Pulse plating power supply dc bus power supply system and method

Abstract

The application belongs to the technical field of power supply devices, and particularly relates to a pulse electroplating power supply direct current bus power supply system and method. The system comprises: a solid-state transformer, an input end of which is connected to an alternating current power grid, and which is used for converting alternating current provided by the alternating current power grid into direct current output; a common direct current bus, which is connected to an output end of the solid-state transformer, and which is used for collecting the direct current output by the solid-state transformer; and a pulse electroplating power supply unit, an input end of which is connected to the common direct current bus, and which is used for outputting pulse electroplating power to a load unit by using the direct current provided by the common direct current bus. The overall power supply architecture provided by the application is simple and easy to implement, and the power grid power supply efficiency is improved.

Description

Technical Field

[0001] This invention belongs to the field of power supply device technology, and particularly relates to a pulse electroplating power supply DC bus power supply system and method. Background Technology

[0002] Electrolytic copper foil production employs a pulse electroplating process. The instantaneous pulse current of the electroplating load can reach 5000A-10000A or even larger, such as tens of thousands of amperes. The current rises and falls frequently and rapidly, and the power supply operates under square wave pulse conditions with a large current switching slope and huge instantaneous peak power. Meanwhile, electricity costs account for 25% to 50% of production costs in the electroplating industry, making cost reduction a pressing need for manufacturers. High-end ultra-thin copper foil has extremely high requirements for the rising slope and ripple size of the electroplating current waveform. Fluctuations in the power supply bus voltage and low-frequency ripple directly affect the uniformity of the plating layer and surface roughness, determining the yield rate of the finished product. This is especially true for high-end ultra-thin electroplated copper foil used in high-end equipment, where the dynamic response of the power supply's rising slope and ripple is extremely critical. For example, in the application scenarios of pulse power supplies for multi-layer PCB electroplating in AI power supplies and circuit boards, these are key parameters determining product quality. Furthermore, harsh power environments directly affect the mean time between failures (MTBF) of the electroplating power supply and the manufacturer's economic benefits. A shutdown during operation can result in the complete scrapping of all materials.

[0003] Current pulse electroplating power supplies primarily rely on direct grid power, with the voltage stepped down to the secondary side via a power frequency transformer, typically in a 380V AC system. The load-side power supply depends on the AC / DC section of the pulse power supply. One type uses a PFC rectifier with active power correction, directly powering a subsequent isolated DC / DC power supply. The output of this isolated DC / DC power supply then serves as a fixed DC source for the third-stage DC / DC pulse circuit. Another option involves the AC input power supply passing through uncontrolled three-phase rectifier diodes to generate a six-pulse DC voltage. The subsequent isolated DC / DC power supply is identical to the aforementioned third-stage pulse circuit.

[0004] For details on existing power supply solutions with PFC, please refer to [link / reference]. Figure 1 and Figure 2As shown. The disadvantage is that each pulse power supply requires an active power factor correction circuit, resulting in low power supply efficiency and high hardware costs. Pulse power supplies are typically deployed in numbers ranging from dozens to thousands on production lines. Frequent pulse operation causes severe EMC issues and a decline in power quality on the AC power grid. Besides generating numerous harmonics, the grid also produces flicker at different frequencies, causing unstable operation of AC / DC PFC power supplies and frequent PFC power supply failures. Furthermore, PFC power supplies are prone to resonance problems when multiple machines are in the system. This is usually addressed by reducing the speed of the PFC control loop, but this further reduces the dynamic response capability of the PFC power supply. Since the load of a pulse power supply is pulsed, this can lead to frequent overcurrent or bus undervoltage faults, further reducing the equipment's mean time between failures (MTBF). Pulse power supplies have the highest reliability requirements because if they stop midway, all the materials and semi-finished products being electroplated must be scrapped. Additionally, power supplies with PFC cannot meet the high-frequency pulse conditions of pulse power supplies when there is only one machine in the system, and their dynamic performance cannot respond to the pulse power load of the pulse power supply.

[0005] For the reasons mentioned above, pulse power supplies generally do not use power supply schemes with PFC, but instead primarily use power supply schemes with uncontrolled three-phase rectifier diodes. For details on existing power supply schemes with uncontrolled three-phase rectifier diodes, please refer to... Figure 3 and Figure 4 As shown. However, the power supply scheme using uncontrolled three-phase rectifier diodes also has some significant problems: First, in the uncontrolled three-phase rectification mode, the grid-side current harmonics are very high, generally exceeding 20%. The grid power is generally low, mostly below 0.8. Second, to compensate for the adverse effects of the first problem, such as... Figure 3 As shown, power distribution systems generally require passive reactive power compensation equipment. For example... Figure 4 As shown, to reduce harmonics in the rectifier load of the pulse machine, harmonic suppression equipment is typically configured (active filters are not suitable for this scenario because they are easily excited to resonance under pulse load conditions, leading to abnormal system power supply or active filter failure), further increasing system power supply costs, increasing system power distribution complexity, and reducing maintainability. Third, to further reduce harmonics and power factor issues in uncontrolled rectification, the capacitance of the rectifier filter capacitors at the rectifier bridge is much smaller than usual. This results in a very large six-pulse ripple power supply on the rectified bus, such as... Figure 4As shown, this low-frequency six-pulse ripple cannot be effectively suppressed in the second-stage power supply, resulting in a considerable six-pulse voltage at the output of the second-stage isolated DC / DC power supply. The six-pulse ripple of the second-stage output voltage source directly affects the output ripple of the subsequent pulse power supply. To reduce the impact of this six-pulse voltage, a large number of electrolytic capacitors are usually used at the output of the second-stage isolated voltage source. However, this approach is very costly, as the frequency of the disturbance ripple voltage is not high, leading to a significant increase in the cost of the additional second-stage output capacitors and greatly affecting the size of the power supply. Excessive output capacitors also worsen the dynamic response of the second-stage isolated bus power supply. Furthermore, the aforementioned centralized uncontrolled rectification power distribution scheme still carries the risk of resonance. For example, the compensation devices configured between power supplies are prone to resonance, which not only increases costs but also exacerbates debugging and maintenance difficulties and costs. In addition, pulse copper foil power supply systems require uninterrupted power supply, which necessitates the configuration of an uninterruptible power supply (UPS). However, the current architecture cannot be configured with a UPS for the following reasons: ① The power is enormous and the load is distributed, requiring the UPS to be configured according to its rated power, resulting in huge costs and difficulties in construction and power distribution; ② UPS is difficult to meet the dynamic response requirements of pulse power supply.

[0006] In addition to the inherent problems mentioned above, the two pulse power supply schemes also suffer from incompatibility with energy storage access: First, AC-powered energy storage access, regardless of whether it is for self-consumption, requires grid quotas and grid connection certification. With the increasing application and proportion of new energy sources in recent years, grid consumption quotas are decreasing rapidly, and even existing quotas are being reduced, making it increasingly difficult to apply for new energy storage access quotas. Second, grid connection requires strict approval and review, which consumes significant time and money, resulting in substantial costs and making it difficult for manufacturing enterprises to choose. Pulse electroplating plants consume a large amount of electricity, with electricity costs accounting for a high proportion of production costs, and these enterprises have a real need for self-consumption of energy storage. However, neither of the existing pulse electroplating power supply schemes can meet the conditions for accessing new energy storage (such as requiring no approval and providing efficient power supply). Furthermore, traditional energy storage requires grid approval, and all energy must first reach the grid side before being converted from AC to DC, involving multiple energy conversion stages, numerous converters, and low efficiency.

