Battery heating system, method, and vehicle

Abstract

The present disclosure relates to a battery heating system, method and vehicle, and relates to the technical field of battery heating. The battery heating system comprises a power battery, an energy storage module and a control module. The control module is configured to control the power battery to perform pulse discharge and transmit at least part of the pulse discharge released electric energy to the energy storage module when the temperature of the power battery during charging is lower than a target threshold. The embodiment of the present disclosure can still complete pulse energy absorption through the vehicle-side energy storage module in the ordinary charging scene without pile-side energy storage support, guarantee the rapid heating of the power battery in a low-temperature environment, create temperature conditions for subsequent high-power fast charging, reduce low-temperature charging time, and significantly improve the charging facility compatibility and the vehicle low-temperature operation reliability.

Description

Technical Field

[0001] This disclosure relates to the field of battery heating technology, and in particular to a battery heating system, method and vehicle. Background Technology

[0002] With the continuous advancement of supercharging technology for electric vehicles, charging time is decreasing daily. However, in low-temperature environments, electric vehicles experience issues such as increased internal resistance, intensified polarization, and reduced charging and discharging capabilities in their power batteries. This results in limited charging power and extended charging time at low temperatures, and in severe cases, the vehicle may not even be able to directly enter high-power fast charging mode. One solution in related technologies is to employ vehicle-charging station coordinated low-temperature heating technology: after the vehicle is connected to the charging station, the power battery is controlled to undergo pulse discharge, causing Joule heating and polarization heat to be generated inside the power battery due to the current, thereby achieving rapid temperature rise of the power battery.

[0003] However, most existing DC charging piles on the market currently use a unidirectional AC-DC rectifier topology, meaning energy can only flow from the grid to the vehicle. They lack the ability to invert the DC power output from the vehicle into AC power and feed it back to the grid. Therefore, during pulse discharge of the power battery, the reverse energy directly affects the DC output bus of the charging pile, causing the bus voltage to spike instantaneously. This voltage spike can exceed the withstand voltage threshold of devices such as Insulated Gate Bipolar Transistors (IGBTs) and filter capacitors, resulting in permanent hardware damage or triggering overvoltage protection, forcing the charging pile system to shut down. Furthermore, if charging piles are to be modified to adapt to pulse heating conditions, additional energy storage devices such as energy storage battery packs, dedicated energy absorption devices, or energy feedback inverter units are required. This will significantly increase the construction cost of charging infrastructure and the cost of upgrading existing charging piles. Moreover, the modification is difficult to implement and the adaptation period is long, making it difficult to promote and apply on a large scale in the existing charging network. Summary of the Invention

[0004] To address the aforementioned technical issues, this disclosure provides a battery heating system, method, and vehicle that can still absorb pulse energy through the vehicle-side energy storage module in ordinary charging scenarios without pile-side energy storage support. This ensures rapid heating of the power battery in low-temperature environments, creating the necessary temperature conditions for subsequent high-power fast charging, thereby reducing low-temperature charging time and significantly improving the compatibility of charging facilities and the reliability of vehicle operation at low temperatures.

[0005] In a first aspect, embodiments of this disclosure provide a battery heating system, the battery heating system comprising: Power battery, energy storage module and control module; The control module is configured to: when the temperature of the power battery is below a target threshold during charging, control the power battery to perform pulse discharge, and transfer at least a portion of the electrical energy released by the pulse discharge to the energy storage module.

[0006] In some embodiments of this disclosure, the control module is optionally further configured to: control the power battery to exit the pulse discharge heating mode when the power battery temperature reaches the target temperature threshold.

[0007] Optionally, in some embodiments of this disclosure, the battery heating system further includes a power conversion module and a port module; The port module is electrically connected to the power battery and is used to establish an electrical connection between the power battery and an external charging pile. The power conversion module is configured to adjust its operating state to establish a bidirectional energy transmission path between the power battery and the energy storage module, and / or to adjust the energy transmission relationship between the power battery or the energy storage module and the port module.

[0008] Optionally, in some embodiments of this disclosure, the power conversion module includes a bidirectional conversion unit, and the power battery and the energy storage module are both electrically connected to the bidirectional conversion unit; The bidirectional conversion unit includes a first operating state and a second operating state. In the first operating state, the pulse discharge energy of the power battery is transmitted to the energy storage module for storage through the bidirectional conversion unit, and the electrical energy input by the port module is transmitted to the energy storage module through the bidirectional conversion unit. In the second operating state, the energy transmission path between the power battery and the energy storage module is disconnected, and the power battery and the energy storage module operate independently.

[0009] Optionally, in some embodiments of this disclosure, the power conversion module further includes a first switching unit and a second switching unit; the first switching unit is connected in series between the power battery and the bidirectional conversion unit; the second switching unit is connected in series between the energy storage module and the bidirectional conversion unit. The control module is configured to acquire the operating status of the power battery and the energy storage module, and based on the operating status, control the on / off state of the first switching unit and the second switching unit to adjust the working state of the bidirectional conversion unit.

[0010] In some embodiments of this disclosure, optionally, the energy storage module is connected to any one of a low-voltage or medium-voltage power supply platform of 12V, 24V, 48V and 72V; or the energy storage module is a high-voltage auxiliary energy storage branch independently set on the high-voltage platform of the vehicle.

[0011] In some embodiments of this disclosure, the energy storage module optionally includes at least one of a sodium-ion battery, a lithium titanate battery, a lithium capacitor, and a supercapacitor.

[0012] In some embodiments of this disclosure, the energy storage module optionally includes a 48V sodium-ion battery.

[0013] In some embodiments of this disclosure, the energy storage module optionally includes a 12V sodium-ion battery.

[0014] In some embodiments of this disclosure, the power conversion module may optionally be any one of a bidirectional DC / DC converter, a multi-port DC / DC converter, a DC / AC and AC / DC combined conversion structure, and a bus-coupled switch control structure.

[0015] In some embodiments of this disclosure, the energy storage module is optionally further configured to supply power to a low-voltage or medium-voltage load of the vehicle, the load including at least one of a vehicle controller, body electronics, actuator, parking power supply module, and cold start assist module.

[0016] In some embodiments of this disclosure, the system may optionally further include a battery management unit, which is used to collect voltage, current, temperature and SOC status information of the power battery and the energy storage module, and transmit it to the control module; The control module is also configured to dynamically adjust the peak current, frequency, duty cycle, and duration parameters of the pulse discharge based on the temperature, SOC state, and internal resistance state of the power battery, as well as the temperature and SOC state of the energy storage module.

[0017] Optionally, in some embodiments of this disclosure, the system further includes a vehicle-to-charging-pile communication module, which is used to realize state interaction and collaborative control between the power battery and the charging pile.

[0018] In a second aspect, embodiments of this disclosure provide a battery heating method applied to a battery heating system as described in the first aspect, the battery heating system comprising a power battery, an energy storage module, and a control module; The method includes: When the temperature of the power battery is below the target threshold and the power battery is in a pulse discharge heating mode, the control module controls the power conversion module to transfer at least a portion of the electrical energy released by the power battery through pulse discharge to the energy storage module.

[0019] Thirdly, embodiments of this disclosure provide a vehicle including the battery heating system as provided in the first aspect.

