Pulse aging method for high-voltage aluminum electrolytic capacitors, and pulse aging system

Abstract

The present application relates to the technical field of aluminum electrolytic capacitor, in particular to a pulse aging method and a pulse aging system for high-voltage aluminum electrolytic capacitor; the pulse aging is a multiple pulse boosting-discharging cycle process; the cycle process of one pulse boosting-discharging is: first, pulse boosting and charging at the same time with a charging voltage and a charging current, maintaining a high-voltage charging state after charging; then, pulse discharging and boosting at the same time with a discharging voltage and a discharging current, maintaining a low-voltage discharging state after discharging; by setting the pulse charging-discharging voltage, current density, cycle number and other parameters, the rejection rate of latent defect capacitors can be significantly improved, and the leakage current of the capacitor can be additionally reduced by at least 25%; the present application provides a quantifiable process scheme for efficient and high-reliability aging screening of high-voltage aluminum electrolytic capacitors.

Description

Technical Field

[0001] This invention relates to the field of aluminum electrolytic capacitor technology, specifically to a pulse aging method and system for high-voltage aluminum electrolytic capacitors. Background Technology

[0002] During the production of aluminum electrolytic capacitors, the anodic oxide film can be damaged by processes such as cutting, winding, and riveting, which is the main cause of leakage current. Repairing the oxide film and reducing leakage current through aging processes is a key step in ensuring product reliability. For high-voltage capacitors, the traditional aging process involves gradually increasing the voltage of the capacitor under high-temperature conditions, ensuring that the leakage current is reduced to a certain threshold at each voltage level before proceeding to the next aging step. This aging method takes 5-6 hours, posing a significant challenge to production efficiency. Especially for capacitors with high CV values ​​and high core duty cycles (core volume / capacitor aluminum shell internal volume), the leakage current (Lc) after aging is relatively large and has high dispersion, requiring secondary or multiple aging processes to ensure aging quality.

[0003] To overcome the shortcomings of traditional aging methods, such as low efficiency and high leakage current, pulse voltage aging technology has been proposed. CN2155061Y discloses a pulse voltage aging device for aluminum electrolytic capacitors, which uses rectangular wave pulses to charge and discharge the capacitors, and points out that pulse aging can shorten the time and reduce leakage current. Subsequently, many improved solutions have emerged, such as the aluminum electrolytic capacitor aging method disclosed in CN115274303A, which uses two aging stages and performs charging and discharging at a pulse frequency in a high-temperature environment; CN116631777B proposes an aging method that uses a high-frequency power supply, asymmetrical voltage waveform, and independent control for each channel, and its leakage current after aging is reduced by 30% compared with the traditional method.

[0004] However, the aforementioned existing technologies mainly focus on the circuit structure, multi-stage process, or waveform morphology of pulse aging, without systematically studying and clearly defining key process parameters during pulse charging and discharging, including charging voltage amplitude (a multiple of the rated voltage), charging current density, depth of discharge (residual voltage value), charging and discharging time, and number of cycles. Those skilled in the art only know that pulse aging is effective, but lack quantifiable parameter guidance, leading to significant differences and instability in aging effects in practical applications, making it difficult to simultaneously achieve the dual goals of efficiently eliminating hidden defective capacitors and significantly reducing leakage current. Summary of the Invention

[0005] Firstly, addressing the technical problems of low efficiency, inability to completely and effectively eliminate defective capacitors in traditional aging methods for high-voltage aluminum electrolytic capacitors, a certain probability of defective capacitors escaping, and high leakage current and poor consistency in traditional aging methods, this invention provides a pulse aging method for high-voltage aluminum electrolytic capacitors. After conventional aging of the capacitors, this invention further eliminates defective capacitors by applying deep pulse high-current charging and discharging. Appropriately increasing the discharge current density and the number of pulses can effectively reduce the average leakage current and improve the consistency of leakage current, resulting in a reduction of at least 25% in the average leakage current and within-group variance.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solution:

[0007] A pulse aging method for high-voltage aluminum electrolytic capacitors involves pulse aging of high-voltage aluminum electrolytic capacitors at the end of the conventional aging process.

[0008] The pulse aging process is a cyclical process involving multiple pulse boost-discharge cycles.

[0009] One cycle of pulse boost-discharge processing is as follows: first, with a charging voltage U c and charging current I c A high-voltage aluminum electrolytic capacitor is pulse-charged while simultaneously being pulse-boosted, and then maintained in a high-voltage charging state for a time t after reaching the set voltage. ch Then, with discharge voltage U d and discharge current I d During pulsed discharge, the voltage is simultaneously reduced, and after the discharge reaches the set voltage, the low-voltage discharge state is maintained for a time t. dh ;

[0010] The parameters for the pulse boost-pulse charge stage are as follows:

[0011] The rated voltage of the high-voltage aluminum electrolytic capacitor is U. r U c It's U r 1.05 to 1.1 times;

[0012] Based on the specifications of the high-voltage aluminum electrolytic capacitor, with a capacitance value of 100μF as the benchmark, I c The range is from 1 amp to 10 amps;

[0013] t ch The duration is 0.5 to 5 seconds;

[0014] The parameters for the pulse discharge-pulse voltage reduction stage are as follows:

[0015] U d <50 volts;

[0016] According to the specification of the high-voltage aluminum electrolytic capacitor, based on every 100μF capacitance value, I d is 0.1 A to 1 A;

[0017] t dh is 0.5 s to 3 s.

