Battery heating circuit, controller and method

Abstract

The invention discloses a battery heating circuit, a controller and a method. The battery heating circuit comprises a battery temperature detection circuit, a heating device and a control circuit. The control circuit is electrically connected to the battery temperature detection circuit and the heating device respectively, thereby improving the safety of heating the battery.

Description

Technical Field

[0001] The present invention relates to the field of battery technology, and in particular to a battery heating circuit, a controller and a method. Background Art

[0002] With the booming development of the electric vehicle industry, various electric vehicles have appeared in people's daily life. At present, most electric vehicle power batteries use lithium-ion power batteries. Due to the characteristics of lithium-ion power batteries, electric vehicles cannot be charged in cold areas and their driving range is greatly reduced, which affects the use of electric vehicles. To solve such problems, traditional industry designs heat lithium-ion power batteries, monitor the battery surface temperature, and stop heating when the temperature reaches the set temperature. However, the traditional heating method has the problem of heating temperature failure, which leads to heating out of control and damage to the power battery. In severe cases, it can cause the power battery to catch fire, posing a safety hazard. Summary of the invention

[0003] The main purpose of the present invention is to provide a battery heating circuit, a controller and a method, aiming to improve the safety of heating the battery.

[0004] To achieve the above object, the present invention provides a battery heating circuit, the battery heating circuit comprising:

[0005] A battery temperature detection circuit, wherein the battery temperature detection circuit is used to detect the temperature of the battery and output a temperature detection signal;

[0006] Heating device; and

[0007] A control circuit is electrically connected to the battery temperature detection circuit and the heating device, respectively, and is used to determine, based on the temperature detection signal, when the temperature of the battery reaches a permissible heating temperature, set a heating time and control the heating device to heat the battery for the heating time before stopping.

[0008] Optionally, the control circuit includes:

[0009] A switch tube circuit, wherein the input end of the switch tube circuit is connected to the power supply end, and the output end of the switch tube circuit is connected to the input end of the heating device;

[0010] A main control circuit, the main control circuit being electrically connected to the battery temperature detection circuit and the controlled end of the heating device respectively;

[0011] A timer, wherein the timer is electrically connected to the main control circuit and the controlled end of the switch tube circuit respectively;

[0012] The main control circuit is used to output a heating duration signal to the timer when it is determined according to the temperature detection signal that the temperature of the battery reaches a temperature allowing heating;

[0013] The timer is used to set the heating duration according to the heating duration signal, and control the switch tube circuit to disconnect the path between the input end of the heating device and the power supply end after the heating device heats the battery for the heating duration;

[0014] The main control circuit is also used to control the heating device to heat the battery for a heating time at a preset heating power.

[0015] Optionally, the battery heating circuit further includes a power detection circuit, the power detection circuit is electrically connected to the main control circuit, and a detection end of the power detection circuit is electrically connected to the heating device, for detecting the heating power of the heating device and outputting a power detection signal to the main control circuit;

[0016] The main control circuit is used to change the heating current flowing through the heating device according to the power detection signal, so that the heating power is maintained within the preset heating power range.

[0017] Optionally, the main control circuit is further used to stop the operation of the heating device when it is determined according to the power detection signal that the heating power of the heating device is greater than a preset alarm power.

[0018] Optionally, the battery heating circuit further includes a heating device temperature detection circuit, which is electrically connected to the main control circuit and is used to detect the temperature of the heating device and output a heating device temperature signal;

[0019] The main control circuit is used to stop the operation of the heating device when it is determined according to the temperature signal of the heating device that the temperature of the heating device is greater than a preset alarm temperature of the heating device.

[0020] Optionally, the number of the battery temperature detection circuit and the number of the heating device temperature detection circuit are both multiple.

[0021] Optionally, the battery heating circuit further includes an indication circuit, and the indication circuit is electrically connected to the main control circuit;

[0022] The main control circuit is used to control the indicating circuit to indicate the heating state of the battery according to the temperature detection signal.

[0023] Optionally, the battery heating circuit further includes a failure protection circuit, through which the main control circuit is electrically connected to the controlled end of the heating device and is used to stop the heating device from operating when the main control circuit fails.

[0024] Optionally, the controlled end of the switch tube circuit is electrically connected to the main control circuit, and the main control circuit is also used to control the switch tube circuit to cut off the path between the input end of the heating device and the power supply end when it is determined according to the temperature detection signal that the temperature of the battery is greater than or equal to a preset target temperature.

[0025] The present invention further provides a battery heating controller, which includes a circuit board and a battery heating circuit as described in any one of the above items.

[0026] Wherein, the battery heating circuit is arranged on the circuit board.

[0027] The present invention further provides a battery heating method. Based on the above battery heating controller, the battery heating method comprises the following steps:

[0028] detecting the temperature of the battery and generating battery temperature information;

[0029] When it is determined according to the battery temperature information that the temperature of the battery reaches the allowable heating temperature, the heating device is controlled to heat the battery for the heating time and then stop working.

[0030] Optionally, when it is determined according to the battery temperature information that the temperature of the battery reaches the allowable heating temperature, controlling the heating device to heat the battery for the heating time and then stop working is specifically:

[0031] Get the target temperature;

[0032] The heating duration is calculated according to the target temperature and the detected temperature of the battery, and the heating device is controlled to heat the battery with the preset heating power.

[0033] Optionally, when it is determined according to the battery temperature information that the temperature of the battery reaches the allowable heating temperature, controlling the heating device to heat the battery for the heating time, the battery heating method further includes:

[0034] detecting the heating power of the heating device and generating heating power information;

[0035] When it is confirmed that the heating power is not within the preset heating power range according to the heating power information, changing the heating current flowing through the heating device so that the heating power remains within the preset heating power range;

[0036] According to the heating power information, when it is confirmed that the heating power is higher than the alarm power, the heating device is controlled to stop working.

[0037] Optionally, the battery heating method further includes:

[0038] detecting the temperature of the heating device and generating heating device temperature information;

[0039] According to the temperature information of the heating device, when it is determined that the temperature of the heating device is higher than a preset alarm temperature of the heating device, the heating device is controlled to stop working.