[0020] The battery heating system, method, and vehicle disclosed herein employ an energy storage unit architecture consisting of a power battery and an energy storage module. A bidirectional energy transfer path is established between the two via a DC-DC converter module, and a control module and a port module are provided. The control module triggers a pulse heating mode based on the temperature state of the power battery. On one hand, it controls the power battery to perform pulse discharge to achieve self-heating; on the other hand, it controls the DC-DC converter module to transfer at least a portion of the electrical energy released by the pulse discharge to the energy storage module for storage. The pulse energy buffering is entirely completed by the vehicle-side energy storage unit. In this way, energy self-balancing for low-temperature pulse heating of the power battery can be achieved without configuring an energy storage unit or dedicated energy absorption device on the charging pile side. In ordinary charging scenarios without charging pile-side energy storage support, pulse energy absorption can still be completed through the vehicle-side energy storage module, ensuring rapid heating of the power battery in low-temperature environments and significantly improving the compatibility of charging facilities and the reliability of vehicle operation at low temperatures. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate embodiments consistent with this disclosure and, together with the description, serve to explain the principles of this disclosure.

[0022] To more clearly illustrate the technical solutions in the embodiments of this disclosure or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0023] Figure 1 A schematic diagram of the structure of a battery heating system according to some embodiments of the present disclosure is shown; Figure 2 The diagram illustrates the energy flow of a battery heating system under low-temperature pulse heating mode according to some embodiments of this disclosure; Figure 3 A schematic flowchart of a battery heating method according to some embodiments of the present disclosure is shown.

[0024] Reference numerals: 1. Power battery; 2. Energy storage module; 3. Power conversion module; 4. Port module; 5. Charging pile; 6. BMS; 7. VCU; 8. Communication module; 9. Low-voltage / medium-voltage load. Detailed Implementation

[0025] To better understand the above-mentioned objectives, features, and advantages of this disclosure, the solutions disclosed herein will be further described below. It should be noted that, unless otherwise specified, the embodiments and features described herein can be combined with each other.

[0026] Numerous specific details are set forth in the following description to provide a thorough understanding of this disclosure, but this disclosure may also be implemented in other ways different from those described herein; obviously, the embodiments in the specification are only a part of the embodiments of this disclosure, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of the embodiments of this disclosure.

[0027] Before describing the embodiments of this disclosure in detail, the technical background involved in this disclosure will be described here first.

[0028] With the rapid development of fast charging technology for new energy vehicles, the charging time at room temperature has been significantly shortened. However, the low charging efficiency of power batteries in low-temperature environments remains a common problem in the industry. Under low-temperature conditions, the electrochemical activity inside the power battery decreases, internal resistance increases, polarization intensifies, and the charging acceptance capacity decreases significantly, making it impossible to directly enter the high-power fast charging mode, resulting in a significant extension of the overall charging time. Therefore, it is necessary to preheat the power battery before fast charging in low temperatures to raise its temperature to a suitable operating range and restore its charging performance.

[0029] Currently, the mainstream high-efficiency preheating solution in the industry is pulse self-heating technology. This technology controls the power battery to perform high-frequency pulse charging and discharging, utilizing the internal resistance of the battery cell to generate Joule heat and polarization heat, thereby achieving rapid internal temperature rise. This solution offers fast heating rate and good temperature uniformity.

[0030] However, most existing DC charging piles on the market currently use a unidirectional AC-DC rectification topology, meaning energy can only flow from the grid to the vehicle. They lack the ability to invert the DC power output from the vehicle into AC power and feed it back to the grid. Therefore, during pulse discharge of the power battery, the reverse energy directly affects the DC output bus of the charging pile, causing the bus voltage to spike instantaneously, exceeding the withstand voltage thresholds of components such as IGBTs and filter capacitors. This can result in permanent hardware damage or trigger overvoltage protection, forcing the charging pile system to shut down. This issue needs improvement.

[0031] To address the aforementioned problems, this disclosure provides a battery heating system. Figure 1 A schematic diagram of the structure of a battery heating system according to some embodiments of the present disclosure is shown. Figure 2 The diagram illustrates the energy flow of a battery heating system under low-temperature pulse heating mode according to some embodiments of this disclosure. For example... Figure 1 and Figure 2 As shown, the battery heating system includes: a power battery 1, an energy storage module 2, and a control module 7. The control module 7 is configured to: control the power battery 1 to perform pulse discharge when the temperature of the power battery 1 during charging is lower than a target threshold, and transfer at least a portion of the electrical energy released by the pulse discharge to the energy storage module 2.

[0032] In some embodiments, the battery heating system further includes a power conversion module 3 and a port module 4. The port module 4 is electrically connected to the power battery 1 to establish an electrical connection between the power battery 1 and an external charging pile. The power conversion module 3 is configured to adjust its operating state to construct a bidirectional energy transfer path between the power battery 1 and the energy storage module 2, and / or adjust the energy transfer relationship between the power battery 1 or the energy storage module 2 and the port module 4.

[0033] In this example, the power battery 1 is electrically connected to the energy storage module 2 via the power conversion module 3. The power conversion module 3 is used to construct a bidirectional energy transmission path between the power battery 1 and the energy storage module 2. The control module is configured to: detect the temperature of the power battery 1 when the power battery 1 is electrically connected to the charging pile via the port module 4, and control the power battery 1 to perform pulse discharge to heat up when the temperature of the power battery 1 is lower than the target threshold; and control the power conversion module 3 to transfer at least a portion of the electrical energy released by the pulse discharge of the power battery 1 to the energy storage module 2 for storage.

[0034] In one specific embodiment, the battery heating system includes a power battery 1, an energy storage module 2, a power conversion module 3, a control module, and a port module 4. The power battery 1 is electrically connected to the port module 4, used to receive charging energy input from an external charging pile through the port module 4, and simultaneously output high-voltage energy to the vehicle's drive system. The power battery 1 also forms a bidirectional electrical connection with the energy storage module 2 through the power conversion module 3. The energy storage module 2 is used to receive at least a portion of the electrical energy released by the power battery 1 during pulse discharge, realizing vehicle-side buffering and storage of pulse energy. The control module is communicatively connected to the power battery 1, energy storage module 2, and power conversion module 3, used to collect the operating status of each module and output control commands, coordinating the system's switching between pulse heating mode and normal charging mode.

[0035] For example, the power battery 1 is a vehicle high-voltage active power battery 1 pack (i.e., active power battery 1), which is composed of multiple lithium-ion cells connected in series and parallel, with a rated voltage covering the range of 300V-1500V, and is used to provide the high-voltage electrical energy required for the vehicle to drive.

[0036] For example, the energy storage module 2 is an on-board energy storage unit independent of the power battery 1, and has pulse power throughput capability and low temperature charging acceptance capability, and can stably receive high-frequency pulse power in low temperature environment.

[0037] For example, port module 4 is a vehicle DC charging interface that conforms to the GB / T 20234.3 standard and is used to establish an electrical connection with an external DC charging pile to transmit high-voltage DC power.

[0038] For example, the control module may be integrated into the vehicle control unit (VCU), or it may be set up independently as a dedicated thermal management control unit, or it may be integrated into the battery management system (BMS). This disclosure does not limit it in this way.

[0039] For example, when the battery heating system is connected to the charging pile and the temperature of the power battery 1 meets the heating conditions, the control module controls the system to enter pulse heating mode. In pulse heating mode, the control module outputs a pulse control signal to the management unit of the power battery 1, controlling the power battery 1 to perform periodic pulse discharge according to preset parameters. Under the action of the pulse current, the internal cells of the power battery 1 generate Joule heat and polarization heat due to the ohmic internal resistance and polarization internal resistance. The heat diffuses from the inside of the cells to the outside, achieving a uniform and rapid increase in the temperature of the entire pack. At the same time, the control module outputs a control signal to the power conversion module 3, controlling the power conversion module 3 to work in buck mode, converting the high-voltage pulse energy on the power battery 1 side into energy adapted to the voltage level of the energy storage module 2, and delivering it to the energy storage module 2 for storage, completing the vehicle-side reception of pulse discharge energy.

