Defrosting circuit and defrosting method for front windshield of new energy vehicle and vehicle

Abstract

The invention discloses a front windshield defrosting circuit and defrosting method of a new energy vehicle and the vehicle, and belongs to the technical field of automatic driving. A charging and discharging circuit in the front windshield defrosting circuit comprises a super capacitor and a bidirectional DC-DC converter, the super capacitor is connected with the bidirectional DC-DC converter, and the bidirectional DC-DC converter is connected with a generator, a storage battery and a resistor in a heating film. The charging and discharging circuit charges the super capacitor by using the recovered energy of the generator or the storage battery; the controller detects whether the visual field area of the camera in the front windshield is shielded or not; and if the visual field area of the camera is shielded, the controller controls the super capacitor to heat the resistor in the heating film at the first power, so that the ice layer in the visual field area of the camera is melted. Instantaneous high power can be provided to efficiently defrost, the electric energy consumption of the storage battery can be reduced, the endurance of the vehicle is improved, and the service life of the storage battery can be prolonged.

Description

Technical Field

[0001] This application relates to the technical field of autonomous driving, and particularly to a front windshield defrosting circuit, a defrosting method and a vehicle for new energy vehicles. Background Art

[0002] In new energy vehicles, a front-view camera is usually integrated with a rain / light sensor and arranged inside the front windshield to implement auxiliary driving functions (such as lane keeping, pedestrian recognition, obstacle detection, etc.). However, in a low-temperature and high-humidity environment, this area is prone to being blocked by water vapor condensation or ice and snow coverage, directly affecting the environmental perception ability of new energy vehicles, causing the auxiliary driving function to fail, and seriously threatening driving safety.

[0003] In related technologies, a heating film can be provided on the front windshield, and the resistance in the heating film is heated by a storage battery in a new energy vehicle to achieve the defrosting function. However, the instantaneous discharge power of the storage battery is limited, making it difficult to support the high-power and fast defrosting requirements; defrosting through the storage battery will increase the power consumption, affecting the endurance of new energy vehicles; defrosting through the storage battery will increase the charge and discharge times of the storage battery, thus accelerating the aging of the storage battery and reducing the service life of the storage battery. Summary of the Invention

[0004] This application provides a front windshield defrosting circuit, a defrosting method and a vehicle for new energy vehicles, which are used to solve the problems of insufficient transient power, affecting the vehicle endurance and reducing the service life of the storage battery when the defrosting function is achieved through the storage battery. The technical solutions are as follows:

[0005] According to the first aspect of this application, a front windshield defrosting circuit for a new energy vehicle is provided. The front windshield defrosting circuit includes a charge and discharge circuit, an internal resistance self-checking circuit, a temperature detection circuit and an overvoltage detection circuit;

[0006] The charge and discharge circuit includes a super capacitor and a bidirectional DC-DC converter. The super capacitor is connected to the bidirectional DC-DC converter. The bidirectional DC-DC converter is respectively connected to a generator, a storage battery and a resistance in a heating film. The heating film is located around the camera vision area in the front windshield;

[0007] The internal resistance self-checking circuit, the temperature detection circuit and the overvoltage detection circuit are respectively connected to the super capacitor;

[0008] The charging and discharging circuit is used to charge the super capacitor with the recovered energy of the generator when the new energy vehicle is in a driving state, or charge the super capacitor with the storage battery when the new energy vehicle is in a parking state; when it is determined that the defrosting function needs to be started, the super capacitor is used to heat the resistor in the heating film;

[0009] The internal resistance self-checking circuit is used to detect the capacitance internal resistance of the super capacitor and alarm when the internal resistance is greater than the internal resistance threshold;

[0010] The temperature detection circuit is used to detect the temperature of the super capacitor and reduce the heating power of the resistor when the temperature is greater than the temperature threshold;

[0011] The overvoltage detection circuit is used to detect the voltage of the super capacitor and stop charging when the voltage reaches the rated voltage.

[0012] According to the second aspect of the present application, a front windshield defrosting method for a new energy vehicle is provided, which is used in a new energy vehicle. The new energy vehicle includes a controller and the front windshield defrosting circuit as described above. The method includes:

[0013] The charging and discharging circuit charges the super capacitor with the recovered energy of the generator or the storage battery;

[0014] The controller detects whether the camera vision area in the front windshield is blocked;

[0015] If the camera vision area is blocked, the controller controls the super capacitor to heat the resistor in the heating film at a first power so as to melt the ice layer in the camera vision area.

