Vehicle-mounted compressor power control method

Abstract

The invention discloses a vehicle-mounted compressor power control method, which relates to the technical field of automobile electronic control, and comprises the following steps: receiving a refrigeration mode signal through voltage detection and stability analysis on bus input, and judging whether a refrigeration request is effective or not according to a temperature setting signal; by sampling and analyzing bus voltage, current, temperature and power operation parameters, after power input stability is confirmed, dynamic control is executed according to a refrigerating or heating mode signal and a temperature setting request, when it is detected that power is close to an upper limit or the temperature deviates from a set range, linear derating control is achieved by adjusting the PWM duty ratio, and the control precision is improved. And smooth recovery is executed after the power is recovered to a safety interval, and a continuous power regulation and energy consumption balance mechanism is formed, so that self-adaptive power optimization and energy efficiency improvement of compressor operation are realized, and instability and element stress damage caused by transient power fluctuation are effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of automobile electronic control, in particular to a vehicle-mounted compressor power control method. BACKGROUND

[0002] The vehicle-mounted compressor is a core component used in vehicle air conditioning and thermal management, and its main function is to compress, transport and circulate refrigerant to achieve temperature regulation and heat conversion in the vehicle cabin. The device is usually driven by an electric motor, which sucks low-pressure gaseous refrigerant into the compression chamber and compresses it into high-pressure high-temperature gas, and then completes the refrigeration cycle through condensation, throttling and evaporation processes, thereby maintaining the comfort of the vehicle environment. With the development of new energy vehicles and intelligent vehicles, the vehicle-mounted compressor has gradually evolved from traditional mechanical drive to electric brushless DC motor drive. The electric compressor realizes precise regulation of motor speed, power and temperature through an electronic control unit, so that it can automatically match the vehicle thermal management demand under different working conditions. Such compressors have the advantages of fast response speed, high energy efficiency ratio, low vibration and noise, and support bus communication with the vehicle control to realize real-time monitoring and feedback of voltage, current, power, speed and refrigeration state. The existing vehicle-mounted compressor adopts fixed logic or simple threshold control method, which lacks multi-signal cooperative judgment mechanism for voltage, current, temperature and load state, resulting in compressor misstart or lagging shutdown under complex vehicle power fluctuation conditions, and insufficient stability. In view of the above technical defects, a solution is proposed. SUMMARY

[0003] In view of the deficiencies of the prior art, the present application provides a vehicle-mounted compressor power control method.

[0004] To achieve the above purpose, the present application realizes the following technical scheme: a vehicle-mounted compressor power control method, comprising: S1, through voltage detection and bus input stability analysis, receiving a refrigeration mode signal, judging whether the refrigeration request is valid according to the temperature setting signal, if the set temperature exceeds the allowed range, performing boundary limiting correction; S2, collecting current environmental temperature data through a temperature sensor, judging the refrigeration start condition according to the difference between the set temperature and the real-time temperature and the hysteresis threshold, when the temperature meets the start judgment relationship, generating a refrigeration start flag signal and triggering the compressor and fan operation logic; S3, after receiving the heating mode signal, monitoring voltage, current and temperature data, evaluating the running load through a power calculation unit, when the running power is higher than the control threshold, performing a smooth shutdown strategy to reduce the drive output and delay the fan shutdown; S4, when the compressor power is detected to be close to the upper limit of power, the dynamic limit control logic is started, the PWM duty cycle is adjusted to reduce the output power, and the driving signal is periodically corrected according to the power change trend; S5, when the compressor power is detected to fall back to the safe interval and there is still a refrigeration demand, the duty cycle is restored according to the rising control function, and the compressor output is gradually increased; S6, during operation, the bus voltage, current and power device temperature are continuously monitored, and when an under-voltage, over-voltage, over-current or over-temperature state is detected, safety shutdown and recovery judgment logic is executed.

[0005] When the bus voltage Vbus satisfies the under-voltage threshold VUV=10.5V and the over-voltage threshold VOV=16.0V, and the compressor is in a fault-free state, enter the power valid determination stage, and execute the following logic details: Smoothly filter the average value of the bus voltage Vbus sampled for N=5 cycles, and calculate the smooth voltage value Vavg: When the smooth voltage value Vavg satisfies VUV<Vavg<VOV and the voltage change rate |ΔV / Δt|<0.2V / s at the same time, it is determined that the power input is stable; Receive the refrigeration mode signal, if the refrigeration mode signal is "refrigeration", read the temperature setting signal, and check whether the temperature setting value is within the range of -6℃-15℃; when the setting value is out of range, limit the correction to the nearest valid boundary value, and generate the internal standardization parameter Tsetstd.

