Method, system and device for adjusting parallel voltage difference of lithium batteries of hydrogen-lithium coupled micro-grid

Abstract

The invention relates to the technical field of fuel cells and energy storage, and discloses a lithium battery parallel voltage difference adjusting method, system and device for a hydrogen-lithium coupled micro-grid. The voltage difference adjusting method comprises the following steps: respectively calculating the real-time voltage difference between the open-circuit voltage and the average voltage of each lithium battery cluster to be connected in parallel; identifying a target lithium battery cluster of which the voltage is higher than the average voltage and the voltage difference with the average voltage is maximum; auxiliary equipment of a fuel cell in the hydrogen-lithium coupled micro-grid is used as an adjustable load, the corresponding adjustable load is scheduled to be connected with the target lithium battery cluster in a grading mode according to the maximum voltage difference, and the open-circuit voltage of the target lithium battery cluster is adjusted; and when the voltage differences between the open-circuit voltages of all the lithium battery clusters to be connected in parallel and the average voltage are smaller than a first threshold value, executing parallel operation. Fuel cell auxiliary equipment is reused, a current-limiting resistor or an equalization module does not need to be additionally configured, and the size and cost of the system are reduced; quick pressure reduction and precise pressure control are achieved through graded adjustment, the circulating current restraining effect is remarkable, and the adjusting efficiency and precision are high.

Description

Technical Field

[0001] This invention relates to the fields of fuel cells and energy storage technology, specifically to a method, system, and device for regulating the differential voltage of lithium batteries in a hydrogen-lithium coupled microgrid. Background Technology

[0002] In a park's microgrid, when multiple lithium battery clusters operate in parallel, the voltage difference between clusters can easily trigger large circulating currents, leading to equipment damage and potential safety hazards to the battery cells. Therefore, an effective voltage difference regulation scheme is needed. Currently, the mainstream solutions are mainly divided into three categories: The first type is the "passive current limiting scheme," which connects a high-power current-limiting resistor in series at the DC output of each lithium battery cluster. During the initial power-up of the microgrid, the instantaneous parallel current is limited by voltage division using these resistors. When the voltage difference between clusters is less than 3VDC, the current-limiting resistors are disconnected via a relay to complete the parallel connection. This scheme is widely used in small and medium-sized energy storage projects in China, but it has significant drawbacks: First, the conflict between heat loss and size is prominent. When the voltage difference between clusters reaches 5VDC and the internal resistance of the circuit is 10mΩ, the instantaneous current of the current-limiting resistor reaches 500A, and the temperature rise can exceed 300℃ in a short time, requiring large heat dissipation equipment. This results in the resistor module accounting for about 15% of the energy storage cabinet's volume. Second, the adjustment is limited; the resistor can only passively limit the current and cannot eliminate the voltage difference. When the voltage difference is greater than 10VDC, the resistor is prone to overheating and burning out. Third, the power density is low; the additional resistors and heat dissipation components reduce the power density of the energy storage system to below 0.8kW / L, which does not meet the requirements for compact installation.

[0003] The second type is the "active balancing solution," which involves connecting a DC / DC balancing module in parallel across each cell or battery cluster to detect and adjust the cell voltage in real time to reduce the voltage difference between clusters. This solution is often used in power battery packs or high-precision energy storage systems, but it suffers from insufficient cost and adaptability: a single 209kWh lithium battery cluster requires more than 12 DC / DC modules, with a single set costing over 5,000 yuan, which is 3-4 times higher than the passive solution; moreover, the balancing modules are mostly designed for cells of specific capacities, and after more than 500 cycles of lithium battery clusters, parameter changes caused by cell degradation can easily lead to inaccurate balancing modules.

[0004] The third type is the "pre-charge control" scheme, which uses a PLC to control an adjustable power supply to pre-charge the battery clusters with lower voltage until the voltage difference with the high-voltage cluster is less than 2VDC before parallel connection. This scheme requires an additional pre-charge power supply, has an energy conversion efficiency of only 85%-90%, suffers from high energy loss, and typically takes more than 10 minutes to adjust, making it difficult to meet the rapid start-up requirements of microgrids.

[0005] In summary, the three existing solutions have shortcomings such as high heat loss, high cost, low efficiency, and poor adaptability, making it difficult to meet the core requirements of safety, efficiency, and economy of the park's microgrid. There is an urgent need for a lithium battery cluster differential pressure regulation solution that can comprehensively solve the above problems. Summary of the Invention

[0006] This invention provides a method, system, and device for regulating the differential voltage of lithium batteries in a hydrogen-lithium coupled microgrid, in order to solve the problems of high heat loss, high cost, and low efficiency in existing lithium battery cluster differential voltage regulation schemes.

[0007] In a first aspect, the present invention provides a method for regulating the parallel voltage difference of lithium batteries in a hydrogen-lithium coupled microgrid, the method comprising: Real-time acquisition of the open-circuit voltage of all lithium battery clusters to be connected in parallel in the hydrogen-lithium coupled microgrid; Calculate the average voltage of all lithium battery clusters to be connected in parallel, calculate the real-time voltage difference between the open-circuit voltage and the average voltage of each lithium battery cluster to be connected in parallel, and identify the target lithium battery cluster with a voltage higher than the average voltage and the largest voltage difference between the open-circuit voltage and the average voltage. Using auxiliary equipment for fuel cells in a hydrogen-lithium coupled microgrid as adjustable loads, the corresponding adjustable loads are connected to the target lithium battery cluster in stages according to the magnitude of the maximum pressure difference, thereby adjusting the open-circuit voltage of the target lithium battery cluster. The auxiliary equipment includes an air compressor and a hydrogen pump. When the voltage difference between the open-circuit voltage and the average voltage of all lithium battery clusters to be connected in parallel is less than the first threshold, the DC contactor of each lithium battery cluster is closed to execute the parallel connection operation.

[0008] This invention provides a method for regulating the differential voltage of lithium batteries in a parallel connection in a lithium-hydrogen coupled microgrid. Before power-on, the open-circuit voltage of the lithium battery cluster is acquired, the average voltage is calculated, and the target lithium battery cluster and initial differential voltage are determined. Based on the initial differential voltage, the air compressor and hydrogen pump of the fuel cell are scheduled as adjustable loads and connected to the target lithium battery cluster to regulate the voltage. When the maximum differential voltage between clusters is less than a first threshold, non-circulating current parallel connection is triggered. This application reuses fuel cell auxiliary equipment, eliminating the need for additional current-limiting resistors or equalization modules, thus reducing system size and cost. The tiered regulation achieves rapid voltage reduction and precise voltage control, with significant circulating current suppression, resulting in high regulation efficiency and accuracy. It also improves the integration and energy utilization of the lithium-hydrogen coupled system, adapting to various complex scenarios.