[0016] In a possible implementation manner, the charging and discharging circuit charges the super capacitor with the recovered energy of the generator or the storage battery, including:

[0017] The controller obtains the power of the super capacitor;

[0018] If the power is lower than the power threshold and there is recovered energy in the new energy vehicle, the controller controls the charging and discharging circuit to charge the super capacitor with the recovered energy;

[0019] If the power is lower than the power threshold and there is no recovered energy in the new energy vehicle, the controller controls the charging and discharging circuit to charge the super capacitor with the storage battery.

[0020] In a possible implementation, the charge and discharge circuit charges the super capacitor using the recovered energy, including:

[0021] The charge and discharge circuit converts a first voltage corresponding to the recovered energy into a second voltage corresponding to the super capacitor through the bidirectional DC-DC converter, and the second voltage is lower than the first voltage;

[0022] The charge and discharge circuit charges the super capacitor with the second voltage.

[0023] In a possible implementation, the charge and discharge circuit charges the super capacitor using the storage battery, including:

[0024] The charge and discharge circuit converts a third voltage corresponding to the storage battery into a second voltage corresponding to the super capacitor through the bidirectional DC-DC converter, and the second voltage is higher than the third voltage;

[0025] The charge and discharge circuit charges the super capacitor with the second voltage.

[0026] In a possible implementation, the method further includes:

[0027] The controller obtains the rated voltage, the current voltage, and the line impedance of the super capacitor;

[0028] The controller divides the difference between the rated voltage and the current voltage by the line impedance to obtain the maximum charging current of the super capacitor;

[0029] If the maximum charging current exceeds the rated current of the super capacitor, the controller controls the charge and discharge circuit to charge the super capacitor with the rated current;

[0030] If the maximum charging current does not exceed the rated current of the super capacitor, the controller controls the charge and discharge circuit to charge the super capacitor with the maximum charging current.

[0031] In a possible implementation, the method further includes:

[0032] The controller obtains the starting voltage of the super capacitor before heating, the actual energy consumed during heating, and the total energy storage of the super capacitor;

[0033] The controller calculates the current voltage of the super capacitor after heating based on a predetermined formula using the starting voltage, the actual energy, and the total energy storage, and the current voltage is used to calculate the maximum charging current of the super capacitor.

[0034] In a possible implementation, the method further includes:

[0035] During the process of the super capacitor heating the resistor, the controller obtains the temperature of the super capacitor through the temperature detection circuit;

[0036] If the temperature exceeds the temperature threshold, the controller reduces the first power by a predetermined proportion, and controls the charge and discharge circuit to heat the resistor in the heating film with the reduced second power, so as to melt the ice layer in the camera's field of view.

[0037] In a possible implementation, the method further includes:

[0038] During the process of charging the super capacitor, the controller obtains the voltage of the super capacitor;

[0039] If the voltage reaches the rated voltage, the controller controls the charge and discharge circuit to stop charging the super capacitor.

[0040] According to the third aspect of the present application, a new energy vehicle is provided, and the new energy vehicle includes the front windshield defrosting circuit of the above new energy vehicle.

[0041] The beneficial effects of the technical solution provided by the present application at least include:

[0042] When the new energy vehicle is in a driving state, the recovered energy of the generator can be used to charge the super capacitor, and then the super capacitor is used to heat the resistor in the heating film. This can not only provide instantaneous high power for efficient defrosting, but also reduce the power consumption of the battery, improve the endurance of the new energy vehicle, and increase the service life of the battery, avoiding the negative impact of defrosting on the low-voltage power grid and battery life.

[0043] If the internal resistance of the super capacitor is relatively large, it indicates that the super capacitor has aged. At this time, the energy consumption of the super capacitor is high and the power conversion efficiency is low. Therefore, it is necessary to detect whether the internal resistance of the capacitor is greater than the internal resistance threshold through the internal resistance self-checking circuit, and alarm when the internal resistance of the capacitor is greater than the internal resistance threshold to prompt the user to replace the super capacitor, thereby improving the power conversion efficiency.

