A direct current voltage reduction charging and voltage increase output energy storage system

Abstract

The utility model discloses a kind of energy storage systems of direct-current voltage reduction charging simultaneously boosting output, including cabinet, DC bus is arranged in the cabinet, two-way DC-DC power converter, control module and anti-inrush protection unit;Adopt double Buck-Boost topological structure, through switching tube time sequence control, seamless switching voltage reduction / boosting mode is realized, support wide input voltage range (such as 48V-400V DC) and high efficiency, have intelligent charging and discharging strategy, based on LSTM neural network prediction load demand, dynamically adjust charging and discharging power, limit charging and discharging times in combination with battery SOC (state of charge), reduce cycle loss, current monitoring, voltage protection and overvoltage protection can be realized by anti-inrush protection mechanism, through multidimensional monitoring and quick response, avoid battery reverse charging and equipment overvoltage damage, guarantee system safe operation.

Description

Technical Field

[0001] This utility model relates to the field of energy storage system technology, specifically an energy storage system that provides DC buck charging and simultaneous boost output. Background Technology

[0002] Traditional energy storage systems typically require multi-stage conversion (such as AC-DC-AC) for charging and discharging when connected to a DC power source, resulting in high energy loss (approximately 15%-20%). Existing bidirectional DC-DC converters struggle to simultaneously achieve wide-range buck charging and efficient boost output, leading to shortened battery life due to frequent charging and discharging. Reverse current is prone to occur during grid-connected / off-grid switching, threatening power safety. Therefore, those skilled in the art have proposed an energy storage system that simultaneously performs DC buck charging and boost output to address the problems mentioned in the background section. Utility Model Content

[0003] The purpose of this invention is to provide an energy storage system that simultaneously performs DC buck charging and boost output, in order to solve the problems mentioned in the background art.

[0004] To achieve the above objectives, this utility model provides the following technical solution:

[0005] An energy storage system that enables DC buck charging and simultaneous boost output includes a chassis, which houses a DC bus, a bidirectional DC-DC power converter, a control module, and a reverse current protection unit.

[0006] DC bus, used to connect external DC solar panels, energy storage batteries and loads;

[0007] A bidirectional DC-DC power converter, connected to the DC bus and the energy storage battery pack, adopts a dual Buck-Boost parallel circuit topology and includes at least two sets of switching transistor arrays. Seamless switching between buck charging mode and boost output mode is achieved through PWM timing control.

[0008] The control module integrates an MPPT algorithm unit, an LSTM neural network prediction unit, and a battery management system (BMS). The control module tracks the maximum power point of the external power source in real time through the MPPT algorithm unit, predicts the load demand in future periods through the LSTM neural network prediction unit, and dynamically adjusts the charging and discharging power based on the battery SOC state obtained by the BMS.

[0009] The anti-reverse current protection unit includes a DC bus current sensor and a solid-state transfer switch (STS). When an abnormal direction of the bus current is detected, the STS is triggered to cut off the reverse current path.

[0010] Furthermore, the input voltage range of the bidirectional DC-DC power converter is 48V-400V DC, and the conversion efficiency is ≥95% in buck charging mode and ≥94% in boost output mode.

[0011] Furthermore, the control module also includes:

[0012] The charge / discharge strategy optimization unit generates the optimal charge / discharge scheduling instructions based on the prediction results of the LSTM neural network and the battery SOC state using a dynamic programming algorithm.

[0013] The multi-mode switching control unit supports automatic switching between grid-connected and off-grid modes and access to various types of DC power sources, including photovoltaic and wind power.

[0014] Furthermore, the anti-backflow protection unit also includes:

[0015] Voltage comparator to monitor DC bus voltage and battery pack voltage in real time;

[0016] The overvoltage protection module activates current limiting protection when the bus voltage exceeds a preset threshold.

[0017] Furthermore, the energy storage battery pack is a sodium-ion battery or a lithium iron phosphate battery pack, equipped with a battery equalization management circuit, and supports operation in a wide temperature range of -20℃ to 55℃.

[0018] Furthermore, the system also includes:

[0019] The energy flow visualization module displays the working status of each module, the remaining battery power, and the charge / discharge power curves in real time through a human-computer interaction interface.

[0020] Redundant output interfaces, including at least two USB 5V / 2A interfaces, four DC12V / 2A interfaces, and one AC220V / 50Hz inverter output interface.

