A method for protecting the instantaneous current overload of a car air purifier during startup

Abstract

This invention provides a method for protecting a vehicle-mounted air purifier from instantaneous current overload during startup, comprising: S1: starting the vehicle-mounted fan, detecting the current value of the vehicle-mounted fan, and after the current value of the vehicle-mounted fan stabilizes within a certain period of time, setting the output voltage of the DC-DC module to the highest voltage level; S2: starting the ion generator, detecting the current value of the ion generator, and recording the current value if the detection fluctuation time is reached and the current value stabilizes; S3: calculating the PWM value for adjusting the speed level using the set rated power and the current value of the ion generator; S4: gradually increasing the speed of the vehicle-mounted fan according to the PWM value, and completing the startup when the current value of the vehicle-mounted fan reaches the set current threshold and stabilizes for a period of time; In this invention, by limiting the speed of the fan and then driving the ion generator to start, and by adjusting the speed level of the vehicle-mounted fan by detecting the actual operating current of the ion generator, the startup is completed, effectively solving the problems of voltage drop and poor stability caused by both during startup.

Description

Technical Field

[0001] This invention relates to the field of vehicle air purifier control, and more particularly to a method for protecting vehicle air purifier from instantaneous current overload during startup. Background Technology

[0002] A car air purifier is a device used to purify the air inside a vehicle, removing dust, formaldehyde, and other harmful substances, thereby improving air quality, ensuring user safety, and enhancing the user experience. During vehicle use, users may sometimes operate the air purifier and fan simultaneously. However, when both are running at the same time, the combined current can exceed the power supply's capacity. Specifically, for safety reasons, the car fan must be started before the air purifier's ion generator. The car fan generates a transient high current upon startup. The ion generator, its main component, requires a voltage conversion from low to high, also generating a transient high current during startup, which fluctuates for a period, leading to system power instability and potential restarts.

[0003] To ensure both functions work properly, the existing solution is to first start the air purifier via software, and then gradually increase the fan speed to start it after a certain period. However, this method has the following problems:

[0004] 1. There is no control over voltage fluctuations during the control process. During the start-up of the air purifier and fan, there may be voltage drops, which may cause the system to restart and affect normal operation.

[0005] 2. Existing technologies limit the fan speed, resulting in reduced air circulation capacity.

[0006] 3. During startup, fans and air purifiers do not provide feedback on voltage fluctuations and cannot monitor voltage fluctuations in real time, thus affecting the stability of air purifiers and fans during operation. Summary of the Invention

[0007] To overcome the shortcomings of existing technologies, this invention provides a method for protecting the instantaneous current overload during the startup of a car air purifier. The startup process is completed through the cooperation of a car fan and an ion generator. When the car fan starts, its speed is limited before driving the ion generator. The startup is then completed by adjusting the car fan speed setting based on the actual operating current of the ion generator. This effectively solves the problems of voltage drop and poor stability caused by the startup of both components. Specifically, when the car fan starts, a comparator module monitors the output voltage of the DC-DC module in real time during startup. When the voltage drops to a set value, the comparator module outputs a corresponding control signal to control the output voltage of the DC-DC module, allowing the voltage to rise back to a stable threshold value, ensuring stable total power during startup. During startup, a compensation module is also used to compensate for voltage drops during the increase in car fan speed, effectively solving the problem of system instability caused by excessive current during the startup of the ion generator and car fan.

[0008] To achieve the above objectives, the present invention provides a method for overload protection of instantaneous current during startup of a vehicle air purifier, the specific steps of which include:

[0009] S1: Start the vehicle fan, detect the current value of the vehicle fan, and after the current value of the vehicle fan stabilizes within a certain period of time, set the output voltage of the DC-DC module to the highest voltage level.

[0010] S2: Start the ion generator and detect the current value of the ion generator. If the detection fluctuation time is reached and the current value is stable during the detection, record the current value.