[0040] When the temperature of the power battery 1 rises to the preset target threshold, the control module controls the system to exit the pulse heating mode and switch to the normal charging mode. In the normal charging mode, the power conversion module 3 can selectively operate in charging mode according to the state of charge (SOC) of the energy storage module 2, so that the charging pile replenishes the energy storage module 2 through the power battery 1 side bus and the power conversion module 3; or stop operating, so that the charging pile directly performs high-power fast charging for the power battery 1 through the port module 4.

[0041] For a specific example, taking the application of a battery heating system in an electric vehicle as an example, after the vehicle is connected to a DC charging pile in a low-temperature environment, the control module first obtains the real-time temperature data of the power battery 1. When it determines that the temperature is lower than the fast-charging allowable temperature threshold, it activates the pulse heating mode. The control module sets the initial pulse parameters and controls the power battery 1 to perform intermittent pulse discharge with a set peak current, frequency, and duty cycle. The pulse current flows through the inside of the cell, generating heat and causing the cell temperature to rise continuously. Simultaneously, the power conversion module 3 tracks the timing of the pulse discharge in real time, converts the voltage of the electrical energy released in each pulse, and sends it to the energy storage module 2, which then stores the energy. Throughout the heating process, the charging pile only needs to provide basic electrical energy replenishment, without the need for any energy storage unit or dedicated energy absorption device. The buffering of pulse energy is entirely handled by the vehicle-side energy storage module 2.

[0042] When the temperature of the power battery 1 rises to the target temperature threshold allowed for fast charging, the control module controls the power battery 1 to stop pulse discharge, and at the same time controls the power conversion module 3 to gradually reduce the power until it stops outputting, so that the system smoothly transitions to normal fast charging mode. The charging pile charges the power battery 1 at its rated high power, and at the same time, it can replenish the energy storage module 2 with restorative energy through the power conversion module 3 according to the remaining power of the energy storage module 2, so as to reserve energy for the next heating condition.

[0043] In some embodiments of this disclosure, the energy storage module 2 may optionally include any one of sodium-ion batteries, lithium titanate batteries, lithium capacitors, and supercapacitors, or a hybrid energy storage unit consisting of any two or more of the above.

[0044] For example, energy storage module 2 uses sodium-ion batteries as the energy storage medium. Sodium-ion batteries have excellent low-temperature electrochemical performance, significantly better than conventional lithium-ion batteries. They can stably accept high-frequency pulse charging energy in low-temperature environments, avoiding problems such as pulse energy discharge failure and bus overvoltage caused by insufficient low-temperature charging acceptance. At the same time, sodium-ion batteries have a long cycle life and excellent high-rate charge and discharge performance, making them suitable for high-frequency, high-current charge and discharge conditions in pulse heating scenarios, resulting in higher reliability throughout their entire life cycle.

[0045] For example, energy storage module 2 uses lithium titanate batteries as the energy storage medium. Lithium titanate batteries have ultra-long cycle life and excellent rate performance, and can withstand pulse currents tens of times higher than the rated capacity, making them suitable for high-power, high-frequency pulse energy throughput scenarios.

[0046] For example, energy storage module 2 uses a supercapacitor as the energy storage medium. Supercapacitors have extremely high power density, and their charge and discharge response speed can reach the millisecond level. They can perfectly match the transient power characteristics of pulse discharge, resulting in higher energy throughput efficiency, longer cycle life, and lower system maintenance costs.

[0047] For example, energy storage module 2 adopts a hybrid energy storage unit composed of sodium-ion batteries and supercapacitors. The supercapacitor is responsible for the peak power throughput of high-frequency pulses, while the sodium-ion batteries are responsible for continuous energy storage. The combination of the two balances power density and energy density, while ensuring low-temperature performance and system cost, achieving optimal overall performance.

[0048] In some embodiments of this disclosure, the energy storage module 2 may optionally be connected to any one of the low-voltage or medium-voltage power supply platforms of 12V, 24V, 48V and 72V; or the energy storage module 2 may be a high-voltage auxiliary energy storage branch independently set on the high-voltage platform of the vehicle.

[0049] For example, the energy storage module 2 is connected to the vehicle's 48V power supply platform, with a rated voltage of 48V. Compared to the 12V platform, the 48V platform draws only one-quarter of the current at the same transmission power, which can significantly reduce line losses and device current stress. It can also handle higher pulse heating power and has a faster heating rate, making it suitable for vehicles equipped with high-power fast charging and requiring high heating efficiency.

[0050] Furthermore, in one preferred embodiment, the energy storage module 2 includes a 48V sodium-ion battery. The 48V sodium-ion battery heating system combines the advantages of low-temperature performance with the power advantages of a medium-voltage platform. It can stably receive pulse energy in extreme low-temperature environments of -30℃, while supporting pulse heating power of up to 10kW. It can shorten the time for the power battery 1 to heat up from -20℃ to 0℃ to less than 8 minutes, significantly improving heating efficiency.

[0051] For example, the energy storage module 2 is connected to the vehicle's 12V power supply platform, with a rated voltage of 12V. The 12V platform is a universal low-voltage power supply platform for the whole vehicle, which can directly reuse the existing low-voltage power supply architecture of the whole vehicle without the need to add an additional medium-voltage power distribution circuit. The integration difficulty of the whole vehicle is low and the modification cost is small, which is suitable for entry-level models with low pulse heating power requirements and high cost control requirements.

[0052] Furthermore, in one embodiment, the energy storage module 2 includes a 12V sodium-ion battery. The 12V sodium-ion battery can directly replace a traditional 12V lead-acid battery or a lithium-ion low-voltage battery, and without increasing the hardware size, it has both low-voltage power supply and pulse energy absorption functions, resulting in higher system integration.

[0053] For example, energy storage module 2 is a high-voltage auxiliary energy storage branch independently set on the high-voltage platform of the vehicle, including any one of an independent high-voltage small battery pack, a high-voltage energy storage buffer module, and a high-voltage supercapacitor module. The voltage level of the high-voltage auxiliary energy storage branch matches the voltage level of the power battery 1, which can eliminate the voltage conversion stage from high voltage to low voltage, resulting in higher energy conversion efficiency and making it suitable for high-power pulse heating scenarios in vehicles with 300-1500V high-voltage platforms.

[0054] In some embodiments of this disclosure, the energy storage module 2 may adopt a hybrid power supply platform architecture of 12V and 48V, or independently undertake the function of medium-voltage energy storage buffer.

[0055] In the hybrid platform implementation, energy storage module 2 is equipped with dual voltage output ports, connected to the vehicle's 12V low-voltage network and 48V medium-voltage network respectively. The 48V port handles the main energy throughput for pulse heating and also supplies power to 48V medium-voltage loads (such as electric power steering, electric air conditioning compressor, and active suspension). The 12V port draws power from the 48V bus via a secondary DC / DC converter to supply power to the vehicle's 12V low-voltage loads (such as controllers, sensors, and body electronics). This architecture can simultaneously cover vehicle loads of different voltage levels without requiring two separate energy storage units, further improving system integration and making it suitable for mid-to-high-end models equipped with a 48V mild hybrid system. During pulse heating, the 48V side energy storage capacity is prioritized to handle the pulse energy, while the 12V side maintains a stable power supply, preventing low-voltage loads from being interfered with by the pulse conditions.