[0009] In one optional implementation, auxiliary equipment of the fuel cell in the hydrogen-lithium coupled microgrid is used as an adjustable load. The adjustable load is connected to the target lithium battery cluster in stages according to the magnitude of the maximum voltage difference, thereby regulating the open-circuit voltage of the target lithium battery cluster, including: When the maximum pressure difference is greater than the second threshold, the air compressor is controlled to establish a connection with the target lithium battery cluster, and the open circuit voltage of the target lithium battery cluster is adjusted with the first preset power to reduce the open circuit voltage of the target lithium battery cluster to below the third threshold. When the maximum pressure difference is greater than the fourth threshold and not greater than the second threshold, the connection between the air compressor and the target lithium battery cluster is disconnected, the hydrogen pump is controlled to establish a connection with the target lithium battery cluster, and the open circuit voltage of the target lithium battery cluster is adjusted with the second preset power to reduce the open circuit voltage of the target lithium battery cluster to below the fifth threshold.

[0010] In one optional implementation, auxiliary equipment of the fuel cell in the hydrogen-lithium coupled microgrid is used as an adjustable load. The adjustable load is connected to the target lithium battery cluster in stages according to the magnitude of the maximum voltage difference, thereby regulating the open-circuit voltage of the target lithium battery cluster. The implementation also includes: Continuously monitor the real-time open-circuit voltage of the target lithium battery cluster and dynamically update the maximum voltage difference; The load power of the air compressor and hydrogen pump is dynamically adjusted based on the rate of decrease of the maximum pressure difference.

[0011] In one alternative implementation, the method includes: Real-time monitoring of instantaneous parallel current; If the instantaneous current exceeds the sixth threshold, the DC contactor of each lithium battery cluster will be immediately disconnected.

[0012] Secondly, the present invention provides a parallel differential voltage regulation system for lithium batteries in a hydrogen-lithium coupled microgrid, the system comprising: a voltage acquisition module, an EMS central control unit, a load regulation module, and a parallel execution module, wherein... The voltage acquisition module is installed at the DC output terminal of each lithium battery cluster to be connected in parallel, and is used to acquire the open circuit voltage data of each lithium battery cluster in real time and transmit the open circuit voltage data to the EMS central control unit. The EMS central control unit is communicatively connected to the voltage acquisition module, the load adjustment module, and the parallel execution module. The EMS central control unit is used to receive the open-circuit voltage data transmitted by the voltage acquisition module, calculate the average voltage of all lithium battery clusters to be connected in parallel, calculate the real-time voltage difference between the open-circuit voltage and the average voltage of each lithium battery cluster to be connected in parallel, identify the target lithium battery cluster with a voltage higher than the average voltage and the largest voltage difference with the average voltage, and schedule the corresponding adjustable load to connect to the target lithium battery cluster according to the size of the maximum voltage difference. The load regulation module is used to use the auxiliary equipment of the fuel cell in the hydrogen-lithium coupled microgrid as an adjustable load, and under the scheduling of the EMS central control unit, to perform graded regulation of the voltage of the target lithium battery cluster. The parallel execution module is installed on the parallel bus of each lithium battery cluster to be connected in parallel, and is used to realize the non-circulating current parallel connection of each lithium battery cluster under the control of the EMS central control unit.

[0013] This invention provides a parallel differential voltage regulation system for lithium batteries in a hydrogen-lithium coupled microgrid. It reuses fuel cell auxiliary equipment, eliminating the need for additional current-limiting resistors or equalization modules, thus reducing system size and cost. The graded regulation achieves rapid voltage reduction and precise voltage control, with significant circulating current suppression and high regulation efficiency and accuracy. It improves the integration and energy utilization of the hydrogen-lithium coupled system and is suitable for various complex scenarios.

[0014] In one optional implementation, the load regulation module includes a hydrogen pump, an air compressor, a hydrogen pump controller, and an air compressor controller, wherein the hydrogen pump and the air compressor are connected to each lithium battery cluster to be connected in parallel via a DC contactor.

[0015] In one optional implementation, the hierarchical scheduling logic of the EMS central control unit is as follows: When the maximum pressure difference is greater than the second threshold, the air compressor is controlled to establish a connection with the target lithium battery cluster, and the open circuit voltage of the target lithium battery cluster is adjusted with the first preset power to reduce the open circuit voltage of the target lithium battery cluster to below the third threshold. When the maximum pressure difference is greater than the fourth threshold and not greater than the second threshold, the connection between the air compressor and the target lithium battery cluster is disconnected, the hydrogen pump is controlled to establish a connection with the target lithium battery cluster, and the open circuit voltage of the target lithium battery cluster is adjusted with the second preset power to reduce the open circuit voltage of the target lithium battery cluster to below the fifth threshold.

[0016] Thirdly, the present invention provides a parallel differential voltage regulation device for lithium batteries in a hydrogen-lithium coupled microgrid, the device comprising: The acquisition module is used to acquire the open-circuit voltage of all lithium battery clusters to be connected in parallel in the hydrogen-lithium coupled microgrid in real time. The calculation module is used to calculate the average voltage of all lithium battery clusters to be connected in parallel, calculate the real-time voltage difference between the open-circuit voltage and the average voltage of each lithium battery cluster to be connected in parallel, and identify the target lithium battery cluster with a voltage higher than the average voltage and the largest voltage difference between the voltage and the average voltage. The adjustment module is used to use the auxiliary equipment of the fuel cell in the hydrogen-lithium coupled microgrid as an adjustable load, and to schedule the corresponding adjustable load to be connected to the target lithium battery cluster in stages according to the magnitude of the maximum pressure difference, so as to adjust the open circuit voltage of the target lithium battery cluster. The auxiliary equipment includes an air compressor and a hydrogen pump. The parallel module is used to control the DC contactor of each lithium battery cluster to close and perform parallel operation when the voltage difference between the open circuit voltage and the average voltage of all lithium battery clusters to be connected in parallel is less than a first threshold.

[0017] This invention provides a lithium-ion coupled microgrid lithium battery parallel differential voltage regulation device. Before power-on, the open-circuit voltage of the lithium battery cluster is acquired, the average voltage is calculated, and the target lithium battery cluster and initial differential voltage are determined. Based on the initial differential voltage, the air compressor and hydrogen pump of the fuel cell are staged and configured as adjustable loads, connected to the target lithium battery cluster to regulate the voltage. When the maximum differential voltage between clusters is less than a first threshold, non-circulating current parallel connection is triggered. This application reuses fuel cell auxiliary equipment, eliminating the need for additional current-limiting resistors or equalization modules, thus reducing system size and cost. Staged regulation achieves rapid voltage reduction and precise voltage control, with significant circulating current suppression, high regulation efficiency and accuracy. It improves the integration and energy utilization of the lithium-ion coupled system, adapting to various complex scenarios.

[0018] Fourthly, the present invention provides an electronic device, comprising: a memory and a processor, wherein the memory and the processor are communicatively connected to each other, the memory stores computer instructions, and the processor executes the computer instructions to perform the parallel differential voltage regulation method for lithium batteries in a hydrogen-lithium coupled microgrid as described in the first aspect or any corresponding embodiment thereof.

