Integrated device and method for high voltage electrolytic capacitor in power conversion systems

Abstract

The present disclosure relates to a power conversion system comprising a power factor correction (PFC) rectifier configured to convert an AC input to a DC output, an AC bus connected between the AC input and the PFC rectifier, a DC / DC converter configured to generate a regulated DC output, a DC bus connected between an output of the PFC rectifier and an input of the DC / DC converter, and a high voltage electrolytic capacitor (HVEC capacitor) configured to extend hold-up time during input disturbances and to absorb or release energy in response to load changes.

Description

[0001] Cross-reference to related applications This application claims priority to U.S. Provisional Application No. 63 / 795,038, filed April 25, 2025, entitled “Hybrid Electrolytic Capacitor Apparatus and Method”, and U.S. Provisional Application No. 63 / 796,705, filed April 29, 2025, entitled “Hybrid Electrolytic Capacitor Apparatus and Method”, and U.S. Application No. 19 / 656,978, filed April 23, 2026, entitled “Hybrid Electrolytic Capacitor Apparatus and Method”, which is incorporated herein by reference. Technical Field

[0002] This disclosure generally relates to the field of power conversion systems, and specific embodiments relate to an integrated device and method for a high-voltage electrolytic capacitor (HVEC capacitor) in a power conversion system. Background Technology

[0003] In the field of power conversion systems, electrolytic capacitors are widely used for energy storage, voltage smoothing, and transient buffering. Currently, the rated voltage of commonly used electrolytic capacitors is typically around 500V. However, in applications involving three-phase or high-voltage DC systems, capacitors with rated voltages exceeding 500V are usually required. In the past, to meet this high-voltage requirement, two electrolytic capacitors were typically connected in series. Assuming the capacitance of a single capacitor is C, when two capacitors are connected in parallel, according to the characteristics of parallel capacitance, the total capacitance equals the sum of the individual capacitances, i.e., the total capacitance is 2C. However, when these two capacitors are connected in series, the total capacitance can be calculated using the series capacitance formula, resulting in a series capacitance of 0.5C.

[0004]

[0005] Figure 1 A conventional Vienna rectifier is shown, in which two capacitors, Cdc1 and Cdc2, are connected in series between the positive and negative output terminals. Both Cdc1 and Cdc2 are rated at 400V. This architecture is widely used in three-phase AC-DC conversion systems for power factor correction (PFC).

[0006] Figure 2 A conventional three-phase six-switch rectifier is shown, in which two capacitors, Cdc1 and Cdc2, are connected in series between the positive and negative output terminals. Both Cdc1 and Cdc2 are rated at 400V.

[0007] However, connecting capacitors in series not only reduces the capacitance to half that of a single capacitor (compared to a single capacitor), but also to a quarter that of two capacitors connected in parallel, it also introduces increased internal resistance and voltage balance issues. Therefore, capacitors connected in series are inferior to single or parallel capacitors in terms of performance, lifespan, and reliability.

[0008] Figure 3 The diagram illustrates the structure of a conventional power supply unit (PSU), which includes a power factor correction (PFC) rectifier, a filter capacitor Cdc, a DC / DC conversion stage, and a load. The PFC rectifier in the illustrated PSU architecture can be implemented using a Vienna rectifier, a six-switch three-phase rectifier, or a Swiss rectifier, depending on system requirements. The filter capacitor Cdc is located between the PFC rectifier and the DC / DC conversion stage and is configured to provide a hold-up time of approximately 20 milliseconds. To achieve this duration, conventional PSU designs typically require a single large electrolytic capacitor or multiple electrolytic capacitors connected in parallel.

[0009] Therefore, there is an urgent need to develop technologies and mechanisms that can improve the performance of power conversion systems in various aspects and promote their application. Summary of the Invention

[0010] The embodiments disclosed herein generally achieve technical advantages, and describe an integrated device and method for high-voltage electrolytic capacitors in a power conversion system.