[0011] S3: Calculate the PWM value for adjusting the speed range using the set rated power and ion generator current value;

[0012] S4: Gradually increase the speed of the vehicle fan according to the PWM value. If the vehicle fan current value reaches the set current threshold and stabilizes for a period of time, the startup is complete.

[0013] Preferably, the vehicle-mounted fan uses PWM values ​​to set multiple speed levels for control. The PWM value for each level is obtained by calculating the remaining available power quota based on the current consumption and rated power of the ion generator and external devices. The external devices refer to devices other than the ion generator and the vehicle-mounted fan.

[0014] Preferably, the formula for calculating the remaining available quota w is:

[0015] w = Rated power - Ion generator power - External equipment power

[0016] PWM value = Remaining current quota / Remaining available quota;

[0017] The set adjustment current I = w / 5V is used as the maximum speed current detection value for the vehicle fan.

[0018] Preferably, during the process of increasing the speed of the vehicle fan, a comparator module is used to detect the output voltage of the DC-DC module in real time during the startup process. When the voltage drops to the set value, the comparator module outputs a corresponding control signal to control the output voltage of the DC-DC module so that the voltage rises back to the threshold of the stable value.

[0019] Preferably, during the acceleration of the vehicle fan, a compensation module adjusts the output voltage of the DC-DC module according to the control signal output by the comparator module to compensate for hardware voltage drops; the compensation module is connected to the comparator module, the control module and the DC-DC module.

[0020] Preferably, the compensation module includes a compensation switch Q1 and a compensation resistor R8 connected in series, a compensation switch Q2 and a compensation resistor R10 connected in series, and a compensation switch Q3 and a compensation resistor R11 connected in series; the gate of the compensation switch Q1 is used to receive the control signal from the control module, the gates of the compensation switches (Q2, Q3) are used to receive the control signal from the comparator module, and one end of the compensation resistors (R8, R10, R11) are connected together to the DC-DC module.

[0021] Preferably, when the ion generator is started, a startup test is performed to obtain the optimal current detection threshold and fluctuation detection time. The specific steps of the startup test include:

[0022] According to the preset startup sequence, detection current, and detection fluctuation time, the ion generator and vehicle fan are started for a period of time and marked.

[0023] Upon restart, it checks whether the ion generator and the vehicle fan started successfully the last time. If not, the fluctuation detection time is extended for a period of time, and the speed of the vehicle fan follows the change of the current value of the ion generator, and the restart process is re-entered.

[0024] If the detection fluctuation time extends to the set threshold and the vehicle fan speed drops to the lowest set value, the startup process will stop and a power supply abnormality warning will be issued.

[0025] Preferably, the detection current of the ion generator includes transient current and steady-state current. The steps for detecting transient current are as follows: detect and record the maximum current value of the ion generator. If the current value is greater than the set current detection threshold, the current is recorded once every certain period of time. When the detection fluctuation time is reached, if there is no current fluctuation, it indicates that the voltage is stable.

[0026] Preferably, the steady-state current detection method is as follows: after the ion generator is started and the set detection fluctuation time is passed, the current is detected in real time. Samples are taken sequentially at regular intervals. After accumulating a certain number of times, the average current is obtained. The average current is used as the stable current and is used as the basis for judging the speed adjustment of the vehicle fan.

[0027] The present invention provides a method for protecting the instantaneous current overload of a vehicle air purifier during startup, the advantages of which are:

[0028] 1. The present invention uses a vehicle-mounted fan and an ion generator to complete the startup process. When the vehicle-mounted fan starts, the fan speed is limited, and then the ion generator is driven to start. Then, the startup is completed by adjusting the speed of the vehicle-mounted fan by detecting the actual working current of the ion generator. This effectively solves the problems of voltage drop and poor stability caused by the startup process of the two.

[0029] 2. The vehicle-mounted fan uses PWM values ​​to set multiple speed levels. The PWM value for each level is calculated based on the remaining available power quota, calculated from the ion generator's power consumption, the current consumption of external devices, and the rated power. Adjusting the speed level using the remaining power quota allows for adjustable speed levels, overcoming the limitation of fixed speed levels and applicable scenarios in existing technologies.

