High voltage cascaded energy storage system and control method for high voltage cascaded energy storage system

Abstract

The application discloses a high-voltage cascaded energy storage system and a control method thereof. The energy storage system comprises a plurality of cascaded phase units, wherein one cascaded phase unit comprises a plurality of power matching units, one cascaded phase unit corresponds to one phase, and the alternating current output ends of the plurality of cascaded phase units are connected to a target high-voltage power grid through cascading. One power matching unit comprises a power conversion unit and two groups of battery clusters, the power conversion unit converts the direct current voltage output by the battery clusters into alternating current voltage, and the two direct current input ports of each power conversion unit are connected in parallel to the two groups of battery clusters respectively. The application solves the technical problem that the traditional high-voltage energy storage system has low integration, poor fault tolerance and cannot be directly connected to a high-voltage power grid due to the single matching mode of the power conversion system (PCS) and the battery clusters.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and more specifically, to a high-voltage cascaded energy storage system and a control method for the high-voltage cascaded energy storage system. Background Technology

[0002] In high-voltage energy storage systems, the matching and connection between the PCS (Power Conversion System) power conversion unit and the battery cluster is a core aspect of system design, directly affecting the power output, energy utilization, space utilization, and operational stability of the energy storage system.

[0003] Currently, high-voltage energy storage systems mostly use a design approach where a single cluster is matched with a single PCS unit, or multiple clusters are connected in parallel and then matched with a high-power PCS. This approach has the following technical drawbacks: The single-cluster-to-single-PCS design results in a large number of devices, low integration within the storage compartment, a large footprint, and complex system wiring, increasing equipment and construction costs. The multi-cluster parallel connection with a high-power PCS is prone to uneven charging and discharging between battery clusters; a single cluster failure can cause the entire PCS unit to shut down, resulting in poor system fault tolerance. Furthermore, the high-power PCS has high requirements for the battery-side voltage adaptation range, making it difficult to match the voltage gradient of the high-voltage cascaded system. The traditional matching structure has a fixed discharge rate design, which cannot simultaneously consider the power requirements of the high-voltage direct-connection system and the cycle life of the battery, leading to low system efficiency. Additionally, power distribution during cascaded PCS networking is prone to deviations, affecting grid connection stability. Meanwhile, most high-voltage energy storage systems currently use transformers for voltage boosting and grid connection. The matching of PCS and battery clusters does not take into account the technical requirements of transformerless high-voltage direct connection, and cannot adapt to the voltage and power matching requirements of 10kV high-voltage grid connection. It is difficult to meet the application requirements of high integration, high efficiency and high stability of high-voltage cascaded energy storage systems.

[0004] There is currently no effective solution to the above problems. Summary of the Invention

[0005] This invention provides a high-voltage cascaded energy storage system and a control method for the high-voltage cascaded energy storage system, so as to at least solve the technical problems of low integration, poor fault tolerance, and inability to be directly connected to the high-voltage grid caused by the single matching method between the PCS and the battery cluster in traditional high-voltage energy storage systems.

[0006] According to one aspect of the present invention, a high-voltage cascaded energy storage system is provided, comprising: a plurality of cascaded phase units, wherein each cascaded phase unit includes a plurality of power matching units, each cascaded phase unit corresponds to one phase, and the AC output terminals of the plurality of cascaded phase units are connected to a target high-voltage power grid after cascading; each power matching unit includes a power conversion unit and two sets of battery clusters, the power conversion unit converts the DC voltage output by the battery clusters into AC voltage; and the two DC input ports of each power conversion unit are respectively connected in parallel to the two sets of battery clusters.

[0007] Optionally, it also includes: a power conversion unit control module, used to disconnect the faulty battery cluster from the power conversion unit when a fault signal is received from any group of battery clusters, while maintaining the connection between another normally operating battery cluster and the power conversion unit, so that the output power of the power matching unit is not lower than a preset power threshold.

[0008] Optionally, it also includes: each battery cluster is connected to an independent battery management system, wherein the battery management system is used to collect voltage data, current data, state of charge data and temperature data of the battery cluster, and based on the voltage data, current data, state of charge data and temperature data, to determine whether there is a fault in the battery cluster, and to send the fault signal to the corresponding power conversion unit control module through a communication link.

[0009] Optionally, it also includes: multiple cascaded phase units integrated in the same AC / DC cascaded compartment, wherein the multiple cascaded phase units are arranged linearly along the length of the AC / DC cascaded compartment, the power matching units in each cascaded phase unit are symmetrically distributed, the battery clusters in each power matching unit are arranged directly above or below the power conversion unit, and the connection lines between the battery clusters and the power conversion unit adopt short-distance wiring.

[0010] Optionally, it also includes: an insulating support structure, wherein the battery cluster bracket, the power conversion unit housing, and the battery cluster casing are all isolated from the metal frame of the AC / DC cascade compartment through the insulating support structure, and the metal structure of the AC / DC cascade compartment is connected to the same potential through a grounding wire.

[0011] According to another aspect of the present invention, a control method for a high-voltage cascaded energy storage system is also provided, comprising: acquiring voltage data, current data, state of charge data, and temperature data of all battery clusters in the high-voltage cascaded energy storage system; determining whether any of the battery clusters is faulty based on the voltage data, current data, state of charge data, and temperature data; and, in the event that any group of battery clusters is faulty, disconnecting the faulty battery cluster from the corresponding power conversion unit, while maintaining the connection between another normally operating battery cluster and the power conversion unit, so that the output power of the power matching unit is not lower than a preset power threshold, wherein the power matching unit includes a power conversion unit and two groups of battery clusters.