[0011] According to one aspect of this disclosure, a power conversion system is provided, comprising: a power factor correction (PFC) rectifier configured to convert an AC input to a DC output; an AC bus connected between the AC input and the PFC rectifier; a DC / DC converter configured to generate a stable DC output; a DC bus connected between the output of the PFC rectifier and the input of the DC / DC converter; and a high-voltage electrolytic capacitor (HVEC capacitor) configured to extend the hold-up time during input disturbances and to absorb or release energy in response to load changes.

[0012] The features and technical advantages of this disclosure have been summarized above to better understand the detailed description below. Additional features and advantages of this disclosure will be described below and form the subject matter of the claims. Those skilled in the art will understand that the concepts and specific embodiments disclosed herein can be readily used as the basis for modifying or designing other structures or processes to achieve the same purpose as this disclosure. Those skilled in the art will also understand that such equivalent structures do not depart from the spirit and scope of this disclosure as defined by the appended claims. Attached Figure Description

[0013] By reading the following detailed description of exemplary embodiments, those skilled in the art will understand the advantages and benefits of the present invention, as well as other advantages and benefits. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. Wherein: Figure 1 This is a circuit diagram of a traditional Vienna rectifier, in which two DC capacitors are connected in series. Figure 2 This is a circuit diagram of a traditional three-phase six-switch rectifier, in which two DC capacitors are connected in series. Figure 3 The structure of a conventional PSU is shown; Figure 4 An exemplary Vienna rectifier circuit using HVEC capacitors is shown according to various embodiments of the present disclosure; Figure 5 An exemplary three-phase six-switch circuit using HVEC capacitors is shown according to various embodiments of the present disclosure; Figure 6 A block diagram illustrating an exemplary power conversion system using HVEC capacitors according to various embodiments of the present disclosure; Figure 7 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure; Figure 8 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure; Figure 9 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure; Figure 10 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure; Figure 11 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure; Figure 12 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure; Figure 13 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure; Figure 14 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure; Figure 15 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure; Figure 16 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure; Figure 17 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure; Figure 18 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure; Figure 19 The structure of a PSU architecture using HVEC capacitors according to various embodiments of the present disclosure is shown; Figure 20 Modular AC / DC power supply architectures using one or more HVEC capacitors are described according to various embodiments of this disclosure; Figure 21 Exemplary implementations of energy pack modules used in conjunction with a PSU according to various embodiments of this disclosure are shown; Figure 22 Examples of practical power rack systems according to various embodiments of this disclosure are shown; Figure 23 To show Figure 22 A block diagram of an exemplary power rack system; Figure 24 An exemplary Swiss rectifier circuit using an HVEC capacitor is shown according to various embodiments of this disclosure; Figure 25 Timing diagrams are provided to illustrate the power smoothing function of an energy pack module according to various embodiments of the present disclosure.

[0014] Unless otherwise stated, corresponding numbers and symbols in different figures generally refer to corresponding parts. These figures are drawn to clearly illustrate relevant aspects of various embodiments and are not necessarily drawn to scale. Detailed Implementation

[0015] The manufacture and use of embodiments of this disclosure are discussed in detail below. However, it should be understood that the concepts disclosed herein can be embodied in a variety of specific scenarios, and the specific embodiments discussed herein are merely illustrative and not intended to limit the scope of the claims. Furthermore, it should be understood that various changes, substitutions, and modifications can be made herein without departing from the spirit and scope of this disclosure as defined by the appended claims.

[0016] Furthermore, one or more features of the following embodiments may be combined to form alternative embodiments not explicitly described, and features suitable for such combinations are understood to be within the scope of this disclosure. Therefore, the appended claims are intended to cover such modifications or embodiments.

[0017] This disclosure will be described in conjunction with preferred embodiments in a specific scenario, namely, an integrated device and method for high-voltage electrolytic capacitors (HVEC capacitors) in a power conversion system. Various embodiments will be described in detail below with reference to the accompanying drawings.