[0044] The temperature detection circuit can reduce the heating power of the resistor when the temperature of the super capacitor is greater than the temperature threshold, avoiding circuit damage caused by overheating. Description of the Drawings

[0045] To more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0046] Figure 1 is a structural block diagram of the front windshield defrosting circuit of a new energy vehicle provided by an embodiment of the present application;

[0047] Figure 2 is a flowchart of the front windshield defrosting method of a new energy vehicle provided by an embodiment of the present application;

[0048] Figure 3 is a flowchart of the front windshield defrosting method of a new energy vehicle provided by an embodiment of the present application;

[0049] Figure 4 is a schematic diagram of the measured data provided by an embodiment of the present application. Specific Embodiments

[0050] To make the objectives, technical solutions, and advantages of the embodiments of the present application clearer, the following will further describe the embodiments of the present application in detail with reference to the drawings.

[0051] A new energy vehicle includes a high-voltage battery and a storage battery (which can also be called a low-voltage battery). During driving, if the new energy vehicle brakes or decelerates, the energy generated by the generator will be recovered, and the recovered energy will be used to charge the high-voltage battery. In addition to providing power for the new energy vehicle, the high-voltage battery can also charge the storage battery. When the defrosting function needs to be turned on, the storage battery will discharge to the resistor in the heating film, so that the resistor generates heat, thereby melting the ice layer in the camera's field of view and achieving the purpose of defrosting.

[0052] However, the instantaneous discharge power of the storage battery is limited and it is difficult to support the high-power and fast defrosting requirements; defrosting through the storage battery will increase the power consumption, affect the endurance of the new energy vehicle; defrosting through the storage battery will increase the charge and discharge times of the storage battery, thereby accelerating the aging of the storage battery and reducing the service life of the storage battery.

[0053] To solve the above problems, the present application designs a front windshield defrosting circuit. The super capacitor in the front windshield defrosting circuit can replace the storage battery to discharge to the resistor in the heating film, which can not only provide instantaneous high power for efficient defrosting, but also reduce the power consumption of the storage battery, improve the endurance of the new energy vehicle, and improve the service life of the storage battery, avoiding the negative impact of defrosting on the low-voltage power grid and battery life.

[0054] AsFigure 1 As shown, it shows a structural block diagram of the front windshield defrosting circuit of a new energy vehicle provided by an embodiment of the present application. The front windshield defrosting circuit of the new energy vehicle can be applied to the new energy vehicle. The front windshield defrosting circuit of the new energy vehicle may include a charge-discharge circuit 110.

[0055] The charge-discharge circuit 110 includes a supercapacitor 111 and a bidirectional DC-DC converter 112. The supercapacitor 111 is connected to the bidirectional DC-DC converter 112. The bidirectional DC-DC converter 112 is respectively connected to a generator, a battery, and a resistor in a heating film. The heating film is located around the camera vision area of the front windshield. Among them, the generator or the battery can charge the supercapacitor 111 through the bidirectional DC-DC converter 112, and the supercapacitor 111 can discharge to the resistor in the heating film through the bidirectional DC-DC converter 112, so that the resistor generates heat, thereby melting the ice layer within the camera vision area to achieve the purpose of defrosting.

[0056] In one example, the supercapacitor 111 can be formed by connecting a hybrid supercapacitor 111 module in series. The supercapacitor 111 can be an energy storage unit of 16V / 187.5F, with a total capacity of 3000J, and supports continuous discharge at a power of 50W for 60 seconds. The supercapacitor 111 is installed at a position close to the front windshield and is connected to the vehicle body structure through thermal conductive silicone, and can utilize the metal frame for heat dissipation.

[0057] The charge-discharge circuit 110 is used to charge the supercapacitor 111 with the recovered energy of the generator when the new energy vehicle is in a driving state, or charge the supercapacitor 111 with the battery when the new energy vehicle is in a parked state; when it is determined that the defrosting function needs to be started, use the supercapacitor 111 to heat the resistor in the heating film.