[0007] Based on solid-state transformers (SST), there is a publicly available industrial power supply solution designed by Sungrow Power Supply Co., Ltd. that directly powers DC electroplating loads using solid-state transformers. However, this solution lacks engineering value. Specifically, the high-frequency isolation of the second stage requires safety insulation up to 45kV and the solution to partial discharge problems. The insulation structure occupies most of the transformer space, which causes two problems. First, the transformer has a high thermal resistance, making heat dissipation of the transformer coil difficult, thus making it unsuitable for low-voltage, high-current applications. Second, even with the same insulation design, coupling between the primary and secondary sides of the transformer is difficult, especially in the case of low-voltage, high-current secondary windings with fewer turns and thicker coils. This makes it almost impossible for the high-frequency transformer of the solid-state transformer to achieve high coupling, and low coupling results in low efficiency, making it essentially unsuitable for engineering applications. Therefore, solid-state transformers are not suitable for low-voltage, high-current applications.

[0008] Furthermore, to achieve a low-voltage, high-current direct-drive load topology, the solid-state transformer (SST) needs to meet constant voltage and constant current requirements, as well as ultra-wide voltage regulation. However, it is very difficult for SSTs to simultaneously achieve constant voltage, constant current, and ultra-wide voltage regulation. The ideal operating condition for an SST is fixed gain or a small-range voltage regulation, so the above-mentioned conditions are not ideal or stable operating modes for SSTs. Since the secondary side of an SST is composed of multiple highly isolated output power supplies connected in parallel, it is difficult to achieve flexible constant voltage and constant current control, especially constant current control. Current sharing is very difficult to achieve under this architecture, and its own architecture also determines that the dynamic response of the SST power supply cannot be very high. In addition, for pulse power supply applications, pulse power supplies operate at low voltages, such as a few volts to tens of volts, with output currents of several thousand amperes to tens of thousands of amperes. There are two unsolvable fundamental problems here: because high-voltage isolation transformers need to consider the relationship between partial discharge, insulation, heat dissipation, and coupling efficiency, they cannot achieve low-voltage output; otherwise, SSTs cannot be designed. Therefore, SSTs cannot be used in low-voltage, high-current applications. However, both DC electroplating and pulse electroplating are essentially low-voltage, high-current processes, making solid-state transformers unsuitable for these metal plating scenarios. Furthermore, electroplating power supply loads are distributed and vary in power, ranging from several kilowatts to tens of kilowatts. Solid-state transformers cannot flexibly adapt to various loads, resulting in equipment waste. Therefore, direct-connection of solid-state transformers to loads has no practical application value. Since solid-state transformers are not suitable for lower power applications, if their unsuitability for low-voltage, high-current applications is not considered, using solid-state transformers for direct-connection loads would lead to enormous equipment costs. An excessive number of solid-state transformers would increase potential failure points, failing to meet reliability requirements. Therefore, the current application of direct-connection of solid-state transformers to loads has no engineering application value and exists only in the theoretical stage, unable to be truly engineered. In addition, the aforementioned direct-connection of solid-state transformers to loads, lacking photovoltaic and energy storage co-location architectures, lacks energy-saving and cost-reduction capabilities and does not offer the economic benefits of utilizing new energy sources and peak shaving to save on electricity costs.

[0009] like Figures 5 to 7 As shown, where Figure 6In the diagram, the yellow curve represents the AC / DC bus voltage, the blue curve represents the second-stage isolation bus voltage, and the red curve represents the AC side current of the power supply. The pulse power supply's electroplating output mode is a square wave current. Looking at the waveform, the pulse power supply output power exhibits a step-like square wave pulsating power. A key performance indicator for pulse power supplies is the slope of the current rise time. The steeper the slope, the thinner the copper plating layer and the higher the electroplating quality. This is a core indicator for high-end electroplating. Therefore, the core indicators of a pulse power supply are closely related to the power supply. Better power supply dynamics, smaller power supply ripple, smaller input bus ripple voltage and voltage fluctuations, and steeper rise and fall times of the output current all contribute to higher electroplating quality. Therefore, none of the above power supply methods can meet the power supply requirements of high-end pulse electroplating power supplies. Furthermore, small positive and negative amplitude ripple and stable output amplitude are also core indicators of pulse electroplating power supplies, but none of the above power supply methods can achieve these core indicators. For example, in the above three-phase rectifier diode power supply scheme, the bus six-pulse wave fluctuation will be reflected in the output square wave, resulting in large positive and negative amplitude ripple and unstable output amplitude, which in turn makes it impossible to meet the performance requirements of the pulse electroplating power supply. Summary of the Invention

[0010] Therefore, the purpose of this invention is to provide a pulse electroplating power supply DC bus power supply system and method to fundamentally solve the shortcomings of the prior art.

[0011] The present invention is implemented as follows: a pulse electroplating power supply DC bus power supply system is provided, characterized in that it includes: A solid-state transformer, whose input terminal is connected to an AC power grid, is used to convert the AC power provided by the AC power grid into DC power output. A common DC bus is connected to the output terminal of the solid-state transformer and is used to collect the DC power output by the solid-state transformer. A pulse electroplating power supply unit, whose input terminal is connected to the common DC bus, is used to output pulse electroplating power to the load unit using the DC power provided by the common DC bus.

[0012] In some embodiments, the system further includes an auxiliary DC power supply unit for outputting auxiliary DC power, the common DC bus being connected to the output terminal of the auxiliary DC power supply unit, and the common DC bus collecting the DC power output from the solid-state transformer and the auxiliary DC power output from the auxiliary DC power supply unit.

[0013] In some embodiments, the auxiliary DC power supply unit includes a photovoltaic DC power supply unit, which includes a photovoltaic source and an MPPT module. The photovoltaic source is connected to the MPPT module, and the MPPT module is also connected to the common DC bus.

[0014] In some embodiments, the auxiliary DC power supply unit includes a battery DC energy storage unit, which includes an energy storage battery and a bidirectional DC / DC module. The energy storage battery is connected to the bidirectional DC / DC module, and the DC / DC module is also connected to the common DC bus.

[0015] In some embodiments, the auxiliary DC power supply unit includes a photovoltaic DC power supply unit and a battery DC energy storage unit. The photovoltaic DC power supply unit includes a photovoltaic source and an MPPT module. The photovoltaic source is connected to the MPPT module, and the MPPT module is also connected to the common DC bus. The battery DC energy storage unit includes an energy storage battery and a bidirectional DC / DC module. The energy storage battery is connected to the bidirectional DC / DC module, and the DC / DC module is also connected to the common DC bus.

[0016] In some embodiments, the system further includes an energy management system, which is connected to the solid-state transformer, the pulse electroplating power supply unit, and the auxiliary DC power supply unit.

[0017] In some embodiments, the solid-state transformer includes a cascaded H-bridge rectifier module and an isolated DC / DC converter module. The input terminal of the cascaded H-bridge rectifier module is connected to the AC power grid, the output terminal of the cascaded H-bridge rectifier module is connected to the input terminal of the isolated DC / DC converter module, and the output terminal of the isolated DC / DC converter module is connected to the common DC bus.

[0018] This invention also provides a method for supplying power to the DC bus of a pulse electroplating power supply, applied to the pulse electroplating power supply DC bus power supply system as described in any of the above embodiments, comprising the following steps: The solid-state transformer converts the AC power supplied by the AC power grid into DC power and outputs it to the common DC bus. The common DC bus collects the DC power output from the solid-state transformer; The pulse electroplating power supply unit draws power from the common DC bus and outputs pulse electroplating power to the load unit.

[0019] In some embodiments, the system further includes an auxiliary DC power supply unit, which includes a battery DC energy storage unit. The battery DC energy storage unit includes an energy storage battery and a bidirectional DC / DC module. The energy storage battery is connected to the bidirectional DC / DC module, and the DC / DC module is also connected to the common DC bus. The method further includes the following steps: Obtain current grid electricity price information for the specified time period; During off-peak electricity pricing periods, the bidirectional DC / DC module transmits electrical energy from the common DC bus to the energy storage battery for storage. During peak electricity price periods, the bidirectional DC / DC module transmits the electrical energy stored in the energy storage battery to the common DC bus.