[0019] Fifthly, the present invention provides a computer-readable storage medium storing computer instructions for causing a computer to execute the parallel differential voltage regulation method for lithium batteries in a hydrogen-lithium coupled microgrid as described in the first aspect or any corresponding embodiment thereof. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0021] Figure 1 This is a schematic diagram of the first process of the parallel voltage difference regulation method for lithium batteries in a hydrogen-lithium coupled microgrid according to an embodiment of the present invention; Figure 2 This is a schematic block diagram of a lithium battery parallel differential voltage regulation system for a hydrogen-lithium coupled microgrid according to an embodiment of the present invention. Figure 3 This is an electrical architecture diagram according to an embodiment of the present invention; Figure 4 This is a structural block diagram of a lithium battery parallel differential voltage regulation device for a hydrogen-lithium coupled microgrid according to an embodiment of the present invention; Figure 5 This is a schematic diagram of the hardware structure of an electronic device according to an embodiment of the present invention. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0023] It is understood that before using the technical solutions disclosed in the various embodiments of the present invention, users should be informed of the types, scope of use, and usage scenarios of the personal information involved in the present invention and their authorization should be obtained in accordance with relevant laws and regulations through appropriate means.

[0024] 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 one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0025] According to an embodiment of the present invention, a method for regulating the differential voltage of lithium batteries in a hydrogen-lithium coupled microgrid is 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.

[0026] This embodiment provides a method for regulating the parallel differential voltage of lithium batteries in a lithium-hydrogen coupled microgrid. Based on the inherent hardware architecture of the lithium-hydrogen coupled microgrid, and with the energy management system (EMS) as the core, the method realizes the parallel differential voltage regulation of lithium battery clusters through a full-process logic of voltage acquisition, graded load regulation, closed-loop control, and non-circulating current parallel connection. Figure 1 This is a flowchart of a method for regulating the parallel voltage difference of lithium batteries in a hydrogen-lithium coupled microgrid according to an embodiment of the present invention, as shown below. Figure 1 As shown, the process includes the following steps: Step S1: Real-time acquisition of the open-circuit voltage of all lithium battery clusters to be connected in parallel in the hydrogen-lithium coupled microgrid.

[0027] Specifically, before the energy storage system of the lithium-hydrogen coupled microgrid is officially connected to the grid (i.e., before the microgrid is powered on), the energy management system (EMS) central control unit first powers on and initializes, and then starts the voltage acquisition module composed of high-precision voltage sensors and signal conditioning circuits. This module has been pre-installed at the DC output terminal of each lithium battery cluster to be connected in parallel. At this time, each lithium battery cluster is in an open-circuit state without any load connected. The module synchronously acquires the open-circuit voltage signal of all lithium battery clusters at a acquisition frequency of 10Hz, and transmits the acquired accurate voltage data to the EMS central control unit in real time via the CAN bus. The open-circuit voltages of all lithium battery clusters are denoted as U1, U2, ..., U... n (where n is the total number of lithium battery clusters to be connected in parallel), providing basic data support for subsequent differential pressure calculation and target cluster identification.

[0028] Step S2: Calculate the average voltage of all lithium battery clusters to be connected in parallel, calculate the real-time voltage difference between the open-circuit voltage and the average voltage of each lithium battery cluster to be connected in parallel, and identify the target lithium battery cluster with a voltage higher than the average voltage and the largest voltage difference between the voltage and the average voltage.

[0029] Specifically, the EMS central control unit uses the collected open-circuit voltage data of all lithium battery clusters to be connected in parallel (denoted as U1, U2, ..., U...) n The average voltage U_avg is automatically calculated using a built-in customized algorithm. The calculation formula is U_avg = (U1 + U2 + ... + U n Then, calculate the difference between the open-circuit voltage of each lithium battery cluster and U_avg. Identify the battery cluster with the largest voltage difference that is higher than U_avg from all the lithium battery clusters to be connected in parallel, and define it as the "target lithium battery cluster" (denoted as U_target). Finally, the difference between U_target and U_avg is used as the maximum voltage difference ΔU, and the calculation formula is ΔU = U_target - U_avg, which provides the core judgment basis for subsequent graded load adjustment.

[0030] Step S3: Using the auxiliary equipment of the fuel cell in the hydrogen-lithium coupled microgrid as an adjustable load, the corresponding adjustable load is scheduled to be connected to the target lithium battery cluster according to the magnitude of the maximum pressure difference, and the open circuit voltage of the target lithium battery cluster is adjusted. The auxiliary equipment includes an air compressor and a hydrogen pump.

[0031] Specifically, the EMS central control unit dynamically updates the real-time voltage difference of all lithium battery clusters to be connected in parallel based on the voltage data fed back by the voltage acquisition module, and locks the current maximum voltage difference ΔU, thereby executing a precise hierarchical load scheduling strategy: When the maximum voltage exceeds the limit, the EMS central control unit sends a load start command to the air compressor controller (ACU) via a CAN bus with a baud rate of 500kbps. This commands the DC contactor between the target lithium battery cluster and the air compressor to close, consuming the target cluster's electrical energy with a 20kW high-power load. This quickly reduces the target lithium battery cluster voltage U_target to within the average voltage U_avg+20VDC, effectively minimizing the excessive voltage difference.

[0032] When the maximum differential pressure is within the medium range, the EMS central control unit immediately sends a disconnect command to cut off the connection circuit between the air compressor and the target cluster; at the same time, it sends a load start command to the hydrogen pump controller (HCU) via the CAN bus to close the DC contactor between the target lithium battery cluster and the hydrogen pump, switching to a 2kW low-power load for fine adjustment, gradually calibrating U_target to the range of U_avg±1VDC, ensuring high accuracy of differential pressure regulation.

[0033] It should be noted that the air compressor and hydrogen pump mentioned above are both original auxiliary equipment of fuel cells in the hydrogen-lithium coupled microgrid. Their rated voltage is 600-800VDC. While expanding the voltage regulation function, the original hydrogen supply and air conditioning core interfaces and functions of the fuel cell system are fully retained. The voltage regulation load application is expanded only by adding a control loop. There is no need to configure additional special regulation equipment, which effectively controls the system cost and volume.

[0034] If the voltage difference of the current target lithium battery cluster is adjusted to meet the switching conditions or reach the standard, the EMS central control unit immediately recalculates the average voltage U_avg of all lithium battery clusters to be connected in parallel and the real-time voltage difference between each cluster and U_avg, re-identifies the new target lithium battery cluster with a voltage higher than U_avg and the largest voltage difference, and repeats the above-mentioned hierarchical load scheduling process for the new target cluster; this process is repeated until the voltage difference between the open circuit voltage and the average voltage U_avg of all lithium battery clusters to be connected in parallel is less than the first threshold.

[0035] Step S4: When the voltage difference between the open-circuit voltage and the average voltage of all lithium battery clusters to be connected in parallel is less than the first threshold, control the DC contactor of each lithium battery cluster to close and execute the parallel connection operation.

[0036] Specifically, during the graded load adjustment process, the voltage acquisition module continuously feeds back real-time voltage data of all lithium battery clusters to be connected in parallel at a frequency of 10Hz. The EMS central control unit dynamically calculates the real-time voltage difference between each cluster based on this data and locks in the maximum voltage difference. When the maximum voltage difference between all lithium battery clusters is consistently less than 1VDC, the EMS central control unit sends a "parallel connection enabled" command to the parallel execution module via a 500kbps CAN bus, synchronously controlling the closing of the DC contactors corresponding to each lithium battery cluster to avoid local circulating current caused by sequential closing. In this embodiment, the first threshold is 1VDC.

