Control method for high-efficiency energy storage system suitable for vehicle starting in low-temperature environment

Abstract

The application provides a control method of a high-efficiency energy storage system suitable for vehicle starting in a low-temperature environment, belongs to the technical field of new energy storage, and solves the problems of insufficient starting power, low charging efficiency, high energy consumption and poor reliability of the energy storage system in low temperature. The system comprises a main energy storage unit, an auxiliary energy storage unit, a control unit and a thermal management module, and each unit is electrically connected to form a closed loop system; the control method comprises the steps of wake-up detection, temperature determination, preheating, segmented constant-current charging, starting output protection, energy recovery and waste heat recovery, and realizes reliable starting and efficient operation in low temperature. The application improves the reliability and energy utilization efficiency of vehicle starting in extremely cold environment, takes into account the economy, and is suitable for energy storage power supply of starting equipment in extremely cold areas.

Description

Technical Field

[0001] This invention relates to the field of new energy storage technology, and in particular to a control method for a high-efficiency energy storage system suitable for vehicle starting in low-temperature environments. Background Technology

[0002] In extremely low temperature environments, traditional lithium-ion batteries suffer from electrolyte freezing, slower ion migration, and a sharp increase in internal resistance, making it impossible for them to meet the instantaneous high-power demands of starters.

[0003] In the existing technology, farad capacitors have wide temperature range characteristics and capacity decay of less than 10% at -40℃, but their energy density is only 1 / 8 of that of lithium batteries. When used alone, they are difficult to meet the continuous discharge requirements and need to be connected in series or parallel in large quantities, resulting in large system size and high cost. Traditional cell self-heating thermal management technology has high energy consumption and low efficiency in low-temperature environments, with an ideal heating rate of only 0.43℃ / min, which is difficult to meet the requirements for rapid start-up. Adding an external insulation layer will increase the system size and weight. Currently, although researchers have improved the performance of lithium-ion batteries below -20℃ through material modification and other means, the batteries still face the problems of polarization and increased internal resistance in extremely low-temperature environments such as -40℃, resulting in a decrease in energy output capacity.

[0004] Developing a hybrid energy storage system that can start up at low temperatures with high efficiency, while taking into account size, cost, and reliability, is a key area that urgently needs to be addressed. Summary of the Invention

[0005] The main objective of this invention is to provide a control method for a high-efficiency energy storage system suitable for vehicle starting in low-temperature environments, thereby solving the problems of difficulty in starting, high cost, and low reliability in existing technologies under low-temperature conditions.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is: a high-efficiency energy storage system suitable for vehicle starting in low-temperature environments, including a main energy storage unit, an auxiliary energy storage unit, a control unit and a thermal management module; The main energy storage unit uses a supercapacitor bank, which is composed of several supercapacitor cells connected in series and parallel. It has wide temperature range characteristics and instantaneous high power output capability at low temperatures. The auxiliary energy storage unit uses a battery pack, which is composed of several battery cells connected in series and parallel. The control unit integrates a dynamic balancing circuit and a segmented constant current charging controller, and is electrically connected to the main energy storage unit and the auxiliary energy storage unit respectively; The thermal management module includes a cell self-heating component, a temperature sensor, and an internal heat conduction circuit; The cell self-heating component is integrated into the auxiliary energy storage unit. It is used to receive the start signal from the control unit and consume the energy of the auxiliary energy storage unit to preheat the cell in order to reduce the internal resistance of the cell. Temperature sensors are used to collect ambient temperature in real time and monitor the capacitor temperature of the main energy storage unit and the cell temperature of the auxiliary energy storage unit respectively, and transmit the temperature signal to the control unit; the internal heat conduction circuit forms a heat conduction path from the main energy storage unit to the auxiliary energy storage unit.

[0007] In a preferred embodiment, a high-efficiency energy storage system suitable for vehicle starting in low-temperature environments includes a main energy storage unit, an auxiliary energy storage unit, a control unit, and a thermal management module. The units work together to form a closed-loop energy storage starting system, which is used to solve the technical problems of insufficient starting power, low charging efficiency, and high energy consumption of traditional energy storage systems in low-temperature environments.

