Energy storage system, power distribution method, storage medium, electronic equipment and product

Abstract

The invention relates to the technical field of energy storage, and discloses an energy storage system, a power distribution method, a storage medium, electronic equipment and a product, the energy storage system comprises a plurality of valve sections, the plurality of valve sections form a multi-phase bridge arm, the multi-phase bridge arm is connected in parallel, the plurality of valve sections at least comprise a power type valve section and an energy type valve section, the power type valve section comprises one or more cascaded power type energy storage modules, and the energy type valve section comprises one or more cascaded energy type energy storage modules. According to the energy storage system, a multi-phase bridge arm parallel framework is adopted, and the energy type valve section and the power type valve section are configured on the framework at the same time, so that the energy density and the network construction capacity of the energy storage system can be considered, the problem that the overload capacity and the energy density of a high-voltage cascade system are difficult to balance is solved, and the working condition adaptation capacity of the energy storage system is improved.

Description

Technical Field

[0001] This invention relates to the field of energy storage technology, and in particular to an energy storage system and power distribution method, storage medium, electronic equipment, and products. Background Technology

[0002] Existing energy storage systems using a single energy storage medium cannot simultaneously meet requirements for power, capacity, lifespan, and safety. Power-type media (such as supercapacitors) offer fast response but short endurance, while energy-type media (such as lithium batteries) have high capacity but limited power output. Energy storage systems using a single energy storage medium suffer from poor environmental adaptability (such as the performance degradation of lithium batteries at high and low temperatures), concentrated safety hazards, inability to cover the multi-condition requirements of grid frequency regulation and peak shaving, and insufficient flexibility in expansion and maintenance. Summary of the Invention

[0003] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, one objective of this invention is to propose an energy storage system that employs a multiphase bridge arm architecture composed of multiple valve sections, and improves the operating condition adaptability of the energy storage system by integrating power-type and energy-type valve sections.

[0004] The second objective of this invention is to provide a power distribution method.

[0005] A third objective of this invention is to provide a computer-readable storage medium.

[0006] The fourth objective of this invention is to provide an electronic device.

[0007] The fifth objective of this invention is to provide a computer program product.

[0008] To achieve the above objectives, a first aspect of the present invention provides an energy storage system comprising: multiple valve sections, the multiple valve sections forming a multiphase bridge arm, the multiphase bridge arm being connected in parallel, and the multiple valve sections including at least power-type valve sections and energy-type valve sections, wherein the power-type valve section includes one or more cascaded power-type energy storage modules, and the energy-type valve section includes one or more cascaded energy-type energy storage modules.

[0009] The energy storage system according to an embodiment of the present invention adopts a multi-phase bridge arm parallel architecture. By simultaneously configuring energy-type and power-type valve sections in this architecture, the energy storage system can take into account both the energy density and grid-building capability of the energy storage system. This solves the problem of balancing the overload capacity and energy density of high-voltage cascaded systems, and enables single-unit hybrid energy storage. It has the advantages of high flexibility and good battery compatibility.

[0010] In addition, the energy storage system proposed in the above embodiments of the present invention may also have the following additional technical features: According to one embodiment of the present invention, the energy storage system further includes: a controller, which is connected to the plurality of valve sections respectively, for determining the basic modulation signal and modulation compensation amount of each valve section in the energy storage system based on the target power and the maximum allowable output power of the energy-type valve section in the energy storage system, and performing power control on each valve section based on the basic modulation signal and the modulation compensation amount.

[0011] According to one embodiment of the present invention, the power-type energy storage module includes: a power-type energy storage unit; a first DC-DC converter, wherein a first DC terminal of the first DC-DC converter is connected to the power-type energy storage unit; and a first AC-DC converter, wherein a DC terminal of the first AC-DC converter is connected to a second DC terminal of the first DC-DC converter, wherein one end of the AC terminals of a plurality of the first AC-DC converters connected in series serves as the midpoint of the bridge arm, and the other end serves as a parallel terminal of the bridge arm.

[0012] According to one embodiment of the present invention, the energy storage module includes: an energy storage unit; a second DC-DC converter, wherein a first DC terminal of the second DC-DC converter is connected to the energy storage unit; and a second AC-DC converter, wherein a DC terminal of the second AC-DC converter is connected to a second DC terminal of the second DC-DC converter, wherein one end of the series connection of the AC terminals of the plurality of second AC-DC converters serves as the midpoint of the bridge arm, and the other end serves as a parallel terminal of the bridge arm.

[0013] According to one embodiment of the present invention, the power-type energy storage unit includes one of a sodium-ion battery pack and a supercapacitor array; the energy-type energy storage unit includes a lithium-ion battery pack.

[0014] According to one embodiment of the present invention, the midpoint of the multiphase bridge arm is adapted to connect to an AC power grid, and the target power is determined according to the state of the AC power grid.

[0015] To achieve the above objectives, a second aspect of the present invention provides a power allocation method for an energy storage system as proposed in the first aspect of the present invention, the method comprising: performing power control on each of the valve segments according to a target power and the maximum allowable output power of an energy-type valve segment in the energy storage system.

[0016] The power allocation method of this invention controls the power of each valve segment according to the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system. Under the premise of meeting the total power output of the energy storage system with basic modulation requirements, the target power can be decomposed and dynamically allocated to different types of internal energy storage valve segments as needed.

[0017] In addition, the power allocation method proposed in the above embodiments of the present invention may also have the following additional technical features: According to one embodiment of the present invention, the step of power control of each valve segment based on the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system includes: determining the basic modulation signal of each valve segment in the energy storage system based on the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system; and performing power control of each valve segment based on the basic modulation signal.

[0018] According to one embodiment of the present invention, the step of power control of each valve segment based on the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system includes: determining the basic modulation signal and modulation compensation amount of each valve segment in the energy storage system based on the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system; and performing power control of each valve segment based on the basic modulation signal and the modulation compensation amount.

[0019] According to one embodiment of the present invention, determining the basic modulation signal and modulation compensation amount of each valve segment in the energy storage system based on the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system includes: determining the basic modulation signal of each valve segment based on the target power; and determining the modulation compensation amount of each valve segment based on the target power and the maximum allowable output power.

[0020] According to one embodiment of the present invention, determining the modulation compensation amount of each valve segment based on the target power and the maximum allowable output power includes: calculating the deviation power borne by the power-type valve segment in the energy storage system based on the target power and the maximum allowable output power; obtaining a circulating current reference value based on the deviation power and the DC voltage of the energy storage system; and generating the modulation compensation amount of each valve segment based on the circulating current reference value and the actual circulating current value of each valve segment.