[0040] Optionally, the battery heating method further includes:

[0041] According to the battery temperature information, when the temperature of the battery is greater than or equal to the preset target temperature, the heating device is controlled to stop working.

[0042] The present invention detects the temperature of the battery by setting a battery temperature detection circuit, and outputs a temperature detection signal to the control circuit, so that when the control circuit determines that the temperature of the battery reaches the allowable heating temperature according to the temperature detection signal, the heating time is set and the heating device is controlled to stop working after heating the battery for the heating time. The present invention can effectively prevent the situation where the heating is out of control due to battery temperature detection failure or heating control failure, and ensure the safety of battery heating and the safety of electrical equipment and users using electrical equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying creative work.

[0044] Figure 1 A schematic diagram of a module of an embodiment of a battery heating circuit of the present invention;

[0045] Figure 2 A schematic diagram of a module of another embodiment of a battery heating circuit of the present invention;

[0046] Figure 3 A schematic diagram of a module of another embodiment of a battery heating circuit of the present invention;

[0047] Figure 4 A circuit diagram of an embodiment of a battery heating circuit of the present invention;

[0048] Figure 5 A circuit diagram of another embodiment of a battery heating circuit of the present invention;

[0049] Figure 6 A circuit diagram of another embodiment of a battery heating circuit of the present invention;

[0050] Figure 7 A circuit diagram of another embodiment of a battery heating circuit of the present invention;

[0051] Figure 8 A circuit diagram of another embodiment of a battery heating circuit of the present invention;

[0052] Fig. 9 A schematic diagram of a method for heating a battery according to an embodiment of the present invention;

[0053] Fig.10 A schematic diagram of another embodiment of a battery heating method of the present invention;

[0054] Fig.11 A schematic diagram of another embodiment of a battery heating method of the present invention;

[0055] Fig.12 A schematic diagram of another embodiment of a battery heating method of the present invention;

[0056] Fig.13 FIG. 4 is a schematic diagram of another embodiment of a battery heating method according to the present invention.

[0057] Description of Figure Numbers:

[0058] Label name Label name 00 Battery temperature detection circuit 10 Control Circuit 20 Heating device 11 Switching tube circuit 12 Main control circuit 13 Timer 30 Power detection circuit 40 Heating device temperature detection circuit 60 Fail-safe circuit

[0059] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0060] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0061] The present invention provides a battery heating circuit, which is applied to electrical equipment driven by batteries, especially lithium batteries, such as pure electric vehicles, electric motorcycles, etc.

[0062] To improve the safety of battery heating, refer to Figure 1 The present invention proposes a battery heating circuit for improving the safety of battery heating, including a battery temperature detection circuit 00, a heating device 20 and a control circuit 10. The control circuit 10 is electrically connected to the battery temperature detection circuit 00 and the heating device 20, respectively.

[0063] Among them, the battery can be a single battery or a battery pack formed by combining multiple batteries in series and parallel. The battery temperature detection circuit 00 is used to detect the temperature of the battery and output a temperature detection signal. The control circuit 10 is used to determine that when the temperature of the battery reaches the allowable heating temperature based on the temperature detection signal, set the heating time and control the heating device 20 to heat the battery and stop working after the heating time.

[0064] In real applications, when power-consuming equipment driven by batteries, especially lithium batteries, such as electric vehicles, are driven in colder areas, the lower ambient temperature will cause the battery temperature to be too low, thereby affecting the battery's working performance, causing the electric vehicle to be unable to drive normally or greatly reducing the mileage of the driving range. To solve this problem, a battery heating circuit is often installed inside the electric vehicle.

[0065] In the process of heating the battery by the traditional battery heating circuit, when the battery temperature is detected to be too low, the heating device is powered to generate heat to increase the battery temperature until the preset target temperature is reached, and then the heating device is powered off to stop working. However, the heating risk of this method is relatively high, and it is easy to cause the heating to be out of control, thereby damaging the heating device 20 or the device, and even causing the battery to spontaneously combust or explode, making it difficult to ensure the safety of the battery, electrical equipment and the user himself.

[0066] To this end, in this embodiment, the battery temperature detection circuit 00 can use a temperature detection device, such as a temperature sensor, a thermistor, an infrared temperature sensor, etc., which is close to the battery to detect the temperature information of the battery, and convert the thermal signal into an electrical signal to output a temperature detection signal to the control circuit 10, so that the control circuit 10 calculates the temperature of the battery.

[0067] At the same time, in this embodiment, multiple battery temperature detection circuits 00 can be set, and they are set at various positions of the battery. For example, battery temperature detection circuits 00 are set in the battery's weekly measurement to detect temperature information of different positions of the battery, and output multiple temperature detection signals to the control circuit 10. The control circuit 10 then calculates the average temperature of the battery, so as to more accurately determine whether the current battery temperature has reached the allowable heating temperature.

[0068] In addition, in another embodiment, a temperature detection circuit can be further provided outside the battery to detect the current ambient temperature and output an ambient temperature detection signal to the control circuit 10. The control circuit 10 can calculate the battery temperature based on the ambient temperature detection signal and the temperature detection signal and according to the preset battery temperature change model, thereby preventing the control circuit 10 from misjudging the battery due to interference with the actual temperature of the battery caused by a sudden change in the external ambient temperature. This further improves the safety of the battery heating circuit.

[0069] In this embodiment, the heating device 20 can be attached to the surface of the battery, for example, a heating film is used to cover the surface of the battery, so that it can conduct heat to the battery faster and with lower loss, so as to heat the battery. An infrared heater can also be used to cover the battery placement space with infrared radiation to heat the battery, and when the heating time is reached, it is directly turned off, so that no additional residual heat will be generated to affect the temperature of the battery.