[0008] In the preferred scheme, the main energy storage unit adopts a high-capacitance supercapacitor bank, which is composed of several supercapacitor cells connected in series and in parallel. The series and parallel topology design is adapted to the system voltage range. The selection of high-capacitance farad capacitor banks should be based on meeting the instantaneous high power requirements of the starting equipment and have the ability to output high power instantaneously; the theoretical starting time is 9.2s, which is shortened to 5.5s in a low temperature environment of -40℃; by utilizing the high power density and wide temperature range (-45℃~+70℃) characteristics of farad capacitors, the defects of power output attenuation of traditional lithium-ion batteries at low temperatures can be made up for, and the instantaneous power supply of the starting equipment can be guaranteed in extremely cold environments.

[0009] In the preferred scheme, the auxiliary energy storage unit adopts a conventional lithium battery pack, which is composed of lithium-ion battery cells connected in series and parallel. The capacity selection should support the charging requirements of the high-capacity supercapacitor pack and the system's redundant energy supply. Conventional lithium battery packs provide continuous charging energy for high-capacity supercapacitor packs, preventing the system from failing to restart due to energy depletion after a single discharge of the supercapacitors. At the same time, they maintain the system's basic energy supply during non-starting conditions. Through energy complementarity with the main energy storage unit, the system can achieve multiple consecutive starts at room temperature and fewer consecutive starts at -40℃, improving the system's cycle start capability.

[0010] In the preferred embodiment, the control unit includes a dynamic balancing circuit and a segmented constant current charging controller, and is electrically connected to the main energy storage unit and the auxiliary energy storage unit; wherein: The dynamic balancing circuit collects the voltage signals of each cell in the high-capacitance supercapacitor bank in real time through the voltage sampling module. When the voltage difference between cells exceeds the preset threshold, the internal power switch adjusts the charging current distribution to prioritize the charging energy of the conventional lithium battery pack to the supercapacitor cells with lower voltage, thus avoiding overcharging or over-discharging of some cells. This maintains the voltage consistency of each cell in the supercapacitor bank, extends the cycle life of the supercapacitors, and reduces the risk of system failure caused by cell voltage imbalance. The segmented constant current charging controller establishes a current control circuit with the conventional lithium battery pack and the high-capacity supercapacitor pack, and executes a current limiting strategy based on the real-time voltage state of the high-capacity supercapacitor pack. When the voltage of the supercapacitor bank is in the preset low voltage range, the controller outputs a preset large charging current to achieve rapid energy replenishment; when the voltage rises to the preset high voltage range, the controller automatically reduces the charging current to a preset small charging current to avoid the risk of thermal runaway caused by internal failure of the supercapacitor due to high current charging; this control strategy can shorten the charging time of high-capacity supercapacitor banks, improve system safety, and solve the technical problem of limited charging speed of supercapacitors at low temperatures.

[0011] In the preferred embodiment, the thermal management module includes a cell self-heating component and an insulation layer; the cell self-heating component is integrated between the cells of a conventional lithium battery pack and adopts a heating element or resistive heating film structure; the insulation layer is wrapped around the main energy storage unit, auxiliary energy storage unit and control unit and adopts polyurethane foam or aerogel thermal insulation material. Before low-temperature startup, the cell self-heating component receives the startup signal from the control unit and preheats the lithium battery cell by consuming a small amount of energy from the conventional lithium battery pack, raising the cell temperature to above -10℃ and reducing the cell's internal resistance. During startup, the thermal management module collects the discharge temperature of the high-capacity supercapacitor pack in real time through a temperature sensor, and introduces the waste heat generated by the capacitor discharge into the lithium battery pack through the heat conduction path, reducing the energy consumption of independent heating, improving the problem of increased internal resistance of lithium battery and insufficient self-heating power of supercapacitor at low temperatures, and improving the overall energy utilization rate of the system.