[0018] In applications involving three-phase or high-voltage DC systems, capacitors with rated voltages exceeding 500V are typically required. The HVEC capacitors used in this disclosure have rated voltages ranging from 700V to 1200V. Compared to conventional capacitors with a rated voltage of approximately 500V, HVEC capacitors have similar dimensions for the same capacitance value.

[0019] To further illustrate the advantages of HVEC capacitors, a comparison of the energy storage capacity between 400V and 800V capacitors is provided below. According to the energy storage formula for capacitors:

[0020] (Where E is energy storage, C is capacitance, and V is voltage), when capacitance C remains constant, the energy stored in a 400V capacitor is

[0021] The energy stored in an 800V capacitor is

[0022] By calculating their energy storage ratio, i.e.

[0023] Clearly, for the same capacitance value, an 800V capacitor stores four times the energy of a 400V capacitor. This illustrates the principle behind the use of HVEC capacitors in this disclosure to increase energy storage density. In high-voltage applications, because the HVEC capacitors of this disclosure have high rated voltage, it is no longer necessary to connect multiple low-voltage capacitors in series as before.

[0024] HVEC capacitors can be used individually or connected in parallel, depending on actual needs. This configuration effectively avoids the capacitance reduction problem caused by series connection. Therefore, the available capacitance of the configuration using HVEC capacitors in this disclosure is approximately four times that of capacitors using a traditional series connection scheme, greatly expanding the application range and enabling a variety of application scenarios.

[0025] In three-phase rectifier and inverter systems, a DC bus with a voltage of approximately 800V is typically present. The DC bus is the high-voltage line between the positive and negative output terminals of the rectifier, with energy storage capacitors connected across its two ends. The positive terminal of the DC bus has a voltage of 400V to ground, and the negative terminal has a voltage of -400V to ground. Figure 1 and Figure 2Compared to the prior art method of connecting two 400V electrolytic capacitors in series, as shown in the present disclosure, the HVEC capacitor can be directly integrated into the DC bus. The HVEC capacitor solution of this disclosure eliminates the capacitor voltage balance problem, resulting in a smaller capacitor size and better reliability and lifespan than traditional low-voltage series connection methods. Furthermore, the HVEC capacitor solution of this disclosure can achieve functions such as lightning protection, voltage stabilization, and providing hold-up time, with an energy density more than four times that of conventional solutions.

[0026] Figure 4 Exemplary Vienna rectifier circuits using HVEC capacitors according to various embodiments of this disclosure are shown. Figure 4 As shown, the HVEC capacitor (Cdc) is directly connected between the positive and negative terminals of the DC bus. In some embodiments, the voltage to ground of the positive terminal of the DC bus is 400V, the voltage to ground of the negative terminal is -400V, and the rated voltage of the HVEC capacitor is 800V.

[0027] Figure 5 Exemplary three-phase six-switch circuits using HVEC capacitors according to various embodiments of this disclosure are shown. Figure 5 As shown, the HVEC capacitor (Cdc) is directly connected between the positive and negative terminals of the DC bus. In some embodiments, the voltage to ground of the positive terminal of the DC bus is 400V, the voltage to ground of the negative terminal is -400V, and the rated voltage of the HVEC capacitor is 800V.

[0028] In applications such as server power supplies, power supply units (PSUs) typically require a hold-up time of 20ms. Currently, to meet this requirement, a common practice is to connect a large number of electrolytic capacitors in parallel on the DC bus. For example, in server AC power applications, electrolytic capacitors that can provide a hold-up time of 2-3ms on the DC bus under normal operating conditions are sufficient to ensure the normal operation of the PSU. However, under extreme conditions such as input grid fluctuations or load abrupt changes, the power conversion system may require a hold-up time of up to 20ms to maintain stable and continuous operation. Therefore, this disclosure provides a solution in which conventional electrolytic capacitors are configured on the DC bus to provide only a hold-up time of 2-3ms to maintain PSU operation under normal conditions; simultaneously, a high-energy-density capacitor bank including one or more HVEC capacitors is introduced to provide an additional 17-18ms hold-up time to cope with extreme operating conditions. In some embodiments, one or more HVEC capacitors can be integrated within the PSU to provide the required energy throughout the entire hold-up time. The HVEC capacitors can be placed inside the PSU to provide the necessary energy support for the entire hold-up duration. Regarding methods for integrating one or more HVEC capacitors into a power conversion system, there are 13 implementations according to various embodiments of this disclosure. For practical applications, please refer to... Figures 6 to 18Based on specific working conditions, these 13 integration methods are optimized to select the most suitable integration scheme.