[0006] In S2, when the current temperature Tmeas collected by the temperature sensor needs to satisfy the following relationship: Where, ΔTh=0.8℃ is the starting hysteresis threshold, the compressor state flag code is set to "1", and the refrigeration mode signal is "refrigeration"; if Tmeas-Tsetstd<ΔTh, no operation is performed.

[0007] In the execution of the heating mode switching control, including: When the heating mode signal is received, and the bus voltage is between the under-voltage threshold and the over-voltage threshold, enter the heating mode switching process: Sample the current bus voltage Vbus, compressor current Icom and temperature sensor signal Tmeas, calculate the compressor power Pcom=Vbus×Icom, if the compressor power Pcom>10W, execute the smooth mode switching strategy: Gradually reduce the duty cycle DUT, so that it linearly decays to zero within tdec=3s; After the compressor is turned off, delay tfan=30s, and then turn off the large fan.

[0008] When the compressor power Pcom≥0.9Plim is detected, the power dynamic limit logic is started: The duty cycle DUT is adjusted to achieve power reduction according to the linear derating DUTnew formula: Where DUTcur is the duty cycle, kp is the power derating coefficient, which ranges from 0.1 to 0.3, and is used to control the derating rate; when the compressor power continues to exceed the limit, the duty cycle adjustment amount is calculated according to a fixed period to achieve derating control.

[0009] When the power recovers to the safe interval Pcom<0.8Plim and the temperature sensor detects that the refrigeration demand still exists, the duty cycle recovery control is performed according to the recovery function DUTrec: Where kr is the power recovery coefficient, Tset is the set temperature, and Tcur is the current temperature.

[0010] The safety shutdown and recovery judgment logic includes: When the bus voltage Vbus is detected to be lower than the under-voltage threshold VUV=10.5V or higher than the over-voltage threshold VOV=16.0V, the duty cycle DUTcur is reduced by a linear derating ratio to within 50%; if it continues to exceed the set duration tabn=3s, the PWM drive signal is turned off and the compressor enable signal ENA is turned off, and the shutdown is executed; When the compressor current Icom exceeds the current threshold Ilim=5A or the continuous upward trend exceeds the set change rate ΔIcom / Δt>0.5A / s, it is determined that the overload operation is running, and the duty cycle step attenuation control logic is executed. When the power device temperature Tcom exceeds the temperature threshold Tlim=85℃, the compressor output power is gradually reduced to 70% of the rated power; if the temperature continues to rise to Tshut=95℃, the emergency shutdown is triggered, and the compressor drive output and fan control signals are turned off.

[0011] The compressor power is limited, including: When the compressor enters the oiling stage, the high load operation control link is triggered when the compressor power Pcom>60W is detected; if the high load continues to exceed 1min and the fan voltage FAN≥12V, the power secondary determination is executed, When the compressor power Pcom>60W and exceeds 15min, the compressor speed RPM is reduced by 100rpm and not less than 2700rpm to reduce the load; if the power is still >60W after reduction and exceeds 1min, the load reduction is executed again; If the power drops to ≤60W or the fan voltage does not reach 12V at any stage, the steady-state control strategy is performed.

[0012] The steady-state control strategy comprises: When the compressor power Pcom is ≤60W and the fan voltage drops below 9.3V, the low-voltage protection mode is entered, and when the compressor power Pcom is <50W and is maintained for more than 1 min, the steady-state maintenance is performed; if the compressor power Pcom is ≥50W, the operation is maintained to wait for the fan voltage to rise, and when the voltage does not drop to 9.3V, the consistency of the actual speed RPM and the set speed RPMset is determined, and if the actual speed reaches the set value, the speed is increased by 100 rpm.