[0021] Furthermore, the switching array of the bidirectional DC-DC power converter uses silicon carbide (SiC) MOSFET devices with a switching frequency range of 20kHz-100kHz.

[0022] Furthermore, the control module communicates with external devices via a CAN bus and supports the MODBUS RTU protocol and remote monitoring functions.

[0023] By adopting the above technical solution

[0024] Compared with the prior art, the beneficial effects of this utility model are:

[0025] 1. The bidirectional DC-DC converter features an optimized design. By monitoring the voltage difference between the bus and the battery in real time, the system completes mode switching within 50μs, avoiding circulating current losses. It adopts a dual Buck-Boost topology and achieves seamless switching between buck and boost modes through switching transistor timing control. It supports a wide input voltage range (such as 48V-400V DC) and high efficiency.

[0026] 2. It has an intelligent charging and discharging strategy. When a sudden increase in load is predicted, the system will increase the discharge power in advance. If the SOC is lower than the threshold, it will prioritize limiting the power supply to non-critical loads, reduce the number of deep discharge cycles of the battery, and extend the life by 20%-30%. Based on the LSTM neural network, it predicts the load demand and dynamically adjusts the charging and discharging power. Combined with the battery SOC (state of charge), it limits the number of charging and discharging cycles to reduce cycle loss.

[0027] 3. The reverse current protection mechanism enables current monitoring, voltage protection, and overvoltage protection. Through multi-dimensional monitoring and rapid response, it avoids reverse charging of the battery and damage to the equipment due to overvoltage, ensuring the safe operation of the system. Attached Figure Description

[0028] Figure 1 A schematic diagram of the enclosure structure of an energy storage system that simultaneously performs DC step-down charging and step-up output.

[0029] In the diagram: 1. Box. Detailed Implementation

[0030] To make the technical means, creative features, achieved objectives and effects of this utility model easier to understand, the present utility model is further described below in conjunction with specific embodiments. In the description of this utility model, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description. For those skilled in the art, the specific meaning of the above terms in this utility model can be understood according to the specific circumstances.

[0031] Please see Figure 1This utility model provides an embodiment of an energy storage system that simultaneously performs DC buck charging and boost output. The system includes a chassis 1, which houses a DC bus, a bidirectional DC-DC power converter, a control module, and a reverse current protection unit. The DC bus connects to external DC solar panels, energy storage batteries, and loads. The bidirectional DC-DC power converter is connected to the DC bus and the energy storage battery pack, employing a dual Buck-Boost parallel circuit topology. It includes at least two sets of switching transistor arrays and achieves seamless switching between buck charging and boost output modes through PWM timing control. The input voltage range of the bidirectional DC-DC power converter is 48V-400V DC, with a conversion efficiency ≥95% in buck charging mode and ≥94% in boost output mode. The switching transistor array of the bidirectional DC-DC power converter is made of silicon carbide (SiC). The system utilizes MOSFET devices with a switching frequency range of 20kHz-100kHz. It also includes an energy flow visualization module that displays the real-time operating status of each module, remaining battery capacity, and charge / discharge power curves via a human-machine interface. The energy storage battery pack is either a sodium-ion battery or a lithium iron phosphate battery pack, equipped with a battery balancing management circuit, supporting operation over a wide temperature range of -20℃ to 55℃. Bidirectional energy flow is achieved through the coordinated control of two sets of switching transistor arrays (such as SiC MOSFETs). In buck charging mode, when the input voltage (48V-400V DC) is higher than the battery voltage, two Buck circuits alternately conduct, adjusting the duty cycle to reduce the input voltage to the battery voltage (e.g., 48V→54V), achieving a conversion efficiency ≥95%. In boost output mode, the battery voltage is boosted to the load voltage (e.g., 48V→12V) via a Boost circuit. Two Boost circuits are connected in parallel to increase the output current capability, achieving an efficiency ≥94%. By real-time monitoring of the voltage difference between the bus and the battery, the system achieves a 50μs... The internal mode switching is completed to avoid circulating current loss. It adopts a dual Buck-Boost topology and achieves seamless switching between buck and boost modes through switching transistor timing control. It supports a wide input voltage range (such as 48V-400V DC) and high efficiency.

