Energy storage device and heating control method thereof

Abstract

The application discloses an energy storage device and a heating control method thereof. The method comprises the following steps: when the actual charging current value is greater than or equal to a first difference value, and the actual power value is greater than a preset power value, a first heating control signal is obtained according to the obtained heating current value and the parameters of the heating unit, so that the heating unit heats the battery unit according to the first heating control signal; a second heating control signal is obtained according to the current actual charging current value, the first difference value, a second difference value and the parameters of the heating unit, so that the heating unit heats the battery unit according to the second heating control signal, and the steps of obtaining the current actual charging current value and the second preset current value of the battery unit are repeatedly executed until the current actual charging current value of the battery unit is greater than the second difference value and less than the first difference value. The output of the charging device can be tracked to adjust the heating unit, improve the heating efficiency of the heating unit, and improve the utilization rate of the energy storage device.

Description

Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to an energy storage device and its heating control method. Background Technology

[0002] A photovoltaic power supply system includes photovoltaic modules, a power source, a heating film, and a switching transistor. The heating film and the switching transistor are connected in series, and the series-connected heating film and switching transistor are connected in parallel with the power source. The photovoltaic modules are used to charge the power source.

[0003] Currently, the heating film is controlled by switching the switching transistor on or off. However, the power supply provided by the photovoltaic module is insufficient to meet the heating film's needs, causing the heating film to malfunction and resulting in low utilization. Summary of the Invention

[0004] The main technical problem addressed by this application is to provide a power supply system and its control method to solve the problem of the heating film failing to function.

[0005] This application provides a heating control method for an energy storage device, applied to an energy storage device for connecting a charging device and a load, the charging device for supplying power to the energy storage device and the load, the energy storage device including a battery unit and a heating unit connected in parallel, and the heating control method including:

[0006] Obtain the actual charging current value of the battery cell and the preset limit charging current value of the battery cell; obtain the actual power value of the load and the preset power value of the load.

[0007] Calculate the first difference between the limited charging current value and the obtained first preset current value;

[0008] When the actual charging current value is greater than or equal to the first difference and the actual power value is greater than the preset power value, a first heating control signal is obtained based on the acquired heating current value and the parameters of the heating unit, so that the heating unit heats the battery unit according to the first heating control signal.

[0009] Obtain the current actual charging current value of the battery cell and the second preset current value;

[0010] Calculate the second difference between the limited charging current value and the obtained second preset current value, wherein the first preset current value is less than the second preset current value;

[0011] Based on the current actual charging current value, the first difference, the second difference, and the parameters of the heating unit, a second heating control signal is obtained so that the heating unit heats the battery unit according to the second heating control signal. The steps of obtaining the current actual charging current value and the second preset current value of the battery unit are repeatedly executed until the current actual charging current value of the battery unit is greater than the second difference and less than the first difference. After a first preset time interval, the steps of obtaining the actual charging current value of the battery unit and the preset limit charging current value of the battery unit are repeatedly executed.

[0012] Specifically, based on the current actual charging current value, the first difference, the second difference, and the parameters of the heating unit, a second heating control signal is obtained, including:

[0013] When the current actual charging current value is greater than or equal to the first difference, the first updated current value is obtained based on the first updated value and the heating current value.

[0014] The second heating control signal is obtained based on the first updated current value and the parameters of the heating unit.

[0015] The first update current value is obtained based on the acquired first update value and the heating current value, including:

[0016] The sum of the first updated value and the heating current value is used as the updated current value.

[0017] Specifically, based on the current actual charging current value, the first difference, the second difference, and the parameters of the heating unit, a second heating control signal is obtained, including:

[0018] When the current actual charging current value is less than or equal to the second difference, the second updated current value is obtained based on the acquired second updated value and the heating current value.

[0019] The second heating control signal is obtained based on the second updated current value and the parameters of the heating unit.

[0020] This also includes:

[0021] The difference between the limit charging current value and the current actual charging current value of the battery cell is used as the second update value.

[0022] The process of obtaining the second updated current value based on the acquired second updated value and the heating current value includes:

[0023] The difference between the heating current value and the second update value is used as the second update current value.

[0024] This also includes:

[0025] Obtain the current hysteresis value and the power hysteresis value, wherein the current hysteresis value is less than the first difference value and the power hysteresis value is greater than the preset power value;

[0026] When the actual current value is greater than or equal to the current hysteresis value, and the actual power value is greater than the power hysteresis value, the first heating control signal is obtained based on the preset heating current value and the parameters of the heating unit.

[0027] The parameters of the heating unit include the rated voltage and resistance values. A first heating control signal is obtained based on the acquired heating current value and the parameters of the heating unit, including:

[0028] The duty cycle is calculated by dividing the heating current value by the ratio of the rated voltage value to the resistance value.

[0029] Generate a first heating control signal with a duty cycle.