[0018] Further, the number of cycles of the pulse boosting-discharging treatment is 10 to 50 times.

[0019] Further, the rated voltage U of the high-voltage aluminum electrolytic capacitor r is at least 350 V.

[0020] Further, the total time of the pulse aging is less than 10 minutes.

[0021] Further, the volume proportion of the core package in the high-voltage aluminum electrolytic capacitor is greater than 90%.

[0022] In a second aspect, directed to the above pulse aging method for high-voltage aluminum electrolytic capacitors, the present invention further provides a pulse aging system matched with the pulse aging method. While the system of the present invention achieves the above pulse aging effect, it recovers energy aiming at the problem that the discharge energy is directly dissipated in the form of heat energy in the pulse aging process in the prior art, which causes electric energy waste, and can achieve a capacitance discharge energy recovery rate of more than 85%.

[0023] The pulse aging system of the present invention comprises: a main power supply, a capacitor placement area, a high-voltage capacitor bank, a low-voltage capacitor bank, a DC-DC converter, a first switch, and a second switch;

[0024] The capacitor placement area is configured to place a plurality of high-voltage aluminum electrolytic capacitors to be subjected to pulse aging treatment, and the plurality of high-voltage aluminum electrolytic capacitors are connected in parallel; the high-voltage capacitor bank, the low-voltage capacitor bank and the plurality of high-voltage aluminum electrolytic capacitors to be treated are connected in parallel; the DC-DC converter is arranged between the high-voltage capacitor bank and the low-voltage capacitor bank and forms an electrical connection;

[0025] The high-voltage capacitor bank is configured to perform pulse boosting on the plurality of high-voltage aluminum electrolytic capacitors to be treated; the boosted high-voltage aluminum electrolytic capacitors discharge to the low-voltage capacitor bank;

[0026] The DC-DC converter is configured to charge and replenish energy for the high-voltage capacitor bank after recovering energy from the low-voltage capacitor bank;

[0027] The first switch is arranged between the connecting circuit of the high-voltage capacitor bank and the capacitor placement area;

[0028] The second switch is arranged between the connecting circuit of the low-voltage capacitor bank and the capacitor placement area;

[0029] When the first switch is on, the second switch is off, and vice versa.

[0030] Furthermore, the main power supply first charges the high-voltage capacitor bank to its rated voltage;

[0031] Then, the first switch is closed, and the high-voltage capacitor bank pulses and charges the multiple conventionally aged and discharged high-voltage aluminum electrolytic capacitors in the capacitor placement area with charging voltage and charging current, so that the high-voltage aluminum electrolytic capacitors reach the charging voltage and maintain a high-voltage charging state. The first switch is then opened and the second switch is closed. The multiple high-voltage aluminum electrolytic capacitors pulse discharge and pulse voltage drop according to the set discharge voltage and discharge current. After discharging to the set voltage, they maintain a low-voltage discharge state, so that the electricity in the multiple high-voltage aluminum electrolytic capacitors is released into the low-voltage capacitor bank.

[0032] Finally, the low-voltage capacitor bank boosts the stored electrical energy to the rated voltage of the high-voltage capacitor bank through the DC-DC converter, and then recharges the high-voltage capacitor bank for recharging and energy replenishment, undergoing multiple pulse aging cycle treatments.

[0033] Furthermore, the rated voltage of the high-voltage aluminum electrolytic capacitor is U. r The charging voltage is U c The charging current is I c The time for maintaining the high-voltage charging state is t. ch The discharge voltage is U d The discharge current is I d The time for maintaining the low-voltage discharge state is t. dh The parameters are set as follows:

[0034] U c It's U r 1.05 to 1.1 times; based on the capacitance value per 100μF of the high-voltage aluminum electrolytic capacitor, I c From 1 amp to 10 amps; t ch The duration is 0.5 to 5 seconds;

[0035] U d <50V; based on the capacitance value per 100μF of the high-voltage aluminum electrolytic capacitor as specified above, I d The range is from 0.1 amps to 1 amp; t dh The duration is between 0.5 and 3 seconds.