[0012] According to another aspect of the present invention, a control device for a high-voltage cascaded energy storage system is also provided, comprising: an acquisition module for acquiring voltage data, current data, state of charge data, and temperature data of all battery clusters in the high-voltage cascaded energy storage system; a judgment module for judging whether any of the battery clusters is faulty based on the voltage data, current data, state of charge data, and temperature data; and a disconnection module for disconnecting the connection between the faulty battery cluster and the corresponding power conversion unit when any group of battery clusters is faulty, while maintaining the connection between another normally operating battery cluster and the power conversion unit, so that the output power of the power matching unit is not lower than a preset power threshold, wherein the power matching unit includes a power conversion unit and two groups of battery clusters.

[0013] According to another aspect of the present invention, a non-volatile storage medium is also provided, the non-volatile storage medium including a stored program, wherein, when the program is running, the device where the non-volatile storage medium is located is controlled to execute any of the above-described control methods for high-voltage cascaded energy storage systems.

[0014] According to another aspect of the present invention, a computer device is also provided, the computer device including a processor, the processor being configured to run a program, wherein the program, when running, executes any of the above-described control methods for a high-voltage cascaded energy storage system.

[0015] According to another aspect of the present invention, a computer program product is also provided, including a computer program that, when executed by a processor, implements any of the above-described control methods for a high-voltage cascaded energy storage system.

[0016] In this embodiment of the invention, a high-voltage cascaded energy storage system is adopted, which uses multiple cascaded phase units. Each cascaded phase unit includes multiple power matching units, and each cascaded phase unit corresponds to one phase. The AC output terminals of the multiple cascaded phase units are connected to the target high-voltage grid after cascading. Each power matching unit includes a power conversion unit and two sets of battery clusters. The power conversion unit converts the DC voltage output by the battery clusters into AC voltage. The two DC input ports of each power conversion unit are connected in parallel to the two sets of battery clusters, which achieves the purpose of improving system redundancy and voltage adaptation accuracy without increasing the number of PCS. This achieves the technical effects of maintaining the continuous operation of PCS even when a single cluster fails, accurately matching the DC voltage of the system to the 10kV direct connection requirement, and significantly improving the overall integration. This solves the technical problems of traditional high-voltage energy storage systems, which have low integration, poor fault tolerance, and inability to be directly connected to the high-voltage grid due to the single matching method of PCS and battery clusters. Attached Figure Description

[0017] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0018] Figure 1 This is a schematic diagram of a high-voltage cascaded energy storage system according to an optional embodiment of the present invention;

[0019] Figure 2 This is an electrical connection diagram of a power matching unit provided according to an optional embodiment of the present invention;

[0020] Figure 3 This is a schematic diagram of a cascaded structure of a single-phase AC / DC cascaded phase unit according to an optional embodiment of the present invention;

[0021] Figure 4 This is a schematic diagram of the overall layout of a three-phase integrated AC / DC cascaded compartment according to an optional embodiment of the present invention;

[0022] Figure 5 A hardware block diagram of a computer terminal for a control method of a high-voltage cascaded energy storage system is shown.

[0023] Figure 6 This is a schematic flowchart of a control method for a high-voltage cascaded energy storage system provided according to an embodiment of the present invention;

[0024] Figure 7 This is a structural block diagram of a control device for a high-voltage cascaded energy storage system provided according to an embodiment of the present invention.

[0025] Figure label:

[0026] 1-PCS power unit; 2-First cluster battery pack; 3-Second cluster battery pack; 4-PCS and battery AC / DC unit; 5-Liquid cooling system; 6-PCS main control system; 7-BMS integrated control system; 8-Phase A power unit; 9-Phase B power unit; 10-Phase C power unit; 11-AC / DC integrated system compartment. Detailed Implementation

[0027] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0028] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover a non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0029] According to an embodiment of the present invention, a high-voltage cascaded energy storage system embodiment is provided. Figure 1 This is a schematic diagram of a high-voltage cascaded energy storage system according to an optional embodiment of the present invention. Figure 2 This is an electrical connection diagram of a power matching unit according to an optional embodiment of the present invention. Figure 3 This is a schematic diagram of a cascaded structure of a single-phase AC / DC cascaded phase unit according to an optional embodiment of the present invention. Figure 4 This is a schematic diagram of the overall layout of a three-phase integrated AC / DC cascaded module according to an optional embodiment of the present invention, as shown below. Figures 1 to 4 As shown, the system includes: multiple cascaded phase units, wherein:

[0030] A cascaded phase unit includes multiple power matching units. One cascaded phase unit corresponds to one phase. The AC output terminals of multiple cascaded phase units are connected to the target high-voltage power grid after being cascaded.