[0020] In some embodiments, the system further includes an auxiliary DC power supply unit, which includes a photovoltaic DC power supply unit and a battery DC energy storage unit. The photovoltaic DC power supply unit includes a photovoltaic source and an MPPT module, with the photovoltaic source connected to the MPPT module and the MPPT module also connected to the common DC bus. The battery DC energy storage unit includes an energy storage battery and a bidirectional DC / DC module, with the energy storage battery connected to the bidirectional DC / DC module and the DC / DC module also connected to the common DC bus. The method further includes the following steps: The photovoltaic source outputs auxiliary DC power to the MPPT module; The MPPT module performs maximum power point tracking and voltage conversion on the auxiliary DC power output from the photovoltaic source, and then outputs it to the common DC bus. The voltage of the common DC bus is detected. When the voltage of the common DC bus is higher than a preset voltage threshold, the bidirectional DC / DC module transfers at least a portion of the electrical energy on the common DC bus to the energy storage battery for storage.

[0021] This invention provides a DC bus power supply system and method for pulse electroplating power supplies. By employing a solid-state transformer to convert AC power from the AC grid into DC power, which is then output to a common DC bus, the pulse electroplating power supply unit draws power from the common DC bus and outputs the pulse electroplating power to the load unit. This restructures the power supply architecture of the pulse electroplating power supply, replacing the traditional AC power supply method with common DC bus power supply. The overall power supply architecture is simple and easy to implement, and it improves the efficiency of the power grid. The solid-state transformer, as the only power access channel on the AC grid side, achieves electrical isolation between the AC grid and the load unit, and can... Power can only flow unidirectionally from the AC grid to the common DC bus, preventing reverse energy feedback to the AC grid and eliminating the need for grid connection approval. The solid-state transformer output is the common DC bus rather than a load unit, allowing it to operate at the ideal resonant operating point under high voltage and constant voltage. This results in low power conversion losses and high efficiency, while also achieving extremely low power supply internal resistance. It effectively suppresses bus voltage fluctuations under pulsating load unit conditions, ensuring the steepness of the pulse current's rising and falling edges and improving electroplating quality. The centralized power supply mode of the common DC bus significantly reduces line current and line losses, simplifies the factory's power line laying scheme, and improves power supply reliability. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the structure of the first power supply system provided by existing technology; Figure 2This is a schematic diagram of the structure of a second power supply system provided by existing technology; Figure 3 This is another structural diagram of a second type of power supply system provided by existing technology; Figure 4 This is another structural diagram of a second type of power supply system provided by existing technology; Figure 5 This is a schematic diagram of the response waveform of a busbar to a load in a conventional power supply system provided by existing technology; Figure 6 This is a voltage diagram of a traditional power supply system provided by existing technology; Figure 7 This is a schematic diagram of the pulse power supply output waveform of a conventional power supply system provided by existing technology; Figure 8 This is a schematic diagram of the DC bus power supply system for pulse electroplating provided in an embodiment of the present invention; Figure 9 This is another structural schematic diagram of the pulse electroplating power supply DC bus power supply system provided in the embodiments of the present invention; Figure 10 This is another structural schematic diagram of the pulse electroplating power supply DC bus power supply system provided in the embodiments of the present invention; Figure 11 This is another structural schematic diagram of the pulse electroplating power supply DC bus power supply system provided in the embodiments of the present invention; Figure 12 This is a schematic diagram of the response waveform of the DC bus power supply system for pulse electroplating power supply provided in an embodiment of the present invention to the load. Figure 13 This is a voltage schematic diagram of the DC bus power supply system for pulse electroplating provided in an embodiment of the present invention; Figure 14 This is a schematic diagram of the pulse power output waveform of the DC bus power supply system for pulse electroplating provided in an embodiment of the present invention. Detailed Implementation

[0023] To facilitate understanding of the present invention, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of the invention are illustrated in the drawings. However, the invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete.

[0024] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0025] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the specification of this invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0026] This invention provides a DC bus power supply system for pulse electroplating power supplies, as per reference. Figure 8 ,include: Solid-state transformer 200, whose input terminal is connected to AC power grid 100, is used to convert the AC power provided by AC power grid 100 into DC power output; A common DC bus 300 is connected to the output terminal of the solid-state transformer 200 and is used to collect the DC power output by the solid-state transformer 200. The pulse electroplating power supply unit 420 has its input terminal connected to the common DC bus 300, and is used to output pulse electroplating power to the load unit 500 using the DC power provided by the common DC bus 300.

[0027] The solid-state transformer 200 (SST) is the power access channel from the AC grid 100 side to the common DC bus 300. The input terminal of the solid-state transformer 200 is connected to the AC grid 100, for example, if the AC grid 100 is a 10kV high-voltage grid. The solid-state transformer 200 is used to convert the high-voltage AC power provided by the AC grid 100 into DC power output. The solid-state transformer 200 adopts high-frequency isolation conversion technology, which can achieve high-voltage isolation between the primary and secondary sides, with an isolation withstand voltage of up to 45kV.

[0028] In some implementations, the output voltage of the solid-state transformer 200 is set to a constant value and operates at that constant voltage. This allows the power conversion circuitry within the solid-state transformer 200 to operate near its designed ideal operating point, which helps maintain high conversion efficiency. Since the output voltage of the solid-state transformer 200 is constant, rather than wide-range adjustable, its control strategy is relatively simple and stable, reducing system control complexity. Furthermore, the solid-state transformer 200 operates in constant voltage mode, exhibiting low internal resistance characteristics. This is particularly important for applications requiring pulsed power supply to the load unit 500; the low internal resistance DC source can maintain stable output voltage during sudden current changes in the load unit 500, reducing voltage drops and fluctuations. In other implementations, the output voltage of the solid-state transformer 200 can also be variable. The solid-state transformer 200 adjusts the output voltage according to actual conditions to meet requirements, for example, allowing for active adjustments within a very small range (e.g., ±2% to ±5%) necessary to suppress circulating currents, such as those caused by switching ripple from power devices, transient fluctuations due to load changes, and the need to suppress circulating currents.

[0029] The common DC bus 300 connects to the output of the solid-state transformer 200 and is used to collect the DC power output from the solid-state transformer 200. The common DC bus 300 is a shared DC transmission line; the electrical energy output from the solid-state transformer 200 is first transmitted to this common DC bus 300. The common DC bus 300 uses DC transmission; compared to traditional three-phase AC power supply, the DC bus only requires two conductors (positive and negative) to achieve power transmission, resulting in lower line losses, lower laying costs, and easier construction. The voltage level of the common DC bus 300 is determined by the output voltage of the solid-state transformer 200. The common DC bus 300 can operate at a constant voltage, ensuring that each load unit 500 connected to it receives a stable power supply voltage.

[0030] The input terminal of the pulse electroplating power supply unit 420 is connected to the common DC bus 300, and is used to output pulse electroplating power to the load unit 500 using the DC power provided by the common DC bus 300. The pulse electroplating power supply unit 420 is an electrical load connected to the common DC bus 300. Since the common DC bus 300 already provides DC power, the pulse electroplating power supply unit 420 does not need to perform AC-to-DC conversion, therefore, the pulse electroplating power supply unit 420 does not have an internal AC / DC rectifier stage. After drawing power from the common DC bus 300, the pulse electroplating power supply unit 420 converts the DC power from the bus into a square wave pulse current that meets the requirements of the electroplating process, and supplies it to the load unit 500. The load unit 500 can be used in an electrolytic copper foil pulse electroplating production line; for example, the load unit 500 is an electroplating tank. Since the common DC bus 300 can be a low-resistance constant voltage source, when the pulse electroplating power supply unit 420 outputs pulse electroplating power, the bus voltage on its input side is not easily affected by pulse power fluctuations, which is beneficial to improving the rise slope of the pulse electroplating power supply current and the quality of the output waveform. In some embodiments, the pulse electroplating power output by the pulse electroplating power supply unit 420 reaches tens of thousands of amperes.

