JPH0583168B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] This invention is applied as a final treatment for commercialization of electrolytic capacitors to repair the oxidizable oxide film on the anode side electrode and to stabilize and equalize the characteristics. This article relates to an aging method for electrolytic capacitors.

[Conventional technology]

Generally, an electrolytic capacitor consists of an anode that has a dielectric oxide film on its surface and a cathode that does not have a dielectric oxide film, which are placed facing each other with a separator interposed between the two electrodes, and are impregnated with electrolyte and sealed in an exterior case. This is what I did. Etched aluminum foil or the like is used for both the anode and the cathode, and a dielectric oxide film is formed on the surface of the anode by chemical conversion treatment. The internal leads of the anode and cathode are connected by stitching or the like, and after being cut to a predetermined length, they are wound together with the cathode with separator paper in between to form a cylindrical electrolytic capacitor element.
After being impregnated with electrolyte, it is enclosed in an outer case.

Anodes that have undergone such mechanical processing are subjected to mechanical processing and mechanical stress due to internal lead connections, cutting, and winding, resulting in exposure of the base metal or damage to the dielectric oxide film. It is. If an anode with such defects is left to its own self-healing action, which is a characteristic feature of electrolytic capacitors, it will not be possible to stabilize and equalize its characteristics. An aging treatment, which is a reformulation treatment, is performed to repair the dielectric oxide film and stabilize the characteristics.

[Problem to be solved by the invention]

Conventionally, aging processing uses a resistor and constant current element as a current control element to set the aging voltage and aging current corresponding to the electrolytic capacitor's rating (low voltage, medium voltage, and high voltage), the type of electrolyte, the capacity, etc. , by the connected voltage and current. In other words, since electrolytic capacitors before aging have variations in characteristics, it is desirable to add aging inputs that correspond to these variations to individual electrolytic capacitors. is very difficult to change. Furthermore, if the aging input is increased in order to speed up the aging time, the electrolytic capacitor may generate heat due to variations in characteristics and internal pressure may increase due to rapid chemical changes, which may lead to breakdown.
Therefore, on the production line, we standardized the current control means for multiple electrolytic capacitors, and
In order to improve the safety of aging, the aging process starts with a low current and adjusts the voltage and current depending on the time, so the aging process tends to take a long time.

Conventionally, as an aging method that shortens the aging treatment time, there is Japanese Patent Publication No. 62-56648 ``Method for Aging Electrolytic Capacitors''. This aging method is unique in that aging treatment is performed intermittently and discharge treatment is performed, but the aging treatment itself uses continuous voltage and current, so it still has the disadvantage that the aging treatment time is long. be.

Therefore, this invention aims to optimize aging by controlling electrical factors of the aging input to electrolytic capacitors, thereby shortening aging time and improving reconstitution characteristics such as product uniformity and stability. The purpose is to provide an aging method for

[Means to solve the problem]

As illustrated in FIGS. 1 and 2, the method for aging an electrolytic capacitor of the present invention is to apply a pulse voltage of the same frequency to the electrolytic capacitor after it has been sealed, which alternately repeats the same high level section and low level section. Alternatively, the aging process is performed by continuously supplying pulsed current.

[Effect]

In this electrolytic capacitor aging method, a pulse voltage or pulse current of the same frequency is continuously supplied to the electrolytic capacitor after it is sealed, with the same high level section and low level section repeating alternately as aging input. . Therefore, an aging current that corresponds to the voltage or current level flows through the electrolytic capacitor in a periodic or intermittent manner depending on the form of the pulse. Since the lower limit level of the aging input is set to zero or a value far lower than the upper limit level, the upper limit level is the aging operation period, and the lower limit level is the rest period.In other words, the electrolytic capacitor generates heat during the operation period. , cooling is performed in the rest section. That is, as a result of alternately repeating heat generation and cooling to perform a chemical conversion reaction, an optimal aging operation is performed without abnormal heat generation or thermal accumulation. It is clear from the experimental results described below that this processing result is appropriate.

In the method for aging an electrolytic capacitor of the present invention, if the aging input is a rectangular-wave pulse voltage or pulse current with an arbitrary pulse width or duty, the aging charge applied to the electrolytic capacitor can be reduced by controlling the pulse width. Any aging characteristics can be obtained by freely changing the aging characteristics, and aging processing can be performed efficiently and with good characteristics.

〔Example〕

FIG. 1 shows an embodiment of an aging device used in the method of aging an electrolytic capacitor of the present invention.

The power supply device 2 is an aging power supply that generates an intermittent aging output with periodicity such as voltage, current, frequency, duty ratio, etc., and can arbitrarily control the electrical factors of the aging process of the electrolytic capacitor, for example. , consists of a pulse power supply.

This power supply device 2 is provided with a plurality of pairs of connection terminals 4a and 4b via a diode 3 to prevent backflow, and each connection terminal 4a and 4b is subjected to aging treatment as a final treatment after manufacturing. Electrolytic capacitors of the same rating 6 ₁ , 6 ₂ ...6
_N is connected to each electrolytic capacitor 6 ₁ to 6 _N ,
An aging input is applied from the power supply device 2.

FIG. 2 shows a case where a pulse voltage of the same frequency is used as an intermittent aging input having periodicity, which alternately repeats a high level section and a low level section set at the same time.

This pulse voltage has a specific repetition frequency f, an upper limit voltage V _H (>0) as the upper limit level of the aging input at time T ₁ , and a lower limit voltage V _L = 0 as the lower limit level of the aging input at time T ₂ . , the duty ratio r is T ₁ /(T ₁ +T ₂ ). When the aging process is performed using such a pulse voltage, each of the electrolytic capacitors 6 ₁ to 6 _N is energized at time T ₁ and cut off at time T ₂ , thereby generating heat at time T ₁ and cooling at time T ₂ alternately. The repetition depends on the frequency f and the heating time depends on the duty ratio.