[0058] In this embodiment, the recovered energy can be directly used to charge the supercapacitor 111, and then the supercapacitor 111 is used for defrosting. Compared with first using the recovered energy to charge the high-voltage battery, then using the high-voltage battery to charge the battery, and finally using the battery for defrosting, it can not only save energy loss during the charging process; but also the supercapacitor 111 can increase the instantaneous high power to improve the defrosting efficiency; it can also reduce the charge and discharge times of the battery and improve the service life of the battery.

[0059] In addition to the charge-discharge circuit 110, the front windshield defrosting circuit may further include an internal resistance self-checking circuit 120, a temperature detection circuit 130, and an overvoltage detection circuit 140, and the internal resistance self-checking circuit 120, the temperature detection circuit 130, and the overvoltage detection circuit 140 are respectively connected to the supercapacitor 111.

[0060] In this embodiment, the super capacitor 111 gradually ages over time, which causes the internal resistance of the capacitor to increase, thereby increasing the energy consumption of the super capacitor and reducing the power conversion efficiency of the electric energy. Therefore, it is necessary to set up an internal resistance self-checking circuit 120 to detect the internal resistance of the super capacitor 111 through the internal resistance self-checking circuit 120, and give an alarm when the internal resistance of the capacitor is greater than the internal resistance threshold. After receiving the alarm, the user can replace the super capacitor 111.

[0061] In this embodiment, the temperature of the super capacitor 111 can also be detected through the temperature detection circuit 130, and the heating power of the resistor is reduced when the temperature is greater than the temperature threshold to avoid circuit damage caused by overheating.

[0062] In this embodiment, the voltage of the super capacitor 111 can also be detected through the overvoltage detection circuit 140, and the charging is stopped when the voltage reaches the rated voltage to avoid circuit damage caused by overcharging.

[0063] In summary, the front windshield defrosting circuit of the new energy vehicle provided by the embodiment of the present application can use the recovered energy of the generator to charge the super capacitor when the new energy vehicle is in a driving state, and then use the super capacitor to heat the resistor in the heating film. It can not only provide instantaneous high power for efficient defrosting, but also reduce the power consumption of the storage battery, improve the endurance of the new energy vehicle, and improve the service life of the storage battery, avoiding the negative impact of defrosting on the low-voltage power grid and battery life.

[0064] If the internal resistance of the super capacitor is large, it means that the super capacitor has aged. At this time, the energy consumption of the super capacitor is high and the power conversion efficiency is low. Therefore, it is necessary to detect whether the internal resistance of the capacitor is greater than the internal resistance threshold through the internal resistance self-checking circuit, and give an alarm when the internal resistance of the capacitor is greater than the internal resistance threshold to prompt the user to replace the super capacitor, thereby improving the power conversion efficiency.

[0065] The temperature detection circuit can reduce the heating power of the resistor when the temperature of the super capacitor is greater than the temperature threshold, avoiding circuit damage caused by overheating.

[0066] As Figure 2 shown, it shows the method flow chart of the front windshield defrosting method of the new energy vehicle provided by an embodiment of the present application. The front windshield defrosting method of the new energy vehicle can be applied to the new energy vehicle, and the new energy vehicle includes a controller and a front windshield defrosting circuit as Figure 1 shown. The front windshield defrosting method of the new energy vehicle may include:

[0067] Step 201, the charge and discharge circuit charges the super capacitor using the recovered energy of the generator or the storage battery.

[0068] In this embodiment, when the new energy vehicle is in a driving state, the recovered energy of the generator is used to charge the super capacitor. Alternatively, when the new energy vehicle is in a parked state, the battery is used to charge the super capacitor.

[0069] Step 202, the controller detects whether the camera's field of view area in the front windshield is blocked.

[0070] The camera can send the captured image to the controller, and the controller can analyze the image to detect whether the camera's field of view area is blocked. Alternatively, the controller can detect whether it receives an occlusion alarm sent by the Advanced Driving Assistance System (ADAS). If an occlusion alarm is received, it is determined that the camera's field of view area is blocked, and step 203 is executed; if no occlusion alarm is received, it is determined that the camera's field of view area is not blocked, and the process ends.

[0071] Step 203, if the camera's field of view area is blocked, the controller controls the super capacitor to heat the resistor in the heating film at a first power so as to melt the ice layer in the camera's field of view area.