[0030] The energy storage device includes a first switching transistor, one end of which is connected to a battery cell, and the other end is connected to a heating unit. The heating unit includes a heating film and a second switching transistor, which are connected in series with the heating film. The heating unit heats the battery cell according to a first heating control signal, including:

[0031] When the duty cycle is greater than or equal to the preset duty cycle, the first switch is turned on.

[0032] After a second preset time interval, the second switching transistor is controlled to turn on or off according to the duty cycle by a pulse width modulation signal.

[0033] Heating control methods also include:

[0034] Stop outputting pulse width modulation signals to the second switch transistor, and control the first switch transistor to turn off at a second preset time interval.

[0035] This application also provides an energy storage device for connecting a charging device and a load. The charging device supplies power to the energy storage device and the load. The energy storage device includes a control unit, a battery unit and a heating unit connected in parallel. The control unit is connected to the charging device, the battery unit, the heating unit and the load respectively. The control unit controls the energy storage device according to the above-described heating control method.

[0036] The energy storage device includes a first switching transistor, and the heating unit includes a capacitor, an inductor, a heating film, a second switching transistor, and a diode. One end of the battery unit is connected to one end of the heating film through the first switching transistor and the inductor. One end of the capacitor is connected to one end of the heating film, and the other end of the capacitor is connected to the other end of the battery unit. The other end of the battery unit is connected to the source of the second switching transistor, and the drain of the second switching transistor is connected to the other end of the heating film. The anode of the diode is connected to the other end of the heating film, and the cathode of the diode is connected to one end of the heating film. The control unit is connected to the gate of the second switching transistor.

[0037] The beneficial effects of this application are as follows: When the actual charging current value is greater than or equal to a first difference and the actual power value is greater than a preset power value, this application obtains a first heating control signal based on the acquired heating current value and the parameters of the heating unit, so that the heating unit heats the battery unit according to the first heating control signal; this ensures that the charging device meets the charging requirements of the battery unit and the preset power of the load before controlling the heating unit to heat, avoiding overload of the charging device. This application obtains a second heating control signal based on the current actual charging current value, the first difference, the second difference, and the parameters of the heating unit, so that the heating unit heats the battery unit according to the second heating control signal, and repeatedly executes the steps of obtaining the current actual charging current value and the second preset current value of the battery unit until the current actual charging current value of the battery unit is greater than the second difference and less than the first difference, which enables the heating unit to be adjusted according to the output of the charging device, improving the heating efficiency of the heating unit and improving the utilization rate of the energy storage device. This application dynamically adjusts the heating unit by controlling the first and second heating signals, ensuring the battery unit remains within a suitable temperature range and preventing performance degradation or safety hazards due to overheating or overcooling. Furthermore, by acquiring the actual and preset power values ​​of the load in real time, and ensuring the actual power value exceeds the preset power value, this application guarantees sufficient power supply to meet the load's power requirements even at high load power levels, preventing excessive power consumption by the heating unit from affecting the normal operation of the load. Attached Figure Description

[0038] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0039] Figure 1 This is a schematic diagram of the energy storage device provided in this application;

[0040] Figure 2 yes Figure 1 A flowchart illustrating an embodiment of a heating control method for a medium-sized energy storage device;

[0041] Figure 3 yes Figure 2 A schematic flowchart of an embodiment of step S106;

[0042] Figure 4 yes Figure 2 A flowchart illustrating another embodiment of step S106;

[0043] Figure 5 yes Figure 1 A schematic flowchart of another embodiment of the heating control method for medium-energy storage equipment;

[0044] Figure 6 yes Figure 2 A schematic flowchart of an embodiment of step S103;

[0045] Figure 7 yes Figure 1 A circuit diagram of an embodiment of a medium-sized energy storage device;

[0046] Figure 8 yes Figure 7 A schematic flowchart of an embodiment of step S103 of the energy storage device. Detailed Implementation

[0047] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0048] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0049] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly indicating the number, specific order, or primary and secondary relationship of the indicated technical features.

[0050] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0051] In the description of the embodiments of this application, the term "multiple" refers to two or more (including two), similarly, "multiple sets" refers to two or more (including two sets), and "multiple pieces" refers to two or more (including two pieces).

[0052] In the description of the embodiments of this application, the technical terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the accompanying drawings. They are only for the convenience of describing the embodiments of this application and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the embodiments of this application.

[0053] In the description of the embodiments of this application, unless otherwise expressly specified and limited, the technical terms such as "installation," "connection," "joining," and "fixing" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a connection between two components or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. For those skilled in the art, the specific meaning of the above terms in the embodiments of this application can be understood according to the specific circumstances.

[0054] Please see Figure 1 and Figure 2 As shown, Figure 1 This is a schematic diagram of the energy storage device provided in this application. Figure 2 yes Figure 1 A schematic flowchart of an embodiment of a heating control method for an energy storage device. The control method of this embodiment is applied to an energy storage device 100, which can be applied to a photovoltaic power supply system or other power supply systems.