[0012] A control method for a high-efficiency energy storage system suitable for vehicle starting in low-temperature environments includes: S1. After receiving an external start-up trigger signal, the control unit wakes up from sleep mode. It collects the current voltage Vc of the high-capacitance supercapacitor group and the current voltage Vb of the conventional lithium battery group through the voltage sampling circuit. It also collects the ambient temperature T and the cell temperatures of the two energy storage units, denoted as Tc and Tb, through the temperature sensor and transmits the collected parameters to the built-in microprocessor of the control unit. The microprocessor performs threshold judgment on the collected parameters. If it determines that T or Tb is less than the preset temperature, it outputs a start signal to the thermal management module and enters S2. If it determines that T or Tb is greater than the preset temperature, it enters S3. S2. The control unit sends a preheating command to the thermal management module, and the cell self-heating component is powered on and starts to heat the conventional lithium battery pack with a preset power. During the heating process, the control unit collects Tb in real time. When Tb rises to the preset temperature, the control unit sends a stop heating command, the cell self-heating component is powered off, and the thermal management module switches to waste heat recovery mode. S3. The control unit sends a charging command to the segmented constant current charging controller. The segmented constant current charging controller connects the charging circuit between the conventional lithium battery pack and the high-capacity supercapacitor pack, and executes the segmented constant current charging strategy according to Vc: When Vc is in the preset low voltage range, the segmented constant current charging controller outputs a preset large charging current; when Vc is in the preset high voltage range, the charging current is reduced to a preset small charging current; during the charging process, the dynamic balancing circuit collects the voltage of each individual cell of the high-capacitance supercapacitor bank in real time. If the difference between the voltage of any individual cell and the average voltage of the bank exceeds a preset error, the dynamic balancing circuit adjusts the charging current of that individual cell; thus replenishing the high-capacitance supercapacitor bank to the instantaneous power output capability required to start the equipment. S4. The control unit continuously monitors Vc and Tc. When Vc is higher than the starting voltage threshold and Tc is higher than the preset starting temperature, the system is confirmed to meet the starting conditions. The control unit sends a conduction command to the power output circuit of the high-capacitance supercapacitor bank, and the high-capacitance supercapacitor bank outputs power to the starting device. During the output process, the control unit collects the output current Ic through the current sensor. If Ic exceeds the preset safety threshold of the rated output current, the overcurrent protection mechanism is triggered, and the output circuit is temporarily disconnected and then reconnected to avoid damage to the starting device due to overload. S5. When the starting device completes the start-up, it sends a start-up completion signal to the control unit. After receiving the signal, the control unit disconnects the high-capacity supercapacitor bank from the starting device and simultaneously controls the segmented constant current charging controller to resume operation, charging the high-capacity supercapacitor bank from the conventional lithium battery bank until Vc rises to the rated voltage of the high-capacity supercapacitor bank. During the charging process, the dynamic balancing circuit continuously monitors the voltage of each individual capacitor to maintain the consistency of the voltage of each individual capacitor and restore the system's secondary start-up capability. S6. During charging, the control unit controls the thermal management module to switch to waste heat recovery mode. Temperature sensors monitor Tc and Tb respectively. If Tc is found to be higher than the preset temperature difference value of Tb, the internal heat conduction circuit of the thermal management module is activated to conduct the waste heat of the high-capacity supercapacitor group to the conventional lithium battery group through the heat conduction path. If the temperature difference between Tc and Tb is less than the preset temperature difference value, the heat conduction circuit is turned off to reduce the independent heating energy consumption of the system and improve the overall energy utilization rate. S7. After charging is complete, the system enters standby mode. The control unit reduces its own power consumption and only retains the real-time monitoring function of voltage and temperature, waiting for the next start command. This invention provides a control method for a high-efficiency energy storage system suitable for vehicle starting in low-temperature environments. Through the complementary functions and closed-loop control logic of the main energy storage unit, auxiliary energy storage unit, control unit, and thermal management module, it effectively improves the technical defects of traditional energy storage systems such as power attenuation, slow charging, and excessive energy consumption at low temperatures. It ensures that the equipment can be started multiple times within seconds in an environment of -40℃. At the same time, it recovers waste heat after starting to reduce independent heating energy consumption. Overcurrent protection and voltage balancing control ensure the safety of system operation. The overall system cost is controlled within 1,000 yuan. It takes into account the reliability of low-temperature starting, energy utilization efficiency, and economy, and is suitable for energy storage power supply scenarios for starting equipment in extremely cold environments. Attached Figure Description