[0072] After the controller learns that the camera's field of view area is blocked and determines that defrosting is required, it notifies the super capacitor in the charge-discharge circuit to heat the resistor in the heating film at a first power until the ice layer melts and then stops heating.

[0073] The value range of the first power is 30 - 50W, and the specific value can be determined by the ice layer thickness. For example, when the ice layer is thick, the first power can be set to 50W to achieve efficient defrosting; when the ice layer is thin, the first power can be set to 30W to save power.

[0074] In summary, for the front windshield defrosting method of the new energy vehicle provided by the embodiment of the present application, when the new energy vehicle is in a driving state, the recovered energy of the generator can be used to charge the super capacitor, and then the super capacitor is used to heat the resistor in the heating film. This can not only provide instantaneous high power for efficient defrosting, but also reduce the power consumption of the battery, improve the endurance of the new energy vehicle, and increase the service life of the battery, avoiding the negative impact of defrosting on the low-voltage power grid and battery life.

[0075] As Figure 3 shown, it shows a flowchart of the front windshield defrosting method of the new energy vehicle provided by an embodiment of the present application. This front windshield defrosting method of the new energy vehicle can be applied to a new energy vehicle, and the new energy vehicle includes a controller and a front windshield defrosting circuit as Figure 1 shown. This front windshield defrosting method of the new energy vehicle may include:

[0076] Step 301, the controller obtains the power of the super capacitor.

[0077] The controller can measure the power of the super capacitor and determine whether to charge the super capacitor according to the power. Specifically, the controller can obtain a preset power threshold and compare the power with the power threshold; if the power is lower than the power threshold, it is determined that the super capacitor needs to be charged, and step 302 or 303 is executed; if the power is higher than the power threshold, the super capacitor does not need to be charged, and step 304 is executed.

[0078] In this embodiment, when the new energy vehicle is in a driving state, the recovered energy of the generator is used to charge the super capacitor, that is, step 302 is executed; or, when the new energy vehicle is in a parked state, the battery is used to charge the super capacitor, that is, step 303 is executed.

[0079] Step 302, if the power is lower than the power threshold and there is recovered energy in the new energy vehicle, the controller controls the charge-discharge circuit to charge the super capacitor with the recovered energy.

[0080] Specifically, the charge-discharge circuit charging the super capacitor with the recovered energy may include: the charge-discharge circuit converts the first voltage corresponding to the recovered energy into the second voltage corresponding to the super capacitor through a bidirectional DC-DC converter, and the second voltage is lower than the first voltage; the charge-discharge circuit charges the super capacitor with the second voltage.

[0081] When charging the super capacitor with the recovered energy, the bidirectional DC-DC converter plays a role in stepping down the voltage.

[0082] During charging, the controller obtains the rated voltage, current voltage and line impedance of the super capacitor; the controller divides the difference between the rated voltage and the current voltage by the line impedance to obtain the maximum charging current of the super capacitor; if the maximum charging current exceeds the rated current of the super capacitor, the controller controls the charge-discharge circuit to charge the super capacitor with the rated current; if the maximum charging current does not exceed the rated current of the super capacitor, the controller controls the charge-discharge circuit to charge the super capacitor with the maximum charging current. Among them, the rated currents of different charging methods are different. For example, the rated current when charging the super capacitor with the recovered energy is 20A, and the rated current when charging the super capacitor with the battery is 5A. The specific values can be set according to actual needs and are not limited in this embodiment.

[0083] In one example, the rated voltage is 16V, the current voltage is 12V, and the rated current is 20A. Assuming the line impedance is 0.5Ω, then the maximum charging current = (16 - 12) / 0.5 = 8A. Since 8 < 20, the supercapacitor is finally charged with 8A. Assuming the line impedance is 0.1Ω, then the maximum charging current = (16 - 12) / 0.1 = 40A. Since 40 > 20, the supercapacitor is finally charged with 20A.

[0084] Step 303, if the power is lower than the power threshold and there is no recovered energy in the new energy vehicle, the controller controls the charge and discharge circuit to use the storage battery to charge the supercapacitor.

[0085] Specifically, the charge and discharge circuit using the storage battery to charge the supercapacitor may include: the charge and discharge circuit converts the third voltage corresponding to the storage battery into the second voltage corresponding to the supercapacitor through a bidirectional DC-DC converter, and the second voltage is higher than the third voltage; the charge and discharge circuit charges the supercapacitor with the second voltage.