[0070] In this embodiment, the control circuit 10 can set the heating time according to the needs of the user, or the manufacturer can set it by default according to the results of multiple tests during research and development at the factory. It is also possible to set different heating times for different ambient temperatures according to the preset ambient temperature and heating time mapping table. For example, when the ambient temperature is 0 degrees, the heating time is set to 5 minutes, when the ambient temperature is -20 degrees, the heating time is set to 10 minutes, etc. When the heating reaches the heating time, the control circuit 10 will directly output a control signal to control the heating device 20 to stop working. In this way, there is no need for a temperature sensor to feedback the heating temperature of the battery, that is, there is no need to realize the work stop control of the heating device 20 by temperature detection, which effectively avoids the battery heating time being too long or the battery overheating caused by the long-term operation of the heating device 20 when the temperature sensor fails, thereby improving the safety of battery heating.

[0071] The present invention detects the temperature of the battery by setting a battery temperature detection circuit 00, and outputs a temperature detection signal to the control circuit 10, so that when the control circuit 10 determines that the temperature of the battery reaches the allowable heating temperature according to the temperature detection signal, the heating time is set and the heating device 20 is controlled to heat the battery and then stop working after the heating time. The present invention can effectively prevent the situation where heating is out of control due to battery temperature detection failure or heating control failure, and ensure the safety of battery heating and the safety of electrical equipment and users using electrical equipment.

[0072] refer to Figure 2 and Figure 3 In one embodiment of the present invention, the temperature detection circuit includes a first temperature detection resistor NTC1 and a first resistor R1. The power input terminal is connected to a first voltage V1. The first end of the first temperature detection resistor NTC1 is connected to the first voltage. The second end of the first temperature detection resistor NTC1 is connected to the first end of the first resistor R1. The second end of the first resistor R1 is grounded.

[0073] Among them, the first temperature detection resistor NTC1 will change its resistance value according to the temperature. For example, "at 25°, the resistance value is 10K" can be set close to the battery and change its own resistance value according to the temperature of the battery. At the same time, the first temperature detection resistor NTC1 and the first resistor R1 with a fixed resistance value will divide the first voltage V1 according to the ratio of the two resistance values ​​and output a temperature detection signal. The voltage value of the temperature detection signal is the voltage value on the first resistor R1. The main control circuit 12 can obtain the current resistance value of the first temperature detection resistor NTC1 according to the voltage value on the first resistor R1, and then obtain the current battery temperature according to the preset resistance-temperature comparison table of the first temperature detection resistor NTC1. By adopting the first temperature detection resistor NTC1, in addition to being able to detect temperature, it also has a simple structure and is easy to implement, which is conducive to reducing the volume of the PCB board of the battery heating circuit, while reducing production costs and subsequent maintenance costs.

[0074] Optionally, in addition to NTC, thermocouples, infrared temperature measurement, etc. may also be used, which is not limited here.

[0075] refer to Figure 2 and Figure 3 In one embodiment of the present invention, the control circuit 10 includes a switch tube circuit 11, a main control circuit 12 and a timer 13. The input end of the switch tube circuit 11 is connected to the power supply end, the output end of the switch tube circuit 11 is connected to the input end of the heating device 20, the main control circuit 12 is electrically connected to the controlled ends of the battery temperature detection circuit 00 and the heating device 20 respectively, the timer 13 is electrically connected to the controlled ends of the main control circuit 12 and the switch tube circuit 11 respectively, and the controlled end of the switch tube circuit 11 is electrically connected to the main control circuit.

[0076] The main control circuit 12 is used to control the switch circuit 11 to cut off the path between the input end and the power end of the heating device 20 when it is determined that the temperature of the battery is greater than or equal to the preset target temperature according to the temperature detection signal.

[0077] In this embodiment, the main control circuit 12 includes a main controller U1 and its peripheral circuits, the peripheral circuits may include a reset circuit, a filter circuit, etc., and the timer 13 may be implemented by a timing chip U2. The switch tube circuit 11 may be implemented by a first switch tube Q1, and the heating device 20 may use a heating film HL1 and a second switch tube Q2 to realize the heating function.

[0078] Taking the above device as an example, the main controller U1 has a battery temperature input pin WD1, a heating device 20 control pin D1, a time signal output pin T1 and a heating power control pin D2. The heating power control pin D2 is connected to the gate of the first switch tube Q1. The timing chip U2 has an input pin TI and a switch control output pin TO. The power supply end is connected to the first voltage V1. Q1 is a PMOS tube and Q2 is an NMOS tube. The source of the first switch tube Q1 is connected to the first voltage V1, the gate of the first switch tube Q1 is connected to the switch control output pin TO of the timing chip U2, the drain of the first switch tube Q1 is connected to the first end of the heating film HL1, the second end of the heating film HL1 is connected to the drain of the second switch tube Q2, the gate of the second switch tube Q2 is connected to the heating device 20 control pin D1 of the main controller U1, and the source of the second switch tube Q2 is grounded. The first end of the first resistor R1 is connected to the battery temperature input pin WD1 of the main controller U1.

[0079] In this embodiment, the preset target temperature is set according to user needs or multiple tests during the development period. The main controller U1 will monitor the temperature of the battery in real time according to the temperature detection signal. When the temperature of the battery reaches the preset target temperature, the first switch tube Q1 can be turned off to disconnect the path between the input end and the power end of the heating device 20, thereby stopping the operation of the heating device 20 to reduce the overall power consumption. At the same time, if the ambient temperature of the battery heating changes rapidly, for example, in plateau areas, the temperature difference between morning and noon is large, the ambient temperature is low in the morning, and the temperature of the battery reaches the allowable heating temperature in the morning, the timing chip U2 and the main controller U1 control the heating device 20 to control the heating time of the battery with the preset heating power, but before the heating time is reached, the external temperature of the battery changes rapidly and gradually rises, for example, from "5 degrees to 25 degrees", and the increase in ambient temperature will also affect the temperature of the battery, causing the battery to rise faster than in a normal temperature environment. At this time, if the heating device 20 is turned off after the heating time, the battery will be overheated and the temperature will be too high, and the battery will easily have the hidden danger of spontaneous combustion or explosion. In addition to using the timing chip U2 to stop the heating device 20 after the heating time, the present invention can also directly stop the heating device 20 when confirming that the temperature of the battery has reached the preset target temperature through the main controller U1. The safety of battery heating is improved. In addition, since the heating device 20 will not instantly lower its own temperature after heating for the heating time and stops, it will retain a certain residual temperature to heat the battery for a period of time until the temperatures of the two are balanced, which may cause the battery temperature to overheat and produce the above-mentioned hidden dangers. Therefore, when the battery reaches the preset target temperature, the main controller U1 stops the heating device 20, which can effectively prevent the residual temperature of the heating device 20 from causing the battery temperature to overheat. The safety of the battery heating circuit is further improved.