[0013] The present invention will be further described below with reference to the accompanying drawings and embodiments: Figure 1 This is a schematic diagram of a high-efficiency energy storage system suitable for vehicle starting in low-temperature environments according to the present invention. Figure 2 This is a flowchart of a control method for a high-efficiency energy storage system suitable for vehicle starting in low-temperature environments, according to the present invention. In the diagram: Main energy storage unit 1, auxiliary energy storage unit 2, control unit 30, dynamic balancing circuit 31, segmented constant current charging controller 32, thermal management module 4, cell self-heating component 41, temperature sensor 42. Detailed Implementation

[0014] like Figure 1-2 As shown, a control method for a high-efficiency energy storage system suitable for vehicle starting in low-temperature environments is presented. The system includes a main energy storage unit 1, an auxiliary energy storage unit 2, a control unit 30, and a thermal management module 4. Each unit is electrically connected through wires and signal transmission lines, and can adapt to the energy storage power supply requirements of starting equipment in environments ranging from -40℃ to +50℃. The control unit 30 integrates a dynamic balancing circuit 31 and a segmented constant current charging controller 32.

[0015] In an embodiment suitable for vehicle starting in low-temperature environments: In the preferred embodiment, the main energy storage unit 1 employs a high-capacity farad capacitor bank, which consists of 12 individual farad capacitors with a specification of 6.4V / 360F. The series-parallel topology adopts a design of four groups of three series-connected farad capacitors in parallel: first, four farad capacitors are connected in series to form a submodule with a rated voltage of 25.6V, and then three groups of this submodule are connected in parallel, so that the rated voltage of the entire farad capacitor bank is 25.6V and the rated capacity is 270F. The selection is based on the maximum instantaneous power of the starting equipment of 4.5kW. When discharging at -40℃, the capacitor bank can output a peak current of 1800A, which meets the instantaneous high power requirements of the starting equipment; the capacity decay at -40℃ is less than 10%, and the theoretical starting time is about 11s. By utilizing the wide temperature range (-45℃~+70℃) of farad capacitors, the low-temperature power decay defect of traditional lithium batteries is compensated.

[0016] In the preferred embodiment, the auxiliary energy storage unit 2 uses a ternary lithium-ion battery pack, consisting of 16 lithium battery cells with a specification of 3.7V / 5Ah. The series-parallel topology adopts an eight-series, two-parallel design: first, eight lithium battery cells are connected in series to form a sub-module with a rated voltage of 29.6V, and then two groups of this sub-module are connected in parallel, so that the entire lithium battery pack has a rated voltage of 29.6V and a rated capacity of 10Ah. The capacity selection is based on the charging requirements of the main energy storage unit 1: when the main energy storage unit 1 is charged from the discharge termination voltage of 17V to the rated voltage of 25.6V, according to the formula:

[0017] Where E is the charging energy, C is the total capacitance, and V is the capacitance value. MAX The rated voltage of the capacitor bank, V MIN This is the minimum voltage value for the capacitor bank; The required charging energy is approximately 13.75Wh, and the lithium battery pack can complete 20 full charges on a single charge. At the same time, under non-starting conditions, it can provide approximately 10W of basic energy supply for the system control unit 30 and thermal management module 4 for 30 hours, preventing the main energy storage unit 1 from being unable to start again after a single discharge and improving the system's cycle start capability.

[0018] In the preferred embodiment, the dynamic equalization circuit 31 of the control unit 30 adopts a voltage sampling combined with power switch adjustment architecture. This circuit collects the voltage signal of each of the 12 capacitor cells of the main energy storage unit 1 in real time through 12 voltage sampling channels, and the preset voltage equalization threshold is 0.1V. When the voltage difference between any two capacitor cells exceeds 0.1V, the MOS power switch inside the dynamic equalization circuit 31 is turned on, directing the charging current output by the auxiliary energy storage unit 2 to the capacitor cell with the low voltage, ensuring that the voltage deviation of each cell in the entire farad capacitor bank is controlled within 0.05V, extending the capacitor cycle life and reducing the risk of system failure caused by cell imbalance.