[0056] In the medium-voltage energy storage buffer implementation, energy storage module 2 is connected to a 72V-160V medium-voltage power supply platform, independently undertaking the dual functions of pulse energy buffering and medium-voltage load power supply. The medium-voltage platform has a higher voltage than the conventional low-voltage platform, resulting in lower current for the same power output, lower line losses, and lower component costs. Furthermore, it has lower insulation requirements and higher safety redundancy compared to high-voltage platforms. This solution is suitable for vehicles equipped with medium-voltage electric drive accessories, such as medium-voltage electric air conditioners, medium-voltage oil pumps, and medium-voltage air compressors. Energy storage module 2 can directly power these medium-voltage loads without the need for multi-stage voltage conversion, improving energy utilization efficiency. The medium-voltage energy storage module 2 can be composed of sodium-ion batteries connected in series and parallel. The rated voltage can be configured to multiple levels, such as 72V, 96V, and 144V, depending on the vehicle's medium-voltage platform configuration. The pulse power carrying capacity can reach over 15kW, adapting to high-power pulse heating requirements.

[0057] In some embodiments of this disclosure, optionally, the power conversion module 3 includes a bidirectional conversion unit, and the power battery 1 and the energy storage module 2 are both electrically connected to the bidirectional conversion unit; the bidirectional conversion unit includes a first operating state and a second operating state; in the first operating state, the pulse discharge energy of the power battery 1 is transmitted to the energy storage module 2 for storage through the bidirectional conversion unit, and the electrical energy input to the port module 4 is transmitted to the energy storage module 2 through the bidirectional conversion unit; in the second operating state, the energy transmission path between the power battery 1 and the energy storage module 2 is disconnected, and the power battery 1 and the energy storage module 2 operate independently.

[0058] For example, the bidirectional conversion unit in the power conversion module 3 can be any one of a bidirectional DC / DC converter, a multi-port DC / DC converter, a DC / AC and AC / DC combined conversion structure, and a bus-coupled switch control structure.

[0059] For example, the bidirectional conversion unit adopts a bidirectional DC / DC converter, specifically an isolated bidirectional full-bridge DC / DC converter. The isolated topology can achieve electrical isolation between the high-voltage side of the power battery 1 and the low-voltage side of the energy storage module 2, improve the system's insulation safety performance, prevent high-voltage side faults from spreading to the low-voltage side, and support a wide range of voltage input and output, adapting to power batteries 1 and energy storage modules 2 with different voltage levels.

[0060] For example, the bidirectional conversion unit adopts a non-isolated bidirectional DC / DC converter, specifically a Buck-Boost topology. Non-isolated topologies have a simple structure, fewer components, lower cost, and higher conversion efficiency, making them suitable for scenarios where the difference between high and low voltage levels is small and insulation requirements are low.

[0061] For example, the bidirectional conversion unit adopts a multi-port DC / DC converter. The multi-port DC / DC converter has at least three power ports, which are respectively connected to the power battery 1, the energy storage module 2 and the low-voltage load. It can realize bidirectional energy transmission and multi-path distribution at the same time, without the need to add an additional low-voltage power distribution conversion unit, resulting in higher system integration and lower hardware cost.

[0062] For example, the bidirectional conversion unit adopts a DC / AC and AC / DC combined conversion structure. The DC power from the power battery 1 side is converted into high-frequency AC power by the DC / AC unit, isolated by a high-frequency transformer, and then converted into DC power adapted to the energy storage module 2 by the AC / DC unit. This structure has a high insulation level and good electromagnetic compatibility, making it suitable for automotive-grade scenarios with high safety and EMC requirements.

[0063] In some embodiments of this disclosure, optionally, the power conversion module 3 further includes a first switching unit and a second switching unit; the first switching unit is connected in series between the power battery 1 and the bidirectional conversion unit; the second switching unit is connected in series between the energy storage module 2 and the bidirectional conversion unit; the control module is configured to acquire the operating status of the power battery 1 and the energy storage module 2, and adjust the working status of the bidirectional conversion unit by controlling the on / off state of the first switching unit and the second switching unit based on the operating status.

[0064] For example, the first switching unit is connected in series between the positive output terminal of the power battery 1 and the positive terminal of the first power port of the bidirectional conversion unit, and the second switching unit is connected in series between the positive output terminal of the energy storage module 2 and the positive terminal of the second power port of the bidirectional conversion unit; the negative circuits of the two switching units share a common bus, forming a complete current path. Both the first and second switching units use semiconductor power switching devices with load breaking capability, specifically insulated gate bipolar transistors (IGBTs).

[0065] For example, the first and second switching units can be implemented as a bus-coupled switch control structure. When the energy storage module 2 is a high-voltage auxiliary energy storage branch and its voltage level matches that of the power battery 1, the bus coupling and switching control of the two can be directly realized through high-voltage switching devices, eliminating the power conversion stage and resulting in the simplest system structure and lowest cost.

[0066] When both the first and second switching units are closed, the bidirectional conversion unit can operate in the first working state; in this state, the energy transmission path between the power battery 1 and the energy storage module 2 is open, and it also supports the transmission of external electrical energy input from the port module 4 to the energy storage module 2, specifically including two operating sub-modes: Pulse Energy Recovery Sub-mode: Under pulse heating conditions, the bidirectional converter operates in buck conversion mode. The high-voltage electrical energy output from the pulse discharge of power battery 1 enters the first power port of the bidirectional converter through the first switching unit. After being buck-converted into low-voltage electrical energy adapted to the voltage level of energy storage module 2, it is output to energy storage module 2 through the second switching unit, completing the storage of pulse discharge energy. In this sub-mode, the power transmission of the bidirectional converter is synchronized with the pulse discharge timing of power battery 1, with a pulse response delay of no more than 1ms. It can receive the electrical energy released in each pulse in real time, maintaining the stability of the high-voltage bus voltage.

[0067] External charging replenishment sub-mode: Under normal charging conditions, the charging pile power input from port module 4 is connected to the high-voltage bus on the power battery 1 side. The bidirectional conversion unit operates in buck conversion mode, converting the power from the high-voltage bus and transmitting it to the energy storage module 2, thus enabling the charging pile to replenish the energy storage module 2. Optionally, under emergency power supply conditions, the bidirectional conversion unit can switch to boost conversion mode, boosting the power from the energy storage module 2 and transmitting it to the high-voltage bus to provide emergency power to the power battery 1 or high-voltage loads.

[0068] When the first switching unit and / or the second switching unit are in the open state, the bidirectional conversion unit operates in the second working state; in this state, the energy transmission path between the power battery 1 and the energy storage module 2 is physically cut off, and the two operate independently of each other, with their electrical characteristics not affecting each other.

[0069] For example, when the energy storage module 2 experiences faults such as over-temperature, over-voltage, cell short circuit, or insulation failure, the control module controls the second switching unit to disconnect, and the bidirectional conversion unit enters the second working state. The energy storage module 2 is completely isolated from the system, and the power battery 1 can operate independently in normal charging or discharging mode without being affected by the conduction of faults on the energy storage side. Conversely, when the power battery 1 experiences a serious fault, the control module controls the first switching unit to disconnect, and the bidirectional conversion unit enters the second working state. The energy storage module 2 can independently supply power to the vehicle's key low-voltage / medium-voltage loads 9, maintaining the operation of functions such as emergency steering, braking, and door unlocking.