[0013] The compressor power limiting further comprises: monitoring the panel setting state SET, the compressor power Pcom and the real-time speed RPM at any operating stage of the compressor, and if it is detected that the panel has not set the compressor power and the compressor power Pcom is ≥90W for more than 30s, the compressor speed is reduced by 400r / s to 2700rpm for 3s; if the panel has set the compressor power but it is detected that the actual speed cannot be reduced by 400r / s to 2700rpm for 3s within the preset time window, the fan is delayed for 3 min to perform the heat dissipation protection.

[0014] The application provides a vehicle-mounted compressor power control method. The application samples and analyzes the bus voltage, current, temperature and power operating parameters, performs dynamic control according to the refrigeration or heating mode signal and the temperature setting request after confirming the stability of the power supply input, realizes linear derating control by adjusting the PWM duty cycle when detecting that the power is close to the upper limit or the temperature deviates from the set range, and performs smooth recovery after the power recovers to the safe interval, thereby forming a continuous power regulation and energy consumption balancing mechanism, so as to realize adaptive power optimization and energy efficiency improvement of the compressor operation, and effectively reduce the instability and component stress damage caused by transient power fluctuation. The application performs multi-stage dynamic adjustment on the operating state of the compressor under different power intervals through a cooperative control method, performs speed reduction and delay protection strategy when detecting that the compressor power is continuously higher than the set threshold, automatically performs steady-state maintenance or fine adjustment recovery according to the consistency of the fan voltage and the speed if the power drops to the low load area, monitors the panel setting state and speed anomaly through an independent monitoring unit, actively triggers the speed limiting protection and heat dissipation delay operation at any operating stage, maintains the stability of the compressor under high load and low voltage working conditions, improves the safety and reliability of the compressor control, and prolongs the service life of the whole machine. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 The schematic diagram of the principle framework of the present application. DETAILED DESCRIPTION

[0016] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0017] Please refer to Figure 1 The present application provides a vehicle-mounted compressor power control method, comprising: S1, receiving a refrigeration mode signal by voltage detection and bus input stability analysis, judging whether the refrigeration request is valid according to the temperature setting signal, and executing boundary limiting correction if the set temperature exceeds the allowed range; S2, collecting current environmental temperature data through a temperature sensor, judging the refrigeration start condition according to the difference between the set temperature and the real-time temperature and the hysteresis threshold, generating a refrigeration start flag signal and triggering the compressor and fan operation logic when the temperature meets the start judgment relationship; S3, after receiving a heating mode signal, monitoring voltage, current and temperature data, evaluating the running load through a power calculation unit, and executing a smooth shutdown strategy to reduce the drive output and delay the fan shutdown when the running power is higher than the control threshold; S4, when detecting that the compressor power is close to the upper limit of power, starting the dynamic limit control logic, adjusting the PWM duty cycle to reduce the output power, and periodically correcting the drive signal according to the power change trend; S5, when detecting that the compressor power falls back to the safe interval and there is still a refrigeration demand, restoring the duty cycle according to the rising control function and gradually improving the compressor output; S6, continuously monitoring the bus voltage, current and power device temperature during operation, and executing safety shutdown and recovery judgment logic when detecting under-voltage, over-voltage, over-current or over-temperature state.

[0018] When the bus voltage Vbus satisfies the under-voltage threshold VUV=10.5V and the over-voltage threshold VOV=16.0V, and the compressor is in a fault-free state, enter the power valid judgment stage, and execute the following logic details: Smoothly filter the average value of the bus voltage Vbus sampled for N=5 cycles, calculate the smooth voltage value Vavg: When the smooth voltage value Vavg meets VUV < Vavg < VOV and the voltage change rate |ΔV / Δt| < 0.2 V / s at the same time, it is determined that the power input is stable; The refrigeration mode signal is received, and if the refrigeration mode signal is "refrigeration", the temperature setting signal is read, and it is checked whether the temperature setting value is within the range of -6℃ to 15℃; when the setting value is out of range, the amplitude correction is the nearest valid boundary value, and the internal standardization parameter Tsetstd is generated.

[0019] In the embodiment, when the bus voltage Vbus meets the under-voltage threshold VUV = 10.5V and the over-voltage threshold VOV = 16.0V, and the compressor is in a fault-free running state, the power supply validity determination stage is entered. This stage is mainly completed by the voltage sampling unit, the voltage smoothing processing unit and the power supply stability analysis unit in cooperation.