[0031] In this section, the high-voltage cascaded energy storage system adopts a three-phase independent cascaded architecture, with three cascaded phase units (A, B, and C). Each phase unit independently completes DC-to-AC power conversion and voltage superposition. Each phase cascaded unit consists of 10 high-voltage cascaded PCS power units connected in series. Each PCS outputs approximately 1kV (based on a modulated DC input of 873.6V~1138.8V). After the 10 units are connected in series, the AC output voltage is superimposed to the 10kV level, meeting the grid connection requirements for direct connection to a 10kV grid without a transformer. The three-phase output is connected to a common grid connection point after being connected in parallel with a filter reactor and a circuit breaker, achieving balanced three-phase output. This structure eliminates the need for a traditional medium-voltage step-up transformer, directly cascading the voltage level from the DC side to the 10kV AC output. The overall system efficiency is increased to over 92%, which is 4 percentage points higher than the traditional transformer-connected solution, while significantly reducing equipment size, weight, and maintenance costs.

[0032] A power matching unit includes a power conversion unit and two battery clusters. The power conversion unit converts the DC voltage output by the battery clusters into AC voltage.

[0033] In this section, a power matching unit includes a power conversion unit (PCS) and two battery clusters. Each PCS can be a 167kW high-voltage cascaded converter with dual independent DC input interfaces, each connected to one battery cluster. The battery clusters can be fabricated using 3.2V / 314Ah lithium iron phosphate (LFP) cells, using a 1P104S configuration, with a single-pack voltage of 332.8V. Three battery packs are then connected in series using a 1P312S configuration to form battery cluster 2 / 3, with a single-cluster voltage range of 873.6V~1138.8V, resulting in 60 identical battery clusters 2 / 3. The two battery clusters are connected in parallel to the same PCS, ensuring precise matching of the PCS input voltage range with the parallel battery cluster voltage range, guaranteeing efficient system operation within the state of full charge (SOC) window. Each battery cluster consists of three 1P104S battery packs connected in series, ensuring high voltage consistency and stable PCS input. The PCS employs a multi-level topology (such as H-bridge cascade or NPC structure) to achieve efficient DC / AC conversion while maintaining output current harmonics THD <3%, meeting power quality standards.

[0034] The two DC input ports of each power conversion unit are connected in parallel to two sets of battery clusters.

[0035] In this section, the system constructs a "dual-input-single-output" power unit with fault isolation capability by configuring each PCS with dual DC input ports and independently connecting two sets of battery clusters in parallel. The PCS power unit uses a 167kW high-voltage cascaded PCS power unit, with each PCS connected to two independent battery clusters. The input voltage range is 873.6V~1138.8V, precisely matching 2 / 3 of the battery cluster's voltage range. This process completed the selection and commissioning of 30 PCS power units. When one set of battery clusters is identified by the BMS as having a fault such as overvoltage, undervoltage, overcurrent, or thermal runaway, the PCS main control system can disconnect the electrical connection of the faulty cluster within 20ms via a solid-state relay or DC contactor. Meanwhile, the other normal battery cluster can continue to supply power to the PCS, allowing the power matching unit to maintain partial power output (approximately 50%), ensuring uninterrupted system operation. This mechanism significantly improves the availability and fault tolerance of energy storage systems. Compared to the system-level failure caused by "shutdown upon failure of a single cluster" in the traditional single-cluster single-PCS scheme, this scheme can still maintain more than 95% power output even when a single point of failure occurs in 60 battery clusters. This dual-cluster parallel fault-tolerant architecture is the core technical support for achieving high-reliability operation of high-voltage direct-connection systems.

[0036] As an optional embodiment, it further includes: a power conversion unit control module, used to disconnect the faulty battery cluster from the power conversion unit when a fault signal is received from any group of battery clusters, while maintaining the connection between another normally operating battery cluster and the power conversion unit, so that the output power of the power matching unit is not lower than a preset power threshold.

[0037] Optionally, the power conversion unit control module is integrated into the PCS main control system and interacts with the BMS integrated control system in real time via a high-speed communication bus (e.g., CAN or industrial Ethernet). When any battery cluster is detected by the BMS as being in an unsustainable operating state due to faults such as overvoltage (>1150V), undervoltage (<850V), overcurrent (>120% of rated current), abnormal temperature, or insulation degradation, the BMS immediately sends a fault isolation command to the control module of the corresponding PCS. Within 20ms, the control module triggers a DC-side solid-state switch or contactor to quickly disconnect the electrical path of the faulty battery cluster, while maintaining continuous power supply to another healthy battery cluster, ensuring that the power matching unit can still continuously output at a level not less than 50% of its rated power (i.e., ≥83.5kW). The preset power threshold is set to 50% of the rated output according to the system design requirements. This threshold ensures that a single cluster fault does not trigger system-level protection shutdown, while maintaining the stability of the overall power output of the cascaded phase units, avoiding sudden load changes in adjacent PCS or voltage fluctuations at the grid connection point due to a single-point fault. This mechanism significantly improves the continuity and reliability of system operation, enabling the high-voltage cascaded energy storage system to still meet the grid's requirements for continuous power supply, frequency support, and dynamic response (<10ms) even in the event of a single cluster failure, thus achieving the high-availability operation goal of "no power loss during faults and no power interruption".

[0038] As an optional embodiment, it further includes: each battery cluster is connected to an independent battery management system, wherein the battery management system is used to collect voltage data, current data, state of charge data and temperature data of the battery cluster, and based on the voltage data, current data, state of charge data and temperature data, to determine whether there is a fault in the battery cluster, and to send the fault signal to the corresponding power conversion unit control module through a communication link.