[0036] Furthermore, the rated voltage of the high-voltage capacitor bank is U. B U B ≥1.3Uc ;

[0037] The capacitance of the high-voltage capacitor bank is at least 20 times the capacitance of the high-voltage aluminum electrolytic capacitor;

[0038] The rated voltage of the low-voltage capacitor bank is 55 volts to 85 volts;

[0039] The capacitance of the low-voltage capacitor bank is at least 100 times that of the high-voltage aluminum electrolytic capacitor.

[0040] Furthermore, the pulse aging system performs multiple pulse aging cycles on the high-voltage aluminum electrolytic capacitor, with the number of cycles ranging from 10 to 50.

[0041] The working process of the pulse aging system of this invention is as follows: First, the main power supply charges the high-voltage capacitor bank to its rated voltage U. B (satisfy U) B ≥1.3U C (The capacity of the high-voltage capacitor bank is at least 20 times that of the high-voltage aluminum electrolytic capacitors); then, the first switch is closed, and the high-voltage capacitor bank pulses the voltage of the multiple high-voltage aluminum electrolytic capacitors that have been discharged after normal aging until they reach the charging voltage U. c (1.05-1.1 times U r After the voltage boost is complete, the first switch is disconnected and the second switch is closed, allowing multiple high-voltage aluminum electrolytic capacitors to discharge into the low-voltage capacitor bank until the voltage drops to U. d <50V; the rated voltage of the low-voltage capacitor bank is slightly higher than 50V (e.g., 63V or 80V), and the capacity of the low-voltage capacitor bank is at least 100 times that of the high-voltage aluminum electrolytic capacitor, serving as an intermediate energy buffer; finally, the low-voltage capacitor bank uses a DC-DC converter to boost the stored electrical energy to U B The energy is then recharged to the high-voltage capacitor bank and used again for pulse boosting of the capacitors, thus performing a pulse aging cycle. This process simultaneously achieves pulse aging and energy recovery.

[0042] Beneficial technical effects:

[0043] This invention, through extensive experimentation, has found that parameters such as voltage, current, time, and number of cycles in pulse charging and discharging have a decisive impact on the aging screening effect; when the charging voltage U C Controlled at rated voltage U r The charging current I is set to 1.05-1.1 times the capacitance value, based on a capacitance value of 100μF. cWhen the discharge rate is 1-10A, the depth of discharge is below 50V, and the charge-discharge duration and total number of cycles for a single pulse cycle are within the specific range required above, the rejection rate of latent defect capacitors can be significantly improved, while the leakage current of high-voltage aluminum electrolytic capacitors is reduced by at least 25%; the parameters of this invention break through the limitation of existing technologies that only qualitatively describe pulse aging, and provide a quantifiable process solution for efficient and high-reliability aging screening of high-voltage aluminum electrolytic capacitors;

[0044] This invention achieves energy recovery through a pulse aging system, allowing the electrical energy that was wasted as heat during the discharge phase to be recycled, reducing net energy consumption by approximately 50%-70% and significantly reducing carbon emissions in the production process. Simultaneously, the system directly matches the residual discharge voltage (<50V) of the low-voltage capacitor bank, eliminating the need for an additional step-down circuit, achieving an energy recovery efficiency of over 85%, without affecting the original pulse aging screening effect (average leakage current reduced by 30%, early failure rate approaching 0ppm). This invention organically integrates a highly efficient aging method with green energy-saving technology, meeting the dual requirements of low carbon emissions and high reliability in the manufacturing process of high-voltage aluminum electrolytic capacitors. Attached Figure Description

[0045] Figure 1 This is a schematic diagram of the pulse aging system of the present invention;

[0046] Among them, 1 is the main power supply, 2 is the capacitor placement area, 3 is the high-voltage capacitor bank, 4 is the low-voltage capacitor bank, 5 is the DC-DC converter, 6 is the first switch, and 7 is the second switch.

[0047] Figure 2 This is the working curve of the pulse aging method for high-voltage aluminum electrolytic capacitors of the present invention;

[0048] Figure 3 This is a comparison of the leakage current of Example 1 and Comparative Examples 1-2 after storage for a certain period of time;

[0049] Figure 4 This is a comparison of the leakage current of Example 2 and Comparative Examples 3-4 after storage for a certain period of time;

[0050] Figure 5 This is a comparison of the leakage current of Example 3 and Comparative Examples 5-7 after storage for a certain period of time. Detailed Implementation

[0051] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments and accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The following description of at least one exemplary embodiment is merely illustrative and is in no way intended to limit the present invention or its application or use. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0052] Unless otherwise specifically stated, the numerical values ​​set forth in these embodiments do not limit the scope of the invention. Techniques and methods known to those skilled in the art may not be discussed in detail, but where appropriate, such techniques and methods should be considered part of the specification. In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not as limitations. Therefore, other examples of exemplary embodiments may have different values. It should be noted that values ​​expressed, for example, as "within the range of ab" or "between the range of ab," do not include the endpoint values ​​a and b; values ​​expressed as "for ab," "is ab," or "ab" include the endpoint values ​​a and b.