[0020] Specifically, the voltage sampling unit samples the bus voltage Vbus continuously through the analog-to-digital conversion module ADC with a timer triggered synchronous update event, and records the voltage values in the last N = 5 sampling periods; then, the voltage smoothing processing unit uses the moving average algorithm to smooth the sampling values to eliminate transient peak interference and electromagnetic fluctuations, and obtains the smooth voltage value Vavg.

[0021] After the smoothing processing is completed, the power supply stability analysis unit performs interval determination on Vavg, and when Vavg meets the voltage condition VUV < Vavg < VOV at the same time, and the voltage change rate |ΔV / Δt| is less than 0.2 V / s in the adjacent sampling period, it is determined that the bus input voltage is in a stable state.

[0022] At this time, the controller sets the power supply state flag to "valid", and sends a "power supply allowed" signal to the compressor control logic module to allow entering the subsequent refrigeration or heating mode initialization process. If the voltage fluctuation exceeds the above interval, the "power supply invalid" state is maintained, and the compressor start instruction is not executed, so as to ensure that the control logic is activated only under stable power supply conditions, effectively preventing the compressor from being started by mistake in the power supply fluctuation or under-voltage stage.

[0023] In the S2, the current temperature Tmeas collected by the temperature sensor needs to meet the following relationship: Where ΔTh = 0.8℃ is the start hysteresis threshold, the compressor state flag code is set to "1", and the refrigeration mode signal is "refrigeration"; if Tmeas-Tsetstd < ΔTh, no operation is performed.

[0024] In the execution of the heating mode switching control, it includes: When receiving the heating mode signal, and the bus voltage is between the under-voltage threshold and the over-voltage threshold, enter the heating mode switching process: Sample the current bus voltage Vbus, compressor current Icom and temperature sensor signal Tmeas, calculate the compressor power Pcom = Vbus x Icom, if the compressor power Pcom > 10W, execute the smooth mode switching strategy: Gradually reduce the duty cycle DUT to zero within tdec = 3s; After the compressor is turned off, delay tfan = 30s, and then turn off the large fan.

[0025] In the specific implementation, when the controller receives the heating mode signal from the whole vehicle control, first determine by the mode recognition unit whether the bus voltage Vbus is between the under-voltage threshold VUV = 10.5V and the over-voltage threshold VOV = 16.0V, if the voltage interval meets the running condition, then enter the heating mode switching process.

[0026] In this process, the bus voltage Vbus and the compressor working current Icom are collected by the voltage sampling module and the current detection module respectively, and the real-time temperature signal Tmeas is collected by the temperature sensor. Then, the power calculation unit calculates the real-time power Pcom of the compressor according to the sampling results of Vbus and Icom, which is used to judge the current refrigeration load. When Pcom > 10W is detected, the controller determines that the compressor is still in the refrigeration state, and needs to execute the smooth mode switching strategy to avoid power surge caused by power surge.

[0027] In the smooth mode switching stage, the microcontroller MCU gradually reduces the duty cycle DUT of the PWM drive signal, adopts linear attenuation strategy, so that the compressor output is smoothly reduced to zero within tdec = 3s. During this process, the current and bus voltage changes are monitored in real time to ensure that there is no sharp fluctuation in the power reduction process.

[0028] When the compressor drive signal is completely turned off, the controller enters the delay control stage, and the fan runs for tfan = 30s through the delay timer, which is used to carry away the residual heat and complete the pressure balance of the refrigeration circuit. After the delay is over, the large fan output is turned off by the fan control module, so that the whole machine switches to the heating standby state.

[0029] When the compressor power Pcom ≥ 0.9Plim is detected, start the power dynamic limitation logic: Adjust the duty cycle DUT to realize power reduction according to the linear reduction DUTnew formula: Wherein, DUTcur is the duty ratio, kp is the power derating coefficient, and its value range is 0.1-0.3, which is used to control the derating rate; when the compressor power continuously exceeds the limit, the duty ratio adjustment amount is calculated according to the fixed period to realize the derating control.

[0030] When the power recovers to the safe interval Pcom<0.8Plim and the temperature sensor detects that the refrigeration demand still exists, the duty ratio recovery control is performed according to the recovery function DUTrec: Wherein, kr is the power recovery coefficient, Tset is the set temperature, and Tcur is the current temperature.