[0030] 3. When adjusting the speed of the vehicle fan, the remaining quota is calculated based on the actual losses to obtain the PWM value. The speed level of the vehicle fan is determined by the PWM value, thereby realizing the adjustment of the vehicle fan speed in different application scenarios, which is highly adaptable.

[0031] 4. This invention uses a compensation module to compensate for voltage drops at the fan end and terminals in the hardware circuit, so that the power supply voltage of the entire system remains stable and the hardware system can operate normally. Attached Figure Description

[0032] Figure 1 A flowchart of a method for protecting the instantaneous current overload of a vehicle-mounted air purifier during startup, provided by the present invention;

[0033] Figure 2 A circuit diagram of the comparator module provided by the present invention;

[0034] Figure 3 The circuit diagram of the DC-DC module and compensation module provided by the present invention. Detailed Implementation

[0035] The following specific examples illustrate the implementation of the present invention. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that, unless otherwise specified, the following embodiments and features described therein can be combined with each other.

[0036] like Figure 1 As shown, the present invention provides a method for overload protection of instantaneous current during startup of a vehicle air purifier, the steps of which include:

[0037] S1: Start the vehicle fan, detect the current value of the vehicle fan, and after the current value of the vehicle fan stabilizes within a certain period of time, set the output voltage of the DC-DC module to the highest voltage level.

[0038] S2: Start the ion generator and detect the current value of the ion generator. If the detection fluctuation time is reached and the current value is stable during the detection, record the current value.

[0039] S3: Calculate the PWM value for adjusting the speed range using the set rated power and ion generator current value;

[0040] S4: Gradually increase the speed of the vehicle fan according to the PWM value. If the vehicle fan current value reaches the set current threshold and stabilizes for a period of time, the startup is complete.

[0041] Specifically, this invention uses a vehicle-mounted fan and an ion generator to complete the startup process. When the vehicle-mounted fan starts, its speed is limited before the ion generator is activated. The actual operating current of the ion generator is then detected to adjust the vehicle-mounted fan speed level, effectively solving the problems of voltage drop and poor stability during startup. When adjusting the vehicle-mounted fan speed, the remaining allowance is calculated based on actual losses to obtain a PWM value. This PWM value is used to determine the vehicle-mounted fan speed level, thus enabling adjustment of the fan speed for different application scenarios with strong adaptability. Setting the output voltage of the DC-DC module to the highest level (at which point the voltage is low) serves two purposes: maintaining a low voltage level during standby reduces standby power consumption; high voltage during no-load operation places high demands on components, so maintaining a low voltage when not in disinfection mode is beneficial for vehicle operation. In this embodiment, if the average current after sampling and calculation does not exceed 20mA, the current value is considered stable.

[0042] In this embodiment, the vehicle fan sets the speed to multiple levels through PWM values. The PWM value for each level is obtained by calculating the remaining available power quota based on the power of the ion generator, the current consumption of external devices, and the rated power. External devices refer to devices other than the ion generator and the vehicle fan.

[0043] Specifically, this invention uses the remaining power quota to obtain the PWM value for adjusting the vehicle's engine speed. The remaining power quota is the power remaining after subtracting the power of the ion generator and external devices from the system's rated power. Adjusting the engine speed using this remaining power quota allows for adjustable speed settings, overcoming the limitation of fixed speed settings and applicable scenarios in existing technologies. In this embodiment, the external devices are working devices other than the vehicle fan and ion generator, such as LED displays.

[0044] In this embodiment, the formula for calculating the remaining available quota w is:

[0045] w = Rated power - Ion generator power - External equipment power

[0046] PWM value = Remaining current quota / Remaining available quota;

[0047] The set adjustment current I = w / 5V is used as the maximum speed current detection value for the vehicle fan.