[0053] Furthermore, it should be noted that the use of terms such as "first" and "second" to define the relevant switching components is merely for the purpose of distinguishing the components. Unless otherwise stated, the above terms have no special meaning and therefore should not be construed as limiting the scope of protection of this invention.

[0054] Experimental methods not specified in the following examples are generally performed according to national standards; if there is no corresponding national standard, they are performed according to general standard requirements or general methods.

[0055] The unit of voltage is volt or volt, abbreviated as V; the unit of current is ampere or ampere, abbreviated as A; the unit of capacitance of a capacitor is microfarad, abbreviated as μF; leakage current is abbreviated as Lc; capacitance value and capacitance are the same concept.

[0056] Example 1

[0057] The pulse aging method for high-voltage aluminum electrolytic capacitors, and the working curve of the pulse aging method are as follows: Figure 2 As shown, pulse aging was performed on high-voltage aluminum electrolytic capacitors (specifications: 450V 820μF 35×50, core-pack volume ratio 92%) at the end of the conventional aging stage;

[0058] The parameters for routine aging are shown in Table 1 below;

[0059] Table 1 Parameters of routine aging

[0060]

[0061] The pulse aging process described therein is a cyclical process of multiple pulse boost-discharge cycles.

[0062] One cycle of pulse boost-discharge processing is as follows: first, with a charging voltage U c and charging current I c For high-voltage aluminum electrolytic capacitor C x Simultaneously perform pulse boosting and pulse charging, and maintain the high-voltage charging state for a time t after reaching the required voltage. ch Then, with discharge voltage U d and discharge current I d During pulsed discharge, the voltage is simultaneously reduced, and after the discharge reaches the set voltage, the low-voltage discharge state is maintained for a time t. dh ;

[0063] The parameters for the pulse boost-pulse charge stage are as follows:

[0064] The rated voltage of the high-voltage aluminum electrolytic capacitor is U. r Charging voltage U c =495V;

[0065] The charging current I is set according to the specifications of the high-voltage aluminum electrolytic capacitor, based on a capacitance value of 100μF. c =3A;

[0066] The charging time t is used to maintain the high voltage charging state. ch =4 seconds;

[0067] The parameters for the pulse discharge-pulse voltage reduction stage are as follows:

[0068] Discharge voltage U d <50V;

[0069] The discharge current I is set according to the specifications of the high-voltage aluminum electrolytic capacitor, based on a capacitance value of 100μF. d =0.2A;

[0070] Discharge sustains low-voltage discharge state for time t dh =1 second;

[0071] Repeat the process 15 times.

[0072] Adopting such Figure 1 The pulse aging system shown implements the above pulse aging method. The system includes a main power supply 1, a capacitor placement area 2, and a high-voltage capacitor bank (C). BH 3. Low-voltage capacitor bank (in C) BL 4. DC-DC converter (represented as DC / DC) 5. First switch (represented as S1) 6. Second switch (represented as S2) 7.

[0073] The capacitor placement area 2 is used to place multiple high-voltage aluminum electrolytic capacitors (in C) that have been routinely aged and discharged and are awaiting pulse aging treatment. X (represented by) multiple C X For parallel connection; C BH C BL , and multiple C X The two are connected in parallel; the DC / DC converter is set at C. BH With C BL They form an electrical connection;

[0074] C BH Used for multiple C X Perform pulse boost; the boosted C X Discharge to C BL ;

[0075] DC / DC is used to control C BL After energy recovery, C BH To recharge and replenish energy;

[0076] S1 is set in C BH Between the connection circuit and the capacitor placement area;

[0077] S2 is set in C BL Between the connection circuit and the capacitor placement area;

[0078] During operation: First, the main power supply to C... BH Charge to its rated voltage U B (satisfy U) B ≥1.3U C C BH Capacity ≥ 20 times C X (capacity)

[0079] Then, close S1, C BH Multiple Cs that have been discharged after conventional aging X Perform pulse boosting, setting the charging current I based on a capacitance value of 100μF. c =3A until it reaches the charging voltage U c =495V and maintain high-voltage charging state for time t ch =4 seconds; after the voltage boost is complete, disconnect S1, close S2, C X To C BL Discharge is performed with the discharge current I set based on a capacitance value of 100μF. d =0.2A until the voltage drops to U d <50V and maintain low-voltage discharge state for time t dh =1 second; C BL The rated voltage is 63V, C BLCapacity ≥ 100 times C X The electrical capacity serves as an intermediate energy buffer.

[0080] Finally, C BL The stored electrical energy is boosted to U via a DC / DC converter. B Recharge to C BH The pulse boosting process for the capacitor is then repeated. This pulse aging cycle is repeated multiple times.