[0031] In the specific implementation, the duty ratio adjustment control process adopts a two-way dynamic adjustment mechanism combining linear derating and recovery, which is used to realize adaptive output control in the process of compressor power exceeding the limit and falling back.

[0032] In the power limiting phase, when it is detected that the compressor power exceeds the limit threshold, the current driving duty ratio is adjusted according to the linear derating rule. Specifically, the current duty ratio is taken as the initial value, a new target duty ratio value is calculated according to the power overrun amplitude and the derating coefficient, and step-by-step execution is performed in the continuous control period, so that the compressor output power gradually decreases to the safe interval. The value range of the derating coefficient is 0.1-0.3, which is used to adjust the smoothness of the derating rate; when the power continuously exceeds the limit, the adjustment amount is repeatedly calculated according to the fixed period to form a closed-loop control, so that the compressor power is maintained at a value close to the rated value but not exceeding the safe upper limit. The entire derating process realizes the gradual reduction of power through the smooth modified duty ratio change, avoiding the transient load impact.

[0033] When the compressor power gradually falls back and stabilizes in the safe interval, and the temperature sensor detects that the refrigeration demand still exists, the power recovery phase is automatically entered. At this time, the duty ratio recovery amount is calculated according to the power recovery function to realize the step-by-step recovery of the driving output. The recovery function comprehensively considers the difference between the set temperature and the current temperature, and proportionally modifies the duty ratio through the power recovery coefficient, so that the compressor output capacity is dynamically adjusted with the temperature difference. The greater the temperature difference, the higher the recovery rate; when the temperature difference decreases, the recovery tends to be gentle, thereby avoiding the energy fluctuation caused by frequent start-stop.

[0034] The safe shutdown and recovery judgment logic includes: When the bus voltage Vbus is detected to be lower than the under-voltage threshold VUV=10.5V or higher than the over-voltage threshold VOV=16.0V, the duty ratio DUTcur is reduced to within 50% according to the linear derating proportion; if it continuously exceeds the set duration tabn=3s, the PWM driving signal is turned off to shut down the compressor enable signal ENA, and the shutdown is executed. When the compressor current Icom exceeds the current threshold Ilim=5A or the continuous rising trend exceeds the set change rate ΔIcom / Δt>0.5A / s, it is determined that the overload operation is executed, and the duty ratio step attenuation control logic is executed; When the power device temperature Tcom exceeds the temperature threshold Tlim=85℃, the compressor output power is gradually reduced to 70% of the rated power, and if the temperature continues to rise to Tshut=95℃, the emergency shutdown is triggered, and the compressor drive output and fan control signals are turned off.

[0035] In the specific implementation, the safe shutdown and recovery determination logic is composed of a voltage monitoring unit, a current protection unit, a temperature protection unit, and a safety management module, forming a multi-threshold multi-level protection mechanism to ensure the safe shutdown and controlled recovery of the compressor in abnormal states.

[0036] When the bus voltage Vbus detected by the bus voltage detection module is lower than the under-voltage threshold VUV=10.5V or higher than the over-voltage threshold OOV=16.0V, the safety management module immediately enters the first level of safety protection state. At this time, the microcontroller MCU controls the compressor drive module to perform linear derating operation on the current PWM duty ratio DUTcur, so that it is gradually reduced to within 50% of the initial value within a limited time, thereby reducing the current impact and limiting the power output. If the voltage anomaly lasts for more than a set duration tabn=3s, the PWM drive signal is further turned off, and the compressor enable signal ENA is turned off to perform safe shutdown to prevent damage to the compressor and related electrical elements caused by voltage fluctuations.

[0037] When the current detection unit detects that the compressor current Icom exceeds the current threshold Ilim=5A, or the change rate ΔIcom / Δt of the current rising trend exceeds 0.5A / s in the continuous monitoring period, it is determined that the compressor is in an overload operation state. At this time, the safety management module calls the duty ratio step attenuation logic to make the PWM drive signal gradually decrease by a fixed step ratio until the compressor current returns to the normal range, thereby realizing orderly power reduction and avoiding line overheating or drive module damage caused by sudden current increase.