[0080] In another embodiment, the main control circuit 12 is further used to output a heating duration signal to the timer 13 when it is determined according to the temperature detection signal that the temperature of the battery reaches the allowable heating temperature. The timer 13 is used to set the heating duration according to the heating duration signal, and control the switch tube circuit 11 to disconnect the path between the input end and the power end of the heating device 20 after the heating device 20 heats the battery for the heating duration. The main control circuit 12 is also used to control the heating duration of the heating device 20 heating the battery at a preset heating power.

[0081] Taking the above device as an example, in this embodiment, after the main controller U1 receives the temperature detection signal through WD1, it will obtain the current battery temperature according to the above process, and obtain the current resistance value of NTC1 by calculation and the preset NTC1 resistance-temperature comparison table. If the current battery temperature reaches the allowable heating temperature, for example, "the allowable heating temperature is 15°", the main controller U1 outputs the heating time signal to the timing chip U2 through T1, and outputs the heating drive signal according to the preset heating power through D1. The heating drive signal is a PWM signal, so that the main control chip U1 can control the second switch tube Q2 to adjust the voltage output to the heating film HL1, and then adjust the current on the heating film HL1 to adjust the heating power. After receiving the heating time signal through TI, the timing chip U2 will set the heating time and output a low-level signal through TO to turn on the second switch tube Q1, so that Q1, HL1, and Q2 form a complete conduction loop, and the heating film HL1 starts to generate heat according to the preset heating power, thereby heating the battery. When the heating time is over, the timing chip U2 will directly output a high-level signal through TO to directly cut off the path between the input end and the power end of the heating device 20 to stop the heating device 20. This ensures that the battery heating circuit will not be unable to stop the heating device 20 due to temperature detection failure or loss of control of the main controller U1, thereby improving the safety of the heating device 20. At the same time, the use of a heating film can better fit the battery, reduce heat conduction losses, and improve heating efficiency. In addition, using a switch tube instead of a relay as a switching device can reduce costs and reduce the size of the PCB.

[0082] It should also be noted that the heating time can be calculated based on the preset target temperature. For example, when the heating time is just reached, the heating device can just reach the preset target temperature. Through the above settings, the present invention can not only stop the operation of the heating device in time when the battery is heated to the preset target temperature. In addition, when the main control circuit fails and the heating device is out of control, the additionally set timer can be used to timely shut off the path between the heating device and the power supply end when the heating time is reached, thereby ensuring the safety of battery heating and achieving double insurance for battery heating.

[0083] Optionally, the main controller U1 may be an MCU, a DSP (Digital Signal Process), a FPGA (Field Programmable Gate Array), etc., which is not limited here.

[0084] Optionally, the heating device 20 may also be an infrared heating device, etc., which is not limited here.

[0085] Optionally, the first switch tube Q1 and the second switch tube Q2 may also be PMOS, IGBT, triode, etc., which are not limited here.

[0086] refer to Figure 5 In one embodiment of the present invention, the battery heating circuit also includes a power detection circuit 30, the power detection circuit 30 is electrically connected to the main control circuit 12, the detection end of the power detection circuit 30 is electrically connected to the heating device 20, and the detection end of the power detection circuit 30 is electrically connected to the heating device 20.

[0087] Among them, the power detection circuit 30 is used to detect the heating power of the heating device 20 and output a power detection signal to the main control circuit 12. The main control circuit 12 is used to change the heating current flowing through the heating device 20 according to the power detection signal so that the heating power is maintained within a preset heating power range.

[0088] In this embodiment, taking the above-mentioned device as an example, the main controller U1 also has a current detection first pin CD1 and a current detection second pin CD2. The power detection circuit 30 can be implemented by a current detection resistor R2. The first end of the current detection resistor R2 and the source of the second switch tube Q2 are respectively connected to the current detection first pin CD1 of the main controller U1, and the second end of the current detection resistor R2 and the source of the second switch tube Q2 are respectively connected to the current detection first pin CD1 of the main controller U1.

[0089] The current detection resistor R2 is a resistor with a very small resistance, such as "5mΩ". The main controller U1 can detect the voltage across the current detection resistor R2, calculate the voltage difference across the current detection resistor R2, and then obtain the current value flowing through the current detection resistor R2. Since the current detection resistor R2 is connected in series with HL1 and Q2, the current flowing through the heating film HL1 is the current flowing through the current detection resistor R2, so the main controller U1 can calculate the power according to the power to obtain the current heating power of the heating film. Since the power input end may be an external power source such as AC power or a charger, it is easy to have unstable voltage, which leads to excessive heating current on the heating device 20. The main controller U1 can obtain the current value through the feedback of the current detection resistor R2, and then determine whether the current heating power exceeds the preset heating power range. For example, the preset heating power of "50W±10W" is set by the user or the factory default setting after multiple tests during the research and development period. If the current heating power exceeds the preset maximum value of the heating power, for example, "60W", the main controller U1 will reduce the duty cycle of the heating drive signal, that is, reduce the duty cycle of the PWM signal. The smaller the duty cycle, the smaller the voltage value passing through the heating film HL1, and the generated current value will also become smaller, thereby reducing the heating power. If the ambient temperature is too low and the heating power is lower than the preset minimum value of the heating power, similarly, the main controller U1 increases the duty cycle of the heating drive signal, thereby increasing the heating current and controlling the heating power to remain within the preset range of the velvet rate.