[0029] The 13 integration methods for connecting one or more HVEC capacitors to a power conversion system can be divided into three categories: (1) direct connection, such as Figure 6 As shown; (2) connected via a bidirectional converter, such as Figures 7 to 9 As shown; (3) connected through two single-phase converters, as shown Figures 10 to 18 As shown.

[0030] Figure 6 A block diagram illustrating an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure. (See attached diagram.) Figure 6 As shown, HVEC capacitors (Cdc) can be directly connected to power conversion systems without going through a converter. Figure 6 The power conversion system shown includes an AC power supply and an AC bus ( Figure 6 (marked as 1), PFC rectifier, small-capacity filter capacitor, HVEC capacitor, DC bus ( Figure 6 Marked as 2), DC / DC converter, DC output ( Figure 6 The load is marked as 3. The AC power supply can be single-phase or three-phase AC. PFC rectifiers can be implemented in various topologies, such as Vienna rectifiers, six-switch boost rectifiers, or Swiss rectifiers.

[0031] The power conversion system has three interfaces for connecting electrolytic capacitors: AC bus (marked 1), DC bus (marked 2), and DC output terminal (marked 3).

[0032] In a direct-connect configuration, HVEC capacitors can only be connected to the DC bus. For example... Figure 6 As shown, the HVEC capacitor is connected in parallel to the output of the PFC rectifier, replacing the two series-connected DC capacitors used in traditional rectifier topologies. To improve the energy utilization efficiency of the capacitor during hold-up time, methods such as increasing the DC bus voltage or using a wide-input-range DC / DC converter can be employed. When the HVEC capacitor is used for power smoothing, its energy storage can be regulated by changing the DC bus voltage: increasing the DC bus voltage causes the HVEC capacitor to absorb energy, while decreasing the DC bus voltage causes it to release energy. The advantage of this direct connection method is that the system integration requires no additional converter configuration, resulting in a simple structure; however, its disadvantage is that the energy utilization efficiency of the HVEC capacitor is relatively low.

[0033] In a configuration connected via a bidirectional converter, the HVEC capacitor can be connected to the power conversion system via the bidirectional converter, such as... Figure 7-9As shown. The bidirectional converter has three possible connection points: AC bus, DC bus, and DC output terminal. Connecting via a bidirectional converter can significantly improve the energy utilization efficiency of HVEC capacitors, but the control logic for charging and discharging HVEC capacitors is more complex.

[0034] Figure 7 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure. Figure 7 As shown, a bidirectional power converter is connected between the AC power source and the HVEC capacitor bank. According to various embodiments of this disclosure, the bidirectional converter can control the energy flow between the AC power source and the HVEC capacitors, supporting peak shaving, energy buffering, and potential grid support functions.

[0035] Figure 8 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure. Figure 8 As shown, a bidirectional power converter is connected between the output of the PFC rectifier and the HVEC capacitor bank. Unlike existing architectures where bidirectional converters interface with AC power supplies, this configuration enables direct energy buffering and bidirectional energy control in the intermediate DC link, improving voltage stability, load response speed, and energy reuse efficiency according to various embodiments of this disclosure.

[0036] Figure 9 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure. Figure 9 As shown, the bidirectional power converter is connected between the output of the DC / DC converter and the HVEC capacitor bank. This configuration enables bidirectional energy flow between the HVEC capacitor bank and the load side, providing advanced functions such as energy buffering, load balancing, and transient voltage stabilization.