[0086] When using the storage battery to charge the supercapacitor, the bidirectional DC-DC converter plays a role in boosting the voltage.

[0087] During charging, the controller obtains the rated voltage, current voltage, and line impedance of the supercapacitor; the controller divides the difference between the rated voltage and the current voltage by the line impedance to obtain the maximum charging current of the supercapacitor; if the maximum charging current exceeds the rated current of the supercapacitor, the controller controls the charge and discharge circuit to charge the supercapacitor with the rated current; if the maximum charging current does not exceed the rated current of the supercapacitor, the controller controls the charge and discharge circuit to charge the supercapacitor with the maximum charging current.

[0088] In one example, the rated voltage is 16V, the current voltage is 12V, and the rated current is 5A. Assuming the line impedance is 0.5Ω, then the maximum charging current = (16 - 12) / 0.5 = 8A. Since 8 > 5, the supercapacitor is finally charged with 5A. Assuming the line impedance is 1Ω, then the maximum charging current = (16 - 12) / 1 = 4A. Since 4 < 5, the supercapacitor is finally charged with 4A.

[0089] During the charging process, the voltage of the supercapacitor can also be detected through an overvoltage detection circuit, and charging is stopped when the voltage reaches the rated voltage to avoid circuit damage caused by overcharging.

[0090] Specifically, during the process of charging the supercapacitor, the controller obtains the voltage of the supercapacitor; if the voltage reaches the rated voltage, the controller controls the charge and discharge circuit to stop charging the supercapacitor.

[0091] Step 304, the controller detects whether the field of view area of the camera in the front windshield is blocked.

[0092] The camera can send the captured image to the controller, and the controller can analyze the image to detect whether the field of view area of the camera is blocked. Alternatively, the controller can detect whether it receives a blocking alarm sent by the Advanced Driving Assistance System (ADAS). If a blocking alarm is received, it is determined that the field of view area of the camera is blocked, and step 305 is executed; if no blocking alarm is received, it is determined that the field of view area of the camera is not blocked, and the process ends.

[0093] Step 305, if the field of view area of the camera is blocked, the controller controls the super capacitor to heat the resistor in the heating film at a first power to melt the ice layer in the field of view area of the camera.

[0094] After the controller learns that the field of view area of the camera is blocked and determines that defrosting is required, it notifies the super capacitor in the charge and discharge circuit to heat the resistor in the heating film at a first power until the ice layer melts and then stops heating.

[0095] The value range of the first power is 30 - 50W, and the specific value can be determined by the ice layer thickness. For example, when the ice layer is thick, the first power can be set to 50W to achieve efficient defrosting; when the ice layer is thin, the first power can be set to 30W to save power.

[0096] Assume that the total capacity of the super capacitor is 3000J, the current power is 85%, and the first power is 50W. Then the heating duration t = 3000×85%÷50≈51 seconds. Assume that the ice layer melts in advance at 20 seconds of heating. Then the actual energy consumed during heating = 50×20 = 1000J.

[0097] Optionally, the controller obtains the starting voltage of the super capacitor before heating, the actual energy consumed during heating, and the total energy storage of the super capacitor; the controller calculates the starting voltage, actual energy, and total energy storage according to a predetermined formula to obtain the current voltage of the super capacitor after heating, and the current voltage is used to calculate the maximum charging current of the super capacitor.

[0098] The preset formula is

[0099] where, V start represents the starting voltage, V end represents the current voltage after heating, E represents the actual energy consumed, and C represents the total charge.

[0100] Assume V start= 15V, E = 1000J, C = 187.5C, then

[0101] Optionally, during the process of the super capacitor heating the resistor, the controller obtains the temperature of the super capacitor through the temperature detection circuit; if the temperature exceeds the temperature threshold, the controller reduces the first power by a predetermined proportion, and controls the charge and discharge circuit to heat the resistor in the heating film with the reduced second power, so as to melt the ice layer in the camera's field of view.

[0102] Among them, the temperature threshold and the predetermined proportion can be set according to actual needs. Assuming that the temperature threshold is 65°, the first power is 50W, and the predetermined proportion is 30%, then when it is detected that the temperature of the super capacitor is higher than 65°, calculate the second power = 50W × (1 - 30%) = 35W, and heat the resistor in the heating film with 35W.