[0037] This invention provides a method for regulating the differential voltage of lithium batteries in a parallel connection in a lithium-hydrogen coupled microgrid. Before power-on, the open-circuit voltage of the lithium battery cluster is acquired, the average voltage is calculated, and the target lithium battery cluster and initial differential voltage are determined. Based on the initial differential voltage, the air compressor and hydrogen pump of the fuel cell are scheduled as adjustable loads and connected to the target lithium battery cluster to regulate the voltage. When the maximum differential voltage between clusters is less than a first threshold, non-circulating current parallel connection is triggered. This application reuses fuel cell auxiliary equipment, eliminating the need for additional current-limiting resistors or equalization modules, thus reducing system size and cost. The tiered regulation achieves rapid voltage reduction and precise voltage control, with significant circulating current suppression, resulting in high regulation efficiency and accuracy. It also improves the integration and energy utilization of the lithium-hydrogen coupled system, adapting to various complex scenarios.

[0038] In one optional implementation, step S3 includes: Step S31: When the maximum pressure difference is greater than the second threshold, control the air compressor to establish a connection with the target lithium battery cluster, and adjust the open circuit voltage of the target lithium battery cluster with the first preset power to reduce the open circuit voltage of the target lithium battery cluster to below the third threshold.

[0039] Specifically, the EMS central control unit captures the voltage data of all lithium battery clusters to be connected in parallel in real time through the voltage acquisition module, dynamically calculates and locks the maximum voltage difference ΔU. When ΔU > 50VDC (ultra-large voltage difference state) is detected, the EMS central control unit sends a load start and power scheduling command to the air compressor controller (ACU) via the CAN bus, controls the DC contactor corresponding to the target lithium battery cluster and the air compressor to close, so that the air compressor is officially connected to the circuit loop of the target cluster.

[0040] At this point, the air compressor operates at the first preset power of 20kW (rated high power mode). During the operation of the air compressor, the EMS central control unit does not output this power at a fixed rate. Instead, it continuously monitors the real-time open-circuit voltage of the target lithium battery cluster using the voltage acquisition module, dynamically updates the maximum voltage difference ΔU, and calculates the rate of decrease of ΔU in real time. Based on the rate of decrease of the maximum voltage difference, it dynamically adjusts the air compressor speed (adjustment range 5000-15000rpm) via CAN signal, thereby dynamically adjusting the load power of the air compressor. The speed and load power are positively correlated; the higher the speed and the greater the load power, the faster the voltage of the target cluster decreases. Ultimately, this efficiently reduces the voltage U_target of the target lithium battery cluster to within the average voltage U_avg+20VDC, quickly resolving the problem of excessive voltage difference. The second threshold is 50VDC, and the third threshold is U_avg+20VDC.

[0041] Step S32: When the maximum pressure difference is greater than the fourth threshold and not greater than the second threshold, disconnect the air compressor from the target lithium battery cluster, control the hydrogen pump to establish a connection with the target lithium battery cluster, and adjust the open circuit voltage of the target lithium battery cluster with the second preset power to reduce the open circuit voltage of the target lithium battery cluster to below the fifth threshold.

[0042] Specifically, when the EMS central control unit detects that the maximum pressure difference ΔU is in the range of 1VDC < ΔU ≤ 50VDC, it immediately performs two operations simultaneously: first, it sends a load stop command to the ACU to disconnect the DC contactor between the air compressor and the target cluster, cutting off the high-power load circuit; second, it sends a load start command to the hydrogen pump controller (HCU) via the CAN bus to close the DC contactor corresponding to the target cluster and the hydrogen pump, switching the regulating load to the hydrogen pump.

[0043] The hydrogen pump starts at a second preset power of 2kW. During operation, the EMS central control unit continuously monitors the real-time open-circuit voltage of the target lithium battery cluster using a voltage acquisition module (10Hz acquisition frequency), dynamically updates the maximum differential voltage ΔU, and calculates the rate of decrease of ΔU in real time. Based on the rate of decrease of the maximum differential voltage, the EMS dynamically adjusts the hydrogen pump speed (adjustment range 3000-20000rpm) and the load power of the hydrogen pump. The speed and load power are positively correlated; the lower the speed and the lower the load power, the slower the rate of decrease of the target cluster voltage, laying a solid foundation for subsequent high-precision voltage regulation. If ΔU decreases too quickly (e.g., approaching the 1VDC threshold), the hydrogen pump speed is immediately reduced and the load power is decreased to prevent the target cluster voltage from falling below U_avg and causing overshoot. If ΔU decreases too slowly, the hydrogen pump speed is appropriately increased and the load power is increased to ensure that the target cluster voltage steadily approaches the precise adjustment target of U_avg±1VDC, ensuring high precision and stability of differential voltage regulation. The fourth threshold is 1VDC, and the fifth threshold is U_avg±1VDC.

[0044] This application uses an active balancing strategy to precisely control the inter-cluster voltage difference within 1VDC, and the parallel instantaneous circulating current can be stably reduced to below 100A, which is more than 66.7% lower than the traditional current-limiting resistor solution (instantaneous circulating current usually exceeds 300A). This completely avoids the impact damage of large current to the cell separator and DC contactor, and can extend the cycle life of lithium battery by more than 30%.

[0045] This application innovatively reuses the inherent auxiliary equipment (hydrogen pump, air compressor) of the hydrogen-lithium coupling system, eliminating the need for additional high-power current-limiting resistors or DC / DC equalization modules. This not only reduces the overall volume of the energy storage unit by 15%-20% (for example, the volume of three 209kWh energy storage systems can be optimized from 1.2m³ to 1.0m³), but also reduces the cost of a single system by 4,000-6,000 yuan, mainly by saving the purchase and installation costs of current-limiting resistors and supporting heat dissipation components in traditional solutions.

[0046] The graded load regulation mode of this application achieves the synergistic effect of "high-power rapid voltage drop + low-power precise voltage control", with the total regulation time controlled within 5 minutes, which is 50% more efficient than the traditional pre-charging scheme (regulation time usually exceeds 10 minutes); the voltage drop control accuracy reaches ±1VDC, which is 66.7% more efficient than the traditional current limiting scheme (accuracy is only ±3VDC), fully meeting the operation requirements of high-reliability energy storage systems.

[0047] In one alternative implementation, the method includes: Step S5: Monitor the instantaneous current in parallel in real time.

[0048] Step S6: If the instantaneous current is greater than the sixth threshold, the DC contactor of each lithium battery cluster is immediately disconnected.

[0049] Specifically, after the lithium battery clusters are connected in parallel without circulating current, the current shunt in the parallel execution module continuously monitors the instantaneous current of the parallel circuit in real time and synchronously feeds the current data back to the EMS central control unit. When the instantaneous current exceeds the safety threshold of 100A (i.e., an abnormally large current occurs), the EMS central control unit immediately triggers the safety protection mechanism, quickly disconnecting the DC contactors corresponding to all lithium battery clusters through the control circuit to cut off the parallel circuit and avoid equipment damage; at the same time, an alarm signal is triggered simultaneously to promptly remind maintenance personnel to investigate the anomaly and ensure the safe operation of the entire hydrogen-lithium coupled microgrid energy storage system.