[0031] In some embodiments, a constant-gain isolated DC / DC unit 410 is provided between the common DC bus 300 and the pulse electroplating power supply unit 420. Specifically, the input terminal of the constant-gain isolated DC / DC unit 410 is connected to the common DC bus 300, and the output terminal is connected to the input terminal of the pulse electroplating power supply unit 420. The constant-gain isolated DC / DC unit 410 uses a fixed-ratio isolated DC / DC converter to convert the high-voltage DC power on the common DC bus 300 to a fixed voltage gain before outputting it to the pulse electroplating power supply unit 420. Since the voltage gain of the constant-gain isolated DC / DC unit 410 is a fixed value, its internal power devices always operate near their optimal operating point, enabling soft switching across the entire load range and achieving high conversion efficiency. The constant-gain isolated DC / DC unit 410 also provides electrical isolation between the common DC bus 300 side and the pulse electroplating power supply unit 420 side, enhancing the system's safety and anti-interference capability. Furthermore, since the constant-gain isolated DC / DC unit 410 operates in fixed-gain mode, its control is simple and highly reliable, eliminating the need for complex closed-loop regulation required by wide-range voltage regulators. In practical implementation, this constant-gain isolated DC / DC unit 410 can employ an LLC resonant converter, operating at the resonant frequency point to achieve the highest conversion efficiency and optimal electromagnetic compatibility performance.

[0032] Regarding the solid-state transformer 200, in specific implementations, considering efficiency and cost-effectiveness, the silicon carbide devices commonly used in pulse power supplies are currently 1200V. Therefore, in this embodiment, the DC voltage output by the solid-state transformer 200 is set in the range of 700V to 900V, for example, the DC voltage is 700V, 750V, 800V, 850V or 900V. Through extensive experiments and engineering verification, the applicant discovered that the selection of this voltage range has non-obvious technical effects: When the voltage of the common DC bus 300 is below 700V, the current of the common DC bus 300 increases significantly under the same transmission power. On the one hand, this leads to a quadratic increase in the copper loss of the common DC bus 300 line. On the other hand, the input voltage of the constant gain isolation DC / DC unit 410 is too low, making it difficult to maintain sufficient gain at the resonant frequency point to support the pulse peak power. The voltage drop of the common DC bus 300 exceeds 8% when the load unit 500 is switched in, which seriously affects the rise slope of the pulse current. When the voltage of the common DC bus 300 is above 900V, SiC devices with a withstand voltage of 1700V or higher must be selected. These devices not only cost more than 2.5 times that of 1200V devices, but also significantly increase switching losses. The insulation level of the high-frequency transformer needs to be upgraded from basic insulation to reinforced insulation, resulting in increased transformer leakage inductance, decreased coupling coefficient, and an overall reduction in conversion efficiency of 2% to 3%. This invention sets the bus in the range of 700V to 900V, which can achieve low-loss high-frequency soft switching using mature 1200V SiC devices, and ensure that the voltage drop of the common DC bus 300 does not exceed 5% when the pulse electroplating power supply unit 420 outputs tens of thousands of amperes of transient peak current. It is the optimal engineering range that takes into account device cost, conversion efficiency and pulse dynamic response.

[0033] In this invention, reference Figures 12 to 14 , Figure 12 A schematic diagram of the busbar and its response waveform to the load is shown. Figure 13 The diagram shows the voltage supply curves, where the yellow curve represents the power supply curve for the solid-state transformer 200, and the blue curve represents the power supply curve for the common DC bus 300. Figure 14A schematic diagram of the pulse power supply output waveform is shown. By using a solid-state transformer 200 to convert the AC power from the AC grid 100 to DC power and outputting it to the common DC bus 300, the pulse electroplating power supply unit 420 draws power from the common DC bus 300 and outputs the pulse electroplating power to the load unit 500. This eliminates the need for an AC / DC rectifier circuit for each pulse power supply in traditional PFC rectifier or uncontrolled three-phase rectifier bridge schemes. It also eliminates harmonics, grid flicker, and resonance problems caused by multiple pulse power supplies operating simultaneously in traditional AC power supply schemes. Furthermore, it avoids overcurrent or bus undervoltage faults caused by insufficient dynamic response of the PFC control loop. Simultaneously, it completely eliminates the influence of the six-pulse low-frequency ripple on the pulse power supply output current waveform in three-phase uncontrolled rectifier schemes, achieving a reconstructed power supply architecture for the pulse electroplating power supply. The overall power supply architecture is simple and easy to implement, and it improves grid power supply efficiency. The solid-state transformer 200 serves as the only power access channel on the AC grid 100 side, realizing… The system achieves electrical isolation between the AC grid 100 and the load unit 500, and ensures that energy can only flow unidirectionally from the AC grid 100 to the common DC bus 300, preventing reverse energy feedback to the AC grid 100 and eliminating the need for grid connection approval. The solid-state transformer 200 outputs to the common DC bus 300 instead of the load unit 500, allowing it to operate at the ideal resonant operating point under high voltage and constant voltage conditions. This eliminates the need for complex constant current control, solving the problem of the solid-state transformer 200 being unengineerable in low-voltage, high-current direct-connected load scenarios due to its own design difficulties. The system features low power conversion losses and high efficiency, while achieving extremely low power supply internal resistance. It effectively suppresses bus voltage fluctuations under pulsating conditions in the load unit 500, ensuring the steepness of the pulse current's rising and falling edges and improving electroplating quality. The centralized power supply mode of the common DC bus 300 significantly reduces line current and line losses, simplifies the factory power line laying scheme, and improves power supply reliability.

[0034] In some specific embodiments of this application, reference is made to Figures 9-11 The system also includes an auxiliary DC power supply unit for outputting auxiliary DC power. The common DC bus 300 is connected to the output terminal of the auxiliary DC power supply unit. The common DC bus 300 collects the DC power output by the solid-state transformer 200 and the auxiliary DC power output by the auxiliary DC power supply unit.

[0035] The system also includes an auxiliary DC power supply unit, which is used to output auxiliary DC power. The common DC bus 300 is connected to the output terminal of the auxiliary DC power supply unit, so that the DC power output by the solid-state transformer 200 and the auxiliary DC power output by the auxiliary DC power supply unit are collected on the common DC bus 300.

[0036] The auxiliary DC power supply unit can take various forms, such as an energy storage unit or a renewable energy generation unit. The introduction of the auxiliary DC power supply unit transforms the common DC bus 300 into a multi-terminal DC power supply network. The solid-state transformer 200 and the auxiliary DC power supply unit complement each other: the solid-state transformer 200 provides basic power, while the auxiliary DC power supply unit supplements the common DC bus 300 under specific conditions, or draws power from the common DC bus 300 for storage when there is excess power. This multi-terminal power supply architecture improves power supply flexibility and reliability. When one power supply unit fails to supply power, other power supply units can continue to supply power, achieving the effect of an uninterruptible power supply. Through the energy collection function of the common DC bus 300, the power output from each power supply unit is uniformly collected and then supplied to the pulse electroplating power supply unit 420, which in turn supplies power to the load unit 500, eliminating the need for separate power distribution lines for each power supply unit.

[0037] In some implementations, since the pulse electroplating power supply in the factory is huge and many load units 500 are distributed, the number of the above-mentioned solid-state transformer 200, auxiliary DC power supply unit and pulse electroplating power supply unit 420 can be flexibly configured according to the actual power size and distribution requirements of the load units 500, that is, configured into a power matrix that can meet the requirements, thereby meeting the different loads and site equipment installation requirements of the factory and improving the convenience of engineering construction and maintenance.

[0038] In some specific embodiments of this application, reference is made to Figure 9 The auxiliary DC power supply unit includes a photovoltaic DC power supply unit 600, which includes a photovoltaic source 620 and an MPPT module 610. The photovoltaic source 620 is connected to the MPPT module 610, and the MPPT module 610 is also connected to the common DC bus 300.