[0070] In this example, the control module is configured to acquire real-time operating status information of the power battery 1 and the energy storage module 2, including parameters such as total voltage, individual cell voltage, charging and discharging current, cell temperature, SOC, fault level, and insulation resistance. Based on preset state machine logic, it controls the switching unit's on / off state and the bidirectional switching unit's operating state. The specific control rules are as follows: When both the power battery 1 and the energy storage module 2 are in a non-fault state, and the system is in pulse heating mode or when energy storage replenishment is required, the control module controls the first switch unit and the second switch unit to close, controls the bidirectional conversion unit to switch to the first working state, and runs the corresponding energy transmission sub-mode according to the current working condition requirements. When a serious fault is detected in energy storage module 2, the control module immediately sends a disconnect command to the second switching unit, and simultaneously controls the bidirectional conversion unit to stop power output and switch to the second working state, physically isolating the faulty energy storage module 2 to prevent the fault from spreading. When a serious fault is detected in the power battery 1, the control module immediately sends a disconnect command to the first switching unit, and simultaneously controls the bidirectional conversion unit to stop power output and switch to the second working state, so that the energy storage module 2 independently maintains the power supply to the critical load and ensures the basic safety functions of the vehicle. When the system enters maintenance, hibernation, or vehicle power-off mode, the control module controls both the first and second switching units to disconnect, and the bidirectional conversion unit enters the second working state, achieving complete power-off isolation of the two energy storage paths and improving static safety.

[0071] In some embodiments of this disclosure, the bidirectional DC / DC converter may specifically adopt an isolated structure or a non-isolated structure to adapt to different vehicle requirements.

[0072] In the isolated structural implementation, the power conversion module 3 adopts a dual active bridge DAB isolated bidirectional DC / DC topology. Complete electrical isolation between the high-voltage and low-voltage sides is achieved through a high-frequency transformer, with an insulation withstand voltage rating of no less than 2.5kV, meeting automotive-grade functional safety requirements ASILC and above. The high-voltage side connects to the DC bus of the power battery 1, with a voltage range covering 250V-850V; the low-voltage side connects to the energy storage module 2, with a voltage range covering 9V-60V. The topology employs zero-voltage switching (ZVS) soft-switching technology, resulting in low switching losses. This structure is suitable for energy conversion between the high-voltage active power battery 1 and the low-voltage energy storage module 2, offering a high safety level, strong anti-interference capability, and effectively preventing high-voltage side faults from propagating to the low-voltage side, ensuring the reliability of the low-voltage power supply system.

[0073] In the non-isolated structural implementation, the power conversion module 3 adopts a synchronous rectification Buck-Boost non-isolated bidirectional DC / DC topology, without a high-frequency transformer or isolation winding, achieving energy storage and voltage conversion solely through a power inductor. The overall structure is simple and boasts high power density. This structure is suitable for scenarios where the voltage levels of the energy storage module 2 and the power battery 1 are relatively similar, such as high-voltage auxiliary energy storage branches and dual-battery pack architectures on the same platform. It can also be used in scenarios where 48V medium-voltage energy storage is directly coupled to a 48V load, reducing conversion losses. The non-isolated solution is equipped with an independent insulation monitoring unit to monitor the insulation status of the high and low voltage sides in real time, meeting the vehicle's safety requirements.

[0074] In some embodiments of this disclosure, the energy storage module 2 is optionally configured to supply power to a low-voltage or medium-voltage load of the vehicle, the load including at least one of a vehicle controller, body electronics, actuator, parking power supply module, and cold start assist module.

[0075] In this embodiment, the energy storage module 2 is not a dedicated energy storage unit set only for the pulse heating function, but is also connected to the vehicle's low-voltage or medium-voltage power supply network to undertake the load power supply function under normal operating conditions, thus realizing multiple uses of one source.

[0076] For example, under normal vehicle operating conditions, the energy storage module 2, as a component of the vehicle's low-voltage power supply system, provides stable power to low-voltage loads such as the vehicle controller, battery management unit, body electronic equipment, lighting system, and sensors, replacing the function of traditional low-voltage batteries.

[0077] For example, when the vehicle is parked and powered off, the energy storage module 2 acts as a parking power supply to power constantly powered loads such as parking monitoring, vehicle terminal, and anti-theft system, thus avoiding the lifespan degradation caused by long-term low-current discharge of the power battery 1.

[0078] For example, under the condition of cold start of vehicle in low temperature, the energy storage module 2 serves as a cold start auxiliary power source, providing a large current output to the starter motor and DC / DC converter to ensure that the vehicle can be powered on and started smoothly in low temperature environment.

[0079] For example, energy storage module 2 uses a 48V sodium-ion battery heating system. Under pulse heating conditions, it receives the pulse energy released by power battery 1, enabling rapid heating of power battery 1. Under normal driving conditions, it supplies power to the vehicle's 48V medium-voltage loads such as electric power steering, electric air conditioning compressor, and active suspension through the 48V power supply network. Under parking conditions, it provides power to the vehicle's constant-voltage low-voltage loads. By reusing functions, the system redundancy and increased cost caused by adding a dedicated energy storage unit for a single pulse heating function are avoided, significantly improving the utilization rate of energy storage module 2 and the integration of the entire vehicle system.

[0080] In some embodiments of this disclosure, the battery heating system may optionally include a battery management unit, which is used to collect voltage, current, temperature and SOC status information of the power battery 1 and the energy storage module 2, and transmit it to the control module. The control module is also configured to dynamically adjust the peak current, frequency, duty cycle and duration parameters of the pulse discharge based on the temperature, SOC state and internal resistance state of the power battery 1 and the temperature and SOC state of the energy storage module 2.

[0081] In this embodiment, the battery management unit is specifically implemented as BMS 6 or integrated within BMS 6, and this disclosure does not limit this. Optionally, the battery management unit includes a power battery 1 management subunit and an energy storage management subunit, which respectively collect the operating status parameters of the power battery 1 and the energy storage module 2. All parameters are transmitted to the control module in real time to provide a basis for the dynamic adjustment of pulse parameters.

[0082] For example, the battery management unit collects parameters of the power battery 1 including: total voltage, single cell voltage, charging and discharging current, maximum cell temperature, minimum cell temperature, SOC, SOH, DC internal resistance, insulation resistance, etc.

[0083] For example, the parameters collected by the battery management unit from the energy storage module 2 include: total voltage, individual cell voltage, charging current, discharging current, cell temperature, SOC, SOH, maximum allowable charging power, and maximum allowable discharging power.

[0084] For example, the control module has a built-in pulse parameter adaptive adjustment algorithm that dynamically optimizes the peak current, pulse frequency, duty cycle and single pulse duration of pulse discharge based on the real-time collected dual-battery status parameters, so as to maximize heating efficiency while ensuring battery safety.

[0085] For example, when the temperature of power battery 1 is below -20℃, the internal resistance of the cell is large and the polarization is severe. The control module appropriately reduces the pulse peak current and increases the pulse duty cycle to avoid the cell voltage from exceeding the safety threshold due to polarization overvoltage. When the temperature of power battery 1 rises to above -10℃, the internal resistance of the cell decreases and the charging acceptance capability is improved. The control module gradually increases the pulse peak current to accelerate the heating rate.

[0086] When the SOC of energy storage module 2 is higher than 90%, the control module reduces the average power of pulse discharge and controls the power conversion module 3 to discharge some energy to the low-voltage load to avoid overcharging of energy storage module 2. When the SOC of energy storage module 2 is lower than 20%, the control module can replenish the energy storage module 2 with power through the charging pile during the pulse interval to ensure the ability to receive subsequent pulse energy.

[0087] When abnormal conditions such as abnormally high internal resistance of power battery 1 or excessive inconsistency in single cell voltage are detected, the control module immediately reduces the pulse power or stops heating to avoid battery damage and ensure system safety.

[0088] In some embodiments of this disclosure, the pulse control parameters can be adjusted in a multi-dimensional adaptive closed loop based on ambient temperature, the SOC of the main power battery 1, the internal resistance state, and the SOC of the auxiliary power supply.