[0039] Optionally, the system configures an independent distributed battery management system (BMS) for each 1P312S battery cluster (i.e., the first or second cluster) to achieve fine-grained monitoring of the operating status of a single cluster. Each BMS unit is deployed on the electrical interface side of the corresponding battery cluster, and uses high-precision sensors to collect in real time the total voltage, charge / discharge current, state of charge (SOC), and temperature distribution of multiple key nodes of its series-connected cells. The sampling frequency is no less than 10Hz to ensure the real-time performance and accuracy of the data response. The BMS incorporates a multi-level fault diagnosis algorithm, which, based on preset thresholds and dynamic trend analysis (such as voltage mutation rate, temperature rise rate, and SOC deviation), comprehensively judges whether the battery cluster has fault states such as overvoltage, undervoltage, overcurrent, thermal runaway, insulation abnormalities, or excessive differential voltage between individual cells. When any battery cluster is determined to have a valid fault, its corresponding BMS unit immediately sends a structured fault command to the PCS main control system 6 of the corresponding PCS power unit 1 through an electrically isolated high-speed industrial communication link (such as CAN 2.0B or RS-485 bus). The instruction includes key information such as: fault type code (e.g., "overvoltage" or "thermal runaway"), fault occurrence timestamp, and faulty battery cluster number (e.g., "2-1" or "3-2"). The communication link adopts a dual-channel redundancy design and common-mode rejection circuit to ensure stable transmission even in the high electromagnetic interference environment within the AC / DC integrated system compartment 11, preventing signal loss or false triggering. Upon receiving the fault instruction, the PCS main control system 6 triggers its DC-side solid-state relay or high-speed DC contactor within ≤20ms to immediately disconnect the electrical connection between the faulty battery cluster and the PCS power unit 1, while maintaining the continuous connection of another healthy battery cluster. This maintains the stable half-power (≥83.5kW) output of the PCS and battery AC / DC unit 4, ensuring uninterrupted operation of the A-phase power unit 8, B-phase power unit 9, or C-phase power unit 10. The "one cluster, one BMS" architecture enables a closed-loop control system with fault location accuracy down to the single cluster level, controllable response time, and control commands directly reaching the corresponding PCS. This avoids the response delay and misjudgment risks caused by channel sharing in traditional centralized BMS, and significantly improves the system's security and fault tolerance in multi-cluster parallel scenarios.

[0040] As an optional embodiment, it further includes: multiple cascaded phase units integrated in the same AC / DC cascaded compartment, wherein the multiple cascaded phase units are arranged linearly along the length of the AC / DC cascaded compartment, the power matching units in each cascaded phase unit are symmetrically distributed, the battery clusters in each power matching unit are arranged directly above or below the power conversion unit, and the connection lines between the battery clusters and the power conversion unit adopt short-distance wiring.

[0041] Optionally, within the AC / DC cascaded compartment, 10 core matching units are sequentially connected in a cascaded manner to form phase unit 8 of phase A, which has a capacity of 1.67MW. Phase units 9 and 10 of phases B and C are manufactured in the same manner, and the specifications and parameters of the three-phase phase units are completely identical. The three-phase phase units of A, B, and C are integrated into the same AC / DC integrated system compartment 11 in a symmetrical layout. The external dimensions of the compartment are 9600mm (width) × 5800mm (height) × 5200mm (depth). The 10 PCS power units 1 of each phase are arranged linearly along the length direction (i.e., the width direction) of the compartment, forming a compact and regular longitudinal array. The DC input port of each PCS power unit 1 is located on its front or lower side. Two sets of battery clusters (i.e., the first battery cluster PACK and the second battery cluster PACK) are arranged directly above and below the PCS power unit 1, respectively, forming an "up-down" or "down-up" mirror symmetrical structure. This symmetrical layout keeps the length of the DC connection copper busbars inside the PCS and battery AC / DC unit 4 to ≤1.2m, significantly shortening the current path, reducing parasitic inductance and contact resistance in the DC circuit, and effectively improving the overall energy efficiency of the system. All connection lines adopt a short-distance, compact wiring strategy to avoid cross-interference and facilitate the unified layout and maintenance of the liquid cooling system 5's piping. The PCS main control system 6 and the BMS integrated control system 7 are centrally deployed in the cabin control area, realizing centralized monitoring and coordinated control of 30 three-phase PCS power units 1 and 60 battery clusters, greatly simplifying the system wiring, debugging, and subsequent operation and maintenance processes.

[0042] As an optional embodiment, it also includes: an insulating support structure, wherein the battery cluster bracket, the power conversion unit housing, and the battery cluster casing are all isolated from the metal frame of the AC / DC cascade compartment through the insulating support structure, and the metal structure of the AC / DC cascade compartment is connected to the same potential through a grounding wire.