[0090] Through the above-mentioned arrangement, the heating power can be maintained to prevent voltage fluctuations at the power supply end or failures of the heating device itself, such as excessive heating power caused by internal short circuits in the heating device and component falling off, thereby improving the safety of the operation of the heating device 20.

[0091] In another embodiment, the main control circuit 12 is also used to stop the heating device 20 when it is determined according to the power detection signal that the heating power of the heating device 20 is greater than the preset alarm power, thereby preventing a surge in heating power due to a failure of the heating device 20, which may cause excessive temperature to damage the entire heating device 20 or the battery, and further improves the safety of the battery heating circuit.

[0092] In the actual heating process, since the heating device 20 itself has the risk of heating runaway, and it takes a certain amount of time for the heat generated by the heating device 20 to be transferred to the battery, the heating device 20 itself that is heating runaway may cause damage to the entire heating device 20 or the battery.

[0093] To solve the above problems, refer to Figure 6 In one embodiment of the present invention, the battery heating device 20 further includes a heating device temperature detection circuit 40 , and the heating device temperature detection circuit 40 is electrically connected to the main control circuit 12 .

[0094] Among them, the heating device temperature detection circuit 40 is used to detect the temperature of the heating device 20 and output the temperature signal of the heating device 20. The main control circuit 12 is used to stop the heating device 20 when it is determined that the temperature of the heating device 20 is greater than the preset alarm temperature of the heating device 20 according to the temperature signal of the heating device 20.

[0095] In this embodiment, the heating device temperature detection circuit 40 is used to detect the temperature of the heating device 20. When the temperature of the heating device 20 is too high, the main control circuit 12 directly controls the heating device 20 to stop working to prevent the excessively high temperature of the heating device 20 from causing damage to the entire heating device 20 or the battery.

[0096] In another embodiment, the main control circuit 12 can also control the heating device 20 to stop working, and restart the heating device 20 when its temperature drops below the preset alarm temperature of the heating device 20. In this process, the residual temperature of the heating device 20 will continue to heat the battery, and the heating state of the battery will not be affected. At the same time, the temperature of the heating device 20 is prevented from being too high and affecting the overall circuit.

[0097] In addition, in another embodiment, the main control circuit 12 may not stop the operation of the heating device 20, but control the heating power of the heating device 20 to be adjusted to a smaller value within the preset power range, for example, by using a PWM signal to control the heating power of the heating device 20, the duty cycle may be reduced to reduce the heating power, thereby gradually reducing the temperature of the heating device 20.

[0098] In this embodiment, the heating device temperature detection circuit 40 includes a second temperature detection resistor NTC2 and a third resistor R3. The main controller U1 also has a second temperature detection pin WD2. The first end of the second temperature detection resistor is connected to the first voltage V1. The second end of the second temperature detection resistor NTC2 and the first end of the third resistor R3 are respectively connected to the second temperature detection pin WD2 of the main controller U1. The second end of the third resistor R3 is grounded. The main controller U1 can obtain the current resistance value of NTC2 according to the voltage value after the voltage division of NTC2 and R3, and then judge the current temperature of the heating device 20 according to the preset resistance-temperature parameter table of the second temperature detection resistor NTC2, such as "10K resistance at 25 degrees Celsius". According to the preset alarm temperature of the heating device 20, the heating device 20 is controlled to reduce the heating power or stop working, thereby preventing the temperature of the heating device 20 from being too high, and improving the safety of the overall operation of the heating device 20.

[0099] refer to Figure 7In another embodiment, the number of temperature detection circuits and heating device temperature detection circuits 40 can be multiple, and the main controller U1 can determine the temperature of the battery based on multiple temperature detection signals, and determine the temperature of the heating device 20 based on multiple heating device 20 temperature signals. An average value can be taken, or a more accurate temperature of the battery can be obtained based on the temperature detection circuits placed at different positions of the battery and the preset battery temperature module. The same is true for the temperature detection of the heating device 20. Since the heating device 20 may include a number of heating devices greater than or equal to 2, the heating device temperature detection circuit 40 can be set one-to-one, or multiple heating device temperature detection circuits 40 can be set at different positions of the heating device 20, so that the main controller U1 can more accurately determine the current temperature of the heating device 20, thereby improving safety.

[0100] Furthermore, in another embodiment, the additional temperature detection circuit and / or heating device temperature detection circuit 40 can also serve as a backup temperature detection circuit and / or heating device temperature detection circuit 40. When the temperature detection circuit fails, that is, when the main controller U1 cannot receive the temperature detection signal sent by the temperature detection circuit, the backup temperature detection circuit can be enabled to maintain the monitoring of the battery temperature. Similarly, when the backup heating device temperature detection circuit 40 fails, that is, when the main controller U1 cannot receive the heating device 20 temperature signal output by the heating device temperature detection circuit 40, the backup heating device temperature detection circuit 40 can be enabled, thereby further improving the accuracy and real-time performance of the detection, and improving and ensuring the safety of the overall battery heating circuit operation.

[0101] refer to Figure 8 , in one embodiment of the present invention, the battery heating circuit further includes an indication circuit, and the indication circuit is electrically connected to the main control circuit 12;

[0102] The main control circuit 12 is used to control the indicating circuit to indicate the heating state of the battery according to the temperature detection signal.

[0103] In this embodiment, the above device is used as an example for explanation. The main controller U1 also has an indication signal output pin INS, which is connected to the input IND of the indication circuit. The indication circuit can be a display device, such as a display screen, an interactive display screen, etc., which is used to display the current battery temperature, the temperature of the heating device 20, the preset target temperature, and the heating time. It can also be an alarm device, such as a buzzer, an alarm, etc., which is used to timely remind the user when the main control circuit 12 detects a high-risk situation and enters a protection state, such as when the temperature of the heating device 20 is too high. It can also be a prompt element, such as an LED indicator, a voice module, etc., which is used to prompt the user that the heating is completed when the current battery temperature reaches the preset target temperature.