[0039] The auxiliary DC power supply unit includes a photovoltaic DC power supply unit 600. The photovoltaic DC power supply unit 600 consists of a photovoltaic source 620 and an MPPT module 610. The photovoltaic source 620 is connected to the MPPT module 610, and the MPPT module 610 is also connected to a common DC bus 300. Figure 9 As shown, the photovoltaic DC power supply unit 600 is connected to the common DC bus 300 to provide a new energy access port for the system.

[0040] Photovoltaic source 620 is a photovoltaic power generation module that converts solar energy into direct current output. The output characteristics of photovoltaic source 620 are affected by light intensity and temperature, and its output voltage and current vary with environmental conditions. In some embodiments, photovoltaic source 620 is a photovoltaic matrix composed of multiple solar panels.

[0041] The MPPT module 610 is connected between the photovoltaic source 620 and the common DC bus 300. It receives DC power from the photovoltaic source 620 and outputs power to the common DC bus 300. The MPPT module 610, short for Maximum Power Point Tracking module, is an important electrical module in photovoltaic systems. By monitoring the voltage and current output of the photovoltaic source 620 in real time, the MPPT module 610 uses a specific algorithm to adjust the load impedance of the photovoltaic source 620, thereby finding and tracking the operating point where the photovoltaic source 620 outputs maximum power. Commonly used MPPT control algorithms include the perturbation-observation method, the incremental conductance method, and the constant voltage tracking method. For example, the perturbation-observation method periodically changes the load impedance and observes the power change. If the power increases, the impedance is changed in the same direction; otherwise, the direction is changed, and so on, until the system stabilizes near the maximum power point. In this invention, the specific circuit structure of the MPPT module 610 is not limited, as long as it can realize the corresponding function of tracking the maximum power point in the photovoltaic DC power supply unit 600.

[0042] The output of the photovoltaic DC power supply unit 600 is directly connected to the common DC bus 300. The generated power is directly supplied to the pulse electroplating power supply unit 420 through the common DC bus 300, without the need for a grid-connected inverter or AC / DC conversion. This connection method reduces power conversion levels, improves the utilization efficiency of photovoltaic power, and since all power is consumed internally on the DC side, there is no need to feed power back to the grid, and no grid connection approval procedures are required. The factory can flexibly configure the photovoltaic capacity according to its own consumption needs, using solar energy to supply power to the common DC bus 300 during the day, reducing the energy supplemented from the grid.

[0043] In some specific embodiments of this application, reference is made to Figure 10 The auxiliary DC power supply unit includes a battery DC energy storage unit 700, which includes an energy storage battery 720 and a bidirectional DC / DC module 710. The energy storage battery 720 is connected to the bidirectional DC / DC module 710, and the DC / DC module is also connected to the common DC bus 300.

[0044] The auxiliary DC power supply unit includes a battery DC energy storage unit 700. The battery DC energy storage unit 700 consists of an energy storage battery 720 and a bidirectional DC / DC module 710. The energy storage battery 720 is connected to the bidirectional DC / DC module 710, and the bidirectional DC / DC module 710 is also connected to a common DC bus 300. Figure 10 As shown, the battery DC energy storage unit 700 is connected to the common DC bus 300 to realize time-shifted storage and release of electrical energy.

[0045] The energy storage battery 720 is used to store electrical energy and can be a rechargeable battery such as a lithium battery pack. When it is necessary to store electrical energy, the energy storage battery 720 receives electrical energy from the common DC bus 300 and stores it; when it is necessary to release electrical energy, the energy storage battery 720 outputs the stored electrical energy.

[0046] The bidirectional DC / DC module 710 is a module that enables bidirectional power conversion between the energy storage battery 720 and the common DC bus 300. The bidirectional DC / DC module 710 has two DC ports: one connected to the energy storage battery 720 and the other connected to the common DC bus 300. The bidirectional DC / DC module 710 is a DC-to-DC module that can convert input DC power into DC output at different voltage levels. It is available in three types: buck, boost, and buck-boost. For the buck type, when the switching transistor is on, the input voltage is applied to the inductor and the load, the inductor stores energy, and the current increases; when the switching transistor is off, the inductor releases energy to the load through the diode, maintaining the load current. The output voltage can be adjusted by controlling the duty cycle of the switching transistor to achieve the buck function. For boost converters, when the switching transistor is on, the input voltage charges the inductor to store energy; when the switching transistor is off, the induced electromotive force generated by the inductor is superimposed on the input voltage, charging the capacitor and supplying power to the load through the diode, thereby boosting the output voltage. The output voltage can also be adjusted by controlling the duty cycle. For buck-boost converters, the principles of buck and boost are combined, allowing the output voltage to be either higher or lower than the input voltage. In this invention, the specific circuit structure of the bidirectional DC / DC module 710 is not limited, as long as it can achieve the corresponding functions of a bidirectional DC / DC module.

[0047] In this embodiment, when transmitting electrical energy from the common DC bus 300 to the energy storage battery 720, the bidirectional DC / DC module 710 operates in buck mode, converting the high-voltage DC power from the common DC bus 300 to a lower voltage suitable for charging the energy storage battery 720; when transmitting electrical energy from the energy storage battery 720 to the common DC bus 300, the bidirectional DC / DC module 710 operates in boost mode, boosting the low-voltage DC power from the energy storage battery 720 to a level matching the voltage of the common DC bus 300.

[0048] Through the battery DC energy storage unit 700, the system can achieve time-shifting of electrical energy. Specifically, during off-peak hours when grid electricity prices are low, power is drawn from the common DC bus 300 and stored in the energy storage battery 720; during peak hours when grid electricity prices are high, the energy stored in the energy storage battery 720 is released to the common DC bus 300 to power the pulse electroplating power supply unit 420, which then supplies power to the load unit 500, thus achieving peak shaving and valley filling and reducing electricity costs. This energy storage access method is located on the DC side, does not require grid connection approval, and offers flexible configuration.

[0049] In some specific embodiments of this application, reference is made to Figure 11 The auxiliary DC power supply unit includes a photovoltaic DC power supply unit 600 and a battery DC energy storage unit 700. The photovoltaic DC power supply unit 600 includes a photovoltaic source 620 and an MPPT module 610. The photovoltaic source 620 is connected to the MPPT module 610, and the MPPT module 610 is also connected to the common DC bus 300. The battery DC energy storage unit 700 includes an energy storage battery 720 and a bidirectional DC / DC module 710. The energy storage battery 720 is connected to the bidirectional DC / DC module 710, and the DC / DC module is also connected to the common DC bus 300.

[0050] In this embodiment, the auxiliary DC power supply unit includes both a photovoltaic DC power supply unit 600 and a battery DC energy storage unit 700, such as... Figure 11 As shown, this constitutes a three-port DC power supply architecture.

[0051] The structure of the photovoltaic DC power supply unit 600 is the same as described in the above embodiment, including a photovoltaic source 620 and an MPPT module 610. The photovoltaic source 620 is connected to the MPPT module 610, and the MPPT module 610 is also connected to the common DC bus 300. Further details will not be provided. The structure of the battery DC energy storage unit 700 is the same as described in the above embodiment, including an energy storage battery 720 and a bidirectional DC / DC module 710. The energy storage battery 720 is connected to the bidirectional DC / DC module 710, and the bidirectional DC / DC module 710 is also connected to the common DC bus 300. Further details will not be provided.

