Improved aluminum electrolytic capacitor

Abstract

The utility model relates to an improved aluminum electrolytic capacitor which comprises an aluminum shell, a core bag arranged in the aluminum shell and a cover plate sealed with an opening of the aluminum shell, and the core bag comprises an anode aluminum foil with a winding structure, a cathode aluminum foil with a winding structure and electrolytic paper for isolating the anode aluminum foil from the cathode aluminum foil. The positive electrode aluminum foil and the negative electrode aluminum foil are provided with a positive electrode chaff and a negative electrode chaff respectively, a positive terminal and a negative terminal are riveted to the cover plate, the two ends of the positive electrode chaff are connected with the positive terminal and the positive electrode aluminum foil respectively, the two ends of the negative electrode chaff are connected with the negative terminal and the negative electrode aluminum foil respectively, and the lower portion of the negative electrode aluminum foil is exposed out of the bottom of the core package. And the lower part of the cathode aluminum foil abuts against the aluminum shell. The width of the cathode foil is larger than that of the electrolytic paper, the cathode foil is exposed out of the bottom of the core package, and the cathode foil is in contact with the aluminum shell, so that the heat dissipation performance of the electrolytic capacitor is improved, the central temperature rise of the aluminum electrolytic capacitor can be reduced by about 25%, and the ripple current resistance is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of electrolytic capacitors, in particular to an improved aluminum electrolytic capacitor. Background Art

[0002] With the widespread adoption and advancement of power and electronics technology, demand for specialty capacitors such as high-frequency pulse capacitors, DC high-voltage capacitors, and high-voltage shunt capacitors is increasing. Their applications primarily include the following: High-voltage shunt capacitors: These capacitors are designed specifically for high-voltage switchgear used in transmission and alternating current lines, with the goal of improving line performance. High-frequency pulse capacitors: These capacitors generate high pulse currents using stored energy. They are primarily used in performance testing equipment such as electromagnetic accelerators and pulsed laser power supplies. High-voltage DC capacitors: These capacitors are primarily used as filter capacitors in high-voltage, high-capacity, voltage-commutation power supplies. To enhance the performance of electrolytic capacitors, it is necessary to improve their heat dissipation capabilities and heat resistance, promote the integrated development of electronic products (modules and complete devices), and effectively meet the needs of the digital economy. Therefore, improving the heat resistance of capacitors is a key technology in the development of electrolytic capacitors. Electrolytic capacitors with relatively small capacitance and high ESR values ​​tend to operate at high temperatures and cannot withstand high ripple currents. Utility Model Content

[0003] The purpose of the utility model is to provide an electrolytic capacitor with good heat dissipation performance, high temperature resistance and high reliability. The capacitor can withstand high temperatures and large ripple currents.

[0004] The purpose of this utility model is achieved in this way:

[0005] An improved aluminum electrolytic capacitor comprises an aluminum shell, a core package disposed within the aluminum shell, and a cover plate sealed with an opening of the aluminum shell. The core package comprises a wound positive aluminum foil, a negative aluminum foil, and electrolytic paper separating the positive and negative aluminum foils. The positive and negative aluminum foils are provided with positive and negative electrode conductive strips, respectively. A positive terminal and a negative terminal are riveted to the cover plate. The ends of the positive electrode conductive strip are connected to the positive terminal and the positive aluminum foil, respectively. The ends of the negative electrode conductive strip are connected to the negative terminal and the negative aluminum foil, respectively. The lower portion of the negative aluminum foil is exposed outside the bottom of the core package, and the lower portion of the negative aluminum foil abuts against the aluminum shell. The negative foil of the utility model is wider than the electrolytic paper, and the negative foil is exposed outside the bottom of the core package, and the negative foil contacts the aluminum shell, thereby improving the heat dissipation performance of the electrolytic capacitor and reducing the center temperature rise of the aluminum electrolytic capacitor by approximately 25%, thereby improving the ripple current resistance capability.

[0006] The present invention can also be further improved as follows.

[0007] The width of the negative electrode aluminum foil is greater than that of the electrolytic paper.

[0008] The width of the positive electrode aluminum foil is the same as that of the electrolytic paper.

[0009] The width of the negative electrode aluminum foil is 2mm-4mm wider than that of the electrolytic paper.

[0010] The width of the negative electrode aluminum foil is 3mm wider than that of the electrolytic paper.

[0011] The beneficial effects of the utility model are as follows:

[0012] The negative electrode foil of the utility model is wider than the electrolytic paper. The negative electrode foil is exposed at the bottom of the core package and contacts the aluminum shell, thereby improving the heat dissipation performance of the electrolytic capacitor and reducing the center temperature rise of the aluminum electrolytic capacitor by about 25%, thereby improving the ripple current resistance capability. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a structural schematic diagram of the improved aluminum electrolytic capacitor of the utility model.

[0014] Figure 2 It is a front view of the improved aluminum electrolytic capacitor of the utility model.

