present invention. 6 is a diagram illustrating a life year data table according to Embodiment 1. FIG. FIG. 6 is a diagram showing a subtraction time data table according to the first embodiment. It is a figure which shows the flowchart of the operation | movement relevant to the lifetime detection of the electrolytic capacitor of CPU apparatus. It is a figure which shows the lifetime years data table of Embodiment 2. FIG. FIG. 10 is a diagram illustrating a subtraction time data table according to the second embodiment.

Explanation of symbols

3 Commercial AC power supply 5 Input rectifier circuit 7 Input smoothing capacitor (electrolytic capacitor)
9 Switching circuit 11 Transformer 13 Output rectifier circuit 15 Output smoothing capacitor (electrolytic capacitor)
17 Output voltage detection circuit (output voltage detection means)
19 Output current detection circuit (output current detection means)
20 CPU device (load factor calculating means, life calculating means)
21 PWM controller (voltage controller)
24 Temperature sensor (temperature detection means)
26 Memory (storage means)
28 Alarm circuit (notification means)
40 Converter section (power conversion section)
50 power supply device 60 load S103 load factor calculation means S105 life calculation means

Claims (6)

An electrolytic capacitor;
Temperature measuring means for measuring the temperature of the electrolytic capacitor or the ambient temperature of the electrolytic capacitor;
Output current detection means for detecting an output current output toward the load;
Load factor calculating means for calculating a load factor represented based on the detected output current;
Life calculation means for calculating the remaining lifetime of the electrolytic capacitor based on the measured temperature and the calculated load factor,
A power supply apparatus comprising: an informing means for informing a life warning when the calculated remaining life time reaches a warning time. A power conversion unit that converts the input power into power,
The power supply apparatus according to claim 1, wherein the electrolytic capacitor is a voltage smoothing electrolytic capacitor provided in the power conversion unit. Storage means for storing a subtraction time data table;
The subtraction time for the temperature and the load factor is stored in the subtraction time data table,
3. The power supply device according to claim 1, wherein the life calculation unit calculates the remaining life time by subtracting the subtraction time from a predetermined life time corresponding to the electrolytic capacitor. . The subtraction time stored in the subtraction time data table is set to be a constant value in a region below a predetermined temperature and below a predetermined load factor. The power supply device according to claim 1. It is a life warning method for the electrolytic capacitor of the power supply device having a power conversion unit for converting the input power having an electrolytic capacitor for voltage smoothing,
A subtraction time data table storing subtraction times for temperature and load factor is stored in the storage means;
Measure the temperature of the electrolytic capacitor or the ambient temperature of the electrolytic capacitor and calculate the load factor of the power supply device,
From the measured temperature and the calculated load factor, find the subtraction time based on the subtraction time data table,
By calculating the remaining life time by subtracting the subtraction time from the predetermined life time corresponding to the electrolytic capacitor,
An electrolytic capacitor life warning method, characterized in that a life warning is notified when the calculated remaining life time reaches a warning time. The subtraction time stored in the subtraction time data table is set to be a constant value in a region below a predetermined temperature and below a predetermined load factor so that the life of the electrolytic capacitor does not exceed a predetermined time. The electrolytic capacitor life warning method according to claim 5, wherein:

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