[0021] According to one embodiment of the present invention, the power control of each valve segment based on the basic modulation signal and the modulation compensation amount includes: vector superimposing the corresponding basic modulation signal and modulation compensation amount of each valve segment to generate a corresponding target drive signal for each valve segment; and driving the DC-DC converter and AC-DC converter in the corresponding valve segment according to the target drive signal corresponding to each valve segment.

[0022] According to one embodiment of the present invention, the target power is determined based on the state of the AC power grid.

[0023] According to one embodiment of the present invention, the target power includes active power and / or reactive power.

[0024] To achieve the above objectives, a third aspect of the present invention provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the power allocation method as proposed in the second aspect of the present invention.

[0025] To achieve the above objectives, a fourth aspect of the present invention provides an electronic device, including a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, it implements the power allocation method as proposed in the second aspect of the present invention.

[0026] To achieve the above objectives, a fifth aspect of the present invention provides a computer program product comprising a computer program that, when executed by a processor, implements the steps of the power allocation method as proposed in the second aspect of the present invention.

[0027] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of an energy storage system according to an embodiment of the present invention; Figure 2 This is a schematic diagram of a power-type valve section according to an embodiment of the present invention; Figure 3 This is a schematic diagram of an energy-type valve section according to an embodiment of the present invention; Figure 4 This is a schematic diagram of an energy storage system according to another embodiment of the present invention; Figure 5 This is a schematic diagram of a power-type energy storage module according to an embodiment of the present invention; Figure 6 This is a schematic diagram of an energy storage module according to an embodiment of the present invention; Figure 7 This is a schematic diagram of an energy storage system according to a specific embodiment of the present invention; Figure 8 This is a flowchart of a power allocation method according to an embodiment of the present invention; Figure 9 This is a flowchart of a power allocation method according to a specific embodiment of the present invention. Figure 1 ; Figure 10 This is a flowchart of a power allocation method according to a specific embodiment of the present invention. Figure 2 ; Figure 11 This is a schematic diagram of the internal control of a power distribution controller according to an embodiment of the present invention; Figure 12This is a flowchart illustrating the determination of the basic modulation signal and modulation compensation amount according to an embodiment of the present invention; Figure 13 This is a flowchart of determining the modulation compensation amount of each valve section according to an embodiment of the present invention; Figure 14 This is a flowchart of power control for each valve section according to an embodiment of the present invention; Figure 15 This is a schematic diagram of the output power and target power of a power-type valve section and an energy-type valve section according to an embodiment of the present invention; Figure 16 This is a structural block diagram of the controller according to an embodiment of the present invention. Detailed Implementation

[0029] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0030] It should be noted that in hybrid energy storage system (HESS) applications, a typical deployment architecture involves equipping different types of energy storage media (e.g., high-energy-density lithium-ion batteries and high-power-density supercapacitors / flywheels) with their own independent power conversion systems (PCS). Each type of energy storage PCS is typically connected independently to a low-voltage AC bus (AC380V / AC400V, etc.), and then connected to the grid or supplied to local loads via the low-voltage bus. While this "one type of energy storage, one PCS, multiple points connected to the low-voltage grid" approach achieves a certain degree of combined application of multiple energy storage media, it suffers from significant drawbacks such as low dispatch efficiency and low configuration flexibility.

[0031] Specifically, the "one type of energy storage, one PCS, multiple points connected to the low-voltage power grid" solution has the following shortcomings: Relying on a centralized upper-level dispatch system results in slow response times: Hybrid energy storage systems require an additional upper-level management / dispatch system, such as a central energy management system (EMS) or advanced dispatch controller, located above all PCS (Power Control System). This upper-level management / dispatch system is responsible for calculating the specific power allocation command that each PCS should execute based on the grid or load demands (such as power commands and frequency modulation signals) and the status of each energy storage unit. This dispatch process involves multiple stages, including information acquisition, command generation, communication transmission, command reception, and execution. The cumulative delays in each stage (especially communication delays and the calculation time of the centralized controller) cause the overall system response time to reach hundreds of milliseconds or even seconds.

[0032] Hybrid energy storage systems are highly complex, increasing both cost and footprint: each energy storage unit requires an independent PCS cabinet, corresponding AC / DC circuit breakers, protection devices, etc. This results in high overall hardware costs, large equipment size, and increased installation space requirements (multiple PCS cabinets), while also increasing the complexity of wiring and system integration. The core issue is that this hybrid energy storage system fails to achieve physical layer integration of power conversion and control, only implementing a simple system-level combination.

[0033] The precision and efficiency of coordinated control are insufficient: the total power command issued by the centralized EMS needs to be distributed among multiple distributed PCSs. In rapid dynamic processes, the command distribution may not be precise enough or may contain deviations. Due to factors such as incomplete synchronization of switching actions and differences in inner-loop control response between different PCSs, the output power may become unbalanced or oscillate in a short period of time, making it difficult to achieve optimal coordination (such as ensuring that the battery only responds to low-frequency / long-term components, and the supercapacitor accurately responds to high-frequency / transient components). In addition, the basic losses (standby losses, switching losses, etc.) of multiple PCSs operate independently and are also cumulative. The core of this problem is that the control command is a broadcast distribution of "one master to many slaves", lacking the underlying direct, fine-grained, cross-medium coordinated control capability based on power dynamic characteristics, and a unified hardware platform to achieve low-loss distribution of optimal power flow.

[0034] Against the backdrop of large-scale renewable energy integration and grid structure transformation, high-voltage cascaded battery energy storage systems are attracting widespread attention due to their advantages such as direct connection to medium- and high-voltage grids, elimination of step-up transformers, and improved efficiency and power density. By connecting numerous unit power modules containing power electronic converters and battery modules in series, high-voltage AC or DC waveforms are directly synthesized on the output side, enabling the large-scale and efficient application of battery energy storage systems in medium- and high-voltage distribution or transmission networks.

[0035] One of the mainstream topologies for high-voltage cascaded energy storage is the cascaded H-bridge topology. The core principle of the CHB (Cascaded H-Bridge) topology lies in connecting multiple basic units—each consisting of an H-bridge power converter and an independently connected energy storage battery module—in series. Each H-bridge unit can independently control the charging and discharging process of its DC-side battery module and output a controllable rectangular or pulsed wave on the AC side, with the same or opposite magnitude to its DC-side voltage. By precisely coordinating the switching states and output voltage pulse widths of all series-connected units, the voltage waveforms generated by these basic units are superimposed and synthesized at the overall output of the energy storage system, ultimately obtaining the desired sine wave or a high-voltage AC waveform of the required shape, achieving power exchange with the grid or load and high-quality power output.

[0036] However, CHB topologies have significant inherent drawbacks. A core challenge lies in their difficulty in effectively managing uneven power distribution between submodules, and even between phases. This characteristic makes them particularly difficult to adapt to hybrid energy storage systems constructed from energy storage media of different specifications (such as lithium-ion batteries, sodium-ion batteries, and supercapacitors, which have different energy densities, power densities, rate characteristics, voltage characteristics, and aging patterns).