[0050] This invention provides a parallel differential voltage regulation system for lithium batteries in a hydrogen-lithium coupled microgrid, such as... Figure 2 As shown, the system includes: a voltage acquisition module, an EMS central control unit, a load regulation module, and a parallel execution module.

[0051] The voltage acquisition module is installed at the DC output terminal of each lithium battery cluster to be connected in parallel. It collects the open-circuit voltage data of each cluster in real time and transmits the data to the EMS central control unit. The EMS central control unit communicates with the voltage acquisition module, load regulation module, and parallel execution module. It receives the open-circuit voltage data from the voltage acquisition module, calculates the average voltage of all lithium battery clusters to be connected in parallel, calculates the real-time voltage difference between the open-circuit voltage and the average voltage of each cluster, identifies the target cluster with a voltage higher than the average voltage and the largest voltage difference, and schedules the corresponding adjustable load to connect to the target cluster based on the magnitude of the maximum voltage difference. The load regulation module uses auxiliary equipment of fuel cells in the hydrogen-lithium coupled microgrid as an adjustable load and, under the scheduling of the EMS central control unit, performs graded regulation of the voltage of the target lithium battery cluster. The parallel execution module is installed on the parallel bus of each lithium battery cluster to be connected in parallel and, under the control of the EMS central control unit, achieves non-circulating current parallel connection of the lithium battery clusters.

[0052] Specifically, this application leverages the inherent hardware architecture of a lithium-hydrogen coupled microgrid, using an energy management system (EMS) as the core control hub. Through a closed-loop logic encompassing voltage acquisition, tiered load regulation, closed-loop control, and non-circulating current parallel connection, it achieves precise differential voltage regulation before parallel connection of multiple lithium battery clusters. The system architecture comprises a voltage acquisition module, an EMS central control unit, a load regulation module, and a parallel execution module.

[0053] The voltage acquisition module consists of a high-precision voltage sensor with an accuracy of ±0.1VDC and a signal conditioning circuit. The acquisition frequency is set to 10Hz, and it is installed at the DC output terminal of each lithium battery cluster to be connected in parallel. Its core function is to capture the open-circuit voltage data of each lithium battery cluster in real time. After optimization by the signal conditioning circuit, the accurate voltage data is transmitted in real time to the EMS central control unit via the CAN bus, providing reliable data support for subsequent differential pressure calculation and adjustment decisions.

[0054] The EMS central control unit is built around the Infineon TC297 chip, running customized differential pressure calculation and load scheduling algorithms. It integrates core functions such as voltage data analysis, load grading scheduling, and parallel connection triggering. This unit establishes bidirectional communication with the hydrogen pump controller (HCU) and air compressor controller (ACU) via a 500kbps CAN bus. Simultaneously, it uses relay control loops to switch the connection status between adjustable loads and lithium battery clusters, serving as the decision-making center of the entire system.

[0055] The load regulation module reuses the existing auxiliary equipment of the fuel cell in the hydrogen-lithium coupling system—the hydrogen pump and air compressor—eliminating the need for additional dedicated regulation equipment. The hydrogen pump has an average power of 2kW and a rated voltage of 600-800VDC, while the air compressor has an average power of 20kW and a rated voltage of 600-800VDC. Both retain the original fuel cell system's interfaces and core functions, with the addition of voltage regulation load functionality only achieved through expanded control loops. The connection between the load and the lithium battery cluster is achieved via DC contactors, whose on / off states are directly controlled by the EMS central control unit. Its core electrical architecture diagram is as follows: Figure 3 As shown.

[0056] The parallel execution module consists of a battery management system (BMS), DC contactors, and current shunts (range 0-1000A, accuracy ±0.1%), installed on the parallel bus of each lithium battery cluster to be connected in parallel. The EMS central control unit sends a contactor closing command to this module based on the inter-cluster voltage difference meeting the standard; simultaneously, the current shunt monitors the instantaneous current during the parallel connection process in real time, ensuring that the parallel operation is completed without the risk of large circulating currents, thus providing a safety guarantee for system operation.

[0057] This invention provides a parallel differential voltage regulation system for lithium batteries in a hydrogen-lithium coupled microgrid. It reuses fuel cell auxiliary equipment, eliminating the need for additional current-limiting resistors or equalization modules, thus reducing system size and cost. The graded regulation achieves rapid voltage reduction and precise voltage control, with significant circulating current suppression and high regulation efficiency and accuracy. It improves the integration and energy utilization of the hydrogen-lithium coupled system and is suitable for various complex scenarios.

[0058] In one alternative implementation, the load regulation module includes a hydrogen pump, an air compressor, a hydrogen pump controller, and an air compressor controller, wherein the hydrogen pump and the air compressor are connected to each lithium battery cluster to be connected in parallel via DC contactors.

[0059] Specifically, the hydrogen pump supplies hydrogen to the fuel cell, and the air compressor provides the air required for the reaction. Originally dedicated auxiliary equipment for fuel cells in a lithium-hydrogen coupled microgrid, this application reuses them as voltage-regulating loads, utilizing the energy consumption characteristics during device operation to reduce the voltage of the target lithium battery cluster. The hydrogen pump controller and air compressor controller are the load control units, responsible for receiving instructions from the EMS central control unit to adjust the speed of the hydrogen pump / air compressor, thereby controlling the energy consumption rate of the device and achieving adjustable voltage regulation power. The DC contactor is the connection switch between the load and the lithium battery cluster; as an electrical switching component, its closed / open state is directly controlled by the EMS central control unit.

[0060] Each lithium battery cluster to be connected in parallel has a reserved DC contactor interface for the hydrogen pump and air compressor. When the EMS identifies a target lithium battery cluster with a voltage higher than the average voltage and the largest voltage difference, it will send a command to the corresponding controller (HCU / ACU) according to the voltage difference to control the contactor to close, allowing the hydrogen pump / air compressor to be connected to the target cluster's circuit loop. If the voltage difference is large (e.g., >50VDC), the EMS controls the contactor corresponding to the air compressor to close, allowing the 20kW high-power air compressor to be connected to the target cluster to quickly consume electrical energy and reduce voltage. If the voltage difference is in a medium range (e.g., 1VDC < voltage difference ≤50VDC), the EMS disconnects the air compressor circuit and closes the contactor corresponding to the hydrogen pump, allowing the 2kW low-power hydrogen pump to be connected, achieving precise voltage regulation.

[0061] In one optional implementation, the hierarchical scheduling logic of the EMS central control unit is as follows: When the maximum pressure difference exceeds the second threshold, the air compressor is connected to the target lithium battery cluster, and the open-circuit voltage of the target lithium battery cluster is adjusted at a first preset power to reduce it below the third threshold. When the maximum pressure difference exceeds the fourth threshold but not the second threshold, the connection between the air compressor and the target lithium battery cluster is disconnected, and the hydrogen pump is connected to the target lithium battery cluster, adjusting the open-circuit voltage of the target lithium battery cluster at a second preset power to reduce it below the fifth threshold.