[0043] Optionally, a dedicated insulating support structure is installed inside the AC / DC integrated system compartment 11 to achieve electrical isolation and equipotential safety control under high-voltage operating conditions. Specifically, the battery rack (carrying the 2-first cluster battery pack and the 3-second cluster battery pack), the aluminum alloy or steel casing of the PCS power unit 1, and the battery pack casing (i.e., the encapsulated metal structure of 2 and 3) are all physically and electrically isolated from the metal frame of the AC / DC integrated system compartment 11 (including the compartment's base frame, side walls, and top plate) through high-strength, high-insulation engineering ceramic insulating pads, flame-retardant composite insulating sleeves, or customized insulating supports. This completely blocks the leakage path of up to 1138.8V (the system DC voltage formed by the 312S2P configuration) on the DC side through the metal structure to the compartment casing, effectively preventing the risk of short circuits to ground, partial discharge, or electric shock caused by environmental humidity, condensation, dust, or insulation aging. Meanwhile, the metal frame of the AC / DC integrated system compartment 11 is reliably connected to an independent grounding grid with low impedance (≤0.1Ω) via a multi-strand copper braided grounding wire with a cross-sectional area of ​​not less than 25mm². This ensures that all metal components within the compartment, including the PCS power unit 1 housing, battery rack, battery pack housing, liquid cooling system 5 piping supports, BMS integrated control system 7 chassis, and various metal rails, are at the same reference potential, forming a global equipotential body. This "isolation + equipotential" collaborative design ensures that even if a battery cluster experiences insulation failure or instantaneous overvoltage during high-voltage cascaded operation, the compartment housing will not become energized, thus protecting the personal safety of maintenance personnel. This structural design significantly improves the long-term operational reliability of the PCS and battery AC / DC units 4 under harsh conditions such as high temperature, high humidity, salt spray, and dust, enhancing the system's high safety, high stability, and high integration.

[0044] Optionally, an insulating support structure is installed inside the cabin. The battery rack, PCS power unit housing, and battery pack housing are all connected to the cabin body through insulating supports, and the metal parts are reliably conductive to form an equipotential body. To ensure the electrical safety and system stability of the high-voltage cascaded energy storage system in an operating environment with a DC side voltage as high as 1138.8V (312S2P configuration), a dedicated insulating support structure is set up to physically isolate and control the potential of all energized metal components. Specifically, the metal brackets of each battery cluster, the aluminum alloy or steel housing of the PCS power conversion unit, and the metal housing of the battery pack are all electrically isolated from the metal frame of the AC / DC cascaded cabin (e.g., steel cabin base, side walls, and top plate) through high-strength, high-insulation engineering ceramic or flame-retardant composite insulating pads, insulating sleeves, or insulating brackets. This effectively blocks the leakage path of DC high voltage conducted through the metal structure to the cabin housing, preventing the risk of short circuit to ground caused by insulation deterioration or a humid environment. Meanwhile, the metal frame of the AC / DC cascaded cabin is reliably connected to an independent grounding grid with low impedance (≤0.1Ω) via a multi-strand copper braided grounding wire with a cross-sectional area of ​​not less than 25mm², making all metal components of the cabin form a unified equipotential body. This design achieves equipotentiality throughout the cabin. This synergistic design of insulation and equipotential bonding not only improves the long-term reliability of the system in harsh environments such as high temperature, high humidity, and salt spray, but also enables the system to operate safely under high-voltage conditions of direct connection to a 10kV power grid without a transformer.

[0045] According to an embodiment of the present invention, a control method embodiment for a high-voltage cascaded energy storage system is also provided. It should be noted that the steps shown in the flowchart in the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. Furthermore, although a logical order is shown in the flowchart, in some cases, the steps shown or described may be executed in a different order than that shown here.

[0046] The methods and embodiments provided in this application can be executed on mobile terminals, computer terminals, or similar computing devices. Figure 5 A hardware block diagram of a computer terminal for implementing a control method for a high-voltage cascaded energy storage system is shown. Figure 5 As shown, the computer terminal 50 may include one or more processors (shown as 502a, 502b, ..., 502n in the figure) (the processor may include, but is not limited to, a microprocessor MCU or a programmable logic device FPGA, etc.) and a memory 504 for storing data. In addition, it may also include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of a BUS bus), a network interface, a power supply, and / or a camera. Those skilled in the art will understand that... Figure 5The structure shown is for illustrative purposes only and does not limit the structure of the aforementioned electronic device. For example, computer terminal 50 may also include... Figure 5 The more or fewer components shown, or having the same Figure 5 The different configurations shown.

[0047] It should be noted that the aforementioned one or more processors and / or other data processing circuits are generally referred to herein as "data processing circuits". These data processing circuits may be wholly or partially embodied in software, hardware, firmware, or any other combination thereof. Furthermore, the data processing circuits may be a single, independent processing module, or may be wholly or partially integrated into any other element in the computer terminal 50. As involved in the embodiments of this application, the data processing circuit serves as a processor control mechanism (e.g., selection of a variable resistor termination path connected to an interface).

[0048] The memory 504 can be used to store software programs and modules for application software, such as the program instructions / data storage device corresponding to the control method for a high-voltage cascaded energy storage system in this embodiment of the invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 504, thereby implementing the aforementioned application program for the control method of a high-voltage cascaded energy storage system. The memory 504 may include high-speed random access memory and non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memories. In some instances, the memory 504 may further include memories remotely located relative to the processor, which can be connected to the computer terminal 50 via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0049] The display may be, for example, a touchscreen liquid crystal display (LCD) that allows the user to interact with the user interface of the computer terminal 50.

[0050] Figure 6 This is a flowchart illustrating a control method for a high-voltage cascaded energy storage system according to an embodiment of the present invention, as shown below. Figure 6 As shown, the method includes the following steps:

[0051] Step S601: Obtain voltage data, current data, state of charge data, and temperature data of all battery clusters in the high-voltage cascaded energy storage system.