[0037] In practical applications, scenarios requiring energy storage systems to possess both high energy characteristics (long-term support) and high power characteristics (instantaneous response) are becoming increasingly common. This is especially true in grid-based applications (requiring stable voltage / frequency) and long-term energy applications, where it is often necessary to combine energy storage (such as lithium batteries and flow batteries) with power storage (such as supercapacitors) to optimize the performance and cost of the energy storage system.

[0038] When hybrid energy storage (CHB) topologies use energy storage units with vastly different characteristics, current consistency constraints force different units to operate at their suboptimal operating points or subject them to stresses exceeding their design capabilities (e.g., units with weak rate capability are forced to charge and discharge at high currents). This severely limits the synergistic efficiency of different types of media and significantly increases the complexity of system management and the risk of failure. Therefore, to fully realize the comprehensive benefits of hybrid energy storage in complex grid applications, it is particularly necessary to explore and design system topologies that can flexibly regulate internal power distribution and are compatible with heterogeneous energy storage media.

[0039] In contrast, the Modular Multilevel Converter (MMC), although it also adopts a cascaded structure, has a unique sub-module design and internal circulating current control capability, which allows the system to independently adjust the power flowing through the sub-modules, effectively balance the energy distribution between modules, alleviate the power imbalance problem, and has a stronger adaptability.

[0040] This invention, based on the fundamental principles of modular multilevel converters, proposes an energy storage system, a power distribution method, a storage medium, electronic devices, and a product. The energy storage system, power distribution method, storage medium, electronic devices, and product of this invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0041] Figure 1 This is a schematic diagram of an energy storage system according to an embodiment of the present invention. Figure 1 As shown, the energy storage system in this embodiment of the invention may include: multiple valve sections, the multiple valve sections forming a multiphase bridge arm, the multiphase bridge arm being connected in parallel, and the multiple valve sections including at least power-type valve sections and energy-type valve sections, wherein the power-type valve section includes one or more cascaded power-type energy storage modules, and the energy-type valve section includes one or more cascaded energy-type energy storage modules.

[0042] Specifically, each phase bridge arm includes an upper bridge arm and a lower bridge arm, and each phase bridge arm has a corresponding valve section installed in its upper and lower bridge arms. A multiphase bridge arm composed of multiple valve sections includes at least a power-type valve section and an energy-type valve section. It should be noted that the two valve sections installed on the same phase bridge arm can be of the same type or different types. Specifically, one power-type valve section can be installed in each of the upper and lower bridge arms of the same phase bridge arm; another energy-type valve section can be installed in each of the upper and lower bridge arms of the same phase bridge arm; yet another power-type valve section and an energy-type valve section can be installed in each of the upper and lower bridge arms of the same phase bridge arm.

[0043] In this invention, the valve segment types between each phase bridge arm do not affect each other. For example, when a multiphase bridge arm composed of multiple valve segments is a three-phase bridge arm, they are respectively denoted as phase A, phase B, and phase C. The valve segment type settings on each bridge arm can be as follows: energy-type valve segments are set on both phase A and phase B, and power-type valve segments are set on both phase C. When energy-type valve segments are set on phase A and power-type valve segments are set on phase B, any type of valve segment can be set on phase C, or a valve segment without an energy storage module can be set. That is, in this embodiment of the invention, for a multiphase bridge arm composed of multiple valve segments, each phase bridge arm must have one valve segment corresponding to its upper and lower bridge arms. At least one valve segment equipped with a power-type energy storage module and one valve segment equipped with an energy-type energy storage module are required; other valve segments can be equipped with any type of energy storage module, or may not be equipped with a corresponding energy storage module.

[0044] In this embodiment of the invention, the types and positions of valve sections set on the multiphase bridge arm composed of multiple valve sections can be set according to requirements, but it is necessary to ensure that the valve sections set on the multiphase bridge arm composed of multiple valve sections include multiple types of valve sections, such as power type valve sections and energy type valve sections.

[0045] In this embodiment of the invention, each valve section is electrically an independent unit. The energy storage module within each valve section consists of one or more identical energy storage modules connected in series, thereby achieving a high degree of flexibility in the energy storage system. That is, a power-type valve section includes one power-type energy storage module, or includes multiple identical power-type energy storage modules connected in series. See [link to relevant documentation]. Figure 2 An energy-type valve section may include one energy-type energy storage module, or multiple identical energy-type energy storage modules connected in series. See [link to relevant documentation]. Figure 3 .

[0046] In this embodiment of the invention, each valve segment can be equipped with a corresponding bridge arm reactor to suppress current fluctuations, circulating currents and fault current rise rates of the corresponding bridge arm, protect the devices and stabilize power transmission.

[0047] In this embodiment of the invention, a filter reactor can be installed between the energy storage system and the AC power grid to filter out specific frequency harmonics in the circuit (such as harmonics on the grid side and the load side) and improve power quality.

[0048] In one embodiment of the present invention, such as Figure 4 As shown, the energy storage system may also include: The controller is connected to multiple valve sections and is used to determine the basic modulation signal and modulation compensation amount of each valve section in the energy storage system based on the target power and the maximum allowable output power of the energy-type valve section in the energy storage system, and to perform power control on each valve section based on the basic modulation signal and modulation compensation amount.

[0049] In the energy storage system architecture of this invention, there are natural circulating current paths within each phase (between upper and lower bridge arms) and between each phase, which do not need to flow through the AC grid load. By precisely controlling the differential-mode voltage generated by the switching states of the energy storage modules on these bridge arms, the controller can actively induce and regulate the internal circulating currents within and between phases.

[0050] Specifically, the controller can determine the target power of the energy storage system based on the state of the AC power grid. Based on the target power and the maximum allowable output power of the energy-type valve sections in the energy storage system, the controller determines the basic modulation signal and modulation compensation amount for each valve section. By controlling the power of the corresponding valve sections according to their basic modulation signals and modulation compensation amounts, the energy storage system can output the target power of electrical energy.

[0051] The controlled internal circulation in the energy storage system of this invention provides it with a powerful power redistribution capability. The energy storage system can actively transfer energy between different bridge arms and different phases without affecting the overall active and reactive power output on the AC side, thereby effectively balancing the actual power carried by each energy storage unit or phase and solving the power distribution problem caused by the uneven characteristics of the energy storage medium. The energy storage system architecture of this invention is equivalent to having an inherent "energy regulation channel".