[0052] The photovoltaic DC power supply unit 600 and the battery DC energy storage unit 700 are both connected to the common DC bus 300. They can indirectly exchange energy through the common DC bus 300. Specifically, when photovoltaic power generation exceeds load consumption, excess photovoltaic energy can be charged into the energy storage battery 720 via the bidirectional DC / DC module 710 through the common DC bus 300. When photovoltaic power generation is insufficient, the energy storage battery 720 releases energy back to the common DC bus 300 through the bidirectional DC / DC module 710 to supplement power supply. These two auxiliary power supply units work in conjunction with the solid-state transformer 200 to form a three-port DC power supply architecture, achieving multi-energy complementarity between the grid, photovoltaics, and energy storage. The photovoltaic DC power supply unit 600 addresses the issue of renewable energy absorption, while the battery DC energy storage unit 700 addresses the issue of energy time shift. Their combination maximizes renewable energy utilization and reduces electricity costs.

[0053] In some specific embodiments of this application, reference is made to Figures 9-11The system also includes an energy management system 800, which is connected to the solid-state transformer 200, the pulse electroplating power supply unit 420, and the auxiliary DC power supply unit. In the coordinated control mode, when the photovoltaic DC power supply unit 600 or the battery DC energy storage unit 700 releases electrical energy to the common DC bus 300, the energy management system 800 simultaneously issues a power reduction command to the solid-state transformer 200, reducing its power intake from the AC grid 100. This prioritizes the absorption of new energy and stored energy while maintaining a constant voltage on the common DC bus 300, achieving a dynamic balance between grid power supply, photovoltaic power supply, and energy storage power supply. This coordinated control module ensures that the common DC bus 300 always operates in a low internal resistance state, further suppressing the impact of pulse load disturbances on the bus voltage.

[0054] The Energy Management System 800 (EMS) is the core of the system's control. It connects to the solid-state transformer 200, the pulse electroplating power supply unit 420, and the auxiliary DC power supply unit via communication lines. It collects operational status information from each unit and issues control commands. Specifically, the information that the Energy Management System 800 can acquire includes: the voltage of the common DC bus 300, the output power of the solid-state transformer 200, the output / input power of each auxiliary DC power supply unit, the state of charge of the energy storage battery 720, the photovoltaic power generation capacity, the load power of the pulse electroplating power supply, and the current grid electricity price period. Based on the above information, the energy management system 800 executes energy dispatch decisions: for example, when photovoltaic power generation is excessive and the energy storage battery 720 is not full, the bidirectional DC / DC module 710 is dispatched to store excess photovoltaic power in the energy storage battery 720; during peak grid electricity price periods, the energy storage battery 720 and / or photovoltaic source 620 are prioritized to supply power to the common DC bus 300, reducing the amount of power drawn by the solid-state transformer 200 from the AC grid 100; during off-peak grid electricity price periods, the energy storage battery 720 is controlled to draw power from the common DC bus 300 for storage. The introduction of the energy management system 800 makes the coordinated operation between multiple energy supply units possible, effectively maximizing system energy efficiency and economic benefits.

[0055] In some specific embodiments of this application, reference is made to Figures 8-11 The solid-state transformer 200 includes a cascaded H-bridge rectifier module and an isolated DC / DC converter module. The input terminal of the cascaded H-bridge rectifier module is connected to the AC power grid 100, the output terminal of the cascaded H-bridge rectifier module is connected to the input terminal of the isolated DC / DC converter module, and the output terminal of the isolated DC / DC converter module is connected to the common DC bus 300.

[0056] In some implementations, the cascaded H-bridge rectifier module and the isolated DC / DC converter module are integrated into a single module. In other implementations, the cascaded H-bridge rectifier module and the isolated DC / DC converter module are two separate, interconnected modules.

[0057] The cascaded H-bridge (CHB) rectifier module is the front-end section of the solid-state transformer 200, with its input connected to the high-voltage side of the AC power grid 100. The cascaded H-bridge rectifier module consists of multiple cascaded H-bridge rectifier units. The inputs of each H-bridge rectifier unit are connected in series to accommodate high-voltage input, and each H-bridge rectifier unit rectifies the AC power into an independent DC voltage. The outputs of each H-bridge rectifier unit are connected in series or independently on the DC side, providing an intermediate DC voltage for subsequent stages. The cascaded H-bridge structure allows the solid-state transformer 200 to be directly connected to the medium-high voltage AC power grid 100 without the need for a power frequency step-down transformer, while simultaneously achieving power factor correction and low harmonic input on the grid side.

[0058] The isolated DC / DC converter module is the downstream stage of the solid-state transformer 200. Its input is connected to the intermediate DC voltage output from the cascaded H-bridge rectifier module, and its output is connected to the common DC bus 300. The isolated DC / DC converter module uses a high-frequency transformer to achieve electrical isolation between the primary and secondary sides, while simultaneously converting the intermediate DC voltage to a set output DC voltage (a voltage value within the range of 700V to 900V). The isolated DC / DC converter module can further employ an LLC resonant topology, operating at the resonant frequency point. Narrow-range frequency modulation achieves current sharing among multiple modules, maintaining soft switching throughout to achieve maximum conversion efficiency. Due to the use of high-frequency conversion technology, the transformer in the isolated DC / DC converter module is much smaller than a power frequency transformer of the same power rating. The isolated DC / DC converter module can further employ multiple conversion units connected in parallel to expand power capacity.

[0059] Through the two-stage structure of the solid-state transformer 200, a single-stage isolated transformation from the high-voltage AC grid 100 to the low-voltage common DC bus 300 is realized. This eliminates the need for traditional power frequency step-down transformers and independent AC / DC conversion stages for each load node, significantly simplifying the system architecture and improving the efficiency from the grid to the power source.

[0060] This invention also provides a method for supplying power to the DC bus of a pulse electroplating power supply, applied to the pulse electroplating power supply DC bus power supply system as described in any of the above embodiments, comprising the following steps: The solid-state transformer 200 converts the AC power provided by the AC power grid 100 into DC power and outputs it to the common DC bus 300; The common DC bus 300 collects the DC power output from the solid-state transformer 200; The pulse electroplating power supply unit 420 draws power from the common DC bus 300 and outputs pulse electroplating power to the load unit 500.

[0061] First, the solid-state transformer 200 operates, converting the AC power supplied by the AC power grid 100 into DC power and outputting it to the common DC bus 300. In this step, the solid-state transformer 200 performs a complete AC-DC conversion function, with its output voltage set within the range of 700V to 900V.

[0062] Secondly, the common DC bus 300 collects the DC power output from the solid-state transformer 200. As the central node for power collection and distribution, the common DC bus 300 collects the DC power output from the solid-state transformer 200. Since the output voltage of the solid-state transformer 200 can be set to a constant value, the voltage on the common DC bus 300 is maintained near the set value.

[0063] Finally, the pulse electroplating power supply unit 420 draws power from the common DC bus 300 and outputs pulse electroplating power to the load unit 500. The pulse electroplating power supply unit 420 uses the DC power provided by the common DC bus 300 as input and generates a square wave pulse current that meets the requirements of the electroplating process through its internal pulse generation circuit, supplying the load unit 500, such as the electroplating tank. Because the DC power provided by the common DC bus 300 has a stable voltage and low equivalent internal resistance, the bus voltage at the input terminal of the pulse electroplating power supply unit 420 is not easily affected by pulse power fluctuations when outputting pulse current, which helps maintain the waveform quality and rise slope of the output pulse current.

[0064] In some specific embodiments of this application, the system further includes an auxiliary DC power supply unit, which includes a battery DC energy storage unit 700. The battery DC energy storage unit 700 includes an energy storage battery 720 and a bidirectional DC / DC module 710. The energy storage battery 720 is connected to the bidirectional DC / DC module 710, and the DC / DC module is also connected to the common DC bus 300. The method further includes the following steps: Obtain current grid electricity price information for the specified time period; During off-peak electricity pricing periods, the bidirectional DC / DC module 710 transmits electrical energy from the common DC bus 300 to the energy storage battery 720 for storage. During peak electricity price periods, the bidirectional DC / DC module 710 transmits the electrical energy stored in the energy storage battery 720 to the common DC bus 300.