[0062] Specifically, the EMS central control unit captures the voltage data of all lithium battery clusters to be connected in parallel in real time through the voltage acquisition module, dynamically calculates and locks the maximum voltage difference ΔU. When ΔU > 50VDC (ultra-large voltage difference state) is detected, the EMS central control unit sends a load start and power scheduling command to the air compressor controller (ACU) via the CAN bus, controls the DC contactor corresponding to the target lithium battery cluster and the air compressor to close, so that the air compressor is officially connected to the circuit loop of the target cluster.

[0063] At this time, the air compressor operates at the first preset power of 20kW (rated high power mode). During the operation of the air compressor, the EMS central control unit does not output this power at a fixed time. Instead, it continuously monitors the real-time open-circuit voltage of the target lithium battery cluster using the voltage acquisition module, dynamically updates the maximum voltage difference ΔU, and calculates the rate of decrease of ΔU in real time. Based on the rate of decrease of the maximum voltage difference, it dynamically adjusts the air compressor speed (adjustment range 5000-15000rpm) via CAN signal, thereby dynamically adjusting the load power of the air compressor. Ultimately, it efficiently reduces the voltage U_target of the target lithium battery cluster to within the average voltage U_avg+20VDC, quickly resolving the problem of excessive voltage difference.

[0064] When the EMS central control unit detects that the maximum differential pressure ΔU is in the range of 1VDC < ΔU ≤ 50VDC, it immediately performs two operations simultaneously: first, it sends a load stop command to the ACU to disconnect the DC contactor between the air compressor and the target cluster, cutting off the high-power load circuit; second, it sends a load start command to the hydrogen pump controller (HCU) via the CAN bus to close the DC contactor corresponding to the target cluster and the hydrogen pump, switching the regulating load to the hydrogen pump.

[0065] The hydrogen pump starts at the second preset power of 2kW. During the operation of the hydrogen pump, the EMS central control unit continuously monitors the real-time open-circuit voltage of the target lithium battery cluster using the voltage acquisition module (10Hz acquisition frequency), dynamically updates the maximum differential voltage ΔU, and calculates the rate of decrease of ΔU in real time. Based on the rate of decrease of the maximum differential voltage, the EMS dynamically adjusts the hydrogen pump speed (adjustment range 3000-20000rpm) and the load power of the hydrogen pump to ensure that the target cluster voltage steadily approaches the precise adjustment target of U_avg±1VDC, thus ensuring high precision and stability of differential voltage regulation.

[0066] This application is the first to realize the functional reuse of fuel cell auxiliary equipment (hydrogen pump, air compressor) as a differential pressure regulation load in energy storage system, achieving functional synergy of "hydrogen-lithium" equipment, significantly improving the integration and overall energy utilization of the entire microgrid system; the electrical energy consumed during the regulation process can be used for preheating of the fuel cell system, keeping the energy loss rate below 5%, which is far better than the 10%-15% loss level of traditional current limiting schemes.

[0067] This application has good capacity compatibility and can adapt to the parallel regulation requirements of lithium battery clusters of different specifications from 100-500kWh; it can also operate stably in a wide ambient temperature range of -20℃ to 55℃, and is widely applicable to complex application scenarios such as industrial parks, hydrogen energy demonstration bases, and island microgrids. It does not require large-scale hardware modifications for different scenarios, which greatly reduces the cost of scenario adaptation.

[0068] Taking the Mawei Smart Park Energy Storage Microgrid Project as a practical application scenario, the specific implementation parameters and operation procedures of this system are as follows: 1.1 Instance Basic Parameters Lithium battery cluster configuration: 3 sets of 209kWh lithium battery clusters, nominal voltage 665.6VDC, capacity 314Ah, equivalent internal resistance 10mΩ, which need to be connected in parallel on the DC side; Fuel cell system: equipped with a 100kW fuel cell generator set, with built-in hydrogen pump (model HP-2000, average power 2kW, rated voltage 600-800VDC) and air compressor (model AC-20K, average power 20kW, rated voltage 600-800VDC). EMS master control configuration: Based on the Infineon TC297 chip as the core hardware, voltage acquisition frequency 10Hz, CAN communication baud rate 500kbps; Implementation objectives: maximum differential pressure between clusters before parallel connection <1VDC, instantaneous circulating current during parallel connection <100A, and total time for differential pressure regulation <3 minutes.

[0069] 1.2 Specific Implementation Steps Step 1: Initialization and Voltage Acquisition Before the microgrid starts, the EMS (Electronic Management System) is powered on and initialized, then the voltage acquisition module is triggered. The module simultaneously acquires the open-circuit voltage of three lithium battery clusters, with detected values ​​of: Cluster 1# 720VDC, Cluster 2# 650VDC, and Cluster 3# 630VDC. The EMS automatically calculates the average voltage U_avg = (720+650+630) / 3 = 666.7VDC, and identifies Cluster 1# with a voltage higher than U_avg and the largest voltage difference as the target cluster, calculating the initial voltage difference ΔU = 720VDC. 666.7 = 53.3VDC.

[0070] Step 2: High-power rapid adjustment (air compressor load) EMS sends a "load start command" to the air compressor controller (ACU) via a 500kbps baud rate CAN bus, controlling the DC contactor corresponding to cluster #1 and the air compressor to close, allowing the air compressor to connect to the target cluster circuit at its rated power of 20kW. The voltage acquisition module feeds back the real-time voltage of cluster #1 every 0.1 seconds, monitoring that its voltage is decreasing at a rate of 0.3VDC / s; after 180 seconds (exactly within the target time range of 3 minutes), the voltage of cluster #1 drops to 670VDC, at which point ΔU=670. 666.7 = 3.3VDC, which meets the load switching conditions.

[0071] Step 3: Precise adjustment of low power (hydrogen pump load) The EMS first sends a "load stop command" to the ACU to disconnect the air compressor circuit, and then sends a "load start command" to the hydrogen pump controller (HCU) via the CAN bus to close the DC contactor between cluster #1 and the hydrogen pump, allowing the hydrogen pump to connect to the circuit at 2kW power. At this point, the voltage drop rate slows to 0.02VDC / s, and after 115 seconds, the voltage of cluster #1 stabilizes at 666.5VDC, corresponding to ΔU=666.5. 666.7= 0.2VDC, which fully meets the regulation target of "differential pressure < 1VDC".

[0072] Step 4: Parallel connection without circulation The EMS synchronously monitors the voltage status of all clusters: Clusters #2 and #3 have been calibrated from 650VDC and 630VDC to 666.3VDC respectively through the same adjustment logic, with a maximum voltage difference of only 0.5VDC between the three clusters. The EMS then issues a "parallel connection enabled" command, controlling the DC contactors of the three lithium battery clusters to close synchronously; the current sensor of the parallel execution module detects an instantaneous maximum current of 85A (<100A safety threshold), which drops back to the normal operating current of approximately 50A after 0.3 seconds, and there is no risk of circulating current during the entire parallel connection process.