[0048] To better understand the vehicle fan speed adjustment method in this invention, an example is given: Based on the formula for remaining available power, the rated power is set to 10W, the ion generator's operating voltage is 12V*I1, and the external device power is 5V*I2. The ion generator's stable current is I1 = 100mA, and the external device's current is a fixed current, I2 = 200mA. Therefore, the remaining power is: 10 - 12 * 0.1 - 5 * 0.5 = 6W. The maximum starting current of the vehicle fan is limited to 1200mA. The current value of the vehicle fan at speed 1, for example, is 300mA. The PWM value is 25% of the total, so the remaining current is 900mA. The vehicle fan gradually increases in speed until the PWM value reaches 100%. At this point, the following situations will occur:

[0049] (1) When the current value of the ion generator is 150mA, the remaining current quota is: 10-12*0.15-5*0.5=5.7W. The remaining PWM value for controlling the rotation speed can only be output up to 5.7W / 6W=95%.

[0050] (2) When the current value of the ion generator is detected to be the standard 100mA, but the system records that the last time the fan was turned on at its highest speed, the preset total power is reduced to 9.5W. The quota is 9.5 - 12 * 0.1 - 5 * 0.5 = 5.8. Therefore, the PWM value for controlling the maximum speed will be limited to 5.8W / 6.0W = 96%. Among them, the preset power reduction is 0.5W.

[0051] (3) If, during actual testing at the highest speed, the fan is found to be operating below the calculated residual current value, the PWM output value can be further increased as an automatic power adjustment compensation. To ensure stability, the increase will not exceed 0.5% of the calculated value.

[0052] like Figure 2 During the process of increasing the speed of the vehicle fan, a comparator module is used to detect the output voltage of the DC-DC module in real time during the startup process. When the voltage drops to the set value, the comparator module outputs a corresponding control signal to control the output voltage of the DC-DC module so that the voltage rises back to the threshold of the stable value.

[0053] like Figure 3 As shown, during the speed-up process of the vehicle fan, a compensation module adjusts the output voltage of the DC-DC module according to the control signal output by the comparator module to compensate for hardware voltage drops; the compensation module is connected to the comparator module, the control module and the DC-DC module.

[0054] In this embodiment, the compensation module includes a series-connected compensation switch Q1 and compensation resistor R8, a series-connected compensation switch Q2 and compensation resistor R10, and a series-connected compensation switch Q3 and compensation resistor R11. The gate of compensation switch Q1 is used to receive the control signal from the control module, and the gates of compensation switches (Q2, Q3) are used to receive the control signal from the comparator module. One end of the compensation resistors (R8, R10, R11) is connected together to the DC-DC module.

[0055] Specifically, during the process of increasing the speed of the vehicle fan, a voltage drop occurs in the line voltage between the fan end and the motor end. Therefore, the compensation module needs to compensate for the voltage at both ends. The gate of compensation switch Q1 is connected to the control module (MCU) to receive control signals from the MCU; the gates of compensation switches (Q2, Q3) are used to receive control signals from the comparator module for hardware compensation. The compensation circuit includes a first compensation circuit, a second compensation circuit, and a third compensation circuit. The first compensation circuit includes a compensation resistor R8 connected in series and compensation switch Q1; the second compensation circuit includes a compensation resistor R10 connected in series and compensation switch Q2; and the third compensation circuit includes a compensation resistor R11 connected in series and compensation switch Q3.