[0052] In this embodiment of the invention, the energy storage module adopts a standardized design, comprising three core components: an AC-DC converter serving as the core of AC-DC energy conversion; a DC-DC converter responsible for matching and adjusting the operating point of the energy storage module; and an independent energy storage unit (power-type or energy-type energy storage unit) directly connected to it (the DC-DC converter). The AC-DC converter handles the consistency of AC-side voltage synthesis and current output. The DC-DC converter acts as an adapter, effectively isolating the direct coupling between the energy storage unit's own operating characteristics (such as voltage plateau range, internal resistance, and optimal charge / discharge rate) and the AC-side power conversion requirements, paving the way for heterogeneous storage resources.

[0053] It should be noted that when a valve section is not equipped with a power-type energy storage unit or an energy-type energy storage unit, the corresponding DC-DC converter may not be installed in the valve section, but the AC-DC converter on the valve section must be retained.

[0054] In this embodiment of the invention, the energy storage module adopts a modular and hierarchical design. Under the premise that the voltage and current specifications of the AC-DC converter and DC-DC converter of the energy storage module in all valve sections are completely consistent, the valve sections on each phase bridge arm can be flexibly configured to use different types of energy storage media according to actual needs, and there are almost no restrictions on the selection of energy storage units.

[0055] In one embodiment of the present invention, such as Figure 5 As shown, a power-type energy storage module may include: Power-type energy storage unit; The first DC-DC converter has its first DC terminal connected to a power-type energy storage unit. The first AC-DC converter has its DC terminal connected to the second DC terminal of the first DC-DC converter. The AC terminals of multiple first AC-DC converters are connected in series, with one end serving as the midpoint of the bridge arm and the other end serving as a parallel terminal of the bridge arm.

[0056] In this embodiment, the first AC-DC converter may be an H-bridge power converter, and the first DC-DC converter may be a bidirectional DC-DC converter.

[0057] In one specific embodiment of the present invention, the power energy storage unit may include one of a sodium-ion battery pack and a supercapacitor array.

[0058] For example, when the power storage unit in the power-type valve section is a sodium-ion battery pack, the sodium-ion battery pack, the first DC-DC converter, and the first AC-DC converter constitute a power-type energy storage module. Multiple identical power-type energy storage modules can constitute a power-type valve section.

[0059] For example, when the power-type energy storage unit in the power-type valve section is a supercapacitor array, the supercapacitor array, the first DC-DC converter, and the first AC-DC converter constitute a power-type energy storage module. Multiple identical power-type energy storage modules can constitute a power-type valve section.

[0060] In one embodiment of the present invention, such as Figure 6 As shown, an energy storage module may include: Energy storage unit; The second DC-DC converter has its first DC terminal connected to the energy storage unit. The second AC-DC converter has its DC terminal connected to the second DC terminal of the second DC-DC converter. The AC terminals of multiple second AC-DC converters are connected in series, with one end serving as the midpoint of the bridge arm and the other end serving as a parallel terminal of the bridge arm.

[0061] In this embodiment, the second AC-DC converter can be an H-bridge power converter, and the second DC-DC converter can be a bidirectional DC-DC converter.

[0062] In one specific embodiment of the present invention, the energy storage unit may include a lithium-ion battery pack.

[0063] For example, when the energy storage unit in the energy-type valve section is a sodium-ion battery pack, the lithium-ion battery pack, the second DC-DC converter, and the second AC-DC converter constitute an energy storage module. Multiple identical energy storage modules can constitute an energy-type valve section.

[0064] In this embodiment of the invention, the energy storage system benefits from the precise internal power regulation capability of each phase arm, demonstrating excellent compatibility with the distributed configuration of heterogeneous energy storage resources.

[0065] In practice, the energy storage system in this embodiment of the invention can fully utilize the differentiated performance advantages of different energy storage technologies (such as lithium-ion batteries, sodium-ion batteries, and supercapacitors) and flexibly deploy them in different bridge arms. For example, the power storage module in one phase valve segment can be mainly configured with lithium batteries (leveraging their high energy density advantage, suitable for long-term, medium-rate charging and discharging), the power storage module in another phase valve segment can be configured with sodium batteries (utilizing their low-temperature performance or cost advantage), and the power storage module in the third phase valve segment can be configured with supercapacitors (utilizing their ultra-high power density and instantaneous response capability).

[0066] Although from the perspective of the AC side of the power grid, the three-phase output must maintain a balance between active and reactive power (i.e., the total power demand is met on demand, and the three-phase output power is basically symmetrical), within the energy storage system, through the interphase circulation generated by active control, the net energy (and power) "absorbed" or "contributed" by each phase can vary significantly. Specifically, a phase (or bridge arm) equipped with a high-rate supercapacitor can withstand short-term high-power pulsations, while a phase (or bridge arm) equipped with a high-energy lithium battery or sodium battery can stably absorb or release average power for energy throughput. Simultaneously, through internal power flow regulation, energy is "transferred" between energy storage units in different phases (or bridge arms). The phase (or bridge arm) equipped with a supercapacitor can quickly replenish or absorb the power difference that the lithium battery phase (or bridge arm) may not be able to respond to in time during power surges, making the operating point of the lithium battery phase (or bridge arm) more stable and extending its lifespan. Therefore, even though the energy storage modules in each phase store energy storage media with different performance and states, and the actual power requirements they bear are different, the energy storage system can still work together to support the stable AC output required by the AC power grid.

[0067] In one embodiment of the present invention, the midpoint of the multiphase bridge arm is adapted to connect to an AC power grid, and the target power is determined according to the state of the AC power grid. The target power may include active power and / or reactive power.

[0068] In practice, the target power can be dynamically generated by the grid construction algorithm or set by an external constant power source. When dynamically generated by the grid construction algorithm, the active power (P_ref) and / or reactive power (Q_ref) required by the energy storage system can be given in real time by an external system (such as a power grid dispatch center or a local energy management system) based on the power grid status (such as frequency deviation, voltage deviation, and dispatch plan).

[0069] In embodiments of the present invention, the number of phases in the multiphase bridge arm is determined by the number of phases in the AC power grid. For example, when the AC power grid is a three-phase AC power grid, the multiphase bridge arm composed of multiple valve sections is a three-phase bridge arm, and the midpoint of the multiphase bridge arm is suitable for connection to the AC power grid. When the multiphase bridge arm is a three-phase bridge arm, the energy storage system architecture can be as follows: Figure 7 As shown.

[0070] The key structural feature of the energy storage system in the embodiments of the present invention lies in its clear three-phase six-arm layout, namely... Figure 7 The six independent valve sections shown are: upper arm A (valve section A1), lower arm A (valve section A2), upper arm B (valve section B1), lower arm B (valve section B2), upper arm C (valve section C1), and lower arm C (valve section C2).