[0073] The results of the example tests are shown in Table 1: Table 1. Example Test Results

[0074] This embodiment also provides a parallel differential voltage regulation device for lithium batteries in a hydrogen-lithium coupled microgrid. This device is used to implement the above embodiments and preferred embodiments, and details already described will not be repeated. As used below, the term "module" can refer to a combination of software and / or hardware that performs a predetermined function. Although the devices described in the following embodiments are preferably implemented in software, hardware implementation, or a combination of software and hardware, is also possible and contemplated.

[0075] This embodiment provides a parallel differential voltage regulation device for lithium batteries in a hydrogen-lithium coupled microgrid, such as... Figure 4 As shown, it includes: The acquisition module 41 is used to acquire the open-circuit voltage of all lithium battery clusters to be connected in parallel in the hydrogen-lithium coupled microgrid in real time.

[0076] The calculation module 42 is used to calculate the average voltage of all lithium battery clusters to be connected in parallel, calculate the real-time voltage difference between the open-circuit voltage and the average voltage of each lithium battery cluster to be connected in parallel, and identify the target lithium battery cluster with a voltage higher than the average voltage and the largest voltage difference between the voltage and the average voltage.

[0077] The regulating module 43 is used to use the auxiliary equipment of the fuel cell in the hydrogen-lithium coupled microgrid as an adjustable load, and to schedule the corresponding adjustable load to connect to the target lithium battery cluster in stages according to the magnitude of the maximum pressure difference, so as to regulate the open circuit voltage of the target lithium battery cluster. The auxiliary equipment includes an air compressor and a hydrogen pump.

[0078] The parallel module 44 is used to control the DC contactor of each lithium battery cluster to close and perform parallel operation when the voltage difference between the open circuit voltage and the average voltage of all lithium battery clusters to be connected in parallel is less than the first threshold.

[0079] The lithium-hydrogen coupled microgrid parallel differential voltage regulation device provided in this embodiment of the invention can execute the lithium-hydrogen coupled microgrid parallel differential voltage regulation method provided in any embodiment of the invention, and has the corresponding functional modules and beneficial effects of the method. Further functional descriptions of the above modules and units are the same as in the corresponding embodiments described above, and will not be repeated here.

[0080] This invention provides a lithium-ion coupled microgrid lithium battery parallel differential voltage regulation device. Before power-on, the open-circuit voltage of the lithium battery cluster is acquired, the average voltage is calculated, and the target lithium battery cluster and initial differential voltage are determined. Based on the initial differential voltage, the air compressor and hydrogen pump of the fuel cell are staged and configured as adjustable loads, connected to the target lithium battery cluster to regulate the voltage. When the maximum differential voltage between clusters is less than a first threshold, non-circulating current parallel connection is triggered. This application reuses fuel cell auxiliary equipment, eliminating the need for additional current-limiting resistors or equalization modules, thus reducing system size and cost. Staged regulation achieves rapid voltage reduction and precise voltage control, with significant circulating current suppression, high regulation efficiency and accuracy. It improves the integration and energy utilization of the lithium-ion coupled system, adapting to various complex scenarios.

[0081] Figure 5 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present invention.

[0082] The following is a detailed reference. Figure 5 The diagram illustrates a structural schematic suitable for implementing an electronic device according to embodiments of the present invention. The electronic device may include a processor (e.g., a central processing unit, graphics processor, etc.) 501, which can perform various appropriate actions and processes according to a program stored in read-only memory (ROM) 502 or a program loaded from memory 508 into random access memory (RAM) 503. The RAM 503 also stores various programs and data required for the operation of the electronic device. The processor 501, ROM 502, and RAM 503 are interconnected via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0083] Typically, the following devices can be connected to I / O interface 505: input devices 506 including, for example, touchscreens, touchpads, keyboards, mice, cameras, microphones, accelerometers, gyroscopes, etc.; output devices 507 including, for example, liquid crystal displays (LCDs), speakers, vibrators, etc.; memory devices 508 including, for example, magnetic tapes, hard disks, etc.; and communication devices 509. Communication device 509 allows electronic devices to communicate wirelessly or wiredly with other devices to exchange data. Although Figure 5 Electronic devices with various devices are shown, but it should be understood that it is not required to implement or have all of the devices shown, and more or fewer devices may be implemented or have instead.

[0084] In particular, according to embodiments of the present invention, the processes described above with reference to the flowcharts can be implemented as computer software programs. For example, embodiments of the present invention include a computer program product comprising a computer program carried on a non-transitory computer-readable medium, the computer program containing program code for performing the methods shown in the flowcharts. In such embodiments, the computer program can be downloaded and installed from a network via a communication device 509, or installed from a memory 508, or installed from a ROM 502. When the computer program is executed by the processor 501, it performs the functions defined in the parallel differential voltage regulation method for lithium batteries in a hydrogen-lithium coupled microgrid according to embodiments of the present invention.

[0085] Figure 5 The electronic device 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.

[0086] This invention also provides a computer-readable storage medium. The methods described above according to embodiments of the invention can be implemented in hardware or firmware, or implemented as computer code that can be recorded on a storage medium, or implemented as computer code downloaded via a network and originally stored on a remote storage medium or a non-transitory machine-readable storage medium and then stored on a local storage medium. Thus, the methods described herein can be processed by software stored on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. The storage medium can be a magnetic disk, optical disk, read-only memory, random access memory, flash memory, hard disk, or solid-state drive, etc.; further, the storage medium can also include combinations of the above types of memory. It is understood that the computer, processor, microprocessor controller, or programmable hardware includes storage components capable of storing or receiving software or computer code. When the software or computer code is accessed and executed by the computer, processor, or hardware, the parallel differential voltage regulation method for lithium batteries in a hydrogen-lithium coupled microgrid shown in the above embodiments is implemented.

[0087] A portion of this invention can be applied as a computer program product, such as computer program instructions, which, when executed by a computer, can invoke or provide the methods and / or technical solutions according to the invention through the operation of the computer. Those skilled in the art will understand that the forms in which computer program instructions exist in a computer-readable medium include, but are not limited to, source files, executable files, installation package files, etc. Correspondingly, the ways in which computer program instructions are executed by a computer include, but are not limited to: the computer directly executing the instructions, or the computer compiling the instructions and then executing the corresponding compiled program, or the computer reading and executing the instructions, or the computer reading and installing the instructions and then executing the corresponding installed program. Here, the computer-readable medium can be any available computer-readable storage medium or communication medium accessible to a computer.

[0088] Although embodiments of the invention have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the invention, and such modifications and variations all fall within the scope defined by the appended claims.