[0052] In this step, the BMS integrated control system performs real-time, high-precision data acquisition of all 60 battery clusters (each cluster being either the first or second battery pack) within the AC / DC integrated system compartment via distributed acquisition units. Each battery cluster is equipped with an independent BMS acquisition module, with a sampling frequency of no less than 10Hz. The acquired data includes: voltage data: the total voltage of the 1P312S series system (range 873.6V~1138.8V) and the voltage difference of individual cells; current data: monitoring the charging and discharging current of each cluster via Hall current sensors, ranging from 0 to 200A; state of charge (SOC): dynamically estimated based on ampere-hour integration and open-circuit voltage calibration algorithms; temperature data: NTC temperature sensors are placed at key nodes in each cluster (such as positive and negative terminals, and intermediate cells) to monitor the temperature rise rate. All data is uploaded to the PCS main control system in real time via the CAN bus, providing a millisecond-level response basis for subsequent fault diagnosis. This data acquisition mechanism covers all system operating conditions, ensuring no information blind spots during dynamic processes such as charging and discharging, start-up and shutdown, and circulating current.

[0053] Step S602: Based on voltage data, current data, state of charge data, and temperature data, determine whether any battery clusters are faulty.

[0054] In this step, the BMS integrated control system independently diagnoses each battery cluster based on preset multi-dimensional fault criteria. The judgment logic is as follows: Overvoltage fault: voltage > 1150V (exceeding the normal upper limit of 1138.8V); Undervoltage fault: voltage < 850V (below the normal lower limit of 873.6V); Overcurrent fault: current amplitude ≥ 1.2 times the rated value (≥ 240A) for 50ms; Temperature anomaly: temperature of any sensor ≥ 55℃, or temperature difference > 8℃ (adjacent cells); SOC anomaly: SOC deviation > 10% (compared with the average value of other clusters in the same phase); Insulation degradation: insulation resistance to ground < 100kΩ. The above judgments are executed in parallel, with each cluster operating independently, avoiding channel contention and delays in traditional centralized BMS. Once any cluster triggers any fault condition, the BMS integrated control system immediately generates a structured fault message, including the fault type, cluster number (e.g., the first cluster of batteries), and timestamp, and forwards it to the main control system of the corresponding PCS power unit through an isolated communication link. This mechanism enables precise fault location to a single cluster, solving the problem of misjudgment and missed judgment in multi-cluster parallel systems.

[0055] Step S603: If any group of battery clusters in all battery clusters is faulty, disconnect the faulty battery cluster from the corresponding power conversion unit, and keep the connection between the other normally operating battery cluster and the power conversion unit, so that the output power of the power matching unit is not lower than the preset power threshold. The power matching unit includes a power conversion unit and two battery clusters.

[0056] In this step, when the PCS main control system receives a fault command from the BMS integrated control system, it triggers its DC-side solid-state relay or high-speed DC contactor within 20ms to immediately disconnect the electrical connection between the faulty battery cluster and the PCS power unit. Simultaneously, it maintains continuous power supply to the other healthy battery cluster, ensuring the PCS and battery AC / DC units can still operate normally. This power matching unit (i.e., 1 PCS power unit + 2 battery clusters) has a rated output of 167kW. In the event of a single cluster failure, the system automatically reduces its wattage to approximately 83.5kW (50%), which is still higher than the preset power threshold (≥80kW). This ensures that: the cascaded phase unit (such as phase A power unit) is not triggered to shut down; the 10kV grid connection point voltage fluctuates or frequency disturbances are not caused; and the overall system output power of the AC / DC integrated system compartment remains stable, meeting the grid dispatch requirements for non-power-loss operation. This process is controlled in a closed loop by the PCS main control system, requiring no manual intervention, achieving a fully automatic fault-tolerant mechanism from fault detection to isolation to stable output.

[0057] Through the above steps, the goal of improving system redundancy and voltage adaptation accuracy without increasing the number of PCS is achieved. This enables the PCS to continue operating even when a single cluster fails, ensures accurate DC-side voltage matching of the 10kV direct connection requirement, and significantly improves overall integration. This solves the technical problems of traditional high-voltage energy storage systems, which suffer from low integration, poor fault tolerance, and inability to be directly connected to high-voltage grids due to the single matching method between PCS and battery clusters.

[0058] Compared with current technologies, the aforementioned method embodiments have the following advantages:

[0059] (1) Improved integration and space utilization. The structure of matching two groups of 312S1P battery clusters with a single 167kW PCS is adopted, and 30 PCS, 60 battery clusters and BMS are highly integrated in the same AC / DC cascaded compartment. Compared with the traditional compartment / distributed design, the floor space is reduced by 40%, and the short-distance wiring reduces line loss, and the space utilization of the compartment is greatly improved.

[0060] (2) Adapt to high-voltage direct grid connection requirements. The core matching unit is configured according to 2 The system features a 312S1P design with a 312S2P configuration on the DC side, covering a voltage range of 873.6V to 1138.8V. Each phase has 10 PCS units to meet the voltage requirements of a 10kV transformerless high-voltage direct connection, eliminating the need for a traditional step-up transformer and increasing system efficiency to over 92%, a 4% improvement over traditional solutions.

[0061] (3) Improved system fault tolerance and flexibility. Each PCS forms an independent core matching unit with two battery clusters. When a single battery cluster fails, the PCS can disconnect the faulty cluster and keep the other cluster running normally, avoiding PCS unit shutdown due to single cluster failure, greatly improving system operation stability and fault tolerance. At the same time, it supports flexible configuration of maximum 0.5P charge / discharge rate without changing battery capacity.