[0065] The structure of the battery DC energy storage unit 700 is the same as described in the above embodiment, including an energy storage battery 720 and a bidirectional DC / DC module 710. The energy storage battery 720 is connected to the bidirectional DC / DC module 710, and the bidirectional DC / DC module 710 is also connected to the common DC bus 300. The details will not be repeated here.

[0066] First, obtain the current grid electricity price time period information. This information can be obtained through communication with the grid side or determined based on a preset electricity price time period table. Electricity prices are typically divided into off-peak electricity price periods (i.e., periods when grid electricity prices are lower) and peak electricity price periods (i.e., periods when grid electricity prices are higher), and sometimes also include flat electricity price periods (i.e., periods when grid electricity prices are normal).

[0067] During off-peak electricity pricing periods, the bidirectional DC / DC module 710 transfers electrical energy from the common DC bus 300 to the energy storage battery 720 for storage. Specifically, the bidirectional DC / DC module 710 operates in buck mode, reducing the high-voltage DC power from the common DC bus 300 to a voltage suitable for charging the energy storage battery 720, thus storing the electrical energy in the battery 720 as chemical energy. This step utilizes low-cost electricity during off-peak pricing periods for energy storage, reducing energy storage costs.

[0068] During peak electricity price periods, the bidirectional DC / DC module 710 transmits the electrical energy stored in the energy storage battery 720 to the common DC bus 300. Specifically, the bidirectional DC / DC module 710 operates in boost mode, boosting the low-voltage DC power output from the energy storage battery 720 to a level matching the voltage of the common DC bus 300, and releasing it to the common DC bus 300 to power the pulse electroplating power supply unit 420, which in turn supplies power to the load unit 500. This step releases the stored electrical energy during peak electricity price periods, replacing the high-cost electricity drawn from the AC grid 100, thus achieving peak shaving and valley filling.

[0069] Through the above steps, electricity cost optimization is achieved by utilizing the price difference: charging during off-peak hours and discharging during peak hours, thus reducing the average daily electricity price. This scheduling method is automatically executed by the energy management system 800 based on electricity price information, requiring no manual intervention.

[0070] In some specific embodiments of this application, the system further includes an auxiliary DC power supply unit, which includes a photovoltaic DC power supply unit 600 and a battery DC energy storage unit 700. The photovoltaic DC power supply unit 600 includes a photovoltaic source 620 and an MPPT module 610. The photovoltaic source 620 is connected to the MPPT module 610, and the MPPT module 610 is also connected to the common DC bus 300. The battery DC energy storage unit 700 includes an energy storage battery 720 and a bidirectional DC / DC module 710. The energy storage battery 720 is connected to the bidirectional DC / DC module 710, and the DC / DC module is also connected to the common DC bus 300. The method further includes the following steps: The photovoltaic source 620 outputs auxiliary DC power to the MPPT module 610; The MPPT module 610 performs maximum power point tracking and voltage conversion on the auxiliary DC power output from the photovoltaic source 620, and then outputs it to the common DC bus 300. The voltage of the common DC bus 300 is detected. When the voltage of the common DC bus 300 is higher than a preset voltage threshold, the bidirectional DC / DC module 710 transfers at least a portion of the electrical energy on the common DC bus 300 to the energy storage battery 720 for storage.

[0071] The structure of the photovoltaic DC power supply unit 600 is the same as described in the above embodiment, including a photovoltaic source 620 and an MPPT module 610. The photovoltaic source 620 is connected to the MPPT module 610, and the MPPT module 610 is also connected to the common DC bus 300. Further details will not be provided. The structure of the battery DC energy storage unit 700 is the same as described in the above embodiment, including an energy storage battery 720 and a bidirectional DC / DC module 710. The energy storage battery 720 is connected to the bidirectional DC / DC module 710, and the bidirectional DC / DC module 710 is also connected to the common DC bus 300. Further details will not be provided.

[0072] First, the photovoltaic source 620 outputs DC power to the MPPT module 610. Under sunlight conditions, the photovoltaic source 620 converts solar energy into DC power for output, and its output voltage fluctuates with changes in light intensity and temperature.

[0073] Secondly, the MPPT module 610 performs maximum power point tracking and voltage conversion on the DC power output from the photovoltaic source 620 before outputting it to the common DC bus 300. The MPPT module 610 monitors the output voltage and current of the photovoltaic source 620 in real time and adjusts the equivalent input impedance to ensure the photovoltaic source 620 operates at its maximum power output point. Simultaneously, the MPPT module 610 converts the variable output voltage of the photovoltaic source 620 into a constant voltage output that matches the voltage of the common DC bus 300, thus unidirectionally transmitting photovoltaic power to the common DC bus 300.

[0074] Next, the voltage of the common DC bus 300 is detected. The voltage of the common DC bus 300 is an important parameter reflecting the power balance of the system. When the photovoltaic power generation is greater than the load power consumption, the bus voltage tends to increase; conversely, it tends to decrease. The energy management system 800 collects the voltage value of the common DC bus 300 in real time.

[0075] When the voltage of the common DC bus 300 is higher than a preset voltage threshold, it indicates that the photovoltaic power generation exceeds the current load consumption, and the system has excess electrical energy. At this time, the bidirectional DC / DC module 710 transfers at least a portion of the electrical energy on the common DC bus 300 to the energy storage battery 720 for storage. Specifically, the bidirectional DC / DC module 710 operates in buck mode, transferring the excess electrical energy on the common DC bus 300 to the energy storage battery 720 for storage, avoiding waste of photovoltaic power and realizing local consumption and storage of photovoltaic power. When photovoltaic power generation is insufficient or photovoltaic power generation is not occurring at night, the energy storage battery 720 can release the stored electrical energy to the common DC bus 300 through the bidirectional DC / DC module 710 to supply the load unit 500.

[0076] Through the aforementioned coordinated scheduling, an optimized operation strategy is achieved, prioritizing local consumption of photovoltaic power generation, storing excess energy, and supplementing with energy storage when insufficient. This scheduling method enables the photovoltaic DC power supply unit 600 and the battery DC energy storage unit 700 to work together, maximizing the utilization rate of new energy sources and reducing the power and cost of drawing electricity from the grid.

[0077] In some implementations, if the number of current load units 500 is small, or the total power required by all current load units 500 is small, the solid-state transformer 200 only needs to provide a small amount of power to the common DC bus 300, and the function of the photovoltaic DC power supply unit 600 and the battery DC energy storage unit 700 in supplying power to the common DC bus 300 is limited. For example, when the current voltage of the common DC bus 300 is greater than a preset voltage, both the photovoltaic DC power supply unit 600 and the battery DC energy storage unit 700 shut down, and power is ultimately supplied to the load units 500 only through the solid-state transformer 200.

[0078] The present invention has the following advantages: (1) The AC power supply was eliminated, a three-port DC power supply system was constructed, the pulse power supply architecture was reconstructed, and the SST DC single-phase isolation power supply scheme was introduced, which created conditions for the access of photovoltaic and DC energy storage. The AC / DC power supply part of the traditional power transformer and pulse machine power supply was eliminated, which greatly simplified the system structure and improved the system working efficiency.

[0079] (2) A photovoltaic DC power supply unit 600 is set up, which directly converts solar energy to the public DC bus 300 through the MPPT module 610. This avoids the difficult approval of the power bureau's indicators and certifications, giving the factory a high degree of freedom of choice, flexibly configuring new energy sources to meet the factory's own consumption, and using solar energy during the day to supply power to the public DC bus 300, greatly reducing the energy supplemented from the AC grid 100, reducing the enterprise's electricity costs, and improving the utilization rate of new energy sources.

[0080] (3) Set up a 700-cell DC energy storage unit to realize the storage of off-peak electricity at night and the release of peak energy during the day to shave off peaks and fill valleys. Make comprehensive use of the electricity price difference to lower the average daily electricity price, further reduce electricity costs, and improve the efficiency of supporting facilities.