[0019] In the preferred embodiment, the segmented constant current charging controller 32 of the control unit 30 uses an STM32F103 microprocessor as the control core. It establishes a current control loop with the auxiliary energy storage unit 2 and the main energy storage unit 1 through a DC-DC converter. It presets two charging current parameters: when the voltage of the main energy storage unit 1 is in the preset low voltage range of 17V~22V, the controller outputs a large charging current of 15A; when the voltage rises to the preset high voltage range of 22V~25.6V, it automatically switches to a small charging current of 5A. At the same time, the controller has a built-in overcurrent protection threshold of 17A. When the charging current is detected to exceed 17A, the charging loop is immediately cut off to avoid overheating and runaway of the supercapacitor and to solve the problem of limited charging speed of the supercapacitor at low temperatures.

[0020] In the preferred embodiment, the thermal management module 4 includes a cell self-heating component 41 and an insulation layer: the cell self-heating component 41 uses a 12V / 10W polyimide heating element, which is attached to the lithium battery cells of the auxiliary energy storage unit 2 with thermally conductive adhesive. One element is arranged between every two cells, and additionally evenly distributed on the outside of the battery pack. The power supply end of the heating element is connected to the output end of the auxiliary energy storage unit 2, and the heating start and stop are controlled by the PWM signal output by the control unit 30. The insulation layer uses a 10mm thick aerogel insulation material, which is completely wrapped around the main energy storage unit 1, the auxiliary energy storage unit 2 and the control unit 30, so that the temperature drop of the system does not exceed 3℃ per hour when there is no heating in an environment of -40℃, thereby reducing heat loss.

[0021] In the preferred embodiment, the thermal management module 4 also integrates two temperature sensors 42, model DS18B20, to collect the capacitor temperature Tc of the main energy storage unit 1 and the battery temperature Tb of the auxiliary energy storage unit 2, with a temperature measurement range of -55℃ to +125℃. Before low-temperature startup, if the control unit 30 determines that Tb < -10℃, it will trigger the cell self-heating component 41 to work, with a heating power of 10W, so that Tb rises to above -10℃ within 5 minutes, reducing the battery internal resistance. During startup, if Tc is detected to be 5℃ higher than Tb, the aluminum heat-conducting sheet inside the thermal management module 4 will be attached to the outer shell of the main energy storage unit 1 and the auxiliary energy storage unit 2 to conduct the residual heat of capacitor discharge to the battery pack, thereby improving the overall energy utilization rate of the system.

[0022] In the preferred embodiment, the control method of the system includes the following steps: S1. After receiving an external start-up trigger signal, the control unit 30 wakes up from sleep mode and begins to collect the current voltage Vc of the main energy storage unit 1 and the current voltage Vb of the auxiliary energy storage unit 2 through the voltage sampling circuit. It also collects the ambient temperature T, capacitor temperature Tc, and battery temperature Tb through the temperature sensor 42 and transmits the data to the STM32F103 microprocessor. The microprocessor determines: if T < -40℃ or Tb < -15℃, it outputs a start signal to the thermal management module 4 and enters S2; if T ≥ -40℃ and Tb ≥ -15℃, it enters S3. S2, Control Unit 30 sends a preheating command to Thermal Management Module 4, Powering on Cell Self-Heating Component 41 to Heat Auxiliary Energy Storage Unit 2 with 10W Power; During the heating process, Tb is collected, and when Tb rises to -10℃, a stop heating command is sent, Powering on the heating component is cut off, and Thermal Management Module 4 switches to waste heat recovery mode. S3, the control unit 30 sends a charging command to the segmented constant current charging controller 32, the DC-DC converter is turned on, and segmented charging is performed according to Vc: when Vc < 22V, a charging current of 15A is output; when Vc ≥ 22V, a charging current of 5A is output; during charging, the dynamic equalization circuit 31 collects the voltage of each individual capacitor. If the difference between the voltage of an individual capacitor and the average voltage in the group is > 0.1V, the charging current of that individual capacitor is adjusted; until Vc rises to 25.6V, the main energy storage unit 1 has the ability to start. S4. Control unit 30 continuously monitors Vc and Tc. When Vc≥25.5V and Tc≥-30℃ are met, it sends a conduction command to the power output circuit of the main energy storage unit 1, and the capacitor bank outputs power to the starting equipment. The output current Ic is collected by the current sensor. If Ic>2000A (1.1 times the rated output current of 1800A), the overcurrent protection is triggered, the output circuit is cut off for 0.5s and then re-conducted. If the overcurrent still occurs after repeating 3 times, the output is locked to avoid overload damage to the starting equipment. S5. After the starting device completes the startup, it sends a high-level signal to the control unit 30. The control unit 30 disconnects the main energy storage unit 1 from the starting device and simultaneously controls the segmented constant current charging controller 32 to resume operation, charging the main energy storage unit 1 to 25.6V by the auxiliary energy storage unit 2. During the charging process, the dynamic equalization circuit 31 continuously monitors the voltage of each capacitor cell to maintain voltage consistency and restore the system's secondary startup capability. S6. During the charging process, the control unit 30 controls the thermal management module 4 to maintain the waste heat recovery mode: the temperature sensor 42 monitors Tc and Tb in real time. If Tc-Tb>5℃, the heat-conducting plate circuit is turned on; if Tc-Tb≤5℃, the heat-conducting plate is turned off to reduce independent heating energy consumption. S7. After charging is complete, the system enters standby mode. The control unit 30 reduces the sampling frequency to 1Hz, retaining only the real-time voltage and temperature monitoring functions, and waits for the next start command.