[0089] The control module incorporates a multi-parameter coupled lookup table model and a closed-loop correction algorithm. Input variables include six core parameters: ambient temperature, power battery 1 temperature, power battery 1's SOC, power battery 1's DC internal resistance, energy storage module 2 temperature, and energy storage module 2's SOC. Output variables include four control parameters: pulse peak current, pulse frequency, duty cycle, and single pulse duration. Specific adjustment rules are as follows: Ambient temperature dimension: When the ambient temperature is below -20℃, the charging acceptance capability of energy storage module 2 decreases, the control module reduces the average pulse power, increases the pulse frequency, and reduces the single pulse charge to avoid polarization overvoltage of energy storage module 2; when the ambient temperature is above 0℃, the performance of energy storage module 2 is fully released, and the pulse peak current can be gradually increased to accelerate the heating rate.

[0090] Power Battery 1 State Dimension: When the SOC of Power Battery 1 is below 20%, the peak current of pulse discharge is limited to avoid damage from deep discharge of the cells; when the DC internal resistance of Power Battery 1 is more than 30% higher than the reference value, the pulse current amplitude is reduced and the pulse duty cycle is increased to avoid the single cell voltage from exceeding the safety threshold; as the temperature of Power Battery 1 increases and the internal resistance decreases, the pulse power is gradually increased to achieve dynamic optimization of heating efficiency.

[0091] Energy storage module 2 status dimensions: When the SOC of energy storage module 2 is higher than 90%, the average power of pulse discharge is reduced, and the power conversion module 3 is controlled to discharge some energy to the vehicle load to avoid overcharging of energy storage module 2; when the SOC of energy storage module 2 is lower than 10%, energy can be replenished to energy storage module 2 through the charging pile during the pulse interval to ensure the energy carrying capacity of subsequent pulses; when the temperature of energy storage module 2 is too high, the pulse frequency is reduced to reduce the amount of charging charge per unit time and ensure that energy storage module 2 operates within a safe temperature range.

[0092] The control algorithm has an adjustment cycle of 100ms, completing parameter acquisition and command update once per cycle, achieving millisecond-level dynamic response. Simultaneously, a parameter change rate limit is set to avoid electrical shocks caused by sudden pulse parameter changes, ensuring a stable and continuous heating process.

[0093] For example, when the ambient temperature is -25℃, the temperature of power battery 1 is -20℃, the SOC is 30%, and the SOC of energy storage module 2 is 50%, the control module outputs initial pulse parameters: peak current 100A, frequency 0.5Hz, and duty cycle 30%. As heating progresses, the temperature of power battery 1 rises to -10℃, the internal resistance decreases, and the control module gradually increases the peak current to 150A and the duty cycle to 40%. When the SOC of energy storage module 2 rises to 85%, the control module reduces the duty cycle to 35% and simultaneously activates low-voltage load auxiliary energy discharge to maintain the SOC of energy storage module 2 within a safe range until heating is complete.

[0094] In some embodiments of this disclosure, optionally, the control module is further configured to: when the temperature of the power battery 1 is detected to reach the target temperature threshold, control the power battery 1 to exit the pulse discharge heating mode and switch to the normal charging mode.

[0095] In this embodiment of the disclosure, the target temperature threshold is a preset minimum allowable temperature for fast charging, which can be calibrated according to the material system and charging strategy of the power battery 1, for example, set as a fixed value in the range of 0°C to 10°C, and is not limited here.

[0096] For example, during the pulse heating process, the control module obtains the lowest cell temperature of the power battery 1 in real time through the battery management unit. When the lowest cell temperature remains above the target temperature threshold for more than 30 seconds, the heating is determined to be complete, and the mode switching process is triggered.

[0097] For example, the mode switching adopts a smooth transition strategy: the control module gradually reduces the peak current and duty cycle of the pulse discharge, while gradually increasing the charging output power of the charging pile until the pulse discharge stops completely and the charging pile output reaches the rated charging power. The entire switching process lasts 5 to 10 seconds, avoiding bus voltage surges and current fluctuations caused by sudden changes in operating conditions, and protecting power devices and battery cells.

[0098] For example, the target temperature threshold is set to 5℃. When the lowest cell temperature of power battery 1 reaches 5℃ and remains stable, the control module issues a mode switching command: first, the pulse peak current is linearly reduced from 200A to 0A within 3 seconds, while the charging pile output current is linearly increased from 50A to 250A; after the pulse completely stops, the pulse energy transmission channel of the power conversion module 3 is shut down, and the system fully enters the normal fast charging mode, with the charging pile charging power battery 1 at a rated current of 250A. Through smooth switching, fluctuations in the bus voltage exceeding ±5% can be avoided, ensuring the stability of the charging process and the lifespan of the components.

[0099] In some embodiments of this disclosure, the low-temperature pulse heating mode can be implemented in conjunction with other thermal management strategies of the vehicle to form a multi-heat source synergistic heating system, further improving the heating rate and temperature uniformity under extreme low temperatures.

[0100] The combined thermal management strategy is uniformly scheduled by the vehicle's thermal management controller, matching different heating combinations based on ambient temperature and battery status. A specific example is as follows: Combined pulse heating and positive temperature coefficient (PTC) heating: When the ambient temperature is below -25℃, the rate of pulse heating alone is limited, so a combined pulse heating and high-voltage PTC heating mode is activated. Pulse heating is responsible for rapid heat generation inside the cell, while PTC heating is responsible for heating the battery pack coolant. Heat is transferred to the outside of the cell through the liquid cooling circuit, forming bidirectional heating from both inside and outside. When working together, the battery can be heated from -30℃ to 0℃ within 10 minutes. The control module dynamically adjusts the power distribution between the two based on the temperature difference between the inside and outside of the cell. When the temperature difference is greater than 10℃, the PTC power is reduced and the pulse heating power is increased to avoid excessive temperature difference between the cells.

[0101] Combined pulse heating and motor waste heat recovery: When the vehicle is immediately plugged in to charge after use, the drive motor and motor controller still retain residual heat. At this time, while pulse heating is activated, the thermal management circuit recovers the motor's waste heat, transferring it to the power battery 1 via coolant to assist in warming up. This solution fully utilizes waste heat, reduces the energy consumption of pulse heating, and improves the cooling efficiency of the motor system.

[0102] The combination of pulse heating and cell temperature uniformity strategy: During pulse heating, uneven heat generation may occur within the cell. In this case, the battery pack liquid cooling circuit is activated, circulating coolant at a low flow rate to transfer heat from the locally high-temperature areas to the low-temperature areas, achieving uniform temperature across the entire pack. With this combined temperature uniformity strategy, the maximum temperature difference within the battery pack can be controlled within 3℃, preventing cell lifespan degradation caused by localized overheating.

[0103] After heating is complete, it connects with the fast charging cooling strategy: After switching to normal fast charging mode, the thermal management system automatically switches to cooling mode, dynamically adjusting the heat dissipation power according to the charging power to maintain the battery in the optimal charging temperature range and ensure the continuous high-power fast charging.

[0104] Under the combined thermal management mode, the control module uniformly schedules multiple subsystems such as pulse heating, PTC heating, waste heat recovery, and liquid cooling temperature uniformity, sets priority and power allocation logic, and achieves optimal coordination of multiple heat sources, taking into account heating rate, temperature uniformity and energy utilization.

[0105] In some embodiments of this disclosure, the battery heating system may optionally include a vehicle-to-charging-pile communication module 8, which is used to realize state interaction and collaborative control between the power battery 1 and the charging pile.