[0032] In this embodiment, the control module integrates an MPPT algorithm unit, an LSTM neural network prediction unit, and a battery management system (BMS). The control module uses the MPPT algorithm unit to track the maximum power point of the external power source in real time, and the LSTM neural network prediction unit to predict future load demands. Based on the battery SOC state obtained from the BMS, it dynamically adjusts the charging and discharging power. The control module also includes a charging and discharging strategy optimization unit, which generates optimal charging and discharging scheduling instructions using a dynamic programming algorithm based on the LSTM neural network prediction results and the battery SOC state. A multi-mode switching control unit supports automatic switching between grid-connected and off-grid power and access to various types of DC power sources such as photovoltaic and wind power. The control module communicates with external devices via a CAN bus and supports the MODBUS RTU protocol and remote monitoring functions. The control module integrates an LSTM neural network and the MPPT algorithm to achieve dynamic power management. The LSTM model predicts the load demand for the next 15-30 minutes based on historical load data and environmental parameters, and generates optimal charging and discharging instructions based on the battery SOC state (20%-80% threshold). The algorithm tracks the maximum power point of photovoltaics using the incremental conductance method to ensure maximum charging power. When a sudden increase in load is predicted, the system increases the discharge power in advance. If the SOC is below the threshold, the power supply to non-critical loads is restricted first, reducing the number of deep discharge cycles of the battery and extending its lifespan by 20%-30%. Based on the LSTM neural network, the algorithm predicts load demand and dynamically adjusts the charging and discharging power. Combined with the battery SOC (state of charge), the algorithm limits the number of charging and discharging cycles to reduce cycle losses.

[0033] In this embodiment, the anti-reverse current protection unit includes a DC bus current sensor and a solid-state transfer switch (STS). When an abnormality in the direction of the bus current is detected, the STS is triggered to cut off the reverse current path. The anti-reverse current protection unit also includes a voltage comparator to monitor the DC bus voltage and battery pack voltage in real time, an overvoltage protection module to activate current limiting protection when the bus voltage exceeds a preset threshold; the bus current direction is monitored in real time by the current sensor, triggering the STS switch to cut off the reverse current path; the bus current sensor detects the current direction in real time, and when the reverse current is >0.5A, the solid-state switch (response time ≤1ms) is triggered to cut off the reverse current path, realizing current monitoring; when the battery voltage is lower than the bus voltage by 2V, current limiting charging is initiated (current drops to 50% of the rated value), realizing voltage protection; a TVS diode and fuse combination blows the circuit when the bus voltage is >420V, realizing overvoltage protection. Through multi-dimensional monitoring and rapid response, reverse charging of the battery and overvoltage damage to the equipment are avoided, ensuring the safe operation of the system.

[0034] Bidirectional energy flow is achieved through the coordinated control of two sets of switching transistor arrays (such as SiC MOSFETs). In buck charging mode, when the input voltage (48V-400V DC) is higher than the battery voltage, the two Buck circuits alternately conduct, adjusting the duty cycle to reduce the input voltage to the battery voltage (e.g., 48V→54V), with a conversion efficiency ≥95%. In boost output mode, the battery voltage is boosted to the load voltage (e.g., 48V→12V) by the Boost circuit. The two Boost circuits are connected in parallel to improve the output current capability, with an efficiency ≥94%. By monitoring the voltage difference between the bus and the battery in real time, the system completes mode switching within 50μs to avoid circulating current losses. The control module integrates an LSTM neural network and the MPPT algorithm to achieve dynamic power management. The LSTM model predicts the load demand for the next 15-30 minutes based on historical load data and environmental parameters, and generates optimal charging and discharging commands based on the battery SOC state (20%-80% threshold). The algorithm tracks the photovoltaic maximum power point using the incremental conductance method to ensure maximum charging power. When a sudden load increase is predicted, the system increases the discharge power in advance. If the SOC is below the threshold, the power supply to non-critical loads is limited first to reduce the number of deep discharge cycles. The bus current direction is monitored in real time by a current sensor, triggering the STS switch to cut off the reverse current path. The bus current sensor detects the current direction in real time. When the reverse current is >0.5A, the solid-state switch (response time ≤1ms) is triggered to cut off the reverse current path to achieve current monitoring. When the battery voltage is 2V lower than the bus voltage, current-limited charging is started (current drops to 50% of the rated value) to achieve voltage protection. The TVS diode and fuse are combined to blow the circuit when the bus voltage is >420V to achieve overvoltage protection.