[0104] Through the above settings, users can more intuitively understand the current heating status of the battery, which improves the convenience of use. At the same time, in the later maintenance and repair process, it is also more conducive to the maintenance personnel to detect and judge the maintenance situation.

[0105] refer to Figure 8 In one embodiment of the present invention, the battery heating circuit further includes a failure protection circuit 60 , and the main control circuit 12 is electrically connected to the controlled end of the heating device 20 via the failure protection circuit 60 .

[0106] Among them, the failure protection circuit 60 is used to stop the heating device 20 from working when the main control circuit 12 fails. In combination with the above content, the main control circuit 12 is connected to the controlled end of the heating device 20 through the main controller U1 using an internally integrated and / or externally mounted PWM drive module, thereby outputting a heating drive signal (the heating drive signal is a PWM signal) to control the second switch tube Q2 to switch at a certain frequency, thereby changing the voltage and current flowing through the heating film HL1, and then changing the heating power.

[0107] In this embodiment, the above device is used as an example for explanation. The failure protection circuit 60 can be implemented by a capacitive element, because the capacitive element can only allow the signal with frequency to pass through, such as the first capacitor C1. When the original non-failure protection circuit 60 is working, if the main controller U1 has a program BUG or the internal chip is damaged, resulting in damage to the main controller U1, it may cause the control pin D1 of the heating device 20 of the main controller U1 to lose control and fail to output the PWM signal. And due to the internal structure of the chip, the control pin D1 of the heating device 20 may be pulled up by the chip to continuously output a high-level signal or pulled down by the chip to continuously output a low-level signal. It is also possible that the control pin D1 of the heating device 20 is in a suspended state of outputting a high-level signal for a period of time and then outputting a low-level signal for a period of time. As a result, the second switch tube Q2 in the heating device 20 is in a normally open or normally closed state. If it is in a normally open state, it will cause the heating current flowing through the heating film HL1 in the heating device 20 to increase sharply. At this moment, if the timing chip U2 also fails and cannot timely shut off the path between the input end and the power end of the heating device 20 when the heating time ends, the heating device 20 will overheat, causing heating to fail, damaging the entire battery heating circuit, and even affecting the battery. When a failure protection circuit 60, such as the first capacitor C1, is connected between the main controller U1 and the gate of the second switch tube Q2 of the heating device 20, according to the characteristics of the capacitor, when the main controller U1 fails, no matter whether the control pin D1 of the heating device 20 outputs a constant high level or a constant low level signal, it cannot pass through the first capacitor C1, so Q2 will stop working and be in a closed state because it cannot receive the heating drive signal from the main controller U1, thereby stopping the operation of the heating device 20.

[0108] Through the above arrangement, when both the main control circuit 12 and the timer 13 fail, that is, when the main control circuit 12 cannot control the output of the heating drive signal for controlling the heating device, the heating device 20 can still be stopped normally to prevent the heating from being out of control, thereby further improving the safety of the battery heating operation. At the same time, a capacitor is used as a failure protection circuit 60, which has a simple structure and is easy to implement, and is conducive to being widely used in the circuit design of the battery heating circuit, and is conducive to reducing the volume of the PCB board of the battery heating circuit, while reducing the production cost and the cost of subsequent maintenance.

[0109] The present invention also provides a battery heating controller, which includes a circuit board and the battery heating circuit, wherein the battery heating circuit is arranged on the circuit board.

[0110] Since the battery heating controller of the present invention is based on the above-mentioned battery heating circuit, the embodiments of the battery heating controller of the present invention include all technical solutions of all embodiments of the above-mentioned battery heating circuit, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0111] The present invention also provides a battery heating method based on the above-mentioned battery heating controller.

[0112] Since the battery heating method of the present invention is based on the above-mentioned battery heating controller, the embodiments of the battery heating method of the present invention include all technical solutions of all embodiments of the above-mentioned battery heating controller, and the technical effects achieved are also exactly the same, which will not be repeated here.

[0113] refer to Fig. 9 In one embodiment of the present invention, the battery heating method comprises the following steps:

[0114] Step S100, detecting the temperature of the battery and generating battery temperature information;

[0115] Step S200: When it is determined according to the battery temperature information that the temperature of the battery reaches the allowable heating temperature, control the heating device to heat the battery for the heating time and then stop working.

[0116] Since the battery heating method is implemented based on the battery heating controller, the battery heating method can be stored in a main controller of the battery heating controller.

[0117] The battery may be a single battery or a battery pack formed by combining multiple batteries in series and in parallel.

[0118] In this embodiment, a temperature detection device, such as a temperature sensor, a thermistor, an infrared temperature sensor, etc., can be used close to the battery to detect the temperature information of the battery, and convert the thermal signal into an electrical signal and output it to the main controller.

[0119] At the same time, multiple temperature detection devices can be set up and divided into various positions of the battery. For example, a battery temperature detection circuit is set up in the battery's weekly measurement to detect the temperature information of different positions of the battery, and output multiple battery temperature information to the main controller. The main controller then calculates the average temperature of the battery, so as to more accurately determine whether the current battery temperature has reached the allowable heating temperature.

[0120] In addition, in another embodiment, a temperature detection device may be further provided outside the battery to detect the current ambient temperature and output it to the control circuit. The control circuit may calculate the battery temperature based on the ambient temperature detection information and the battery temperature information and in accordance with a preset battery temperature change model, thereby improving the accuracy of the control circuit in determining whether the current battery temperature has reached the allowable heating temperature, and preventing the main controller from misjudging the battery due to sudden changes in the external ambient temperature that interfere with the actual battery temperature. This further improves the safety of the battery heating circuit.

[0121] In this embodiment, a timer can be used to set the heating time and turn off the heating device after the heating time, such as "crystal oscillator, timing chip", etc. The set heating time can be set according to the user's own needs, or the supplier can set several suitable heating times after testing for the customer to choose at the factory. It is also possible to set different heating times for different ambient temperatures according to the preset ambient temperature and heating time mapping table. For example, when the ambient temperature is 0 degrees, the heating time is set to 5 minutes, and when the ambient temperature is -20 degrees, the heating time is set to 10 minutes. Since the heating time is set for the heating operation, if the main controller fails to control during the heating process, or the battery temperature detection fails to cause a misjudgment, the timer can still stop the heating device after a certain heating time to prevent the heating from being out of control due to long-term heating, thereby improving the safety of battery heating.