[0023] In this embodiment, the system can start the vehicle starting device within 1 minute in an environment of -40℃, with a theoretical number of consecutive starts greater than 20 times. The overall cost is controlled at 1,000 to 1,200 yuan, taking into account the reliability of low-temperature starting, energy utilization efficiency and economy. It is suitable for energy storage starting scenarios of equipment such as construction machinery and new energy vehicles in extremely cold regions.

[0024] The above embodiments are merely preferred technical solutions of the present invention and should not be considered as limitations on the present invention. The scope of protection of the present invention should be limited to the technical solutions described in the claims, including equivalent substitutions of the technical features described in the claims. That is, equivalent substitutions and improvements within this scope are also within the scope of protection of the present invention.

Claims

1. A control method for a high-efficiency energy storage system suitable for vehicle starting in low-temperature environments, characterized in that, The high-efficiency energy storage system includes a main energy storage unit, an auxiliary energy storage unit, a control unit, and a thermal management module; The main energy storage unit uses a supercapacitor bank, which is composed of several supercapacitor cells connected in series and parallel. It has wide temperature range characteristics and instantaneous high power output capability at low temperatures. The auxiliary energy storage unit uses a battery pack, which is composed of several battery cells connected in series and parallel. The control unit integrates a dynamic balancing circuit and a segmented constant current charging controller, and is electrically connected to the main energy storage unit and the auxiliary energy storage unit respectively; The thermal management module includes a cell self-heating component, a temperature sensor, and an internal heat conduction circuit; The cell self-heating component is integrated into the auxiliary energy storage unit. It is used to receive the start signal from the control unit and consume the energy of the auxiliary energy storage unit to preheat the cell in order to reduce the internal resistance of the cell. Temperature sensors are used to collect ambient temperature in real time and monitor the capacitor temperature of the main energy storage unit and the cell temperature of the auxiliary energy storage unit respectively, and transmit the temperature signal to the control unit; the internal heat conduction circuit forms a heat conduction path from the main energy storage unit to the auxiliary energy storage unit. The control method includes the following steps: S1. After receiving an external start-up trigger signal, the control unit wakes up from sleep mode, collects the current voltage of the main energy storage unit, the current voltage of the auxiliary energy storage unit, the ambient temperature, the capacitor temperature of the main energy storage unit, and the cell temperature of the auxiliary energy storage unit, and transmits the collected parameters to the built-in microprocessor of the control unit. The microprocessor performs threshold judgment on the collected parameters. If the ambient temperature is lower than -40℃ or the cell temperature of the auxiliary energy storage unit is lower than -15℃, it outputs a start signal to the thermal management module and enters S2. If the ambient temperature is not lower than -40℃ and the cell temperature of the auxiliary energy storage unit is not lower than -15℃, it enters S3. S2. The control unit sends a preheating command to the thermal management module to start the cell self-heating component and heat the auxiliary energy storage unit with a preset power. During the heating process, the control unit collects the cell temperature of the auxiliary energy storage unit in real time. When the cell temperature rises to the preset temperature, it sends a stop heating command to turn off the cell self-heating component and switch the thermal management module to waste heat recovery mode. S3. The control unit sends a charging command to the segmented constant current charging controller. The segmented constant current charging controller connects the charging circuit between the auxiliary energy storage unit and the main energy storage unit, and executes the segmented constant current charging strategy according to the real-time voltage of the main energy storage unit. When the voltage of the main energy storage unit is in the preset low voltage range, a preset large charging current is output. When the voltage of the main energy storage unit rises to the preset high voltage range, the charging current is reduced to a preset small charging current so that the main energy storage unit has the instantaneous power output capability required to start the device. S4. The control unit continuously monitors the voltage and capacitor temperature of the main energy storage unit. When the voltage of the main energy storage unit is higher than the start-up voltage threshold and its capacitor temperature is higher than the preset start-up temperature, the system is confirmed to meet the start-up conditions. The control unit sends a conduction command to the power output circuit of the main energy storage unit, so that the main energy storage unit outputs power to the start-up device. S5. After the starting device completes the startup and sends a startup completion signal to the control unit, the control unit disconnects the connection between the main energy storage unit and the starting device; at the same time, the segmented constant current charging controller resumes operation, and the auxiliary energy storage unit charges the main energy storage unit until the voltage of the main energy storage unit rises to its rated voltage; during the charging process, the dynamic balancing circuit continuously monitors the voltage of each supercapacitor cell in the main energy storage unit to maintain the voltage consistency of each supercapacitor cell in order to restore the system's secondary startup capability; S6. During charging, the control unit keeps the thermal management module in waste heat recovery mode and monitors the capacitor temperature of the main energy storage unit and the cell temperature of the auxiliary energy storage unit through temperature sensors. When the capacitor temperature of the main energy storage unit is higher than the cell temperature of the auxiliary energy storage unit and the temperature difference between the two reaches the preset temperature difference value, the internal heat conduction circuit is activated to guide the waste heat of the main energy storage unit to the auxiliary energy storage unit along the heat conduction path. When the temperature difference between the two is less than the preset temperature difference value, the internal heat conduction circuit is turned off. S7. After charging is complete, the system enters standby mode. The control unit reduces its own power consumption and only retains the real-time monitoring function of voltage and temperature, waiting for the start command.