Electrical factors such as the frequency f, voltages V _H , V _L and duty ratio r are set based on the rated values of the electrolytic capacitors 6 ₁ to 6 _N.

For example, the frequency f is as shown in FIG.
The period of the upper limit voltage V _H is 2T ₁ and the period of the lower limit voltage V _L is 2
If T ₂ is set, the frequency becomes 1/2 (f/2) of the frequency f of the pulse voltage shown in FIG.

In this way, the pulse current connected by the pulse voltage flows to the electrolytic capacitors 6 ₁ to 6 _N ,
Since heat generation and cooling are performed alternately and at optimal time intervals, the start-up time of re-formation can be shortened. When using a continuous DC voltage, continuous heat generation occurs, so conventionally it was necessary to suppress the initial aging current and voltage and then increase the voltage and current in stages, resulting in a decrease in aging efficiency. Although the aging time has become longer, since the aging input is intermittent and periodic, even if the final aging voltage is applied from the initial stage, there will be no abnormal leakage current, heat generation, or thermal accumulation, and the aging process will continue. Efficiency has been increased and it has become possible to perform aging treatment in a short time.

This type of aging process using pulse voltage is performed by effectively varying the current, and the maximum current that contributes to aging is larger than the effective current, and is also characterized by the ability to debug defective products. It is true. In other words, the individual characteristics of the electrolytic capacitors 6 ₁ to 6 _N that undergo aging treatment are uneven, and in extreme cases, some of them are close to defective, so if a sudden large current is applied, the defects will be removed. A concentrated current flows through the electrolytic capacitor of the product, and this current leads to the destruction of the electrolytic capacitor, which may result in insufficient aging treatment of otherwise normal electrolytic capacitors. The use of intermittent aging inputs with periodicity provides greater safety.

Since the aging process depends on the amount of charge to be supplied, shortening the aging time depends on how quickly the amount of charge can be supplied. Therefore,
In such aging processing using a pulse voltage, considering factors on the electrolytic capacitor side such as the capacitance and rating of the electrolytic capacitor, the lower limit voltage V _L of the pulse voltage is set to an initial value of 0, as shown in Fig. 4.
As time passes, _the bias voltage V _B {= _{V 1} , V ₂ ,
V ₃ ... (V ₁ < V ₂ < V ₃ ...)} at time t ₂ ,
At t ₄ , t ₆ , and so on, the values are gradually increased from the initial value 0 to V ₁ , V ₂ , V ₃ , and so on.

One way to change the bias voltage V _B is to change it stepwise at each single pulse interval as shown in Figure 4, but it is also possible to change the bias voltage V B step by step at each single pulse interval, but it is also possible to change the bias voltage V B step by step at each single pulse interval, but it is , it may be a constant voltage or a stepwise or continuously increasing voltage. Further, the bias voltage V _B may be a constant bias current.

_In the above embodiment, the pulse voltage was used as the aging input, but for example, as shown in _FIG . Aging treatment may also be performed. With this pulsed current, the upper limit current I _H at time T ₁ and the lower limit current I _L at time T ₂
(=0), and the duty ratio r is set in the same manner as in the previous embodiment. If we use a pulsed current with a constant current value that does not depend on voltage,
Electrolytic capacitor 6 ₁ - 6 _N heat generation can be suppressed, speed of start-up can be achieved, and electrolytic capacitors for low voltage, medium voltage, and high voltage can be efficiently aged without voltage conversion. I can do it.

〔Experimental result〕

For an electrolytic capacitor with a rated voltage of 400 V and a capacitance of 47 μF, a pulse voltage with a frequency of 1 kHz, a duty ratio of 1/2, and an upper limit voltage V _H set to 425 V is used for the aging input, and a continuous voltage of 425 V is used. Figure 6 shows the aging results when
In FIG. 6, X indicates the electrolytic capacitor terminal voltage due to a pulse voltage, Y indicates the electrolytic capacitor terminal voltage due to a continuous voltage, and Z indicates the temperature of the electrolytic capacitor element corresponding to X.

As is clear from this result, when a pulse voltage is used as an intermittent aging input with periodicity, the terminal voltage rises faster than when a continuous voltage is used, and the aging processing time is reduced to about 1/4. It can be seen that it is shortened.

〔Effect of the invention〕

As explained above, according to the present invention, since the aging process of the electrolytic capacitor is performed by continuously supplying pulse voltage or pulse current of the same frequency that alternately repeats the same high level section and low level section, The aging process is performed by alternately repeating heat generation and cooling, and the aging process is optimized by electrical factors such as frequency, voltage, and current, and the efficient aging process achieves uniformity and stability. You can obtain products with enhanced properties.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of an aging device used in the aging method for electrolytic capacitors of the present invention, FIGS. 2 to 5 are diagrams showing control of electrical factors in the aging process, and FIG. FIG. 3 is a diagram showing aging characteristics according to a conventional aging method. 2... Power supply device, 6 ₁ to 6 _N ... Electrolytic capacitor.

Claims (1)

[Claims] 1. Aging treatment is performed by continuously supplying a pulse voltage or pulse current of the same frequency that alternately repeats the same high level section and low level section to the electrolytic capacitor after sealing. Characteristic aging method for electrolytic capacitors. 2. The method for aging an electrolytic capacitor according to claim 1, wherein the pulse voltage or the pulse current gradually increases the lower limit level of the low level section over time for each section.