[0038] In the temperature protection logic, the temperature sensor real-time collects the power device temperature Tcom, and when the temperature exceeds the temperature threshold Tlim=85℃, the controller gradually reduces the compressor output power to 70% of the rated power through the drive module. If the temperature continues to rise and reaches the emergency shutdown threshold Tshut=95℃, a secondary protection command is immediately triggered to turn off the compressor drive output and fan control signals, realizing emergency power-off and heat dissipation isolation.

[0039] After all protection processes end, when it is detected that the bus voltage, current and temperature return to the safe interval and maintain stable for more than a preset time window, the safety management module automatically clears the fault flag, reopens the compressor driving module and restores the normal running state.

[0040] Beneficial effects: The application samples and analyzes bus voltage, current, temperature and power running parameters, performs dynamic control according to refrigeration or heating mode signals and temperature setting requests after confirming the stability of power input, performs linear derating control by adjusting the PWM duty cycle when detecting that the power is close to the upper limit or the temperature deviates from the set range, and performs smooth recovery after the power returns to the safe interval, forming a continuous power regulation and energy consumption balance mechanism, so as to realize adaptive power optimization and energy efficiency improvement of compressor operation, effectively reducing instability and component stress damage caused by transient power fluctuation. The compressor power is limited, including: When the compressor enters the oiling stage, high load running control link is triggered when the compressor power Pcom is greater than 60W, and if the high load lasts for more than 1 minute and the fan voltage FAN is greater than or equal to 12V, power secondary determination is performed, When the compressor power Pcom is greater than 60W and lasts for more than 15 minutes, the compressor speed RPM is reduced by 100 rpm and is not less than 2700 rpm for load reduction; if the power is still greater than 60W after reduction and lasts for more than 1 minute, load reduction is performed again. If the power is reduced to less than or equal to 60W or the fan voltage does not reach 12V at any stage, steady state control strategy is performed.

[0041] Specifically, when the compressor is in the oiling stage, the running power of the compressor is detected in real time, and when the compressor power is greater than 60W, the high load running state is entered and continuous monitoring is started. If the high load state lasts for more than 1 minute and the fan voltage is not less than 12V, power secondary determination is performed to confirm whether the high load state is stable.

[0042] After confirming that the compressor is in a high load state for a long time, a speed reduction strategy is performed. When the compressor power lasts for more than 60W and the time lasts for more than 15 minutes, the compressor speed is gradually reduced by a step size of 100 rpm until the speed is not less than 2700 rpm. During the speed reduction process, the output duty cycle of the driving signal gradually decays according to a linear change rule, so that the load reduction process of the compressor is smooth, avoiding mechanical impact caused by sudden power drop.

[0043] If the compressor power still exceeds 60W after the reduction and lasts more than 1 minute, the same speed reduction logic is executed again, and the compressor speed is reduced by 100rpm until the power drops to the safe interval or reaches the minimum operating speed limit.

[0044] During operation, if the compressor power is detected to be below 60W or the fan voltage is below 12V, the high load operation logic is exited and the steady state operation control is entered. At this time, the compressor remains at the current speed and is adjusted slightly according to the power and voltage trends to maintain a balanced operation in the low power interval.

[0045] The steady state control strategy includes: When the compressor power Pcom is less than or equal to 60W and the fan voltage drops below 9.3V, the low voltage protection mode is entered, and when the compressor power Pcom is less than 50W and maintains for more than 1 minute, the steady state maintenance is performed; if the compressor power Pcom is greater than or equal to 50W, the operation is maintained and the fan voltage is waited to rise, and when the voltage does not drop to 9.3V, the consistency of the actual speed RPM and the set speed RPMset is determined, and if the actual speed reaches the set value, the speed is increased by 100rpm.

[0046] The compressor power limiting also includes: at any operating stage of the compressor, the panel setting state SET, the compressor power Pcom and the real-time speed RPM are monitored, if the panel is not set to the compressor power and the compressor power Pcom is greater than or equal to 90W for more than 30s, the compressor speed is reduced by 400r / s to 2700rpm for 3s; if the panel has set the compressor power but the actual speed fails to be reduced by 400r / s to 2700rpm for 3s within the preset time window, the fan is delayed for 3 minutes to perform heat dissipation protection.