[0055] The energy storage device 100 is used to connect the charging device 200 and the load 300, and the charging device 200 is used to supply power to the energy storage device 100 and the load 300. The charging device 200 includes, but is not limited to, photovoltaic modules or other power supply components, and the load 300 includes, but is not limited to, a micro-inverter, which converts the direct current (DC) power from the photovoltaic modules into the alternating current (AC) power required by the power grid. For example, the output terminals of the charging device 200 are connected to both the energy storage device 100 and the load 300.

[0056] The energy storage device 100 includes a battery unit 11 and a heating unit 12 connected in parallel. The two ends of the heating unit 12 are electrically connected to the two ends of the battery unit 11, respectively. The battery unit 11 includes, but is not limited to, a battery pack or battery array. For example, a charging device 200 is used to charge the battery unit 11, and the battery unit 11 supplies power to the heating unit 12.

[0057] In some embodiments, the energy storage device 100 further includes a control unit 13, which is connected to the charging device 200, the battery unit 11, the heating unit 12, and the load 300, respectively, and is used to control the energy storage device 100. In other embodiments, the control unit 13 may be located outside the energy storage device 100.

[0058] The heating control method in this embodiment includes the following steps:

[0059] S101: Obtain the actual charging current value of battery cell 11 and the preset limit charging current value of battery cell 11, and obtain the actual power value of load 300 and the preset power value of load 300.

[0060] The control unit 13 acquires the actual charging current value of the battery unit 11 and the preset limit charging current value of the battery unit 11, and acquires the actual power value of the load 300 and the preset power value of the load 300. For example, the control unit 13 acquires the actual charging current value of the battery unit 11 and the preset limit charging current value of the battery unit 11, and acquires the actual power value of the load 300 and the preset power value of the load 300 according to a preset period, thereby achieving periodic acquisition of the actual charging current value of the battery unit 11 and the preset limit charging current value of the battery unit 11; the preset period includes, but is not limited to, 50ms, 100ms, 200ms, 300ms, 500ms, or 1000ms, etc.

[0061] The actual charging current value of battery cell 11 refers to the actual charging current value of the charging device 200 when charging battery cell 11. The preset limited charging current value of battery cell 11 refers to the allowed charging current value of battery cell 11, such as the rated current value of battery cell 11. The actual power value of load 300 refers to the actual power value of the power supplied by the charging device 200 to load 300; the preset power value refers to the allowed power value of load 300, that is, the rated power value of load 300.

[0062] S102: Calculate the first difference between the limited charging current value and the acquired first preset current value.

[0063] The control unit 13 calculates the first difference between the limited charging current value and the acquired first preset current value, that is, the first difference is obtained by subtracting the first preset current value from the limited charging current value.

[0064] S103: When the actual charging current value is greater than or equal to the first difference and the actual power value is greater than the preset power value, a first heating control signal is obtained based on the obtained heating current value and the parameters of the heating unit 12, so that the heating unit 12 heats the battery unit 11 according to the first heating control signal.

[0065] The control unit 13 is used to compare the actual charging current with a first difference and compare the actual power value with a preset power value. When the actual charging current value is greater than or equal to the first difference and the actual power value is greater than the preset power value, the control unit 13 obtains a first heating control signal based on the acquired heating current value and the parameters of the heating unit 12, so that the heating unit 12 heats the battery unit 11 according to the first heating control signal.

[0066] Optionally, the heating current value refers to the current value at which the charging device 200 supplies power to the heating unit 12, and the heating unit 12 heats the battery unit 11. The parameters of the heating unit 12 include, but are not limited to, the rated voltage value and the resistance value of the heating unit 12.

[0067] S104: Obtain the current actual charging current value and the second preset current value of battery cell 11.

[0068] The control unit 13 acquires the current actual charging current value of the battery unit 11 and the second preset current value. That is, after the heating unit 12 heats the battery unit 11 according to the first heating control signal, the control unit 13 acquires the current actual charging current value of the battery unit 11 and acquires the preset second preset current value.

[0069] S105: Calculate the second difference between the limited charging current value and the acquired second preset current value.

[0070] The control unit 13 calculates a second difference between the limited charging current value and the acquired second preset current value; that is, the control unit 13 subtracts the second preset current value from the limited charging current value to obtain the second difference. The first preset current value is less than the second preset current value, therefore the first difference is greater than the second difference. For example, the first preset current value is 0.2A, and the second preset current value is 1.2A.

[0071] S106: Based on the current actual charging current value, the first difference, the second difference, and the parameters of the heating unit, a second heating control signal is obtained so that the heating unit 12 heats the battery unit 11 according to the second heating control signal, and the steps of obtaining the current actual charging current value and the second preset current value of the battery unit 11 are repeatedly executed until the current actual charging current value of the battery unit 11 is greater than the second difference and less than the first difference.

[0072] The control unit 13 obtains a second heating control signal based on the current actual charging current value, the first difference, the second difference, and the parameters of the heating unit; so that the heating unit 12 heats the battery unit 11 according to the second heating control signal. The step of obtaining the current actual charging current value and the second preset current value of the battery unit 11 is repeated, i.e., returning to step S104; when the current actual charging current value of the battery unit 11 is less than or equal to the second difference, or when the current actual charging current value of the battery unit 11 is greater than or equal to the first difference, steps S104 to S106 are executed cyclically until the current actual charging current value of the battery unit 11 is greater than the second difference and less than the first difference.