[0122] In the technical solution of the present invention, when the temperature of the battery is detected and the battery temperature information is generated, and when it is determined according to the battery temperature information that the temperature of the battery reaches the allowable heating temperature, the heating device is controlled to heat the battery for the heating time and then stops working. This prevents the situation where heating is out of control due to battery temperature detection failure or heating control failure, and ensures the safety of battery heating and the safety of electrical equipment and users using electrical equipment.

[0123] refer to Fig.10In one embodiment of the present invention, step S200, when it is determined according to the battery temperature information that the temperature of the battery reaches the allowable heating temperature, controlling the heating device to heat the battery for a certain period of time and then stop working is specifically as follows:

[0124] S210, obtaining a target temperature;

[0125] The target temperature can be set according to the user's needs. For example, the user needs to set the heating to "30 degrees", or use the factory default setting, or the main controller sets the target temperature according to the external ambient temperature. For example, in colder weather, the battery temperature is more likely to drop, so a relatively high target temperature can be set, such as "at -20 degrees, set to 30 degrees, at -10 degrees set to 25 degrees" to put the battery in a better temperature operating range.

[0126] S220, calculating the heating duration according to the target temperature and the detected temperature of the battery, and controlling the heating device to heat the battery with the preset heating power.

[0127] The heating time can be set according to personal needs or the actual heating time required. Since the target temperature is set, the preset heating power and the weight of the battery are known, the heat required for the battery to reach the preset target temperature from the preset temperature can be calculated based on the specific heat capacity of the battery, and the current heating time can be calculated based on the preset heating power.

[0128] refer to Fig.11 In one embodiment of the present invention, when it is determined according to the battery temperature information that the temperature of the battery reaches the allowable heating temperature, when the heating device is controlled to heat the battery for a heating time, the battery heating method further includes:

[0129] Step S230, detecting the heating power of the heating device and generating heating power information;

[0130] Step S240: when it is confirmed that the heating power is not within the preset heating power range according to the heating power information, changing the heating current flowing through the heating device so that the heating power remains within the preset heating power range;

[0131] Step S250: According to the heating power information, when it is confirmed that the heating power is higher than the alarm power, the heating device is controlled to stop working.

[0132] Among them, a voltage detection circuit such as a transformer, a voltage divider circuit, etc. can be used to detect the heating voltage on the heating device. If the heating device is a resistive heating device, the main controller can calculate the current heating power of the heating device based on the heating internal resistance of the heating device. Similarly, a current detection circuit such as a current transformer, a current detection resistor, a current detection chip, a differential resistor, etc. can also be used to detect the heating current flowing through the heating device, and the main controller calculates the current heating power based on the heating internal resistance of the heating device. If the heating device is not a resistive heating device, it is necessary to set up a voltage detection circuit and a current detection circuit at the same time to calculate the heating power of the heating device.

[0133] In addition, the heat change of the heating device can be detected by a heat sensor such as a heat meter temperature sensor, and the main controller can then calculate the current heat release power of the heating device, thereby eliminating the need to set up an additional detection circuit on the circuit board and reducing the size of the circuit board.

[0134] In this embodiment, the voltage connected to the input end of the heating device may vary due to different power supply ends. For example, when the power supply end is a charger, the voltage output by the charger may have certain harmonic interference and voltage fluctuations, which will affect the current heating power of the heating device.

[0135] The main controller can calculate and judge whether the heating power of the current heating device exceeds the preset power range according to the heating power information, for example, by judging the size of the heating current and / or the heating voltage of the heating device, and then judge whether the current heating power is within the preset heating power. When it is not within the preset heating power, the main controller can change the heating voltage on the heating device, for example, by connecting a switch tube between the input end and the power end of the heating device, and the main controller can adjust the switch drive signal of the switch tube, for example, the switch drive signal is a PWM signal, and the main controller can adjust the duty cycle of the PWM signal, adjust the heating voltage on the heating device, and then adjust the heating current of the heating device, that is, adjust the heating current flowing through the heating device, so that the heating power of the heating device remains within the preset heating power range.

[0136] In another embodiment, if the heating device is damaged, or there is a power failure at the power supply end, causing a surge in the heating current on the heating device, making the heating power of the heating device greater than the preset alarm power, the main controller can also directly disconnect the path between the heating device and the power supply end to stop the heating device from working.

[0137] In the actual battery heating process, the heating device itself has the risk of heating out of control, and it takes a certain amount of time for the heat generated by the heating device to be transferred to the battery. However, the heating device itself that is heating out of control may cause damage to the entire heating device or the battery.

[0138] To solve the above problems, refer to Fig.12 In one embodiment of the present invention, the battery heating method further includes:

[0139] Step S260, detecting the temperature of the heating device and generating temperature information of the heating device;

[0140] Step S270: According to the temperature information of the heating device, when it is determined that the temperature of the heating device is higher than the preset alarm temperature of the heating device, the heating device is controlled to stop working.

[0141] The temperature of the heating device may be detected by using the same temperature detection device as the one used to detect the battery temperature, such as a thermistor, an infrared sensor, a thermocouple, etc.

[0142] In this embodiment, the main controller will directly control the heating device to stop working based on the temperature information of the heating device, when it is confirmed that the temperature of the heating device is too high, to prevent the excessively high temperature of the heating device from causing damage to the entire heating device or the battery.

[0143] In another embodiment, the temperature of the heating device may occasionally exceed the preset alarm temperature of the heating device. The main controller can also control the heating device to stop working, and restart the heating device when its temperature drops below the preset alarm temperature of the heating device. During this process, the heating device will continue to heat the battery, and the heating state of the battery will not be affected. At the same time, the heating device temperature is prevented from being too high to affect the overall circuit.