2. The control method according to claim 1, characterized in that, In the high-efficiency energy storage system adopted, the dynamic balancing circuit is equipped with a voltage sampling module, which is used to collect the voltage signal of each supercapacitor cell in the main energy storage unit in real time. The dynamic balancing circuit is also equipped with a power switch, which regulates the charging current to preferentially direct the energy of the auxiliary energy storage unit to the low-voltage supercapacitor cells, so as to maintain the voltage consistency of each supercapacitor cell in the main energy storage unit.

3. The control method according to claim 1, characterized in that, In the high-efficiency energy storage system adopted, the segmented constant current charging controller establishes a current control circuit with the auxiliary energy storage unit and the main energy storage unit to execute the current limiting strategy according to the real-time voltage status of the main energy storage unit. When the voltage of the main energy storage unit is in the preset low voltage range, a preset large charging current is output to achieve rapid energy replenishment; when the voltage of the main energy storage unit rises to the preset high voltage range, the charging current is reduced to a preset small charging current.

4. The control method according to claim 1, characterized in that, In the high-efficiency energy storage system, the thermal management module is also equipped with an insulation layer, which wraps around the main energy storage unit, auxiliary energy storage unit and control unit to reduce heat loss.

5. The control method according to claim 1, characterized in that, It also includes step S31: During the charging process, the dynamic balancing circuit collects the voltage of each supercapacitor cell in the main energy storage unit in real time; if the difference between the voltage of any supercapacitor cell and the average voltage in the group exceeds the preset error, the dynamic balancing circuit adjusts the charging current of that supercapacitor cell.

6. The control method according to claim 1, characterized in that, It also includes step S41: During the output process, the control unit collects the output current through the current sensor; if the output current exceeds the preset safety threshold of the rated output current, the overcurrent protection mechanism is triggered, and the output circuit is temporarily disconnected and then reconnected to avoid damage to the starting device due to overload.

7. The control method according to claim 6, characterized in that, It also includes step S42: if the overcurrent protection mechanism is repeatedly triggered to a preset number of times and still fails to return to normal, the output circuit is shut off and the process proceeds to step S7 to prevent damage to the starting equipment and system components due to continuous overload.

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