[0103] As Figure 4 shown, when using the storage battery to heat the resistor in the heating film, the continuous output time of 50W ≤ 15 seconds, the energy consumption of a single defrosting needs to consume 300Wh of the storage battery, and the start-up success rate at -40° is 68%; when using the recovered energy to heat the resistor in the heating film, the continuous output time of 50W ≥ 60 seconds, the energy consumption of a single defrosting needs to consume 0Wh of the storage battery, and the start-up success rate at -40° is 99.5%.

[0104] In summary, for the front windshield defrosting method of the new energy vehicle provided by the embodiment of the present application, when the new energy vehicle is in a driving state, the recovered energy of the generator can be used to charge the super capacitor, and then the super capacitor is used to heat the resistor in the heating film, which can not only provide instantaneous high power for efficient defrosting, but also reduce the power consumption of the storage battery, improve the endurance of the new energy vehicle, and improve the service life of the storage battery, avoiding the negative impact of defrosting on the low-voltage power grid and battery life.

[0105] If the internal resistance of the super capacitor is large, it means that the super capacitor has aged. At this time, the energy consumption of the super capacitor is high and the efficiency of electric energy conversion is low. Therefore, it is necessary to detect whether the internal resistance of the capacitor is greater than the internal resistance threshold through the internal resistance self-checking circuit, and give an alarm when the internal resistance of the capacitor is greater than the internal resistance threshold to prompt the user to replace the super capacitor, so as to improve the electric energy conversion efficiency.

[0106] The temperature detection circuit can reduce the heating power of the resistor when the temperature of the super capacitor is greater than the temperature threshold, avoiding circuit damage caused by overheating.

[0107] An embodiment of the present application provides a computer-readable storage medium, in which at least one instruction is stored, and the at least one instruction is loaded and executed by a processor to implement the front windshield defrosting method for a new energy vehicle as described above.

[0108] An embodiment of the present application provides a new energy vehicle, and the new energy vehicle includes the front windshield defrosting circuit of any of the above new energy vehicles.

[0109] It should be noted that when the front windshield defrosting circuit of the new energy vehicle provided in the above embodiment defrosts the front windshield of the new energy vehicle, only the division of the above functional modules is used for illustration. In actual application, the above functions can be assigned to different functional modules according to needs, that is, the internal structure of the front windshield defrosting circuit of the new energy vehicle is divided into different functional modules to complete all or part of the functions described above. In addition, the front windshield defrosting circuit of the new energy vehicle provided in the above embodiment and the embodiment of the front windshield defrosting method of the new energy vehicle belong to the same concept, and the specific implementation process is detailed in the method embodiment and will not be repeated here.

[0110] Those of ordinary skill in the art can understand that all or part of the steps to implement the above embodiment can be completed by hardware, or can be completed by a program instructing relevant hardware. The program can be stored in a computer-readable storage medium, and the storage medium mentioned above can be a read-only memory, a magnetic disk or an optical disc, etc.

[0111] The above does not intend to limit the embodiments of the present application. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the embodiments of the present application shall be included in the protection scope of the embodiments of the present application.

Claims

1. A front windshield defrosting circuit for a new energy vehicle, characterized in that: The front windshield defrosting circuit includes a charging and discharging circuit, an internal resistance self-detection circuit, a temperature detection circuit and an overvoltage detection circuit; The charging and discharging circuit includes a super capacitor and a bidirectional DC-DC converter, the super capacitor is connected to the bidirectional DC-DC converter, the bidirectional DC-DC converter is respectively connected to the generator, the battery and the resistor in the heating film, and the heating film is located around the camera field of view area in the front windshield; The internal resistance self-detection circuit, the temperature detection circuit and the overvoltage detection circuit are respectively connected to the supercapacitor; The charging and discharging circuit is used to charge the supercapacitor using the recovered energy of the generator when the new energy vehicle is in a driving state, or to charge the supercapacitor using the battery when the new energy vehicle is in a parking state; When it is determined that the defrost function needs to be started, the super capacitor is used to heat the resistor in the heating film; The internal resistance self-detection circuit is used to detect the internal resistance of the supercapacitor and to alarm when the internal resistance of the supercapacitor is greater than the internal resistance threshold; The temperature detection circuit is used to detect the temperature of the supercapacitor and reduce the heating power of the resistor when the temperature is greater than a temperature threshold; The overvoltage detection circuit is used to detect the voltage of the supercapacitor and stop charging when the voltage reaches the rated voltage.