[0062] (4) Reduced overall costs. The number of auxiliary equipment such as liquid cooling system and fire protection system in traditional compartment schemes has been reduced, the wiring and construction process in the compartment has been simplified, the equipment procurement cost and construction cost have been reduced, and the system efficiency has been improved and the loss has been reduced, further reducing the operating cost of the energy storage system.

[0063] It should be noted that, for the sake of simplicity, the foregoing method embodiments are all described as a series of actions. However, those skilled in the art should understand that the present invention is not limited to the described order of actions, because according to the present invention, some steps can be performed in other orders or simultaneously. Furthermore, those skilled in the art should also understand that the embodiments described in the specification are preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0064] Through the above description of the embodiments, those skilled in the art can clearly understand that the control method for a high-voltage cascaded energy storage system according to the above embodiments can be implemented by means of software plus necessary general-purpose hardware platform. Of course, it can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0065] According to embodiments of the present invention, an apparatus for implementing the control method of the above-described high-voltage cascaded energy storage system is also provided. Figure 7 This is a structural block diagram of a control method device for a high-voltage cascaded energy storage system provided according to an embodiment of the present invention, such as... Figure 7 As shown, the device includes: an acquisition module 71, a judgment module 72, and a cut-off module 73. The device will be described below.

[0066] The acquisition module 71 is used to acquire voltage data, current data, state of charge data and temperature data of all battery clusters in the high-voltage cascaded energy storage system.

[0067] The judgment module 72, connected to the acquisition module 71, is used to determine whether there is a fault in all battery clusters based on voltage data, current data, state of charge data, and temperature data.

[0068] The disconnection module 73, connected to the judgment module 72, is used to disconnect the faulty battery cluster from the corresponding power conversion unit when any group of battery clusters in all battery clusters is faulty, while maintaining the connection between the other normally operating battery cluster and the power conversion unit, so that the output power of the power matching unit is not lower than a preset power threshold. The power matching unit includes a power conversion unit and two battery clusters.

[0069] It should be noted that the acquisition module 71, judgment module 72, and cut-off module 73 mentioned above correspond to steps S601 to 603 in the embodiments. Multiple modules and their corresponding steps implement the same instances and application scenarios, but are not limited to the content disclosed in the above embodiments. It should also be noted that the above modules, as part of the device, can run in the computer terminal 50 provided in the embodiments.

[0070] Embodiments of the present invention may provide a computer device. Optionally, in this embodiment, the computer device may be located in at least one of a plurality of network devices in a computer network. The computer device includes a memory and a processor.

[0071] The memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the control method and device for high-voltage cascaded energy storage systems in this embodiment of the invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, thereby realizing the aforementioned control method for high-voltage cascaded energy storage systems. The memory may include high-speed random access memory, and may also include non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memory. In some instances, the memory may further include memory remotely located relative to the processor, and these remote memories can be connected to a computer terminal via a network. Examples of such networks include, but are not limited to, the Internet, corporate intranets, local area networks, mobile communication networks, and combinations thereof.

[0072] The processor can access the information and application programs stored in the memory via the transmission device to perform the following steps: acquire voltage, current, state of charge (SOC), and temperature data of all battery clusters in the high-voltage cascaded energy storage system; determine whether any battery cluster is faulty based on the voltage, current, SOC, and temperature data; and, in the event of a fault in any group of battery clusters, disconnect the faulty battery cluster from the corresponding power conversion unit while maintaining the connection between the other normally operating battery cluster and the power conversion unit, ensuring that the output power of the power matching unit is not lower than a preset power threshold. The power matching unit includes one power conversion unit and two battery clusters.

[0073] This invention provides a control method for a high-voltage cascaded energy storage system. By acquiring voltage, current, state of charge (SOC), and temperature data of all battery clusters in the system, the method determines whether any battery cluster is faulty. If any battery cluster is faulty, the method disconnects the faulty cluster from the corresponding power conversion unit (PCS), while maintaining the connection between the other normally operating battery cluster and the PCS. This ensures that the output power of the power matching unit is not lower than a preset power threshold. The power matching unit includes one PCS and two battery clusters. This method improves system redundancy and voltage matching accuracy without increasing the number of PCS. It achieves the technical effects of maintaining PCS operation even in the event of a single cluster fault, accurately matching the DC-side voltage to the 10kV direct connection requirement, and significantly improving overall integration. This solves the technical problems of traditional high-voltage energy storage systems, which suffer from low integration, poor fault tolerance, and inability to directly connect to high-voltage grids due to the single matching method between PCS and battery clusters.

[0074] Those skilled in the art will understand that all or part of the steps in the various methods of the above embodiments can be implemented by a program instructing the hardware related to the terminal device. The program can be stored in a non-volatile storage medium, which may include: flash drive, read-only memory (ROM), random access memory (RAM), disk or optical disk, etc.

[0075] Embodiments of the present invention also provide a non-volatile storage medium. Optionally, in this embodiment, the aforementioned non-volatile storage medium can be used to store the program code executed by the control method for a high-voltage cascaded energy storage system provided in the above embodiments.

[0076] Optionally, in this embodiment, the non-volatile storage medium may be located in any computer terminal in a group of computer terminals in a computer network, or in any mobile terminal in a group of mobile terminals.