Claims

1. A method for regulating the differential voltage of lithium batteries in a parallel connection of a hydrogen-lithium coupled microgrid, characterized in that, The method includes: Real-time acquisition of the open-circuit voltage of all lithium battery clusters to be connected in parallel in the hydrogen-lithium coupled microgrid; Calculate the average voltage of all lithium battery clusters to be connected in parallel, calculate the real-time voltage difference between the open-circuit voltage and the average voltage of each lithium battery cluster to be connected in parallel, and identify the target lithium battery cluster with a voltage higher than the average voltage and the largest voltage difference between the open-circuit voltage and the average voltage. Using auxiliary equipment for fuel cells in a hydrogen-lithium coupled microgrid as adjustable loads, the corresponding adjustable loads are connected to the target lithium battery cluster in stages according to the magnitude of the maximum pressure difference, thereby adjusting the open-circuit voltage of the target lithium battery cluster. The auxiliary equipment includes an air compressor and a hydrogen pump. When the voltage difference between the open-circuit voltage and the average voltage of all lithium battery clusters to be connected in parallel is less than the first threshold, the DC contactor of each lithium battery cluster is closed to execute the parallel connection operation.

2. The method for regulating the parallel voltage difference of lithium batteries in a hydrogen-lithium coupled microgrid according to claim 1, characterized in that, Using auxiliary equipment of fuel cells in a hydrogen-lithium coupled microgrid as adjustable loads, the adjustable loads are connected to the target lithium battery cluster in stages according to the magnitude of the maximum voltage difference, thereby regulating the open-circuit voltage of the target lithium battery cluster, including: When the maximum pressure difference is greater than the second threshold, the air compressor is controlled to establish a connection with the target lithium battery cluster, and the open circuit voltage of the target lithium battery cluster is adjusted with the first preset power to reduce the open circuit voltage of the target lithium battery cluster to below the third threshold. When the maximum pressure difference is greater than the fourth threshold and not greater than the second threshold, the connection between the air compressor and the target lithium battery cluster is disconnected, the hydrogen pump is controlled to establish a connection with the target lithium battery cluster, and the open circuit voltage of the target lithium battery cluster is adjusted with the second preset power to reduce the open circuit voltage of the target lithium battery cluster to below the fifth threshold.

3. The method for regulating the parallel voltage difference of lithium batteries in a hydrogen-lithium coupled microgrid according to claim 2, characterized in that, Using auxiliary equipment of fuel cells in a hydrogen-lithium coupled microgrid as adjustable loads, the system tiers and schedules the connection of corresponding adjustable loads to the target lithium battery cluster based on the magnitude of the maximum voltage difference, thereby regulating the open-circuit voltage of the target lithium battery cluster. The system also includes: Continuously monitor the real-time open-circuit voltage of the target lithium battery cluster and dynamically update the maximum voltage difference; The load power of the air compressor and hydrogen pump is dynamically adjusted based on the rate of decrease of the maximum pressure difference.

4. The method for regulating the parallel voltage difference of lithium batteries in a hydrogen-lithium coupled microgrid according to claim 1, characterized in that, The method includes: Real-time monitoring of instantaneous parallel current; If the instantaneous current exceeds the sixth threshold, the DC contactor of each lithium battery cluster will be immediately disconnected.

5. A parallel differential voltage regulation system for lithium batteries in a hydrogen-lithium coupled microgrid, characterized in that, The system includes: a voltage acquisition module, an EMS central control unit, a load regulation module, and a parallel execution module, wherein, The voltage acquisition module is installed at the DC output terminal of each lithium battery cluster to be connected in parallel, and is used to acquire the open circuit voltage data of each lithium battery cluster in real time and transmit the open circuit voltage data to the EMS central control unit. The EMS central control unit is communicatively connected to the voltage acquisition module, the load adjustment module, and the parallel execution module. The EMS central control unit is used to receive the open-circuit voltage data transmitted by the voltage acquisition module, calculate the average voltage of all lithium battery clusters to be connected in parallel, calculate the real-time voltage difference between the open-circuit voltage and the average voltage of each lithium battery cluster to be connected in parallel, identify the target lithium battery cluster with a voltage higher than the average voltage and the largest voltage difference with the average voltage, and schedule the corresponding adjustable load to connect to the target lithium battery cluster according to the size of the maximum voltage difference. The load regulation module is used to use the auxiliary equipment of the fuel cell in the hydrogen-lithium coupled microgrid as an adjustable load, and under the scheduling of the EMS central control unit, to perform graded regulation of the voltage of the target lithium battery cluster. The parallel execution module is installed on the parallel bus of each lithium battery cluster to be connected in parallel, and is used to realize the non-circulating current parallel connection of each lithium battery cluster under the control of the EMS central control unit.

6. The hydrogen-lithium coupled microgrid lithium battery parallel differential voltage regulation system according to claim 5, characterized in that, The load regulation module includes a hydrogen pump, an air compressor, a hydrogen pump controller, and an air compressor controller. The hydrogen pump and the air compressor are connected to each lithium battery cluster to be connected in parallel via DC contactors.

7. The parallel differential voltage regulation system for lithium batteries in a hydrogen-lithium coupled microgrid according to claim 5, characterized in that, The hierarchical scheduling logic of the EMS central control unit is as follows: When the maximum pressure difference is greater than the second threshold, the air compressor is controlled to establish a connection with the target lithium battery cluster, and the open circuit voltage of the target lithium battery cluster is adjusted with the first preset power to reduce the open circuit voltage of the target lithium battery cluster to below the third threshold. When the maximum pressure difference is greater than the fourth threshold and not greater than the second threshold, the connection between the air compressor and the target lithium battery cluster is disconnected, the hydrogen pump is controlled to establish a connection with the target lithium battery cluster, and the open circuit voltage of the target lithium battery cluster is adjusted with the second preset power to reduce the open circuit voltage of the target lithium battery cluster to below the fifth threshold.

8. A parallel differential voltage regulation device for lithium batteries in a hydrogen-lithium coupled microgrid, characterized in that, The device includes: The acquisition module is used to acquire the open-circuit voltage of all lithium battery clusters to be connected in parallel in the hydrogen-lithium coupled microgrid in real time. The calculation module is used to calculate the average voltage of all lithium battery clusters to be connected in parallel, calculate the real-time voltage difference between the open-circuit voltage and the average voltage of each lithium battery cluster to be connected in parallel, and identify the target lithium battery cluster with a voltage higher than the average voltage and the largest voltage difference between the voltage and the average voltage. The adjustment module is used to use the auxiliary equipment of the fuel cell in the hydrogen-lithium coupled microgrid as an adjustable load, and to schedule the corresponding adjustable load to be connected to the target lithium battery cluster in stages according to the magnitude of the maximum pressure difference, so as to adjust the open circuit voltage of the target lithium battery cluster. The auxiliary equipment includes an air compressor and a hydrogen pump. The parallel module is used to control the DC contactor of each lithium battery cluster to close and perform parallel operation when the voltage difference between the open circuit voltage and the average voltage of all lithium battery clusters to be connected in parallel is less than a first threshold.

9. An electronic device, characterized in that, include: A memory and a processor are interconnected, the memory stores computer instructions, and the processor executes the computer instructions to perform the parallel differential voltage regulation method for lithium batteries in a hydrogen-lithium coupled microgrid as described in any one of claims 1 to 5.

10. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores computer instructions for causing the computer to execute the parallel differential voltage regulation method for lithium batteries in a hydrogen-lithium coupled microgrid as described in any one of claims 1 to 5.

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