2. A method for defrosting the front windshield of a new energy vehicle, characterized in that: Used in a new energy vehicle, the new energy vehicle comprises a controller and a front windshield defrosting circuit as claimed in claim 1, the method comprising: The charging and discharging circuit uses the recovered energy of the generator or the battery to charge the supercapacitor; The controller detects whether the camera field of view in the front windshield is blocked; If the camera field of view is blocked, the controller controls the supercapacitor to heat the resistor in the heating film with a first power to melt the ice layer in the camera field of view.

3. The method for defrosting the front windshield of a new energy vehicle according to claim 2, characterized in that: The charging and discharging circuit uses the recovered energy of the generator or the battery to charge the supercapacitor, including: The controller obtains the electric quantity of the super capacitor; If the power level is lower than the power threshold and there is recovered energy in the new energy vehicle, the controller controls the charge and discharge circuit to charge the supercapacitor using the recovered energy; If the power level is lower than the power threshold and there is no recovered energy in the new energy vehicle, the controller controls the charging and discharging circuit to use the battery to charge the supercapacitor.

4. The method for defrosting the front windshield of a new energy vehicle according to claim 3, characterized in that: The charging and discharging circuit uses the recovered energy to charge the supercapacitor, including: The charging and discharging circuit converts a first voltage corresponding to the recovered energy into a second voltage corresponding to the supercapacitor through the bidirectional DC-DC converter, wherein the second voltage is lower than the first voltage; The charge and discharge circuit charges the super capacitor at the second voltage.

5. The method for defrosting the front windshield of a new energy vehicle according to claim 3, characterized in that: The charging and discharging circuit uses the battery to charge the supercapacitor, including: The charging and discharging circuit converts a third voltage corresponding to the battery into a second voltage corresponding to the supercapacitor through the bidirectional DC-DC converter, wherein the second voltage is higher than the third voltage; The charge and discharge circuit charges the super capacitor at the second voltage.

6. The method for defrosting the front windshield of a new energy vehicle according to claim 2, characterized in that: The method further comprises: The controller obtains the rated voltage, current voltage and line impedance of the supercapacitor; The controller divides the difference between the rated voltage and the current voltage by the line impedance to obtain the maximum charging current of the supercapacitor; If the maximum charging current exceeds the rated current of the supercapacitor, the controller controls the charging and discharging circuit to charge the supercapacitor with the rated current; If the maximum charging current does not exceed the rated current of the super capacitor, the controller controls the charging and discharging circuit to charge the super capacitor with the maximum charging current.

7. The method for defrosting the front windshield of a new energy vehicle according to claim 6, characterized in that: The method further comprises: The controller obtains the starting voltage of the supercapacitor before heating, the actual energy consumed during heating, and the total energy storage of the supercapacitor; The controller calculates the starting voltage, the actual energy and the total amount of stored energy according to a predetermined formula to obtain a current voltage of the supercapacitor after heating, and the current voltage is used to calculate a maximum charging current of the supercapacitor.

8. The method for defrosting the front windshield of a new energy vehicle according to claim 2, characterized in that: The method further comprises: In the process of the supercapacitor heating the resistor, the controller acquires the temperature of the supercapacitor through the temperature detection circuit; If the temperature exceeds the temperature threshold, the controller reduces the first power by a predetermined ratio, and controls the charge and discharge circuit to heat the resistor in the heating film with the reduced second power, so as to melt the ice layer in the camera field of view.

9. The method for defrosting the front windshield of a new energy vehicle according to claim 2, characterized in that: The method further comprises: In the process of charging the supercapacitor, the controller obtains the voltage of the supercapacitor; If the voltage reaches the rated voltage, the controller controls the charge and discharge circuit to stop charging the supercapacitor.

10. A new energy vehicle, characterized in that: The new energy vehicle comprises the front windshield defrosting circuit for the new energy vehicle as claimed in claim 1.

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