[0015] Figure 3 It is a structural schematic diagram of the core package of the present utility model. DETAILED DESCRIPTION

[0016] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0017] Example 1, as Figures 1 to 3 As shown, an improved aluminum electrolytic capacitor includes an aluminum shell 1, a core package 7 arranged inside the aluminum shell 1, and a cover plate 8 sealed with an opening of the aluminum shell 1, the core package 7 includes a positive aluminum foil 2 and a negative aluminum foil 3 with a wound structure, and an electrolytic paper 4 separating the positive aluminum foil 2 and the negative aluminum foil 3, a positive electrode conductive strip 9 and a negative electrode conductive strip 10 are respectively provided on the positive aluminum foil 2 and the negative electrode aluminum foil 3, a positive terminal 5 and a negative terminal 6 are riveted on the cover plate 8, two ends of the positive electrode conductive strip 9 are respectively connected to the positive terminal 5 and the positive aluminum foil 2, and two ends of the negative electrode conductive strip 10 are respectively connected to the negative terminal 6 and the negative aluminum foil 3, and the capacitor is characterized in that the lower part of the negative electrode aluminum foil 3 is exposed from the bottom of the core package 7, and the lower part of the negative electrode aluminum foil 3 is against the aluminum shell 1.

[0018] As a more specific technical solution of the utility model.

[0019] The width of the negative electrode aluminum foil 3 is greater than the width of the electrolytic paper 4 .

[0020] The width of the positive electrode aluminum foil 2 is the same as the width of the electrolytic paper 4 .

[0021] The width of the negative electrode aluminum foil 3 is 2 mm to 4 mm greater than that of the electrolytic paper 4 .

[0022] The width of the negative electrode aluminum foil 3 is 3 mm greater than the width of the electrolytic paper 4 .

[0023] The utility model improves the ripple current resistance capability of the aluminum electrolytic capacitor by improving the heat dissipation capability of the aluminum electrolytic capacitor.

[0024] When testing this new aluminum electrolytic capacitor, workers inserted a temperature-sensing wire from the bottom of the test sample into the center of the core package. The sample was sealed with AB glue and placed in a constant temperature chamber set to 105°C. A ripple current meter was used to provide the capacitor's rated voltage and ripple current. The core package's center temperature was measured every hour. Two groups of samples, one each of non-leaking negative foil and leaking negative foil, were tested four times. As shown in the table below, the experimental tests concluded that, under the same conditions, the center temperature rise of the leaking negative foil product can be reduced by approximately 25%.

[0025] time Leak-free negative foil products (℃) Leak-free negative foil products (℃) Leakage negative foil products (℃) Leakage negative foil products (℃) 0h 105.3 105.2 105.2 105.3 1h 110.6 110.8 109.5 109.6 2h 111.2 111.4 108.6 108.7 3h 109.6 109.8 108.4 108.5 4h 109.3 109.4 108.3 108.4

[0026] Calculate the center temperature using formula (1): T'=Ta+△t(I'² / I²) (1)

[0027] In formula (1), T' is the core center temperature; Ta is the ambient temperature; I' is the applied ripple current; I is the rated ripple current of 120Hz at 105℃; △t is the allowable temperature rise.

[0028] The center temperature of the non-leaking negative foil product: T1'=Ta1+△t1(I1'² / I1²) (2)

[0029] The center temperature of the negative foil product: T2'=Ta2+△t2(I2'² / I2²) (3)

[0030] Under the same conditions, the same ambient temperature, the same rated ripple current, the test allows the temperature rise △t1 and △t2. When I1'²=I2'², the temperature rise △t2 is reduced by about 25%.

Claims

1. An improved aluminum electrolytic capacitor, comprising an aluminum shell (1), a core package (7) disposed inside the aluminum shell (1), and a cover plate (8) sealed with an opening of the aluminum shell (1), characterized in that: The core package (7) comprises a positive aluminum foil (2) and a negative aluminum foil (3) in a wound structure, and electrolytic paper (4) for isolating the positive aluminum foil (2) and the negative aluminum foil (3). A positive electrode conductive strip (9) and a negative electrode conductive strip (10) are respectively provided on the positive aluminum foil (2) and the negative electrode foil (3). A positive terminal (5) and a negative terminal (6) are riveted on the cover plate (8). The two ends of the positive electrode conductive strip (9) are respectively connected to the positive terminal (5) and the positive aluminum foil (2), and the two ends of the negative electrode conductive strip (10) are respectively connected to the negative terminal (6) and the negative aluminum foil (3). The core package (7) is characterized in that the lower part of the negative aluminum foil (3) is exposed outside the bottom of the core package (7), and the lower part of the negative aluminum foil (3) is against the aluminum shell (1).

2. The improved aluminum electrolytic capacitor according to claim 1, characterized in that: The width of the positive electrode aluminum foil (2) is the same as the width of the electrolytic paper (4).

3. The improved aluminum electrolytic capacitor according to claim 1, characterized in that: The width of the negative electrode aluminum foil (3) is greater than the width of the electrolytic paper (4).

4. The improved aluminum electrolytic capacitor according to claim 3, characterized in that: The width of the negative electrode aluminum foil (3) is 2 mm to 4 mm greater than the width of the electrolytic paper (4).

5. The improved aluminum electrolytic capacitor according to claim 4, characterized in that: The width of the negative electrode aluminum foil (3) is 3 mm greater than the width of the electrolytic paper (4).

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