[0106] In this embodiment, the vehicle-charging pile communication module 8 conforms to the GB / T 27930 standard, reuses the existing CAN communication link of DC charging piles, and does not require additional communication hardware. It can achieve coordinated control of pulse heating mode only through software protocol upgrade, and is compatible with all existing DC charging piles that conform to national standards.

[0107] For example, the interaction process of the vehicle-to-charging station communication module 8 is divided into four stages: The first stage is the mode negotiation stage: After the vehicle connects to the charging pile and completes the handshake, the control module sends a pulse heating mode request to the charging pile through the vehicle-to-charging pile communication module 8, and synchronizes the voltage fluctuation range, current fluctuation range, pulse frequency and timing characteristics of the pulse operating condition; the charging pile feeds back its maximum output capacity, overvoltage protection threshold, overcurrent protection threshold and grid status information, and the two parties complete the operating condition matching and mode confirmation to avoid the charging pile triggering false protection according to the conventional steady-state charging logic.

[0108] The second stage is the heating operation stage: During the pulse heating process, the control module reports the temperature, SOC and pulse power demand of the power battery 1 to the charging pile in real time through the vehicle-to-charging pile communication module 8. Based on the received dynamic operating condition information, the charging pile adjusts the output voltage and current following strategy in real time to dynamically adapt to the bus power fluctuation caused by pulse discharge and maintain the DC bus voltage within the safe range.

[0109] The third stage is the dynamic adjustment stage: the charging pile feeds back its output margin, equipment temperature, grid power limit and other status information to the vehicle through the vehicle-pile communication module 8; the control module adaptively adjusts the pulse discharge parameters according to the pile end capacity and battery status, maximizes the heating power within the pile end bearing boundary, and achieves the optimal heating efficiency in all scenarios.

[0110] The fourth stage is the mode switching stage: After heating is completed, the control module sends the mode switching command and target charging parameters to the charging pile through the vehicle-to-charging pile communication module 8. The charging pile adjusts its output characteristics synchronously, and the two work together to complete a smooth transition from pulse heating mode to normal charging mode, avoiding electrical shock caused by sudden changes in operating conditions.

[0111] For example, when a vehicle connects to a 60kW DC charging pile, the vehicle-to-pile communication module 8 first completes mode negotiation. The charging pile reports a maximum output current of 150A and an overvoltage protection threshold of 420V. Based on the pile's capacity, the control module sets the peak pulse current to 120A, controls the average pulse power to within 50kW, and reserves a 10kW power margin. During heating, the charging pile receives the pulse timing signal from the vehicle in real time and dynamically adjusts the output current to stabilize the bus voltage within the 380V-400V range, preventing overvoltage protection from being triggered. When the charging pile detects an increase in its power module temperature, it sends a power reduction request to the vehicle via the communication module 8. The control module then reduces the pulse power to ensure the safe operation of the charging pile equipment.

[0112] In some embodiments of this disclosure, the charging pile side may retain only basic power supply and communication functions, without the need to configure any electrochemical energy storage unit.

[0113] The hardware architecture of charging piles compatible with this solution only includes: an AC-DC rectifier power module, a billing and control unit, a national standard communication interface, basic protection circuitry, and charging guns and cables. It does not include energy storage battery packs, dedicated energy-absorbing resistor arrays, large-capacity buffer capacitor banks, energy feedback inverter units, or other pulse energy processing hardware. The charging pile software only needs to be upgraded to improve the communication protocol and add message parsing and output following logic for pulse heating mode; no changes to the hardware circuitry or power topology are required.

[0114] Under this architecture, the core function of the charging pile is to provide stable DC power output and status interaction, while the buffering, storage, and regulation of pulse energy are entirely handled by the vehicle-side system. Compared to traditional pulse heating charging piles with energy storage, this significantly reduces the hardware cost per pile and eliminates the costs of thermal management, maintenance, and replacement of the pile-side energy storage. More importantly, existing DC charging piles require no hardware modification; they can be adapted to the pulse heating function of this solution simply through remote firmware upgrades, greatly lowering the barrier to promotion and achieving full compatibility with existing charging infrastructure.

[0115] like Figure 3 As shown, this disclosure also provides a battery heating method applied to the aforementioned battery heating system. The battery heating system includes a power battery, an energy storage module, a power conversion module, a control module, and a port module. The power battery is electrically connected to the energy storage module through the power conversion module. The method includes the following steps: In step S101, the vehicle connects to the charging pile through the port module to establish electrical and communication connections.

[0116] For example, after the vehicle plugs into the DC charging gun, it first completes the physical connection confirmation, and then completes the handshake and identity authentication through the vehicle-to-charging-gun communication module to establish a stable CAN communication link. The charging gun then reports its output capabilities and configuration information to the vehicle.

[0117] Step S102: Collect the temperature, SOC, and internal resistance information of the power battery, as well as the temperature, SOC, and voltage information of the energy storage module.

[0118] For example, the control module collects all operating parameters of the power battery and energy storage module in real time through the battery management unit, including cell voltage, total voltage, current, multi-point temperature, SOC, DC internal resistance, etc., as the basis for mode judgment and parameter setting.

[0119] Step S103: Determine whether the power battery temperature is lower than the preset fast charging allowable temperature threshold. If so, start the low temperature pulse heating mode; otherwise, directly enter the normal charging mode.

[0120] For example, the preset fast charging allowable temperature threshold is calibrated according to the battery material system, such as 0°C for ternary lithium batteries and 5°C for lithium iron phosphate batteries. When the lowest cell temperature of the power battery is lower than this threshold, it is determined that preheating is required, and the pulse heating mode is activated.

[0121] Step S104: Set the initial parameters of the pulse discharge, including peak current, frequency, duty cycle, and duration.

[0122] For example, the control module calls a preset parameter mapping table to determine the initial pulse parameters based on the current power battery temperature, SOC and energy storage module SOC; at the same time, it adjusts the parameters based on the output capacity reported by the charging pile to ensure that the initial parameters are within the load-bearing range of the charging pile.

[0123] Step S105: Control the power battery to perform pulse discharge, so that Joule heat and polarization heat are generated inside the power battery to achieve self-heating.

[0124] For example, the control module sends pulse control commands to the battery management unit, which controls the main circuit switch and power devices of the power battery to perform periodic pulse discharge according to the set parameters, and uses the internal resistance of the battery cell to generate heat to achieve temperature rise.

[0125] Step S106: Control the power conversion module to transfer at least a portion of the electrical energy released by the power battery pulse discharge to the energy storage module for absorption and storage.

[0126] For example, the control module synchronously controls the power conversion module to start and run, tracks the timing of pulse discharge, converts the high-voltage pulse energy on the power battery side into electrical energy that is compatible with the voltage level of the energy storage module, and delivers it to the energy storage module for storage, thereby achieving vehicle-side buffering of pulse energy.

[0127] Step S107: Monitor the operating status of the power battery and energy storage module in real time, and dynamically adjust the pulse discharge parameters and energy transmission power.

[0128] For example, during the heating process, the control module acquires the status data of the dual batteries in real time, dynamically optimizes the pulse parameters based on temperature changes, SOC changes, and internal resistance changes, and adjusts the power level based on the status information fed back from the charging pile, so as to achieve the optimal balance between heating efficiency, battery safety, and charging pile adaptation.

[0129] Step S108: Determine whether the power battery temperature has reached the preset target temperature threshold. If yes, proceed to the next step; otherwise, return to step S107 to continue running.

[0130] For example, the target temperature threshold is consistent with or slightly higher than the fast charging allowable temperature threshold, reserving a temperature margin to avoid temperature drop after switching. A duration criterion is used for judgment, meaning heating is only considered complete after the temperature has continuously reached the target for a certain period, avoiding erroneous switching caused by temperature fluctuations.