[0073] When the current actual charging current value of battery cell 11 is greater than the second difference and less than the first difference, the cyclic execution of steps S104 to S106 stops. After a first preset time interval, the steps of obtaining the actual charging current value of battery cell 11 and the preset limit charging current value of battery cell 11 are repeated, that is, the process returns to step S101, thereby periodically obtaining the actual charging current value of battery cell 11 and the preset limit charging current value of battery cell 11. The sum of the first preset time and the time for executing steps S101 to S106 can be equal to the preset period.

[0074] In this embodiment, when the actual charging current value is greater than or equal to a first difference and the actual power value is greater than a preset power value, a first heating control signal is obtained based on the acquired heating current value and the parameters of the heating unit. This allows the heating unit 12 to heat the battery unit 11 according to the first heating control signal. This ensures that the charging device 200 meets the charging requirements of the battery unit 11 and the preset power of the load 300 before controlling the heating unit 12 to heat, thus avoiding overload of the charging device 200. By obtaining a second heating control signal based on the current actual charging current value, the first difference, the second difference, and the parameters of the heating unit, the heating unit 12 heats the battery unit 11 according to the second heating control signal. The steps of obtaining the current actual charging current value and the second preset current value of the battery unit 11 are repeated until the current actual charging current value of the battery unit 11 is greater than the second difference and less than the first difference. This enables the heating unit 12 to be adjusted based on the output of the charging device 200, improving the heating efficiency of the heating unit 12 and increasing the utilization rate of the energy storage device 100. By dynamically adjusting the first and second heating control signals, the heating unit 12 is adjusted to ensure that the battery unit 11 is always within a suitable temperature range, preventing performance degradation or safety hazards due to overheating or overcooling. By acquiring the actual power value and preset power value of the load 300 in real time, ensuring that the actual power value exceeds the preset power value, the power supply requirements of the load 300 are adequately met when its power is high, preventing excessive power consumption of the heating unit 12 from affecting the normal operation of the load 300. Furthermore, the heating unit 12 can reach its maximum heating power without overloading the energy storage device 100.

[0075] According to some embodiments of this application, please refer to Figure 3 As shown, Figure 3 yes Figure 2 A flowchart illustrating an embodiment of step S106, wherein step S106 in this embodiment includes the following steps:

[0076] S201: When the current actual charging current value is greater than or equal to the first difference, the first update current value is obtained based on the first update value and the heating current value.

[0077] The control unit 13 compares the current actual charging current with the first difference; when the current actual charging current value is greater than or equal to the first difference, the control unit 13 obtains the first updated current value based on the obtained first updated value and the heating current value.

[0078] In some embodiments, the first updated value may be equal to the first preset current value. For example, if the first preset current value is 0.2A, the first updated value is 0.2A, the heating current value is 0.2A, and the limiting charging current value is 2A, then the control unit 13 calculates a first difference of 1.8A. When the current actual charging current value is greater than or equal to 1.8A, the control unit 13 adds the heating current value to the first updated value to obtain the first updated current value, i.e., the first updated current value is 0.4A. In other embodiments, the first updated value may not be equal to the first preset current value.

[0079] S202: Obtain the second heating control signal based on the first updated current value and the parameters of the heating unit 12.

[0080] The control unit 13 obtains a second heating control signal based on the first updated current value and the parameters of the heating unit 12, so that the heating unit 12 heats the battery unit 11 according to the second heating control signal. It then repeatedly executes the step of obtaining the current actual charging current value and the second preset current value of the battery unit 11, i.e., returns to step S104. When the current actual charging current value of the battery unit 11 is less than or equal to the second difference, or when the current actual charging current value of the battery unit 11 is greater than or equal to the first difference, steps S104 to S106 are executed cyclically until the current actual charging current value of the battery unit 11 is greater than the second difference and less than the first difference.

[0081] In this embodiment, when the current actual charging current value is greater than or equal to the first difference, a first update current value is obtained based on the first update value and the heating current value. A second heating control signal is obtained based on the first update current value and the parameters of the heating unit 12. This ensures that the charging device 200 meets the charging requirements of the battery unit 11 and the preset power of the load 300. Then, the heating unit 12 is controlled to heat the battery unit 11 according to the second heating control signal, avoiding overload of the charging device 200 and improving the heating efficiency of the heating unit 12.

[0082] According to some embodiments of this application, step S201 of this embodiment includes: using the sum of the obtained first update value and the heating current value as the first update current value. That is, the control unit 13 uses the sum of the obtained first update value and the heating current value as the first update current value.