[0144] In another embodiment, based on the above-mentioned method of the main controller controlling the heating current to change the heating power of the heating device, the main controller can control the heating power of the heating device to be adjusted to a smaller value of the preset heating power range within the preset heating power range. For example, when the preset heating power range is 40-50W and the current heating power is 47W, the heating power can be adjusted to 40W to reduce the temperature of the heating device to below the preset heating device alarm temperature, thereby ensuring that the battery is effectively heated within the heating time and ensuring that the temperature of the heating device itself is in a safe range during the heating process to prevent the heating device itself, the battery or electrical equipment from being damaged by excessive temperature.

[0145] In the actual heating process, if the ambient temperature of the battery heating changes rapidly, such as in plateau areas, the temperature difference between morning and noon is large, the ambient temperature is lower in the morning, and the battery temperature reaches the allowable heating temperature in the morning, the heating operation for the heating time will start according to the above content, but before the heating time is reached, the external temperature of the battery changes rapidly and gradually rises, for example, from "5 degrees to 25 degrees", the increase in ambient temperature will also affect the temperature of the battery, causing the battery to rise faster than in normal temperature. At this time, if the heating device is turned off after the heating time, the battery will be overheated and the temperature will be too high, and the battery will easily have the risk of spontaneous combustion or explosion.

[0146] To solve the above problems, refer to Fig.13 In one embodiment of the present invention, the battery heating method further includes:

[0147] Step S300: According to the battery temperature information, when the battery temperature is greater than or equal to a preset target temperature, the heating device is controlled to stop working.

[0148] In this embodiment, in addition to stopping heating when the heating time is reached, the main controller can also calculate the current battery temperature in real time according to the battery temperature information during the heating process. When the battery temperature reaches the preset target temperature but the heating time has not yet arrived, the heating device can be directly controlled to stop working. Therefore, in the above-mentioned environmental conditions, the battery will not have its own temperature too high due to a sudden change in the ambient temperature, which ensures the stability of the battery heating process and further improves the safety of the battery heating circuit.

[0149] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification and drawings under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. A battery heating circuit, It is characterized in that include: A battery temperature detection circuit, wherein the battery temperature detection circuit is used to detect the temperature of the battery and output a temperature detection signal; Heating device; as well as a control circuit, the control circuit being electrically connected to the battery temperature detection circuit and the heating device, respectively, and being used for determining, according to the temperature detection signal, when the temperature of the battery reaches a permissible heating temperature, setting a heating time and controlling the heating device to heat the battery for the heating time before stopping working; The control circuit comprises: A switch tube circuit, wherein the input end of the switch tube circuit is connected to the power supply end, and the output end of the switch tube circuit is connected to the input end of the heating device; A main control circuit, the main control circuit being electrically connected to the battery temperature detection circuit and the controlled end of the heating device respectively; A timer, wherein the timer is electrically connected to the main control circuit and the controlled end of the switch tube circuit respectively; The main control circuit is used to output a heating duration signal to the timer when it is determined according to the temperature detection signal that the temperature of the battery reaches a temperature allowing heating; The timer is used to set the heating duration according to the heating duration signal, and control the switch tube circuit to disconnect the path between the input end of the heating device and the power supply end after the heating device heats the battery for the heating duration; The main control circuit is further used to control the heating device to heat the battery for a heating time at a preset heating power; The battery heating circuit further includes a power detection circuit, the power detection circuit is electrically connected to the main control circuit, and a detection end of the power detection circuit is electrically connected to the heating device, for detecting the heating power of the heating device and outputting a power detection signal to the main control circuit; The main control circuit is used to change the heating current flowing through the heating device according to the power detection signal, so that the heating power is maintained within the preset heating power range; A failure protection circuit, wherein the main control circuit is electrically connected to the controlled end of the heating device through the failure protection circuit, and is used to stop the operation of the heating device when the main control circuit fails.

2. The battery heating circuit as claimed in claim 1, It is characterized in that The battery heating circuit further includes a heating device temperature detection circuit, which is electrically connected to the main control circuit and is used to detect the temperature of the heating device and output a heating device temperature signal; The main control circuit is used to stop the operation of the heating device when it is determined according to the temperature signal of the heating device that the temperature of the heating device is greater than a preset alarm temperature of the heating device.

3. A battery heating controller, It is characterized in that The battery heating controller comprises a circuit board and a battery heating circuit as described in any one of claims 1 to 2 above; Wherein, the battery heating circuit is arranged on the circuit board.

4. A battery heating method, based on the battery heating controller as claimed in claim 3, It is characterized in that The battery heating method comprises the following steps: detecting the temperature of the battery and generating battery temperature information; When it is determined according to the battery temperature information that the temperature of the battery reaches the allowable heating temperature, the heating device is controlled to heat the battery for the heating time and then stop working.

5. The battery heating method according to claim 4, It is characterized in that When it is determined according to the battery temperature information that the temperature of the battery reaches the allowable heating temperature, controlling the heating device to heat the battery for the heating time and then stop working is specifically: Get the target temperature; The heating duration is calculated according to the target temperature and the detected temperature of the battery, and the heating device is controlled to heat the battery with the preset heating power.

6. The battery heating method according to claim 5, It is characterized in that When it is determined according to the battery temperature information that the temperature of the battery reaches the allowable heating temperature, controlling the heating device to heat the battery for the heating time, the battery heating method further includes: detecting the heating power of the heating device and generating heating power information; When it is confirmed that the heating power is not within the preset heating power range according to the heating power information, changing the heating current flowing through the heating device so that the heating power remains within the preset heating power range; According to the heating power information, when it is confirmed that the heating power is higher than the alarm power, the heating device is controlled to stop working.

7. The battery heating method according to claim 4, It is characterized in that The battery heating method further includes: detecting the temperature of the heating device and generating heating device temperature information; According to the temperature information of the heating device, when it is determined that the temperature of the heating device is higher than a preset alarm temperature of the heating device, the heating device is controlled to stop working.

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