[0037] In a configuration connected via two single-phase converters, the HVEC capacitor can be connected to the power conversion system through two single-phase converters (a charge converter and a discharge converter), such as... Figure 10-18 As shown. Both the charge converter and the discharge converter can be connected to the AC bus, DC bus, or DC output terminal, resulting in 3×3=9 possible connection methods. These methods have high capacitor energy utilization efficiency and the simplest charge and discharge control logic, but the size of the single-phase converter may be relatively large.

[0038] During normal operation, the load is powered by an AC power source; when the AC power source fails, the electrolytic capacitor supplies power to the load to maintain the hold time. The HVEC capacitor operates in an intermittent mode, activating only when the AC power source fails and a hold time is required, which is a low-probability event during normal power operation.

[0039] Figure 10 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure. Figure 10 As shown, both the charging converter and the discharging converter are connected to the AC bus.

[0040] Figure 11 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure. Figure 11 As shown, the charging converter is connected to the AC bus, and the discharging converter is connected to the DC bus.

[0041] Figure 12 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure. Figure 12 As shown, the charging converter is connected to the AC bus, and the discharging converter is connected to the DC output terminal.

[0042] Figure 13 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure. Figure 13 As shown, the charging converter is connected to the DC bus, and the discharging converter is connected to the AC bus.

[0043] Figure 14 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure. Figure 14 As shown, both the charging converter and the discharging converter are connected to the DC bus.

[0044] Figure 15 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure. Figure 15 As shown, the charging converter is connected to the DC bus, and the discharging converter is connected to the DC output terminal.

[0045] Figure 16 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure. Figure 16 As shown, the charging converter is connected to the DC output terminal, and the discharging converter is connected to the AC bus.

[0046] Figure 17 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure. Figure 17 As shown, the charging converter is connected to the DC output terminal, and the discharging converter is connected to the DC bus.

[0047] Figure 18 This is a block diagram of an exemplary power conversion system using HVEC capacitors according to various embodiments of this disclosure. Figure 18As shown, both the charging converter and the discharging converter are connected to the DC output terminal.

[0048] In applications such as server power supplies, the power supply unit (PSU) is responsible for providing sufficient hold-up time for the power conversion system, typically around 20ms. In traditional designs, a large number of electrolytic capacitors are usually connected in parallel on the DC bus to meet the system's hold-up time requirements.

[0049] According to another embodiment of this disclosure, the PSU may be equipped with a capacitor that can only provide a hold time of about 2ms, and the remaining energy demand is met by an energy pack placed outside the PSU that contains one or more HVEC capacitors. Figure 19 The structure of a PSU architecture using HVEC capacitors according to various embodiments of this disclosure is shown. For example... Figure 19 As shown, the power pack is located outside the PSU and is electrically connected to the system via one or more power converters. One or more HVEC capacitors provide a hold-up time of approximately 18 ms.

[0050] By adopting this external power pack solution, the PSU can use capacitors with smaller capacities, and due to the significant reduction in capacitor size, the PSU's power density can be significantly improved. In terms of operating logic, the external HVEC capacitor bank functions consistent with conventional scenarios: when the system is operating normally, the load is powered by AC power; if fluctuations in the input grid cause instability in the power conversion system, the external HVEC capacitor bank immediately activates and supplies power to the system. This HVEC capacitor bank only operates during AC power failures, which is an infrequent event during normal operation.

[0051] In graphics processing unit (GPU) and tensor processing unit (TPU) computing systems, the simultaneous start-up and shutdown of numerous GPUs / TPUs can lead to severe load fluctuations. When the load power of the GPUs / TPUs suddenly increases or decreases, the power drawn from the AC power supply also fluctuates drastically, which can easily trigger the uninterruptible power supply (UPS) on the AC power side. In more extreme cases, this can lead to power network instability or even failure. To address this issue, this disclosure employs an energy pack containing HVEC capacitors: when the GPU / TPU power suddenly increases, the energy pack releases energy; when the power suddenly decreases, the energy pack absorbs energy. This process smooths out changes in input power from the AC power supply, avoiding impact on the UPS and power network on the input side. The method of integrating this energy pack into the rectifier system is consistent with the aforementioned system, and has the following characteristics: Figures 6 to 18 The diagram shows 13 connection schemes across three categories. The operating mode is as follows: under normal operating conditions, it is powered by AC power; when the load power suddenly increases, the energy pack releases energy; when the load power suddenly decreases, the energy pack absorbs energy.