[0081] Comparative Example 1

[0082] The high-voltage aluminum electrolytic capacitor in this case underwent only one routine aging process, with a total aging time of 5.5 hours. The routine aging process was the same as in Example 1, without pulse aging.

[0083] Comparative Example 2

[0084] The high-voltage aluminum electrolytic capacitor in this case underwent only two conventional aging processes, each lasting 5.5 hours. The conventional aging process was the same as in Example 1, without pulse aging.

[0085] Example 2

[0086] A pulse aging method for high-voltage aluminum electrolytic capacitors involves pulse aging of high-voltage aluminum electrolytic capacitors (specifications: 450V 1050μF 35×50, core-pack volume ratio 95%) at the end of the conventional aging stage.

[0087] The parameters for routine aging are the same as those shown in Table 1;

[0088] The pulse aging process described therein is a cyclical process of multiple pulse boost-discharge cycles.

[0089] One cycle of pulse boost-discharge processing is as follows: first, with a charging voltage U c and charging current I c For high-voltage aluminum electrolytic capacitor C x Simultaneously perform pulse boosting and pulse charging, and maintain the high-voltage charging state for a time t after reaching the required voltage. ch Then, with discharge voltage U d and discharge current I d During pulsed discharge, the voltage is simultaneously reduced, and after the discharge reaches the set voltage, the low-voltage discharge state is maintained for a time t. dh ;

[0090] The parameters for the pulse boost-pulse charge stage are as follows:

[0091] The rated voltage of the high-voltage aluminum electrolytic capacitor is U. r Charging voltage U c =495V;

[0092] The charging current I is set according to the specifications of the high-voltage aluminum electrolytic capacitor, based on a capacitance value of 100μF. c =2A;

[0093] The charging time t is used to maintain the high voltage charging state. ch =5 seconds;

[0094] The parameters for the pulse discharge-pulse voltage reduction stage are as follows:

[0095] Discharge voltage U d <50V;

[0096] The discharge current I is set according to the specifications of the high-voltage aluminum electrolytic capacitor, based on a capacitance value of 100μF. d =0.3A;

[0097] Discharge sustains low-voltage discharge state for time t dh =2 seconds;

[0098] Repeat the process 20 times.

[0099] The above pulse aging method is implemented using the same pulse aging system as in Example 1. During operation:

[0100] First, the main power supply to C BH Charge to its rated voltage U B (satisfy U) B ≥1.3U C C BH Capacity ≥ 20 times C X (capacity)

[0101] Then, close S1, C BH For multiple high-voltage aluminum electrolytic capacitors C that have been discharged after normal aging X Perform pulse boosting, setting the charging current I based on a capacitance value of 100μF. c =2A until it reaches the charging voltage U c =495V and maintain high-voltage charging state for time t ch =5 seconds; after the voltage boost is complete, disconnect S1 and close S2, C X To C BL Discharge is performed with the discharge current I set based on a capacitance value of 100μF. d =0.3A until the voltage drops to U d <50V and maintain low-voltage discharge state for time t dh =2 seconds; C BL The rated voltage is 63V, C BL Capacity ≥ 100 times C X The electrical capacity serves as an intermediate energy buffer.

[0102] Finally, multiple CsBL After being connected in parallel, the stored electrical energy is boosted to U via a DC / DC converter. B Recharge to C BH This is then used again for pulse boosting of the capacitor. This pulse aging cycle is repeated multiple times.

[0103] Comparative Example 3

[0104] The high-voltage aluminum electrolytic capacitor in this case underwent only one routine aging process, with a total aging time of 5.5 hours. The routine aging process was the same as in Example 2, without pulse aging.

[0105] Comparative Example 4

[0106] The pulse aging method for high-voltage aluminum electrolytic capacitors in this case is the same as in Example 2, except that in the pulse boost-pulse charging stage parameters, the charging current I is set based on a capacitance value of 100μF. c =0.3A.

[0107] Example 3

[0108] A pulse aging method for high-voltage aluminum electrolytic capacitors is used to perform pulse aging on high-voltage aluminum electrolytic capacitors (specifications: 475V 2150μF 35×100, core-pack volume ratio 96%) at the end of the conventional aging stage.

[0109] The parameters for routine aging are shown in Table 2 below;

[0110] Table 2 Parameters of routine aging

[0111]

[0112] The pulse aging process described therein is a cyclical process of multiple pulse boost-discharge cycles.