[0083] In some embodiments, the control unit 13 periodically compares the current actual charging current with a first difference. When the current actual charging current is greater than or equal to the first difference, the control unit 13 uses the sum of the obtained first update value and the heating current value as the first update current value, thereby accumulating the first update value. For example, in the current cycle, the control unit 13 adds the heating current value to the first update value to obtain the first update current value, i.e., the first update current value is 0.4A; in the next cycle, the heating current value is 0.4A, and the control unit 13 adds the heating current value to the first update value to obtain the first update current value, i.e., 0.2 + 0.4 = 0.6A, the first update current value is 0.6A.

[0084] This embodiment uses the sum of the obtained first update value and the heating current value as the first update current value, which is easy to implement. The first update current value is obtained by accumulating the first update value, and the heating unit 12 can be adjusted by tracking the output of the charging device 200.

[0085] According to some embodiments of this application, please refer to Figure 4 As shown, Figure 4 yes Figure 2 A flowchart illustrating another embodiment of step S106 is shown. Step S106 in this embodiment includes the following steps:

[0086] S301: When the current actual charging current value is less than or equal to the second difference, the second update current value is obtained based on the obtained second update value and the heating current value.

[0087] The control unit 13 compares the current actual charging current value with the second difference. When the current actual charging current value is less than or equal to the second difference, the control unit 13 obtains the second updated current value based on the acquired second updated value and the heating current value. For example, if the second preset current value is 1.2A and the limited charging current value is 2A, the control unit 13 calculates the second difference to be 0.8A. When the current actual charging current value is less than or equal to 0.8A, the control unit 13 obtains the second updated current value based on the acquired second updated value and the heating current value.

[0088] S302: Obtain the second heating control signal based on the second updated current value and the parameters of the heating unit.

[0089] The control unit 13 obtains a second heating control signal based on the second updated current value and the parameters of the heating unit, so that the heating unit 12 heats the battery unit 11 according to the second heating control signal. The step of obtaining the actual charging current value of the battery unit 11 is repeated, that is, the process returns to step S101; until the current actual charging current value of the battery unit 11 is greater than the second difference and less than the first difference.

[0090] In this embodiment, when the current actual charging current value is less than or equal to the second difference, a second update current value is obtained based on the acquired second update value and the heating current value. A second heating control signal is then obtained based on the second update current value and the parameters of the heating unit 12. When the current actual charging current value is less than or equal to the second difference, meaning the charging device 200 cannot meet the charging requirements of the battery unit 11, the heating current of the heating unit 12 is adjusted using the second update value to ensure that the charging device 200 meets the charging requirements of the battery unit 11. Finally, the heating unit 12 is controlled to heat the battery unit 11 according to the second heating control signal.

[0091] According to some embodiments of this application, step S301 of this embodiment includes: using the difference between the limited charging current value and the current actual charging current value of the battery cell 11 as a second update value. That is, the control unit 13 subtracts the current actual charging current value from the limited charging current value to obtain the second update value.

[0092] In some embodiments, step S301 of this embodiment includes: using the difference between the heating current value and the second updated value as the second updated current value. Specifically, the control unit 13 uses the difference between the heating current value and the second updated value as the second updated current value. That is, the control unit 13 is used to subtract the second updated value from the heating current value to obtain the second updated current value.

[0093] In this embodiment, the difference between the limiting charging current value and the current actual charging current value of the battery cell 11 is used as the second update value, and the difference between the heating current value and the second update value is used as the second update current value. When the current actual charging current value is less than or equal to the second difference, the charging device 200 cannot meet the charging requirements of the battery cell 11. By using the difference between the heating current value and the second update value as the second update current value, the heating current of the heating unit 12 is reduced so that the charging device 200 can meet the charging requirements of the battery cell 11. Then, the heating unit 12 is controlled to heat the battery cell 11 according to the second heating control signal.

[0094] According to some embodiments of this application, please refer to Figure 5 As shown, Figure 5 yes Figure 1 A schematic flowchart of another embodiment of the heating control method for energy storage devices. The heating control method of this embodiment includes the following steps:

[0095] S401: Obtain the actual charging current value of battery cell 11 and the preset limit charging current value of battery cell 11, and obtain the actual power value of load 300 and the preset power value of load 300.

[0096] S402: Calculate the first difference between the limited charging current value and the acquired first preset current value.

[0097] Steps S401 to S402 are the same as steps S101 to S102 in the above embodiment, and will not be described again here.

[0098] S403: Obtain the current hysteresis value and the power hysteresis value, wherein the current hysteresis value is less than the first difference value and the power hysteresis value is greater than the preset power value.

[0099] The control unit 13 acquires the current hysteresis value and the power hysteresis value, wherein the current hysteresis value is less than the first difference value and the power hysteresis value is greater than the preset power value.

[0100] In some embodiments, the control unit 13 acquires a third preset current value, which is greater than a first preset current value. The control unit 13 subtracts the third preset current value from the limit charging current value to obtain a current hysteresis value. For example, if the first preset current value is 0.2A and the third preset current value is 0.5A, then the current hysteresis value is less than the first difference value.