[0052] One or more HVEC capacitors can be assembled into a standalone module or rack (energy bank), such as Figure 20 As shown. Figure 20 A modular power supply architecture is described, in which traditional AC / DC power supplies are broken down into modular components, offering advantages such as high flexibility, strong scalability, low maintenance costs, high production testing efficiency, and strong fault tolerance and reliability. Figure 20 As shown, a modular power architecture may include one or more energy bank modules, one or more DC / DC modules, and one or more PFC modules. The energy bank modules, composed of HVEC capacitors, are designed to supplement the hold-up time of the power conversion system; these modules can be stacked within a unified enclosure or housing. Regarding the integration method of one or more HVEC capacitors with this modular design, such as... Figures 6 to 18 As shown, there are three categories and 13 connection schemes.

[0053] Figure 21 Exemplary implementations of energy storage modules used in conjunction with a PSU according to various embodiments of this disclosure are shown. The energy storage module, consisting of HVEC capacitors, is shown as a module externally connected to the PSU via a dedicated interface. This modular configuration facilitates the installation, replacement, or upgrading of energy storage components without disassembling the PSU housing, improving maintainability, simplifying maintenance procedures, and allowing for expansion of energy storage capacity as required by system requirements.

[0054] Figure 22 An example of a practical power rack system is shown. For example... Figure 22 As shown, the power rack system includes a PFC module, a DC / DC module, and four energy banks connected in parallel to the DC bus. Although Figure 22 Four energy groups are shown, but other numbers can be flexibly configured according to system requirements.

[0055] Figure 23 To show Figure 22 A block diagram of an exemplary power rack system is shown. The power rack system includes a PFC module, a DC / DC converter module, energy banks (one or more), and a load. Each energy bank may contain a 450V, 47.6mF capacitor. In the illustrated embodiment, four energy banks are connected in parallel on the DC bus, resulting in a total effective capacitance of 190.4mF (4 × 47.6mF). In some embodiments, the PFC module of the power rack system employs a Swiss rectifier topology, such as... Figure 24As shown. The energy bank can also be used in conjunction with other PFC topologies, such as the Vienna rectifier or six-switch rectifier described in previous embodiments. The DC / DC converter module can employ a wide input voltage range topology (e.g., a full-bridge converter topology). The energy bank (one or more) achieves charging and discharging by regulating the DC bus voltage, and the system controls energy flow by dynamically adjusting the DC bus voltage between 200V and 400V. The Swiss rectifier is used as a buck PFC circuit, enabling flexible regulation of the DC bus voltage within the 200-400V range; despite the wide input voltage variation range (e.g., 200-400V), the DC / DC converter maintains a stable 50V output.

[0056] Figure 24 Exemplary Swiss rectifier circuits using HVEC capacitors according to various embodiments of this disclosure are shown. Figure 24 As shown, the HVEC capacitor is connected across the positive and negative terminals of the DC bus, replacing the two series-connected DC capacitors used in a conventional Swiss rectifier topology. In some embodiments, the positive terminal of the DC bus has a voltage of 400V to ground, the negative terminal has a voltage of -400V to ground, and the HVEC capacitor has a rated voltage of 800V.

[0057] The energy bank configuration implements two key operational functions: a hold-up function to ensure uninterrupted power supply to the load during input disturbances; and a power smoothing function to mitigate DC bus voltage fluctuations by dynamically absorbing or releasing energy according to load demand.