[0056] like Figure 3As shown, the voltage compensation process at the fan end is as follows: When preparing to turn on the ion generator, the MCU connected to the compensation module turns on the MCU port signal (MCU_GPIO signal), and the compensation resistor R8 is connected in parallel to the DC-DC module circuit. At this time, the standard 5V voltage is increased to 5.2V, completing the pre-set high output voltage to compensate for the voltage drop at the fan end due to circuit damage. As the fan gradually turns on, due to the increased power, the damage in the circuit will cause the voltage at the motor end to drop. When the voltage at the fan end is less than 5V, the MOTO_FB1 signal (the control electrode of compensation switch Q2) will output a high level. At this time, the second compensation circuit is added to further increase the overall output voltage of the DC-DC module to compensate for the voltage drop caused by the circuit damage. When the voltage at the fan end is less than 4.8V, the MOTO_FB2 signal (the control electrode of compensation switch Q3) outputs a high level, and the third compensation circuit is activated to boost the voltage to the set voltage, ensuring stable operation of the power supply voltage. Compared with the prior art, the compensation circuit in this invention can quickly and effectively compensate for circuit damage by detecting the voltage value of the fan terminal, thus avoiding system abnormalities caused by unstable current when the voltage fluctuates.

[0057] In this embodiment, when the ion generator is started, a startup test is performed to obtain the optimal current detection threshold and fluctuation detection time. The specific steps of the startup test include:

[0058] According to the preset startup sequence, detection current, and detection fluctuation time, the ion generator and vehicle fan are started for a period of time and marked.

[0059] Upon restart, it checks whether the ion generator and the vehicle fan started successfully the last time. If not, the fluctuation detection time is extended for a period of time, and the speed of the vehicle fan follows the change of the current value of the ion generator, and the restart process is re-entered.

[0060] If the detection fluctuation time extends to the set threshold and the vehicle fan speed drops to the lowest set value, the startup process will stop and a power supply abnormality warning will be issued.

[0061] Specifically, the heuristic test in this invention is observed using testing equipment such as an oscilloscope. First, a calibration current detection threshold and fluctuation time are set. The ion generator and vehicle fan start running according to a set sequence, and the preset values ​​are dynamically changed during actual operation. For example, the preset detection current of the ion generator is 200mA, and the detection fluctuation time is 300ms. When the MCU is powered on, the initial power-on state is recorded. Following these preset values, the ion generator and vehicle fan are successfully turned on step by step. If the system remains stable for 1 minute, the startup is marked as complete. When restarting or restarting, the system first checks if the previous startup was successful. If not, the fluctuation time is extended by 50ms. The extension time can be set according to the actual application scenario. The vehicle fan speed changes according to the detected stable current value before resuming the startup process. After operation, if the detection time is extended to 500ms and the fan speed drops to the lowest preset value, the system will not attempt to start again and will issue a power supply abnormality warning to the user, indicating a power supply problem. This invention proactively reduces the system fan power through startup testing to adapt to working conditions where sufficient power cannot be provided.

[0062] In this embodiment, the detected current of the ion generator includes transient current and steady-state current. The steps for detecting transient current are as follows: detect and record the maximum current value of the ion generator. If the current value is greater than the set current detection threshold, the current is recorded every certain period of time. When the fluctuation detection time is reached and there is no current fluctuation, it indicates that the voltage is stable. Specifically, the instantaneous high current during the start-up of the ion generator and the vehicle fan is relatively short in duration and fluctuates significantly. The voltage is compensated by the compensation circuit. At this time, the maximum current during the startup process is recorded in the software. When the maximum current value is greater than the set value of 300mA, the current is recorded every 50ms. When the recording time reaches the fluctuation detection time and no longer there is a high current, the voltage is considered stable (default 300ms).

[0063] In this embodiment, the steady-state current is detected as follows: after the ion generator is started and a preset fluctuation period has elapsed, the current is detected in real time. Samples are taken at regular intervals, and after a certain number of samples are accumulated, the average current is obtained. This average current is used as the stable current and is used as the basis for determining the vehicle fan speed. Specifically, when detecting the steady-state current, after the ion generator is turned on and a preset fluctuation period has elapsed, the current is detected in real time. Samples are taken every 10ms, accumulated 10 times, and the average value is taken as the stable current, which is used to determine the quota of the vehicle fan current.

[0064] Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort should fall within the scope of protection of the present invention.