[0101] The control unit 13 acquires a first preset power value and adds the first preset power value to obtain a power hysteresis value. For example, if the first preset power value is 10W, the control unit 13 adds 10W to the preset power value to obtain the power hysteresis value, so the power hysteresis value is greater than the preset power value.

[0102] S404: When the actual current value is greater than or equal to the current hysteresis value and the actual power value is greater than the power hysteresis value, the first heating control signal is obtained according to the preset heating current value and the parameters of the heating unit.

[0103] When the actual current value is greater than or equal to the current hysteresis value, and the actual power value is greater than the power hysteresis value, the control unit 13 obtains a first heating control signal based on a preset heating current value and the parameters of the heating unit, so that the heating unit 12 heats the battery unit 11 according to the first heating control signal. The preset heating current value can be the heating current value described in the above embodiment.

[0104] Since the current hysteresis value is less than the first difference value and the power hysteresis value is greater than the preset power value, when the actual current value is greater than or equal to the current hysteresis value and the actual power value is greater than the power hysteresis value, the actual charging current value is greater than or equal to the first difference value and the actual power value is greater than the preset power value.

[0105] S405: Obtain the current actual charging current value and the second preset current value of battery cell 11.

[0106] S406: Calculate the second difference between the limited charging current value and the acquired second preset current value.

[0107] S407: Based on the current actual charging current value, the first difference, the second difference, and the parameters of the heating unit, a second heating control signal is obtained so that the heating unit 12 heats the battery unit 11 according to the second heating control signal, and the steps of obtaining the current actual charging current value and the second preset current value of the battery unit 11 are repeatedly executed until the current actual charging current value of the battery unit 11 is greater than the second difference and less than the first difference.

[0108] Steps S405 to S407 are the same as steps S104 to S106 in the above embodiment, and will not be described again here.

[0109] This embodiment obtains the current hysteresis value and the power hysteresis value, wherein the current hysteresis value is less than a first difference value and the power hysteresis value is greater than a preset power value; when the actual current value is greater than or equal to the current hysteresis value and the actual power value is greater than the power hysteresis value, a first heating control signal is obtained according to the preset heating current value and the parameters of the heating unit; this ensures that the charging device 200 meets the charging requirements of the battery unit 11 and the preset power of the load 300 before controlling the heating unit 12 to heat, thus avoiding overload of the charging device 200.

[0110] According to some embodiments of this application, please refer to Figure 6 As shown, Figure 6 yes Figure 2 A schematic flowchart of an embodiment of step S103. The parameters of the heating unit 12 in this embodiment include rated voltage and resistance. Step S103 includes the following steps:

[0111] S501: The duty cycle is calculated by dividing the heating current value by the ratio of the rated voltage value to the resistance value.

[0112] The control unit 13 divides the heating current value by the ratio of the rated voltage value to the resistance value to obtain the duty cycle. For example, if the heating current value is 0.2A, the rated voltage of the heating unit 12 is 16V, and the resistance of the heating unit 12 is 6.4Ω, the control unit 13 will calculate 0.2 * 6.4 / 16 = 0.08, which is a duty cycle of 8%. If the heating current value is 1.2A, the rated voltage of the heating unit 12 is 16V, and the resistance of the heating unit 12 is 6.4Ω, the control unit 13 will calculate 1.2 * 6.4 / 16 = 0.48, which is a duty cycle of 48%.

[0113] S502: Generate a first heating control signal with a duty cycle.

[0114] The control unit 13 generates a first heating control signal with a duty cycle so that the heating unit 12 heats the battery unit 11 according to the first heating control signal; the control unit 13 can also generate a second heating control signal through the above steps, which will not be described in detail here.

[0115] This embodiment generates a first heating control signal with a duty cycle by dividing the heating current value by the ratio of the rated voltage value to the resistance value; the duty cycle can be calculated and a first heating control signal with a duty cycle can be generated, thus improving the accuracy of the duty cycle.

[0116] According to some embodiments of this application, please refer to Figure 7 and Figure 8 As shown, Figure 7 yes Figure 1 A circuit diagram of an embodiment of a medium-voltage energy storage device. Figure 8 yes Figure 7 A schematic flowchart of an embodiment of step S103 in the energy storage device. The energy storage device 100 in this embodiment further includes a first switching transistor 14, one end of which is connected to the battery unit 11, and the other end is connected to a heating unit 12. The heating unit 12 includes a heating film 121 and a second switching transistor 122, which is connected in series with the heating film 121. A control unit 13 is connected to the control terminals of the first switching transistor 14 and the second switching transistor 122, respectively. Step S103 includes the following steps:

[0117] S601: When the duty cycle is greater than or equal to the preset duty cycle, control the first switch tube 14 to turn on.

[0118] The control unit 13 compares the duty cycle with the preset duty cycle; when the duty cycle is greater than or equal to the preset duty cycle, the control unit 13 controls the first switch tube 14 to turn on, at which time the battery unit 11 is connected to the heating unit 12 through the first switch tube 14.

[0119] For example, when the preset duty cycle is 5% or 8%, that is, when the duty cycle is greater than the preset duty cycle, the control unit 13 controls the first switch tube 14 to turn on.