[0071] In this embodiment of the invention, each valve segment is electrically an independent unit, internally composed of N identical sub-modules connected in series. This forms the physical basis for achieving high flexibility. Furthermore, each energy storage module adopts a standardized design, comprising three core components: an AC-DC converter, a DC-DC converter, and an independent energy storage unit (lithium battery, sodium battery, or supercapacitor). Through modular and hierarchical design, while ensuring that the voltage and current specifications of the AC-DC and DC-DC converters in all valve segments are completely consistent, the six valve segments (A1, A2, B1, B2, C1, C2) can be flexibly configured with different types of energy storage media according to actual needs, with virtually no restrictions on the selection of energy storage units.

[0072] Thanks to the physical isolation and standardized power interface design of the energy storage modules, as well as the unique internal power flow control capabilities of the energy storage system, the system demonstrates strong compatibility with distributed heterogeneous energy storage resources during operation. In practice, users can flexibly "zone out" the system at the six valve segment levels based on the performance characteristics of different media and application objectives. For example, phase A (A1+A2 valve segment) can use lithium-ion batteries as the energy storage medium throughout, focusing on long-duration energy applications and leveraging their high energy density advantage; phase B (B1+B2 valve segment) can use sodium-ion battery cells, taking advantage of their strengths in cost, safety, or temperature adaptability; and phase C (C1+C2 valve segment) uses a supercapacitor array, focusing on rapid throughput and high-frequency power support.

[0073] At this point, although from the perspective of the overall energy storage system's AC output ports, the voltage and frequency of the three phases (A, B, C) injected into the grid are stable, the total power meets the requirements, and the output power between phases remains balanced (requiring symmetrical operation) or distributed as needed (allowing for asymmetrical operation), the "output" states of the energy storage units in each valve section within the energy storage system are drastically different. As mentioned earlier, by precisely controlling the circulating current between phases and bridge arms, the energy within the energy storage system can be dynamically redistributed. This means that when the supercapacitor valve section (C1 / C2) needs to absorb or release instantaneous peak power, a portion of the required energy flow can actually be provided or absorbed by the circulating current path through the lithium battery or sodium battery valve sections (A1 / A2 or B1 / B2). Similarly, the energy during the charging and discharging process of the sodium battery valve section can also be coordinated with other phases through internal circulating current. Therefore, although the energy storage medium characteristics, charge / discharge rates, or voltage levels within each valve section are quite different, they are adjusted to a power flow suitable for their respective processing level through their corresponding DC-DC converters and operate collaboratively through a controlled circulating current network. The final result is that the actual power demand of the energy storage units in each phase valve section is efficiently matched with their own physical capabilities (power density, rate characteristics), realizing that different types of energy storage resources can "perform their respective functions and contribute as needed" at the system level, which significantly improves the overall performance and utilization rate of the hybrid energy storage system.

[0074] In essence, the energy storage system architecture in this invention is to interconnect two sets of three-phase structures (a total of six bridge arms) similar to cascaded H-bridges on the DC side to form a complete three-phase AC-DC (direct current to alternating current) or DC-AC (alternating current to direct current) conversion system.

[0075] The core advantage of the energy storage system architecture in this embodiment of the invention lies in its unique internal circulation mechanism. Unlike the CHB where all units are directly connected in series to output current, each arm of the MMC consists of a large number of energy storage modules connected in series and an arm inductor (arm reactor). Its AC terminal is connected to the AC power grid, while the upper and lower pairs of arms (such as the upper and lower arms of phase A) together form a converter channel.

[0076] Compared to hybrid energy storage solutions that distribute lithium and sodium batteries across different systems, the energy storage system of this invention, by simultaneously configuring energy-type and power-type valve sections, can balance the energy density and grid-building capability of the energy storage system. It solves the problem of balancing overload capacity and energy density in high-voltage cascaded systems, and can achieve single-unit hybrid energy storage. It has the advantages of high flexibility and good battery compatibility.

[0077] This invention provides a power distribution method.

[0078] The power distribution method of this invention is used in the energy storage system described above.

[0079] Figure 8This is a flowchart of a power allocation method according to an embodiment of the present invention. Figure 8 As shown, power allocation methods may include: S001, based on the target power and the maximum allowable output power of the energy-type valve section in the energy storage system, performs power control on each valve section.

[0080] Specifically, power control is performed on each valve segment based on the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system. Under the premise of meeting the total power output of the energy storage system with basic modulation requirements, the target power can be decomposed and dynamically allocated to different types of energy storage valve segments as needed.

[0081] In one specific embodiment of the present invention, such as Figure 9 As shown, power control of each valve section is performed based on the target power and the maximum allowable output power of the energy-type valve section in the energy storage system. This may include: S101, Based on the target power and the maximum allowable output power of the energy-type valve section in the energy storage system, determine the basic modulation signal of each valve section in the energy storage system; S102 performs power control on each valve segment based on the basic modulation signal.

[0082] Specifically, in order to enable the hybrid energy storage system in this embodiment of the invention to output electrical energy at the target power, the basic modulation signal of each valve segment in the energy storage system can be determined according to the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system. Based on the basic modulation signal, power control is performed on each valve segment to enable the energy storage system to output electrical energy at the target power and ensure that the performance requirements of the energy storage system to the grid interface are met.

[0083] In one specific embodiment of the present invention, such as Figure 10 As shown, power control of each valve section is performed based on the target power and the maximum allowable output power of the energy-type valve section in the energy storage system. This may include: S111, Based on the target power and the maximum allowable output power of the energy-type valve section in the energy storage system, determine the basic modulation signal and modulation compensation amount of each valve section in the energy storage system; S112 performs power control on each valve segment based on the basic modulation signal and modulation compensation amount.

[0084] Specifically, in order to fully utilize the performance of the hybrid energy storage system in the embodiments of the present invention, the controller can be used to obtain the target power and the maximum allowable output power of the energy-type valve section in the energy storage system. Based on the obtained target power and the maximum allowable output power of the energy-type valve section in the energy storage system, the basic modulation signal and modulation compensation amount of each valve section in the energy storage system are determined. Based on the basic modulation signal and modulation compensation amount corresponding to each valve section, power control is performed on the corresponding valve section to control the electrical energy output of the energy storage system to the target power.

[0085] In one embodiment of the present invention, the target power may be determined based on the state of the AC power grid. The target power may include active power and / or reactive power.

[0086] In practice, the target power can be dynamically generated by the grid construction algorithm or set by an external constant power source. When dynamically generated by the grid construction algorithm, the active power (P_ref) and / or reactive power (Q_ref) required by the energy storage system can be given in real time by an external system (such as a power grid dispatch center or a local energy management system) based on the power grid status (such as frequency deviation, voltage deviation, and dispatch plan).

[0087] In one embodiment of the present invention, the maximum permissible output power of the energy-type valve section in the energy storage system is typically determined by the current total available capacity, state of charge, health status, and preset maximum continuous power limit of the energy-type valve section in the energy storage system (to avoid high-rate damage to lifespan).