[0058] During normal operation, the AC power grid supplies power to the load; during grid disturbances or interruptions, the energy bank module provides backup energy to maintain load operation. The hold-up time can be calculated using the following formula:

[0059] Where: C is the total capacitance of the energy pack module, the maximum voltage is the maximum DC bus voltage (e.g., 400V), the minimum voltage is the minimum allowable DC bus voltage during discharge (e.g., 200V), and the power rack output power is the rated output power of the power rack. For example, if the power rack output power is 50kW, the total capacitance of the energy pack is 190.4mF, and the DC bus voltage range is 400V to 200V, the calculated hold-up time is approximately 228ms. Note that the 50kW output power value is provided as an exemplary example only; the actual power rack output power may vary depending on system design and application requirements, and therefore the calculated hold-up time will also differ accordingly. The wide input range of the DC / DC converter (e.g., 200-400V) ensures a stable 50V output even if the bus voltage decays from 400V to 200V.

[0060] Energy banks mitigate the effects of load transients by releasing energy when the load suddenly increases and absorbing energy when the load decreases. For example, an energy bank can release stored energy in response to power surges from a GPU or TPU and absorb energy when the GPU / TPU power decreases. This smoothing effect reduces input power fluctuations and protects the UPS and power grid, such as... Figure 25 As shown.

[0061] Figure 25 Timing diagrams are provided to illustrate the power smoothing function of an energy pack module according to various embodiments of the present disclosure. Figure 25 The diagram shows the input power of the power rack (red line), the load power (green line), and the energy contribution of the energy bank capacitor modules (dashed line). This diagram illustrates how the energy bank maintains a stable load power by dynamically releasing or absorbing energy, thereby suppressing power transients.

[0062] like Figure 25 As shown, before time t1, the power rack system operates under normal conditions, where the input power and load power of the power rack remain constant at 50kW, without the need for energy group intervention.

[0063] At time t1, the load power drops from 50kW to 0kW. From time t1 to t2, the system enters the energy absorption phase, during which the energy bank modules absorb excess energy, as shown by the dashed line. As the energy bank modules absorb excess energy, the DC bus voltage rises from 200V to 400V; during t1-t2, the input power of the power rack decreases linearly rather than suddenly.

[0064] At time t2, the input power of the power rack drops to 0kW, and the energy module stops absorbing energy.

[0065] The smoothing time can be calculated using the following formula:

[0066] Where: C is the total capacitance of the energy group module; the maximum voltage is the maximum DC bus voltage (e.g., 400V); the minimum voltage is the minimum allowable DC bus voltage during discharge (e.g., 200V); and the average capacitor power is the average capacitor power, equal to 0.5 × power rack output power. For example, if the power rack output power is 50kW, C = 190.4mF, the maximum voltage = 400V, the minimum voltage = 200V, and the average capacitor power = 0.5 × power rack output power = 25kW, then the calculated smoothing time is approximately 456ms.

[0067] At time t3, the load power suddenly increases from 0kW to 50kW. Between t3 and t4, the power rack system enters the energy release phase. As the energy bank modules release stored energy to support the increased load power, the DC bus voltage gradually decreases. During this period, the power rack's input power linearly increases from 0kW to 50kW, rather than suddenly increasing. The energy bank modules release stored energy to fill the gap between the load power and the power rack's initial input power, ensuring uninterrupted power supply and smoothing the system response. The same smoothing time can be obtained through the same calculations: 456ms.

[0068] Although this disclosure has been described in detail, it should be understood that various changes, substitutions, and modifications can be made without departing from the spirit and scope of this disclosure as defined by the appended claims. Furthermore, the scope of this disclosure is not intended to be limited to the specific embodiments described herein. Those skilled in the art will readily understand from this disclosure that currently existing or subsequently developed processes, machines, articles, material compositions, apparatuses, methods, or steps can achieve substantially the same function or effect as the embodiments described herein. Therefore, the appended claims are intended to bring such processes, machines, articles, material compositions, apparatuses, methods, or steps within their scope of protection.