[0120] S602: After a second preset time interval, the second switch 122 is controlled to turn on or off according to the duty cycle by a pulse width modulation signal.

[0121] After a second preset time interval, the control unit 13 controls the second switch 122 to turn on or off according to a duty cycle via a pulse width modulation signal, so that the second switch 122 turns on or off according to the duty cycle of the first heating control signal, which is a pulse width modulation signal. For example, if the second preset time is 10ms, the control unit 13 controls the second switch 122 to turn on or off according to a duty cycle via a pulse width modulation signal after controlling the first switch 14 to turn on, 10ms later.

[0122] The heating control method in this embodiment further includes: stopping the output of pulse width modulation signals to the second switch 122, and controlling the first switch 14 to turn off after a second preset time interval. The control unit 13 stops the output of pulse width modulation signals to the second switch 122, and controls the first switch 14 to turn off after a second preset time interval.

[0123] For example, when the control unit 13 stops outputting pulse width modulation signals to the second switch 122, it controls the first switch 14 to turn off after a 10ms interval.

[0124] This embodiment controls the first switch 14 to conduct when the duty cycle is greater than or equal to a preset duty cycle, and then controls the second switch 122 to conduct or disconnect according to the duty cycle via a pulse width modulation signal after a second preset time interval. This allows the second switch 122 to operate according to the duty cycle while the energy storage device 100 is operating stably, thus improving stability. Stability is further improved by stopping the output of the pulse width modulation signal to the second switch 122 and controlling the first switch 14 to disconnect after a second preset time interval.

[0125] This application also provides an energy storage device 100, such as Figure 1 and Figure 8 As shown, the energy storage device 100 is used to connect the charging device 200 and the load 300, and the charging device 200 is used to supply power to the energy storage device 100 and the load 300. The energy storage device 100 includes a control unit 13, a battery cell 11 connected in parallel, and a heating unit 12, with both ends of the heating unit 12 electrically connected to both ends of the battery cell 11. The control unit 13 is connected to the charging device 200, the battery cell 11, the heating unit 12, and the load 300, and controls the energy storage device 100 according to the heating control method of the above embodiment. The first switching transistor 14 can be one of a transistor, a relay, or a MOSFET.

[0126] The energy storage device 100 further includes a first switching transistor 14. The heating unit 12 includes a capacitor C, an inductor L, a heating film 121, a second switching transistor 122, and a diode D. One end of the battery unit 11 is connected to one end of the heating film 121 through the first switching transistor 14 and the inductor L. One end of the capacitor C is connected to one end of the heating film 121, and the other end of the capacitor C is connected to the other end of the battery unit 11. The other end of the battery unit 11 is connected to the source of the second switching transistor 122. The drain of the second switching transistor 122 is connected to the other end of the heating film 121. The anode of the diode D is connected to the other end of the heating film 121, and the cathode of the diode D is connected to one end of the heating film 121. The control unit 13 is connected to the gate of the second switching transistor 122. The second switching transistor 122 can be an N-type MOSFET; in other embodiments, the second switching transistor 122 can also be a P-type MOSFET.

[0127] In summary, this application obtains a first heating control signal based on the acquired heating current value and the parameters of the heating unit when the actual charging current value is greater than or equal to a first difference and the actual power value is greater than a preset power value. This allows the heating unit 12 to heat the battery unit 11 according to the first heating control signal. This ensures that the charging device 200 meets the charging requirements of the battery unit 11 and the preset power of the load 300 before controlling the heating unit 12 to heat, thus avoiding overload of the charging device 200. By obtaining a second heating control signal based on the current actual charging current value, the first difference, the second difference, and the parameters of the heating unit, the heating unit 12 heats the battery unit 11 according to the second heating control signal. The process of obtaining the current actual charging current value and the second preset current value of the battery unit 11 is repeated until the current actual charging current value of the battery unit 11 is greater than the second difference and less than the first difference. This allows for tracking the output of the charging device 200 to adjust the heating unit 12, improving the heating efficiency of the heating unit 12 and increasing the utilization rate of the energy storage device 100. By dynamically adjusting the first and second heating control signals, the heating unit 12 is adjusted to ensure that the battery unit 11 is always within a suitable temperature range, preventing performance degradation or safety hazards due to overheating or overcooling. By acquiring the actual power value and preset power value of the load 300 in real time, ensuring that the actual power value exceeds the preset power value, the power supply requirements of the load 300 are adequately met when its power is high, preventing excessive power consumption of the heating unit 12 from affecting the normal operation of the load 300. Furthermore, the heating unit 12 can reach its maximum heating power without overloading the energy storage device 100.

[0128] The above description is merely an embodiment of this application and does not limit the patent scope of this application. Any equivalent structural or procedural transformations made using the content of this application's specification and drawings, or direct or indirect applications in other related technical fields, are similarly included within the patent protection scope of this application.