[0088] The power allocation method of this invention decouples the total control signal of the energy storage system into two key parts: a basic modulation signal S (or outer loop control signal) and a modulation compensation amount ΔS (or inner loop / energy balance amount). The basic modulation signal S ensures that the performance requirements of the energy storage system to the grid interface are met. The modulation compensation amount ΔS is used to allocate power / energy to each valve segment (or phase level) to fully utilize the performance of the hybrid energy storage system in this invention.

[0089] The following describes the basic modulation signal and modulation compensation amount in the power distribution method of this invention, using a three-phase AC power grid and a three-phase six-bridge-arm energy storage system as an example: The basic modulation signal S (outer loop) ensures that the three-phase output voltage of the AC port of the energy storage system remains symmetrical and stable, and accurately tracks the grid frequency and voltage reference value, while ensuring that the total three-phase power output of the energy storage system strictly matches the target power.

[0090] Implementable, such as Figure 11 As shown, the grid-connected control unit that generates the basic modulation signal can adopt a dual-closed-loop control structure. It calculates and generates the basic modulation signal acting on all six bridge arm valve sections based on the target power, controlling the total voltage and current vectors on the AC side to ensure that the energy storage system performance meets grid connection or grid construction requirements.

[0091] The modulation compensation amount ΔS (inner loop) focuses on achieving fine-grained management of power / energy distribution in each valve segment (or phase level) based on the preset or dynamically optimized energy storage unit status and capacity.

[0092] Implementable, such as Figure 11 As shown, the control unit that generates the modulation compensation amount can be a power correction unit and an internal power flow control unit.

[0093] The power allocation method of this invention determines the basic modulation signal and modulation compensation amount of each valve segment in the energy storage system based on the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system. Based on the basic modulation signal and modulation compensation amount, the power of each valve segment is controlled. Under the premise of meeting the total power output of the energy storage system with basic modulation requirements, the target power can be decomposed and dynamically allocated to different types of energy storage valve segments as needed.

[0094] In one embodiment of the present invention, such as Figure 12 As shown, based on the target power and the maximum allowable output power of the energy-type valve section in the energy storage system, the basic modulation signal and modulation compensation amount of each valve section in the energy storage system are determined, which may include: S201, determine the basic modulation signal for each valve section based on the target power; S202 determines the modulation compensation amount for each valve section based on the target power and the maximum allowable output power.

[0095] In this embodiment of the invention, the total output power of the energy storage system is the sum of the output power of the energy-type valve section and the power-type valve section. When the AC grid is charged and discharged at a high rate, and the energy-type valve section is saturated, the deviation power is borne by the power-type valve section. This deviation power can be output after flowing from the power-type valve section to the energy-type valve section through interphase circulating current, thus maintaining the power symmetry of the grid interface.

[0096] Specifically, the basic modulation signal S for each valve segment is determined based on the target power to ensure that the performance requirements of the energy storage system to the grid interface are met. Based on the target power and the maximum allowable output power of the energy-type valve segments in the energy storage system, the modulation compensation amount ΔS for each valve segment is determined, so that the power / energy of each valve segment (or phase level) is allocated according to the corresponding modulation compensation amount ΔS.

[0097] In one embodiment of the present invention, such as Figure 13 As shown, the modulation compensation amount for each valve section is determined based on the target power and the maximum allowable output power, and may include: S301, calculate the deviation power borne by the power-type valve section in the energy storage system based on the target power and the maximum allowable output power; S302, based on the deviation power and the DC voltage of the energy storage system, obtain the circulating current reference value; S303 generates the modulation compensation amount for each valve segment based on the circulating reference value and the actual circulating value of each valve segment.

[0098] As a specific example, taking a three-phase six-arm energy storage system with a mixed configuration of AB phases (energy type, such as lithium batteries) and C phases (power type, such as supercapacitors) as an example, the generation logic and mechanism of the modulation compensation amount ΔS corresponding to each valve section in this embodiment of the invention will be introduced: Determine the maximum permissible output power that the energy-type energy storage section (i.e., phase A valve section A1+A2 and phase B valve section B1+B2) in the energy storage system can continuously and safely provide. Subtract the maximum sustainable output power of the energy-type energy storage from the target power to obtain the rapid power component, i.e., the deviation power, which only needs to be handled by the power-type energy storage section (i.e., phase C valve section C1+C2). It should be noted that the calculated deviation power may be instantaneous, rapid, or even negative (representing rapid power absorption).

[0099] In order to direct and independently "inject" the deviation power into phase C, where the power storage is located, without affecting the power sharing of phases AB, the system needs to utilize controlled internal circulating currents to achieve this energy transfer. It should be noted that, in the embodiments of the present invention, the internal circulating current is a current flowing within a phase (between upper and lower bridge arms) or between phases, independent of the main power transmission path.

[0100] The controller calculates and generates a circulating current reference value (usually expressed as a differential-mode or common-mode circulating current component reference value I_circ_ref) based on parameters such as deviation power, DC voltage of the energy storage system, and grid state parameters. In practice, the circulating current reference value is calculated using the formula ΔPW / Vdc, where Vdc is the DC voltage of the energy storage system and ΔPW is the deviation power borne by the power-type valve section.

[0101] The circulating current reference value can be sent to the internal power flow control unit. Based on the actual circulating current values ​​collected from sensors in each valve section and the calculated circulating current reference value, the internal power flow control unit generates the modulation compensation amount for each valve section. Specifically, the internal power flow control unit often uses a PR (proportional-resonant) controller to achieve deadbeat tracking of the circulating current component at a specific frequency, or combines it with a PI (proportional-integral) controller to process the DC component. The internal power flow control unit compares the circulating current reference value with the actual circulating current values ​​in each valve section, generating an additional modulation compensation amount ΔS specifically used to regulate the magnitude of the circulating current.

[0102] In this embodiment of the invention, the modulation compensation amount ΔS achieves power redistribution by adjusting the output voltage of the valve segment, specifically satisfying the following relationships: v_x,p=f(S'x,p), v_x,n=f(S'x,n), x=A, B, C, where v_x,p represents the voltage of the upper arm of phase x, S'x,p represents the target drive signal of the upper arm of phase x, v_x,n represents the voltage of the lower arm of phase x, S'x,n represents the target drive signal of the lower arm of phase x, and f(·) represents the mapping relationship.

[0103] In one specific embodiment, the modulation compensation amount ΔS can be the common-mode voltage increment (ΔV_circ), which is an additional reference amount applied to the upper and lower bridge arm voltages. Specifically, the common-mode voltage increment is generated by the internal power flow control unit: ΔV_circ=(I_circ_ref-IcW)(Kp+Ki / s), where I_circ_ref is the circulating current reference value, IcW is the actual circulating current value, which is calculated from the bridge arm current or acquired by sensors, and Kp and Ki are the proportional and integral coefficients, respectively.