[0077] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: acquiring voltage data, current data, state of charge data, and temperature data of all battery clusters in the high-voltage cascaded energy storage system; determining whether any battery cluster is faulty based on the voltage data, current data, state of charge data, and temperature data; and, in the event that any group of battery clusters is faulty, disconnecting the faulty battery cluster from the corresponding power conversion unit while maintaining the connection between another normally operating battery cluster and the power conversion unit, so that the output power of the power matching unit is not lower than a preset power threshold, wherein the power matching unit includes one power conversion unit and two groups of battery clusters.

[0078] Embodiments of the present invention also provide a computer program product, including a computer program. Optionally, in this embodiment, when the computer program is executed by a processor, it can: acquire voltage data, current data, state of charge data, and temperature data of all battery clusters in a high-voltage cascaded energy storage system; determine whether any of the battery clusters are faulty based on the voltage data, current data, state of charge data, and temperature data; and, in the event that any group of battery clusters is faulty, disconnect the faulty battery cluster from the corresponding power conversion unit, while maintaining the connection between another normally operating battery cluster and the power conversion unit, so that the output power of the power matching unit is not lower than a preset power threshold. The power matching unit includes one power conversion unit and two groups of battery clusters.

[0079] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0080] In the above embodiments of the present invention, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0081] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0082] The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment according to actual needs.

[0083] Furthermore, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit.

[0084] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a non-volatile storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0085] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A high-voltage cascaded energy storage system, characterized in that, include: Multiple cascaded phase units, among which, One of the cascaded phase units includes multiple power matching units, one of the cascaded phase units corresponds to one phase, and the AC output terminals of the multiple cascaded phase units are connected to the target high-voltage power grid after being cascaded. One of the power matching units includes a power conversion unit and two battery clusters, wherein the power conversion unit converts the DC voltage output by the battery clusters into AC voltage; The two DC input ports of each power conversion unit are connected in parallel to the two sets of battery clusters.

2. The system according to claim 1, characterized in that, Also includes: The power conversion unit control module is used to disconnect the faulty battery cluster from the power conversion unit when a fault signal is received from any group of the battery clusters, while maintaining the connection between the other normally operating battery cluster and the power conversion unit, so that the output power of the power matching unit is not lower than a preset power threshold.

3. The system according to claim 2, characterized in that, Also includes: Each battery cluster is connected to an independent battery management system, which collects voltage data, current data, state of charge data, and temperature data of the battery cluster. Based on the voltage data, current data, state of charge data, and temperature data, it determines whether the battery cluster has a fault and sends the fault signal to the corresponding power conversion unit control module through a communication link.

4. The system according to claim 1, characterized in that, Also includes: The multiple cascaded phase units are integrated in the same AC / DC cascaded compartment. The multiple cascaded phase units are arranged linearly along the length of the AC / DC cascaded compartment. The power matching units in each cascaded phase unit are symmetrically distributed. The battery clusters in each power matching unit are arranged directly above or below the power conversion unit. The connection lines between the battery clusters and the power conversion unit adopt short-distance wiring.

5. The system according to claim 4, characterized in that, Also includes: Insulating support structure, wherein, The battery cluster support, the power conversion unit housing, and the battery cluster casing are all isolated from the metal frame of the AC / DC cascade compartment by the insulating support structure. The metal structure of the AC / DC cascade compartment is connected to the same potential through a grounding wire.

6. A control method for a high-voltage cascaded energy storage system, characterized in that, For controlling the high-voltage cascaded energy storage system according to any one of claims 1 to 5, comprising: Acquire voltage, current, state of charge, and temperature data of all battery clusters in the high-voltage cascaded energy storage system; Based on the voltage data, current data, state of charge data, and temperature data, determine whether any of the battery clusters are faulty; In the event that any one of the battery clusters is faulty, the connection between the faulty battery cluster and the corresponding power conversion unit is disconnected, while the connection between the other normally operating battery cluster and the power conversion unit is maintained, so that the output power of the power matching unit is not lower than a preset power threshold. The power matching unit includes one power conversion unit and two battery clusters.

7. A control device for a high-voltage cascaded energy storage system, characterized in that, include: The acquisition module is used to acquire voltage, current, state of charge, and temperature data of all battery clusters in the high-voltage cascaded energy storage system. The judgment module is used to determine whether any of the battery clusters are faulty based on the voltage data, the current data, the state of charge data, and the temperature data. The disconnection module is used to disconnect the faulty battery cluster from the corresponding power conversion unit in the event of a fault in any group of battery clusters, while maintaining the connection between the other normally operating battery cluster and the power conversion unit, so that the output power of the power matching unit is not lower than a preset power threshold. The power matching unit includes one power conversion unit and two groups of battery clusters.

8. A non-volatile storage medium, characterized in that, The non-volatile storage medium includes a stored program, wherein, when the program is executed, it controls the device containing the non-volatile storage medium to perform the control method for a high-voltage cascaded energy storage system as described in claim 6.

9. A computer device, characterized in that, include: Memory and processor The memory stores computer programs; The processor is configured to execute a computer program stored in the memory, wherein when the computer program is executed, the processor performs the control method for a high-voltage cascaded energy storage system as described in claim 6.

10. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the control method for a high-voltage cascaded energy storage system as described in claim 6.

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