Claims

1. A heating control method for an energy storage device, characterized in that, The method is applied to an energy storage device, which is used to connect a charging device and a load. The charging device is used to supply power to the energy storage device and / or the load. The energy storage device includes battery cells and a heating unit connected in parallel. The heating control method includes: Obtain the actual charging current value of the battery cell and the preset limit charging current value of the battery cell; obtain the actual power value of the load and the preset power value of the load. Calculate the first difference between the limited charging current value and the obtained first preset current value; When the actual charging current value is greater than or equal to the first difference and the actual power value is greater than the preset power value, a first heating control signal is obtained based on the acquired heating current value and the parameters of the heating unit, so that the heating unit heats the battery unit according to the first heating control signal. Obtain the current actual charging current value and the second preset current value of the battery cell; Calculate a second difference between the limited charging current value and the obtained second preset current value, wherein the first preset current value is less than the second preset current value; Based on the current actual charging current value, the first difference, the second difference, and the parameters of the heating unit, a second heating control signal is obtained, so that the heating unit heats the battery unit according to the second heating control signal, and the steps of obtaining the current actual charging current value and the second preset current value of the battery unit are repeatedly executed until the current actual charging current value of the battery unit is greater than the second difference and less than the first difference. After a first preset time interval, the steps of obtaining the actual charging current value of the battery unit and the preset limit charging current value of the battery unit are repeatedly executed.

2. The heating control method according to claim 1, characterized in that, The step of obtaining the second heating control signal based on the current actual charging current value, the first difference, the second difference, and the parameters of the heating unit includes: When the current actual charging current value is greater than or equal to the first difference, the first updated current value is obtained based on the first updated value and the heating current value. The second heating control signal is obtained based on the first updated current value and the parameters of the heating unit.

3. The heating control method according to claim 2, characterized in that, The step of obtaining the first updated current value based on the acquired first updated value and the heating current value includes: The sum of the obtained first update value and the heating current value is used as the first update current value.

4. The heating control method according to claim 1, characterized in that, The step of obtaining the second heating control signal based on the current actual charging current value, the first difference, the second difference, and the parameters of the heating unit includes: When the current actual charging current value is less than or equal to the second difference, a second updated current value is obtained based on the acquired second updated value and the heating current value. The second heating control signal is obtained based on the second updated current value and the parameters of the heating unit.

5. The heating control method according to claim 4, characterized in that, Also includes: The difference between the limited charging current value and the current actual charging current value of the battery cell is used as the second update value.

6. The heating control method according to claim 5, characterized in that, The step of obtaining the second updated current value based on the acquired second updated value and the heating current value includes: The difference between the heating current value and the second updated value is used as the second updated current value.

7. The heating control method according to claim 1, characterized in that, Also includes: Obtain the current hysteresis value and the power hysteresis value, wherein the current hysteresis value is less than the first difference value, and the power hysteresis value is greater than the preset power value; When the actual current value is greater than or equal to the current hysteresis value, and the actual power value is greater than the power hysteresis value, a first heating control signal is obtained based on the preset heating current value and the parameters of the heating unit.

8. The heating control method according to claim 1, characterized in that, The parameters of the heating unit include a rated voltage value and a resistance value. Obtaining the first heating control signal based on the acquired heating current value and the parameters of the heating unit includes: The duty cycle is obtained by dividing the heating current value by the ratio of the rated voltage value to the resistance value. Generate the first heating control signal having the stated duty cycle.

9. The heating control method according to claim 8, characterized in that, The energy storage device includes a first switching transistor, one end of which is connected to the battery cell and the other end to the heating unit. The heating unit includes a heating film and a second switching transistor, which is connected in series with the heating film. The battery cell is heated according to the first heating control signal, including: When the duty cycle is greater than or equal to a preset duty cycle, the first switch is turned on. After a second preset time interval, the second switching transistor is controlled to turn on or off according to the duty cycle by a pulse width modulation signal. The heating control method further includes: Stop outputting the pulse width modulation signal to the second switch, and control the first switch to turn off at the second preset time interval.

10. An energy storage device, characterized in that, The energy storage device is used to connect a charging device and a load. The charging device is used to supply power to the energy storage device and the load. The energy storage device includes a control unit, a battery unit and a heating unit connected in parallel. The control unit is connected to the charging device, the battery unit, the heating unit and the load respectively. The control unit controls the energy storage device according to the heating control method according to any one of claims 1-9.

11. The energy storage device according to claim 10, characterized in that, The energy storage device includes a first switching transistor. The heating unit includes a capacitor, an inductor, a heating film, a second switching transistor, and a diode. One end of the battery unit is connected to one end of the heating film through the first switching transistor and the inductor. One end of the capacitor is connected to one end of the heating film, and the other end of the capacitor is connected to the other end of the battery unit. The other end of the battery unit is connected to the source of the second switching transistor. The drain of the second switching transistor is connected to the other end of the heating film. The anode of the diode is connected to the other end of the heating film, and the cathode of the diode is connected to one end of the heating film. The control unit is connected to the gate of the second switching transistor.

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