[0113] One cycle of pulse boost-discharge processing is as follows: first, with a charging voltage U c and charging current I c For high-voltage aluminum electrolytic capacitor C x Simultaneously perform pulse boosting and pulse charging, and maintain the high-voltage charging state for a time t after reaching the required voltage. ch Then, with discharge voltage U d and discharge current I d During pulsed discharge, the voltage is simultaneously reduced, and after the discharge reaches the set voltage, the low-voltage discharge state is maintained for a time t. dh ;

[0114] The parameters for the pulse boost-pulse charge stage are as follows:

[0115] The rated voltage of the high-voltage aluminum electrolytic capacitor is U. r Charging voltage U c =510V;

[0116] The charging current I is set according to the specifications of the high-voltage aluminum electrolytic capacitor, based on a capacitance value of 100μF. c =2A;

[0117] The charging time t is used to maintain the high voltage charging state. ch =5 seconds;

[0118] The parameters for the pulse discharge-pulse voltage reduction stage are as follows:

[0119] Discharge voltage U d <50V;

[0120] The discharge current I is set according to the specifications of the high-voltage aluminum electrolytic capacitor, based on a capacitance value of 100μF. d =0.5A;

[0121] Discharge sustains low-voltage discharge state for time t dh =3 seconds;

[0122] Repeat the process 40 times.

[0123] The above pulse aging method is implemented using the same pulse aging system as in Example 1. During operation:

[0124] First, the main power supply to C BH Charge to its rated voltage U B (satisfy U) B ≥1.3U C C BH Capacity ≥ 20 times C X (capacity)

[0125] Then, close S1, C BH For multiple high-voltage aluminum electrolytic capacitors C that have been discharged after normal aging X Perform pulse boosting, setting the charging current I based on a capacitance value of 100μF. c =2A until it reaches the charging voltage U c =510V and maintain high-voltage charging state for time t ch =5 seconds; after the voltage boost is complete, disconnect S1 and close S2, C X To C BL Discharge is performed with the discharge current I set based on a capacitance value of 100μF. d =0.5A until the voltage drops to U d <50V and maintain low-voltage discharge state for time t dh =3 seconds; C BL The rated voltage is 80V, C BL Capacity ≥ 100 times C X The electrical capacity serves as an intermediate energy buffer.

[0126] Finally, multiple Cs BL After being connected in parallel, the stored electrical energy is boosted to U via a DC / DC converter. B Recharge to C BH This is then used again for pulse boosting of the capacitor. This pulse aging cycle is repeated multiple times.

[0127] Comparative Example 5

[0128] The high-voltage aluminum electrolytic capacitor in this case underwent only two conventional aging processes, each lasting 6 hours. The conventional aging process was the same as in Example 3, without pulse aging.

[0129] Comparative Example 6

[0130] The pulse aging method for high-voltage aluminum electrolytic capacitors in this case is the same as in Example 3, except that in the pulse boost-pulse charging stage parameters: the charging current I is set according to the specifications of the high-voltage aluminum electrolytic capacitor, based on a capacitance value of 100μF. c =0.6A.

[0131] Comparative Example 7

[0132] The pulse aging method for high-voltage aluminum electrolytic capacitors in this case is the same as in Example 3, except that in the pulse discharge-pulse voltage reduction stage parameters: the discharge current I is set according to the specifications of the high-voltage aluminum electrolytic capacitor, based on a capacitance value of 100μF. d =0.05A.

[0133] Test case

[0134] The parameters for each of the above cases are shown in Table 3. All high-voltage aluminum electrolytic capacitors in the above cases used the same batch of materials and manufacturing processes before aging, and the number of test capacitors in each case was ≥2000pcs.

[0135] The breakdown rate, leakage current, and leakage current variance (Lc variance) of the capacitors after aging were statistically analyzed, and the results are shown in Table 4.

[0136] Table 3 Parameters for Each Case

[0137]

[0138] Table 4. Test Results

[0139]

[0140] Analysis of Table 4 and its combination Figures 3 to 5 It can be known that:

[0141] Example 1 involved 15 pulse aging cycles (<5 min) following a standard aging process of 4.5 h. Compared to Comparative Example 1, which involved a standard aging process of 5.5 h, the mean Lc value of Example 1 decreased by 36%, and the within-group Lc variance σ decreased by 53%. After 6 months of storage at room temperature, the Lc growth rate of Example 1 was 103.6%, while that of Comparative Example 1 reached 208.1%. Compared to Comparative Example 2, which involved two standard aging processes of 5.5 h, the mean Lc value of Example 1 decreased by 9.8%, and the within-group Lc variance σ decreased by 36.6%. After 6 months of storage at room temperature, the Lc growth rate of Comparative Example 2 reached 150.8%. It is evident that pulse aging with a total duration of no more than 10 min following standard aging is still more effective than two long standard aging processes. Although multiple standard aging processes can reduce leakage current and within-group variance to some extent, standard aging significantly impacts production efficiency and increases production costs.