[0104] In this embodiment of the invention, the intraphase circulating current I_x,c (x=A,B,C) in the energy storage system satisfies I_x,c=0.5*(I_x,p+I_x,n), where I_x,p is the upper bridge arm voltage and I_x,n is the lower bridge arm voltage.

[0105] In this embodiment of the invention, the total modulation signal finally applied to each valve section is a synthesis of the basic modulation signal S (maintaining the total power on the grid side) and the modulation compensation amount ΔS (used to generate a specific circulating current).

[0106] The power distribution method of this invention, through precise activation and maintenance of the required circulating current, physically enables the energy storage system to ensure that the AB phase of energy-type energy storage always operates close to its maximum permissible output power. The C phase of power-type energy storage, through the circulating current mechanism, "receives" or "transmits" energy, precisely assuming the deviation power required for its rapid response. At this time, the power flowing out of the energy storage system through the C phase valve section comprises two parts: one part is the basic power undertaken under the basic control command to support the target power (maintaining coordination with the AB phase share), and the other part is the deviation power brought about by the circulating current.

[0107] In one embodiment of the present invention, such as Figure 14 As shown, power control of each valve segment based on the basic modulation signal and modulation compensation amount may include: S401, the corresponding basic modulation signal and modulation compensation amount of each valve section are vector superimposed to generate the corresponding target drive signal of each valve section; S402 drives the DC-DC converter and AC-DC converter in the corresponding valve section according to the target drive signal corresponding to each valve section.

[0108] Specifically, the corresponding modulation compensation amount ΔS of each valve segment is vector-superimposed with the basic modulation signal S to generate the corresponding target drive signal S'=S+ΔS for each valve segment. The controller drives the DC-DC converter and AC-DC converter according to the target drive signal S' to realize the dynamic distribution of power between energy-type valve segments and power-type valve segments.

[0109] As a specific embodiment, when the target power Pref is 1.5 MW and the maximum allowable output power Pmax of the energy-type valve segment is 1.0 MW, the S=(Sa1, Sa2, Sb1, Sb2, Sc1, Sc2) of each phase arm is generated based on the target power Pref. The deviation power ΔP=Pref-Pmax=1.5-1.0=0.5MW is calculated. When the energy-type valve segment is saturated, the deviation power ΔP is allocated to the power-type valve segment. The circulating current reference value is calculated based on the deviation power ΔP, and the modulation compensation amount ΔS=[ΔSa1, ΔSa2, ΔSb1, ΔSb2, ΔSc1, ΔSc2] of each valve segment is generated based on the circulating current reference value and the actual circulating current value of each valve segment. The modulation compensation amount ΔS of each valve segment is superimposed on its basic modulation signal S and then used to drive the IGBTs in the corresponding valve segment DC-DC converter and AC-DC converter, so that the voltage difference between the upper arm voltage (vx,p) and the lower arm voltage (vx,n) of each phase is generated.

[0110] When the target power Pref suddenly increases to 2.0MW, ΔP = Pref - Pmax = 2.0 - 1.0 = 1.0MW. The energy-type valve segment saturates, and the deviation power ΔPW = 1.0MW is allocated to the power-type valve segment. Specifically, when the DC voltage Vdc of the energy storage system is 10kV, the calculated circulating current command value ΔPW / Vdc = 1.0MW / 10kV = 100A. A common-mode voltage increment ΔV_circ is generated through a PI controller. ΔV_circ is superimposed on the upper and lower bridge arm reference voltages, driving the circulating current to rise to 100A, thus realizing power transfer from the power-type valve segment to the energy-type valve segment and then to the grid.

[0111] The ingenuity of the hierarchical control mechanism employed in the power allocation method of this invention lies in the fact that the regulation of internal circulating current is essentially a "zero-sum game." It only redistributes energy flow between phases or bridge arms within the energy storage system, without altering the total active and reactive power output to the grid from the AC side, as determined by the basic control loop (i.e., always ensuring P_out = P_ref). Circulating current control ensures that the power (or energy change rate) borne by each valve segment (such as phases A / B and C) carrying different energy storage media and possessing different power characteristics is perfectly matched with its own design capabilities and optimization strategies. A schematic diagram illustrating how the output power of the power valve segment and the output power of the energy valve segment follow the target power (grid-connected power) is provided below. Figure 15 .

[0112] The power distribution method in this embodiment of the invention solves the problem of power saturation of energy storage units during high-rate charging and discharging by using valve segment power hierarchical control and circulating current coordination. Circulating current control enables the directional transmission of deviation power between valve segments, maintaining the three-phase symmetry of the grid interface (e.g., phase current imbalance <2% in implementation), while avoiding power module overload (measured power-type valve segment temperature rise reduced by 40%).

[0113] The power distribution method of this invention not only maximizes the protection of energy-type valve sections in the energy storage system (avoiding overcharging or high-rate operation), but also fully leverages the advantages of power-type valve sections in terms of fast response and strong instantaneous throughput, significantly improving the overall performance, reliability, and economy of the hybrid energy storage system.

[0114] This invention provides a computer-readable storage medium.

[0115] In this embodiment, a computer program is stored on a computer-readable storage medium, and when the computer program is executed by a processor, it implements the power allocation method as described above.

[0116] This invention provides an electronic device.

[0117] In this embodiment, the electronic device may include a memory and a processor. The memory stores a computer program, and when the computer program is executed by the processor, it implements the power distribution method described above.

[0118] The electronic device in the embodiments of the present invention, Figure 16 This is a structural block diagram of an electronic device according to an embodiment of the present invention.

[0119] like Figure 16 As shown, the electronic device 500 includes a processor 501 and a memory 503. The processor 501 and the memory 503 are connected, for example, via a bus 502. Optionally, the electronic device 500 may also include a transceiver 504. It should be noted that in practical applications, the transceiver 504 is not limited to one type, and the structure of this electronic device 500 does not constitute a limitation on the embodiments of the present invention.

[0120] Processor 501 may be a CPU (Central Processing Unit), a general-purpose processor, a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), or other programmable logic devices, transistor logic devices, hardware components, or any combination thereof. It can implement or execute the various exemplary logic blocks, modules, and circuits described in conjunction with the disclosure of this invention. Processor 501 may also be a combination that implements computational functions, such as including one or more microprocessor combinations, a combination of a DSP and a microprocessor, etc.