[0035] By monitoring the voltage difference between the bus and the battery in real time, the system completes mode switching within 50μs, avoiding circulating current losses. It adopts a dual Buck-Boost topology and achieves seamless switching between buck and boost modes through switching transistor timing control, supporting a wide input voltage range (e.g., 48V-400V DC) and high efficiency. When a sudden load increase is predicted, the system proactively increases the discharge power. If the SOC is below a threshold, it prioritizes limiting power to non-critical loads, reducing the number of deep battery discharges and extending battery life by 20%-30%. Based on an LSTM neural network, it predicts load demand and dynamically adjusts charging and discharging power, combined with battery SOC (State of Charge) to limit the number of charge and discharge cycles, reducing cycle losses. It can achieve current monitoring, voltage protection, and overvoltage protection. Through multi-dimensional monitoring and rapid response, it avoids battery reverse charging and equipment overvoltage damage, ensuring safe system operation.

[0036] This specification describes embodiments, but not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. An energy storage system that simultaneously performs DC buck charging and boost output, characterized in that, Includes a chassis (1), which is equipped with a DC bus, a bidirectional DC-DC power converter, a control module and a reverse current protection unit; DC bus, used to connect external DC solar panels, energy storage batteries and loads; A bidirectional DC-DC power converter is connected to the DC bus and the energy storage battery pack. It adopts a dual Buck-Boost parallel circuit topology and includes at least two sets of switching transistor arrays. Seamless switching between buck charging mode and boost output mode is achieved through PWM timing control. The control module integrates an MPPT algorithm unit, an LSTM neural network prediction unit, and a battery management system (BMS). The control module tracks the maximum power point of the external power source in real time through the MPPT algorithm unit, predicts the load demand in future periods through the LSTM neural network prediction unit, and dynamically adjusts the charging and discharging power based on the battery SOC state obtained by the BMS. The anti-reverse current protection unit includes a DC bus current sensor and a solid-state transfer switch (STS). When an abnormal direction of the bus current is detected, the STS is triggered to cut off the reverse current path.

2. The energy storage system with DC buck charging and simultaneous boost output according to claim 1, characterized in that, The input voltage range of the bidirectional DC-DC power converter is 48V-400V DC, and the conversion efficiency is ≥95% in buck charging mode and ≥94% in boost output mode.

3. The energy storage system with DC buck charging and simultaneous boost output according to claim 1, characterized in that, The control module also includes: The charge / discharge strategy optimization unit generates the optimal charge / discharge scheduling instruction based on the prediction results of the LSTM neural network and the battery SOC state using a dynamic programming algorithm. The multi-mode switching control unit supports automatic switching between grid-connected and off-grid operation and access to various types of DC power sources, including photovoltaic and wind power.

4. The energy storage system with DC buck charging and simultaneous boost output according to claim 1, characterized in that, The backflow prevention protection unit also includes: Voltage comparator to monitor DC bus voltage and battery pack voltage in real time; The overvoltage protection module activates current limiting protection when the bus voltage exceeds a preset threshold.

5. The energy storage system with DC buck charging and simultaneous boost output according to claim 1, characterized in that, The energy storage battery pack is a sodium-ion battery or a lithium iron phosphate battery pack, equipped with a battery equalization management circuit, and supports operation in a wide temperature range of -20℃ to 55℃.

6. The energy storage system with DC buck charging and simultaneous boost output according to claim 1, characterized in that, The system also includes: The energy flow visualization module displays the working status of each module, the remaining battery power, and the charge / discharge power curves in real time through a human-computer interaction interface. Redundant output interfaces, including at least two USB 5V / 2A interfaces, four DC12V / 2A interfaces, and one AC220V / 50Hz inverter output interface.

7. The energy storage system with DC buck charging and simultaneous boost output according to claim 1, characterized in that, The switching array of the bidirectional DC-DC power converter uses silicon carbide (SiC) MOSFET devices, with a switching frequency range of 20kHz-100kHz.

8. The energy storage system with DC buck charging and simultaneous boost output according to claim 1, characterized in that, The control module communicates with external devices via a CAN bus and supports the MODBUS RTU protocol and remote monitoring functions.

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