[0142] Example 2 involved 20 pulse aging cycles (<5 min) after a standard aging period of 4.5 h. Compared to Comparative Example 3, which involved a standard aging period of 5.5 h, the mean Lc value of Example 2 decreased by 46.2%, and the within-group Lc variance σ decreased by 51.8%. After 6 months of storage at room temperature, the Lc growth rate of Example 2 was 128.2%, while the Lc growth rate of Comparative Example 3 reached 189.7%. Comparative Example 4 used a charging current of 0.3 A / 100 μF (i.e., a charging current of 0.3 A based on a capacitance value of 100 μF). After the charging current density decreased compared to Example 2, both Lc and variance showed an upward trend. The mean Lc value of Comparative Example 4 was 32% higher than that of Example 2, and the within-group variance σ was 42.2% higher. After 6 months of storage at room temperature, the mean Lc value of Comparative Example 4 was 35.4% higher than that of Example 2, and the within-group variance σ was 65.6% higher. Therefore, although Comparative Example 4 underwent pulse aging, it did not meet the requirements due to the low current density during the pulse boost-pulse charge phase. Figure 2 Despite meeting the requirements, its aging effect still differs somewhat from that of Example 2.

[0143] Example 3 involved 40 pulse aging cycles (<10 min) after a standard 5-hour aging process. Compared to Comparative Example 5, which underwent a standard aging process every 6 hours, the mean Lc value of Example 3 decreased by 25.3%, and the within-group Lc variance σ decreased by 29.3%. After 6 months of storage at room temperature, the Lc growth rate of Example 3 was 117.6%, while the Lc growth rate of Comparative Example 5 reached 149.8%. Comparative Example 6 used a charging current of 0.6 A / 100 μF (i.e., a charging current of 0.6 A based on a 100 μF capacitance value). Despite a decrease in charging current density compared to Example 3, both Lc and variance showed an upward trend. The mean Lc value of Comparative Example 6 was 26.1% higher than that of Example 3, and the within-group variance σ was 41.4% higher. After 6 months of storage at room temperature, the mean Lc value of Comparative Example 6 was 35.6% higher than that of Example 2, and the within-group variance σ was 55.4% higher. Therefore, although Comparative Example 6 underwent pulse aging, the low current density during the pulse boost-pulse charging phase did not meet the requirements. Figure 2 The aging effect of Comparative Example 7 still differs from that of Example 3. The discharge current of Comparative Example 7 was 0.05A / 100μF (i.e., the discharge current was set at 0.05A based on a capacitance of 100μF). While the discharge current density was lower than that of Example 3, the increase in Lc was smaller. However, the variance σ, representing dispersion, was significantly higher. The mean Lc value of Comparative Example 7 was 18.8% higher than that of Example 3, and the variance σ was 68.8% higher. After 6 months of room temperature storage, the mean Lc value of Comparative Example 7 was 32.6% higher than that of Example 3, and the variance σ was 192% higher. This indicates that although Comparative Example 7 underwent pulse aging, the low discharge current density during the pulse discharge-pulse voltage reduction stage did not meet the requirements. Figure 2 The requirements are that its aging effect, especially the leakage current consistency, is poor.

[0144] Overall, the mean Lc value of the comparative examples after aging was higher than that of the examples, and the Lc variance dispersion was also higher. After 6 months of storage, the capacitors were subjected to routine aging again. Comparative Examples 1 and 3 showed sporadic failures (0.2‰-0.3‰), indicating that for compact designs with a core duty cycle >90%, there is sporadic defect escape through conventional single aging, which increases the risk of market application. Defect escape can be reduced by two or more routine aging cycles, but this greatly affects production efficiency. However, by performing pulse aging after routine aging according to the present invention, the breakdown failure rate of the capacitors after 6 months of storage was 0. The method of the present invention can significantly improve the rejection rate of high-voltage aluminum electrolytic capacitors with latent defects, and at the same time reduce the leakage current of high-voltage aluminum electrolytic capacitors by at least 25%. The method of the present invention provides a quantifiable process solution for efficient and high-reliability aging screening of high-voltage aluminum electrolytic capacitors.

[0145] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A pulse aging method for high-voltage aluminum electrolytic capacitors, characterized in that, Pulse aging was performed on high-voltage aluminum electrolytic capacitors at the end of the conventional aging stage. The pulse aging process is a cyclical process involving multiple pulse boost-discharge cycles. One cycle of pulse boost-discharge processing is as follows: First, the high-voltage aluminum electrolytic capacitor is pulse-charged with charging voltage and charging current, and then maintained in a high-voltage charging state after reaching the charging voltage. Then, pulse discharge is performed with discharge voltage and discharge current while pulse voltage is reduced, and after discharge to the voltage limit, a low-voltage discharge state is maintained. The rated voltage of the high-voltage aluminum electrolytic capacitor is U r The charging voltage is U c The charging current is I c The time for maintaining the high-voltage charging state is t. ch The discharge voltage is U d The discharge current is I d The time for maintaining the low-voltage discharge state is t. dh ; The parameters for the pulse boost-pulse charging stage are set as follows: U c It's U r 1.05 to 1.1 times; Based on the specifications of the high-voltage aluminum electrolytic capacitor, with a capacitance value of 100μF as the benchmark, I c The range is from 1 amp to 10 amps; t ch The duration is 0.5 to 5 seconds; The parameters for the pulse discharge-pulse voltage reduction stage are set as follows: U d <50 fall; Based on the specifications of the high-voltage aluminum electrolytic capacitor, with a capacitance value of 100μF as the benchmark, I d The range is from 0.1 amps to 1 amp. t dh The duration is between 0.5 and 3 seconds.