Claims

1. A power conversion system, characterized in that, include: A three-phase power factor correction (PFC) rectifier configured to convert an AC input to a DC output; an AC bus connected between the AC input and the PFC rectifier; a DC / DC converter configured to generate a stable DC output; and a DC bus connected between the output of the PFC rectifier and the input of the DC / DC converter. And an HVEC capacitor module, which consists of one or more high-voltage electrolytic capacitors connected in parallel, for extending the hold time during input disturbances and absorbing or releasing energy in response to load changes.

2. The power conversion system according to claim 1, characterized in that, The HVEC capacitor module is directly connected to the DC bus, and the energy storage of the HVEC capacitor module is regulated by changing the voltage of the DC bus.

3. The power conversion system according to claim 2, characterized in that, The PFC rectifier is a Vienna rectifier or other boost rectifier.

4. The power conversion system according to claim 2, characterized in that, The PFC rectifier is a Swiss rectifier or other step-down rectifier.

5. The power conversion system according to claim 2, characterized in that, The PFC rectifier is a buck-boost rectifier.

6. The power conversion system according to claim 1, characterized in that, It also includes a bidirectional power converter connected between the AC input and the HVEC capacitor module.

7. The power conversion system according to claim 1, characterized in that, It also includes a bidirectional power converter connected between the DC bus and the HVEC capacitor module.

8. The power conversion system according to claim 1, characterized in that, It also includes a bidirectional power converter connected between the output of the DC / DC converter and the HVEC capacitor module.

9. The power conversion system according to claim 1, characterized in that, It also includes a charging converter and a discharging converter, wherein the HVEC capacitor module is charged by the charging converter and releases energy by the discharging converter.

10. The power conversion system according to claim 4, characterized in that, The DC / DC converter is configured to receive a wide input voltage range, and the ratio of the maximum input voltage to the minimum input voltage of the DC / DC converter is at least 2.

11. The power conversion system according to claim 10, characterized in that, The DC / DC converter is a dual active bridge (DAB) converter, and the PFC rectifier is a Swiss rectifier.

12. A power conversion system, characterized in that, include: A DC bus configured to receive a DC voltage; a DC / DC converter configured to generate a stable DC output, the input of the DC / DC converter being connected to the DC bus; and an HVEC capacitor module consisting of one or more high-voltage electrolytic capacitors connected in parallel for extending the hold-up time during input disturbances and for absorbing or releasing energy in response to load changes.

13. The power conversion system according to claim 12, characterized in that, It also includes a bidirectional power converter connected between the DC bus and the HVEC capacitor module.

14. The power conversion system according to claim 12, characterized in that, It also includes a bidirectional power converter connected between the output of the DC / DC converter and the HVEC capacitor module.

15. The power conversion system according to claim 12, characterized in that, It also includes a charging converter and a discharging converter, wherein the HVEC capacitor module is charged by the charging converter and releases energy by the discharging converter.

16. A power rack system, characterized in that, include: A power factor correction (PFC) module configured to convert AC input to DC output; a DC / DC converter module configured to generate a stable DC output; The PFC module, the DC / DC converter module, and the energy pack module include energy storage elements selected from high-voltage electrolytic capacitors (HVEC capacitors), supercapacitors, batteries, and any combination thereof, for extending the hold time during input disturbances and absorbing or releasing energy in response to load changes; wherein the PFC module, the DC / DC converter module, and the energy pack module are located in a housing.

17. The power rack system according to claim 16, characterized in that, The DC / DC converter module includes a dual active bridge (DAB) converter, and the PFC module includes a Swiss rectifier or other buck rectifier.

18. The power rack system according to claim 16, characterized in that, The DC / DC converter module includes a full-bridge converter, and the PFC module includes a Swiss rectifier or other buck rectifier.

19. The power conversion system according to claim 1, 12, or 16, characterized in that, The HVEC capacitor module is an independent pre-packaged component module formed by one or more high-voltage electrolytic capacitors connected in parallel.

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