[0081] (4) By utilizing the energy management system 800 constructed between the photovoltaic DC power supply unit 600 and the battery DC energy storage unit 700, the energy management system 800 can actively schedule DC energy storage to cancel peak-valley pricing and fill valleys when the photovoltaic energy storage cannot be fully absorbed during the day. The photovoltaic system can directly supplement the energy storage battery 720, and make reasonable allocation between the two to make full use of energy, further reduce the factory's electricity costs, and improve the economic benefits and scientific utilization rate of DC power supply.

[0082] (5) The multi-port DC power supply scheme under the pulse DC power supply architecture greatly reduces the internal resistance of the power supply, provides a more ideal voltage source for the pulse electroplating power supply unit 420, perfectly solves the impact problem caused by the pulse power supply pulse condition and the reliability problem caused by the impact, greatly improves the mean time between failures, improves the factory production efficiency, solves the core problem of the impact of pulse on the working reliability of the pulse electroplating power supply unit 420, and greatly improves the power supply quality and power quality of the pulse electroplating power supply unit 420, which is of great significance.

[0083] (6) DC power supply perfectly eliminates the six-pulse ripple problem of pulse electroplating power supply unit 420, improves the output electrical performance index of pulse electroplating power supply unit 420, improves the quality of pulse electroplating power supply, greatly improves product quality, increases product value, and further improves the economic benefits of the factory.

[0084] (7) SST does not require additional power factor and harmonic compensation devices on the grid side, which simplifies the power distribution system, improves the reliability of the power distribution system, avoids harmonic oscillation, and fundamentally solves the structural contradiction that the pulse power supply must be efficient, have low harmonics and high power factor, as well as stable operation, good output dynamics, low output ripple and long fault-free time of the pulse electroplating power supply unit 420, thus achieving a win-win situation of wanting both and being good.

[0085] (8) The distributed DC power supply architecture allows factories to make flexible configurations according to their own needs.

[0086] (9) SST single-phase high-frequency isolation, the factory can connect to the photovoltaic DC power supply unit 600 and the battery DC energy storage unit 700 without approval or certification. The factory can flexibly configure the photovoltaic DC power supply unit 600 and the battery DC energy storage unit 700 according to its own consumption needs, which provides greater freedom for the factory's energy consumption design and creates higher economic benefits.

[0087] (10) The power supply was changed from low-voltage AC three-phase power supply to high-voltage positive and negative two-line centralized power supply mode, which greatly reduced line loss, greatly reduced laying cost, reduced construction difficulty and improved system reliability.

[0088] (11) The access of the three-port DC power supply system also produces the effect of redundant power supply, forming an uninterrupted power supply architecture. In the three power supply modes, except for photovoltaic DC power supply, when any of the other two power supply units fails and exits, the remaining power supply units can continue to supply power, providing a solid power supply guarantee for the factory's fault-free operation and the power supply's fault-free operation, and providing favorable power supply guarantee for improving the factory's high reliability requirements.

[0089] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0090] The embodiments described above are merely illustrative of several implementations of the present invention, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of the invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements all fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the appended claims.

Claims

1. A DC bus power supply system for pulse electroplating, characterized in that, include: A solid-state transformer, whose input terminal is connected to an AC power grid, is used to convert the AC power provided by the AC power grid into DC power output. A common DC bus is connected to the output terminal of the solid-state transformer and is used to collect the DC power output by the solid-state transformer. A pulse electroplating power supply unit, whose input terminal is connected to the common DC bus, is used to output pulse electroplating power to the load unit using the DC power provided by the common DC bus.

2. The pulse electroplating power supply DC bus power supply system according to claim 1, characterized in that, The system also includes an auxiliary DC power supply unit for outputting auxiliary DC power. The common DC bus is connected to the output terminal of the auxiliary DC power supply unit and collects the DC power output by the solid-state transformer and the auxiliary DC power output by the auxiliary DC power supply unit.

3. The pulse electroplating power supply DC bus power supply system according to claim 2, characterized in that, The auxiliary DC power supply unit includes a photovoltaic DC power supply unit, which includes a photovoltaic source and an MPPT module. The photovoltaic source is connected to the MPPT module, and the MPPT module is also connected to the common DC bus.

4. The pulse electroplating power supply DC bus power supply system according to claim 2, characterized in that, The auxiliary DC power supply unit includes a battery DC energy storage unit, which includes an energy storage battery and a bidirectional DC / DC module. The energy storage battery is connected to the bidirectional DC / DC module, and the DC / DC module is also connected to the common DC bus.

5. The pulse electroplating power supply DC bus power supply system according to claim 2, characterized in that, The auxiliary DC power supply unit includes a photovoltaic DC power supply unit and a battery DC energy storage unit. The photovoltaic DC power supply unit includes a photovoltaic source and an MPPT module. The photovoltaic source is connected to the MPPT module, and the MPPT module is also connected to the common DC bus. The battery DC energy storage unit includes an energy storage battery and a bidirectional DC / DC module. The energy storage battery is connected to the bidirectional DC / DC module, and the DC / DC module is also connected to the common DC bus.

6. The pulse electroplating power supply DC bus power supply system according to claim 2, characterized in that, The system also includes an energy management system, which is connected to the solid-state transformer, the pulse electroplating power supply unit, and the auxiliary DC power supply unit.

7. The pulse electroplating power supply DC bus power supply system according to claim 1, characterized in that, The solid-state transformer includes a cascaded H-bridge rectifier module and an isolated DC / DC converter module. The input terminal of the cascaded H-bridge rectifier module is connected to the AC power grid, the output terminal of the cascaded H-bridge rectifier module is connected to the input terminal of the isolated DC / DC converter module, and the output terminal of the isolated DC / DC converter module is connected to the common DC bus.

8. A method for supplying power to a pulse electroplating power supply via a DC bus, characterized in that, The pulse electroplating power supply DC bus power supply system as described in any one of claims 1-7 includes the following steps: The solid-state transformer converts the AC power supplied by the AC power grid into DC power and outputs it to the common DC bus. The common DC bus collects the DC power output from the solid-state transformer; The pulse electroplating power supply unit draws power from the common DC bus and outputs pulse electroplating power to the load unit.

9. The pulse electroplating power supply DC bus power supply method according to claim 8, characterized in that, The system further includes an auxiliary DC power supply unit, which includes a battery DC energy storage unit. The battery DC energy storage unit includes an energy storage battery and a bidirectional DC / DC module. The energy storage battery is connected to the bidirectional DC / DC module, and the DC / DC module is also connected to the common DC bus. The method further includes the following steps: Obtain current grid electricity price information for the specified time period; During off-peak electricity pricing periods, the bidirectional DC / DC module transmits electrical energy from the common DC bus to the energy storage battery for storage. During peak electricity price periods, the bidirectional DC / DC module transmits the electrical energy stored in the energy storage battery to the common DC bus.

10. The pulse electroplating power supply DC bus power supply method according to claim 8, characterized in that, The system further includes an auxiliary DC power supply unit, which comprises a photovoltaic DC power supply unit and a battery DC energy storage unit. The photovoltaic DC power supply unit includes a photovoltaic source and an MPPT module, with the photovoltaic source connected to the MPPT module, and the MPPT module also connected to the common DC bus. The battery DC energy storage unit includes an energy storage battery and a bidirectional DC / DC module, with the energy storage battery connected to the bidirectional DC / DC module, and the DC / DC module also connected to the common DC bus. The method further includes the following steps: The photovoltaic source outputs auxiliary DC power to the MPPT module; The MPPT module performs maximum power point tracking and voltage conversion on the auxiliary DC power output from the photovoltaic source, and then outputs it to the common DC bus. The voltage of the common DC bus is detected. When the voltage of the common DC bus is higher than a preset voltage threshold, the bidirectional DC / DC module transfers at least a portion of the electrical energy on the common DC bus to the energy storage battery for storage.

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