2. The pulse aging method for high-voltage aluminum electrolytic capacitors according to claim 1, characterized in that, The pulse boost-discharge cycle is repeated 10 to 50 times.

3. The pulse aging method for high-voltage aluminum electrolytic capacitors according to claim 1, characterized in that, The rated voltage of the high-voltage aluminum electrolytic capacitor is at least 350 volts.

4. The pulse aging method for high-voltage aluminum electrolytic capacitors according to claim 1, characterized in that, The total time for pulse aging is less than 10 minutes.

5. The pulse aging method for high-voltage aluminum electrolytic capacitors according to any one of claims 1-4, characterized in that, The core volume of the high-voltage aluminum electrolytic capacitor accounts for more than 90%.

6. A pulse aging system, characterized in that, include: Main power supply, capacitor placement area, high-voltage capacitor bank, low-voltage capacitor bank, DC-DC converter, first switch, second switch; The capacitor placement area is used to place multiple high-voltage aluminum electrolytic capacitors to be pulse aging treatment, and the multiple high-voltage aluminum electrolytic capacitors are connected in parallel. The high-voltage capacitor bank, the low-voltage capacitor bank, and the multiple high-voltage aluminum electrolytic capacitors to be processed are connected in parallel. The DC-DC converter is disposed between the high-voltage capacitor bank and the low-voltage capacitor bank and forms an electrical connection therebetween. The high-voltage capacitor bank is used to pulse-boost the voltage of multiple high-voltage aluminum electrolytic capacitors to be processed. The high-voltage aluminum electrolytic capacitor, after being boosted, discharges to the low-voltage capacitor bank; The DC-DC converter is used to recharge the high-voltage capacitor bank after recovering energy from the low-voltage capacitor bank. The first switch is disposed between the connection circuit of the high-voltage capacitor bank and the capacitor placement area; The second switch is disposed between the connection circuit of the low-voltage capacitor bank and the capacitor placement area; When the first switch is on, the second switch is off, and vice versa.

7. The pulse aging system according to claim 6, characterized in that, The main power supply first charges the high-voltage capacitor bank to its rated voltage; Then, the first switch is closed, and the high-voltage capacitor bank pulses and charges the multiple conventionally aged and discharged high-voltage aluminum electrolytic capacitors in the capacitor placement area with charging voltage and charging current, so that the high-voltage aluminum electrolytic capacitors reach the charging voltage and maintain a high-voltage charging state. The first switch is then opened and the second switch is closed. The multiple high-voltage aluminum electrolytic capacitors pulse discharge and pulse voltage drop according to the set discharge voltage and discharge current. After discharging to the set voltage, they maintain a low-voltage discharge state, so that the electricity in the multiple high-voltage aluminum electrolytic capacitors is released into the low-voltage capacitor bank. Finally, the low-voltage capacitor bank boosts the stored electrical energy to the rated voltage of the high-voltage capacitor bank through the DC-DC converter, and then recharges the high-voltage capacitor bank for recharging and energy replenishment, undergoing multiple pulse aging cycle treatments.

8. The pulse aging system according to claim 7, characterized in that, The rated voltage of the high-voltage aluminum electrolytic capacitor is U r The charging voltage is U c The charging current is I c The time for maintaining the high-voltage charging state is t. ch The discharge voltage is U d The discharge current is I d The time for maintaining the low-voltage discharge state is t. dh The parameters are set as follows: U c It's U r 1.05 to 1.1 times; based on the capacitance value per 100μF of the high-voltage aluminum electrolytic capacitor, I c From 1 amp to 10 amps; t ch The duration is 0.5 to 5 seconds; U d <50V; based on the capacitance value per 100μF of the high-voltage aluminum electrolytic capacitor as specified above, I d The range is from 0.1 amps to 1 amp; t dh The duration is between 0.5 and 3 seconds.

9. The pulse aging system according to claim 8, characterized in that, The rated voltage of the high-voltage capacitor bank is U. B U B ≥1.3U c ; The capacitance of the high-voltage capacitor bank is at least 20 times the capacitance of the high-voltage aluminum electrolytic capacitor; The rated voltage of the low-voltage capacitor bank is 55 volts to 85 volts; The capacitance of the low-voltage capacitor bank is at least 100 times that of the high-voltage aluminum electrolytic capacitor.

10. The pulse aging system according to claim 9, characterized in that, The pulse aging cycle is performed 10 to 50 times.

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