[0121] Bus 502 may include a pathway for transmitting information between the aforementioned components. Bus 502 may be a PCI (Peripheral Component Interconnect) bus or an EISA (Extended Industry Standard Architecture) bus, etc. Bus 502 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 16 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0122] The memory 503 is used to store a computer program corresponding to the power allocation method of the above embodiments of the present invention, and the computer program is controlled and executed by the processor 501. The processor 501 is used to execute the computer program stored in the memory 503 to implement the content shown in the foregoing method embodiments. Figure 16 The electronic device 500 shown is merely an example and should not be construed as limiting the functionality and scope of use of the embodiments of the present invention.

[0123] This invention provides a computer program product.

[0124] In this embodiment, the computer program product may include a computer program that, when executed by a processor, implements the steps of the power distribution method as described above.

[0125] The computer-readable storage medium, electronic device, and computer program product in the embodiments of the present invention, based on the above-mentioned power allocation method, not only maximize the protection of energy-type valve sections in the energy storage system (avoiding overcharging or high-rate operation), but also give full play to the advantages of power-type valve sections with fast response and strong instantaneous throughput, significantly improving the overall performance, reliability, and economy of the hybrid energy storage system.

[0126] It should be noted that the logic and / or steps represented in the flowchart or otherwise described herein, for example, can be considered as a sequenced list of executable instructions for implementing logical functions, and can be specifically implemented in any computer-readable medium for use by, or in conjunction with, an instruction execution system, apparatus, or device (such as a computer-based system, a processor-included system, or other system that can fetch and execute instructions from, an instruction execution system, apparatus, or device). For the purposes of this specification, "computer-readable medium" can be any means that can contain, store, communicate, propagate, or transmit programs for use by, or in conjunction with, an instruction execution system, apparatus, or device. More specific examples (a non-exhaustive list) of computer-readable media include: an electrical connection having one or more wires (electronic device), a portable computer disk drive (magnetic device), random access memory (RAM), read-only memory (ROM), erasable and editable read-only memory (EPROM or flash memory), fiber optic devices, and portable optical disc read-only memory (CDROM). Alternatively, the computer-readable medium may be paper or other suitable media on which the program can be printed, since the program can be obtained electronically, for example, by optically scanning the paper or other medium, followed by editing, interpreting, or otherwise processing as necessary, and then stored in a computer memory.

[0127] It should be understood that various parts of the present invention can be implemented in hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented in software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0128] 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.

[0129] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0130] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0131] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0132] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0133] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. An energy storage system, characterized in that, The energy storage system includes: multiple valve sections, which form a multiphase bridge arm connected in parallel, and the multiple valve sections include at least power-type valve sections and energy-type valve sections, wherein the power-type valve section includes one or more cascaded power-type energy storage modules, and the energy-type valve section includes one or more cascaded energy-type energy storage modules.

2. The energy storage system according to claim 1, characterized in that, The energy storage system also includes: The controller is connected to the plurality of valve sections respectively, and is used to determine the basic modulation signal and modulation compensation amount of each valve section in the energy storage system according to the target power and the maximum allowable output power of the energy type valve section in the energy storage system, and to perform power control on each valve section according to the basic modulation signal and the modulation compensation amount.

3. The energy storage system according to claim 1 or 2, characterized in that, The power-type energy storage module includes: Power-type energy storage unit; A first DC-DC converter, wherein the first DC terminal of the first DC-DC converter is connected to the power-type energy storage unit; The first AC-DC converter has its DC terminal connected to the second DC terminal of the first DC-DC converter. The AC terminals of the multiple first AC-DC converters are connected in series, with one end serving as the midpoint of the bridge arm and the other end serving as a parallel terminal of the bridge arm.

4. The energy storage system according to claim 1 or 2, characterized in that, The energy storage module includes: Energy storage unit; A second DC-DC converter, wherein the first DC terminal of the second DC-DC converter is connected to the energy storage unit; The second AC-DC converter has its DC terminal connected to the second DC terminal of the second DC-DC converter. One end of the series connection of the AC terminals of multiple second AC-DC converters serves as the midpoint of the bridge arm, and the other end serves as a parallel connection of the bridge arm.

5. The energy storage system according to claim 4, characterized in that, Power-type energy storage units include either sodium-ion battery packs or supercapacitor arrays; energy-type energy storage units include lithium-ion battery packs.

6. The energy storage system according to claim 2, characterized in that, The midpoint of the multiphase bridge arm is suitable for connecting to an AC power grid, and the target power is determined according to the state of the AC power grid.

7. A power distribution method, characterized in that, For an energy storage system as described in any one of claims 1-6, the method comprises: Power control is performed on each valve segment based on the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system.

8. The power distribution method according to claim 7, characterized in that, The step of controlling the power of each valve segment based on the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system includes: The basic modulation signal for each valve segment in the energy storage system is determined based on the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system. Power control is performed on each valve segment based on the basic modulation signal.

9. The power distribution method according to claim 7, characterized in that, The step of controlling the power of each valve segment based on the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system includes: Based on the target power and the maximum allowable output power of the energy-type valve section in the energy storage system, determine the basic modulation signal and modulation compensation amount for each valve section in the energy storage system; Power control is performed on each valve segment based on the basic modulation signal and the modulation compensation amount.

10. The power distribution method according to claim 9, characterized in that, The step of determining the basic modulation signal and modulation compensation amount for each valve segment in the energy storage system based on the target power and the maximum allowable output power of the energy-type valve segment in the energy storage system includes: The basic modulation signal for each valve segment is determined based on the target power. The modulation compensation amount for each valve segment is determined based on the target power and the maximum allowable output power.

11. The power distribution method according to claim 10, characterized in that, The step of determining the modulation compensation amount for each valve segment based on the target power and the maximum allowable output power includes: Based on the target power and the maximum allowable output power, calculate the deviation power borne by the power-type valve section in the energy storage system; Based on the deviation power and the DC voltage of the energy storage system, the circulating current reference value is obtained; Based on the circulating reference value and the actual circulating value of each valve segment, the modulation compensation amount of each valve segment is generated.

12. The power distribution method according to claim 9, characterized in that, The step of power control of each valve segment based on the basic modulation signal and the modulation compensation amount includes: The corresponding basic modulation signal and modulation compensation amount of each valve segment are vector superimposed to generate the corresponding target drive signal of each valve segment; The DC-DC converter and AC-DC converter in the corresponding valve section are driven according to the target drive signal corresponding to each valve section.

13. A computer-readable storage medium having a computer program stored thereon, characterized in that, When the computer program is executed by the processor, it implements the power distribution method as described in any one of claims 7-12.

14. An electronic device comprising a memory and a processor, wherein the memory stores a computer program, characterized in that, When the computer program is executed by the processor, it implements the power allocation method as described in any one of claims 7-12.

15. A computer program product, comprising a computer program, characterized in that, When the computer program is executed by the processor, it implements the steps of the power distribution method as described in any one of claims 7-12.

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