Claims

1. A method for protecting a vehicle-mounted air purifier from instantaneous current overload during startup, characterized in that, The specific steps include: S1: Start the vehicle fan, detect the current value of the vehicle fan, and after the current value of the vehicle fan stabilizes within a certain period of time, set the output voltage of the DC-DC module to the highest voltage level. S2: Start the ion generator and detect the current value of the ion generator. If the detection fluctuation time is reached and the current value is stable during the detection, record the current value. S3: Calculate the PWM value for adjusting the speed range using the set rated power and ion generator current value; S4: Gradually increase the speed of the vehicle fan according to the PWM value. If the vehicle fan current value reaches the set current threshold and remains stable for a period of time, the startup is complete. The vehicle-mounted fan controls its speed to multiple gears via PWM values. The PWM value for each gear is obtained by calculating the remaining available power quota based on the current consumption and rated power of the ion generator and external devices. The external devices refer to devices other than the ion generator and the vehicle-mounted fan. The formula for calculating the remaining available power quota w is: w = Rated power - Ion generator power - External equipment power PWM value = Remaining current quota / Remaining available power quota; The set adjustment current I = w / 5V is used as the maximum speed current detection value for the vehicle fan.

2. The method for overload protection of instantaneous current during startup of a vehicle air purifier according to claim 1, characterized in that, During the process of increasing the speed of the vehicle fan, a comparator module is used to detect the output voltage of the DC-DC module in real time during the startup process. When the voltage drops to the set value, the comparator module outputs a corresponding control signal to control the output voltage of the DC-DC module so that the voltage rises back to the threshold of the stable value.

3. The method for protecting the instantaneous current overload of a vehicle-mounted air purifier during startup according to claim 2, characterized in that, During the speed increase of the vehicle fan, a compensation module is used to adjust the output voltage of the DC-DC module according to the control signal output by the comparator module in order to compensate for the hardware voltage drop; the compensation module is connected to the comparator module, the control module and the DC-DC module.

4. The method for overload protection of instantaneous current during startup of a vehicle air purifier according to claim 3, characterized in that, The compensation module includes a series-connected compensation switch Q1 and compensation resistor R8, a series-connected compensation switch Q2 and compensation resistor R10, and a series-connected compensation switch Q3 and compensation resistor R11. The gate of compensation switch Q1 is used to receive the control signal from the control module, and the gates of compensation switches (Q2, Q3) are used to receive the control signal from the comparator module. One end of the compensation resistors (R8, R10, R11) is connected together to the DC-DC module.

5. The method for overload protection of instantaneous current during startup of a vehicle air purifier according to claim 1, characterized in that, When the ion generator is started, a startup test is performed to obtain the optimal current detection threshold and fluctuation detection time. The specific steps of the startup test include: According to the preset startup sequence, detection current, and detection fluctuation time, the ion generator and vehicle fan are started for a period of time and marked. Upon restart, it checks whether the ion generator and the vehicle fan started successfully the last time. If not, the fluctuation detection time is extended for a period of time, and the speed of the vehicle fan follows the change of the current value of the ion generator, and the restart process is re-entered. If the detection fluctuation time extends to the set threshold and the vehicle fan speed drops to the lowest set value, the startup process will stop and a power supply abnormality warning will be issued.

6. The method for overload protection of instantaneous current during startup of a vehicle air purifier according to claim 1, characterized in that, The detection current of the ion generator includes transient current and steady-state current. The steps for detecting transient current are as follows: detect and record the maximum current value of the ion generator. If the current value is greater than the set current detection threshold, the current is recorded once every certain period of time. When the detection fluctuation time is reached, if there is no current fluctuation, it indicates that the voltage is stable.

7. The method for overload protection of instantaneous current during startup of a vehicle air purifier according to claim 6, characterized in that, The steady-state current is detected as follows: after the ion generator is started and the set fluctuation detection time is passed, the current is detected in real time. Samples are taken once every certain period of time. After accumulating a certain number of times, the average current is obtained. The average current is used as the stable current and is used as the basis for judging the speed adjustment of the vehicle fan.

Images