[0131] Step S109: Exit pulse heating mode and smoothly switch to normal charging mode.

[0132] For example, the control module gradually reduces the pulse power while simultaneously controlling the charging pile to gradually increase the charging power. After a smooth transition, the pulse heating circuit is shut off, and the normal fast charging process begins. At the same time, the energy storage module can be replenished with energy according to its SOC status.

[0133] This disclosure also provides a vehicle including a battery heating system as provided in any of the above embodiments.

[0134] For example, the vehicle is a pure electric vehicle, a plug-in hybrid electric vehicle, or a range-extended electric vehicle. The vehicle is equipped with an advanced intelligent driving system, a high-power fast charging system, and an intelligent thermal management system. The battery heating system is integrated into the vehicle's thermal management architecture and works in conjunction with the vehicle's air conditioning system and liquid cooling system.

[0135] For example, when a vehicle is connected to a regular DC charging station in a low-temperature environment of -10℃, the battery heating system automatically starts the pulse heating mode, using the on-board sodium ion energy storage module to receive the pulse energy. There is no need for the charging station to have energy storage function. It only takes 8 minutes to raise the temperature of the power battery from -10℃ to 5℃, and then enter the high-power fast charging mode. It only takes 30 minutes to charge to 80% SOC, which is basically the same as the charging time at normal temperature.

[0136] During the heating process, if a fault is detected in one of the energy storage circuits, the control module can immediately adjust the pulse power and use the remaining energy storage capacity to maintain the heating operation without causing heating interruption. If the power conversion module fails, the system can switch to PTC heating mode as a backup to ensure the availability of the low-temperature charging function and achieve multiple redundancy.

[0137] Compared with the prior art, the embodiments of this disclosure have the following significant technical effects: First, it completely eliminates reliance on charging pile-side energy storage, significantly reducing infrastructure costs. This solution completely migrates the pulse energy buffering function to the vehicle end, using an onboard energy storage module to receive pulse discharge energy. Charging piles do not need to be equipped with any energy storage batteries, energy absorption devices, or power buffer modules; they only need to retain basic power supply and communication functions to support pulse heating. Existing charging piles can be adapted without hardware modifications, greatly improving the feasibility of the solution's promotion and infrastructure compatibility.

[0138] Secondly, leveraging the low-temperature performance advantages of onboard energy storage improves the reliability of low-temperature heating. Sodium-ion batteries are selected as the energy storage medium, utilizing their excellent low-temperature charging acceptance capability to solve the technical challenge of conventional low-voltage lithium-ion batteries being unable to withstand high-current pulse charging at low temperatures. This allows for stable operation in extreme low-temperature environments down to -30℃, significantly improving the user experience of vehicles in frigid regions.

[0139] Third, the energy storage function is highly reusable, improving system integration. The energy storage module simultaneously performs the dual functions of pulse energy absorption and low / medium voltage power supply for the vehicle, avoiding the increased weight, size, and cost associated with dedicated energy storage units, resulting in a higher overall system cost-effectiveness. Compared to solutions that require a separate low-temperature heating energy storage unit, this solution reduces additional hardware costs and space requirements.

[0140] Fourth, adaptive pulse control and vehicle-pile coordination balance efficiency and safety. By acquiring the status of dual batteries in real time and dynamically adjusting pulse parameters, the heating efficiency can be optimized globally under different temperatures, SOCs, and pile capacities. Through vehicle-pile communication coordination, false protection of charging piles is effectively avoided, ensuring continuous and stable heating process and reducing the possibility of interruption during heating.

[0141] Fifth, physical isolation architecture enhances system safety. The multi-cavity physical isolation design can confine the failure of a single component to a local cavity, preventing the fault from spreading, while ensuring power redundancy for critical systems under fault conditions, thereby improving the passive safety level of the entire vehicle.

[0142] The above description is merely a preferred embodiment of this disclosure and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of this disclosure is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the above-described concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features disclosed in this disclosure that have similar functions.

[0143] Furthermore, while the operations are described in a specific order, this should not be construed as requiring these operations to be performed in the specific order shown or in a sequential order. In certain environments, multitasking and parallel processing may be advantageous. Similarly, while several specific implementation details are included in the above discussion, these should not be construed as limiting the scope of this disclosure. Certain features described in the context of individual embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented individually or in any suitable sub-combination in multiple embodiments.

[0144] Although the subject matter has been described using language specific to structural features and / or methodological logic, it should be understood that the subject matter defined in the appended claims is not necessarily limited to the specific features and actions described above. Rather, the specific features and actions described above are merely illustrative examples of implementing the claims.

Claims

1. A battery heating system, characterized in that, include: Power battery, energy storage module and control module; The control module is configured to: when the temperature of the power battery is below a target threshold during charging, control the power battery to perform pulse discharge, and transfer at least a portion of the electrical energy released by the pulse discharge to the energy storage module.

2. The battery heating system according to claim 1, characterized in that, The control module is also configured to control the power battery to exit the pulse discharge heating mode when the power battery temperature reaches the target temperature threshold.

3. The battery heating system according to claim 1 or 2, characterized in that, The battery heating system also includes a power conversion module and a port module; The port module is electrically connected to the power battery and is used to establish an electrical connection between the power battery and an external charging pile. The power conversion module is configured to adjust its operating state to establish a bidirectional energy transmission path between the power battery and the energy storage module, and / or to adjust the energy transmission relationship between the power battery or the energy storage module and the port module.

4. The battery heating system according to claim 3, characterized in that, The power conversion module includes a bidirectional conversion unit, and the power battery and the energy storage module are both electrically connected to the bidirectional conversion unit. The bidirectional conversion unit includes a first operating state and a second operating state. In the first operating state, the pulse discharge energy of the power battery is transmitted to the energy storage module for storage through the bidirectional conversion unit, and the electrical energy input by the port module is transmitted to the energy storage module through the bidirectional conversion unit. In the second operating state, the energy transmission path between the power battery and the energy storage module is disconnected, and the power battery and the energy storage module operate independently.

5. The battery heating system according to any one of claims 1-4, characterized in that, The energy storage module is connected to any one of the power supply platforms of 12V, 24V, 48V and 72V; or the energy storage module includes a high-voltage auxiliary energy storage branch independently set on the high-voltage platform of the vehicle.

6. The battery heating system according to any one of claims 1-5, characterized in that, The energy storage module includes at least one of sodium-ion batteries, lithium titanate batteries, lithium capacitors, and supercapacitors.

7. The battery heating system according to any one of claims 1-6, characterized in that, The energy storage module is also configured to supply power to low-voltage or medium-voltage loads of the vehicle, the low-voltage or medium-voltage loads including at least one of the vehicle controller, body electronic equipment, actuator, parking power supply module, and cold start assist module.

8. The battery heating system according to claim 1, characterized in that, The system also includes a battery management unit, which is used to collect voltage, current, temperature and SOC status information of the power battery and the energy storage module, and transmit it to the control module. The control module is also configured to adjust the peak current, frequency, duty cycle, and duration parameters of the pulse discharge based on the temperature, SOC state, and internal resistance state of the power battery, as well as the temperature and SOC state of the energy storage module.

9. A battery heating method, characterized in that, Applied to a battery heating system, the battery heating system includes a power battery, an energy storage module, and a control module; The method includes: When the temperature of the power battery is below the target threshold and the power battery is in a pulse discharge heating mode, the control module controls the power conversion module to transfer at least a portion of the electrical energy released by the power battery through pulse discharge to the energy storage module.

10. A vehicle, characterized in that, Includes the battery heating system as described in any one of claims 1 to 8.

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