[0047] Beneficial effects: the present application performs multi-stage dynamic adjustment on the operating state of the compressor in different power intervals through the synergistic control method, when the compressor power is detected to be continuously higher than the set threshold, the speed reduction and delay protection strategy is executed; if the power drops to the low load interval, the steady state maintenance or fine adjustment recovery is automatically executed according to the consistency of the fan voltage and the speed, the panel setting state and speed abnormality are monitored by the independent monitoring unit, the speed limiting protection and heat dissipation delay operation are actively triggered at any operating stage, the compressor stability is maintained in high load and low voltage conditions, the safety and reliability of the compressor control is improved, and the service life of the whole machine is prolonged.

[0048] The above-described embodiments can be implemented in whole or in part by software, hardware, firmware, or any combination thereof. When implemented by software, the above-described embodiments can be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer instructions or computer programs. When the computer instructions or computer programs are loaded or executed on a computer, the processes or functions described in the embodiments of the present application are generated in whole or in part. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable devices. The computer instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another computer-readable storage medium, for example, the computer instructions can be transmitted from one website, computer, server or data center to another website, computer, server or data center through a wired network or a wireless network. The computer-readable storage medium can be any available medium accessible by a computer or a data storage device such as a server, data center, etc. containing one or more available medium collections. The available medium can be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium. The semiconductor medium can be a solid state disk.

[0049] Some data in the above formula are dimensionless for numerical calculation, and the contents not described in detail in the specification are all prior art known to those skilled in the art.

[0050] The above embodiments are only used to illustrate the technical method of the present application and not to limit it. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical method of the present application can be modified or replaced equivalently without departing from the spirit and scope of the technical method of the present application.

Claims

1. A method for controlling the power of an on-board compressor, characterized in that, Including: S1. By detecting the voltage and analyzing the stability of the bus input, receiving the refrigeration mode signal, judging whether the refrigeration request is valid according to the temperature setting signal, and performing boundary limit correction if the set temperature exceeds the allowable range; S2. Collecting the current ambient temperature data through the temperature sensor, judging the refrigeration start condition according to the difference between the set temperature and the real-time temperature and the hysteresis threshold. When the temperature meets the start judgment relationship, generating a refrigeration start flag signal and triggering the operation logic of the compressor and the fan; S3. After receiving the heating mode signal, monitoring the voltage, current and temperature data, evaluating the operating load through the power calculation unit, and performing a smooth shutdown strategy to reduce the drive output and delay the shutdown of the fan when the operating power is higher than the control threshold; S4. When it is detected that the compressor power is close to the power upper limit, starting the dynamic limit control logic, adjusting the PWM duty cycle to reduce the output power, and periodically correcting the drive signal according to the power change trend; S5. When it is detected that the compressor power drops back to the safe range and there is still a refrigeration demand, restoring the duty cycle according to the recovery control function and gradually increasing the compressor output; S6. Continuously monitoring the bus voltage, current and power device temperature during operation. When an undervoltage, overvoltage, overcurrent or over-temperature state is detected, performing the safety shutdown and recovery judgment logic.

2. The method for controlling the power of an on-board compressor according to claim 1, characterized in that, When the bus voltage Vbus satisfies the condition between the undervoltage threshold VUV = 10.5V and the overvoltage threshold VOV = 16.0V, and the compressor is in a fault-free state, enter the power valid judgment stage and execute the following logical details: Performing smooth filtering on the average value of the continuous sampling of the bus voltage Vbus for N = 5 cycles, and calculating the smoothed voltage value Vavg: When the smoothed voltage value Vavg simultaneously satisfies VUV < Vavg < VOV and the voltage change rate |ΔV / Δt| < 0.2V / s, it is judged that the power input is stable; Receiving the refrigeration mode signal. If the refrigeration mode signal is "refrigeration", reading the temperature setting signal, and verifying whether the temperature set value is within the range of -6°C to 15°C; when the set value is out of bounds, limit correction is performed to the nearest valid boundary value, and the internal standardized parameter Tsetstd is generated.

3. The method for controlling the power of an on-board compressor according to claim 1, characterized in that, In S2, when the current temperature Tmeas collected by the temperature sensor needs to satisfy the following relationship: where ΔTh = 0.8°C is the start hysteresis threshold, setting the compressor status flag code to "1", and the refrigeration mode signal is "refrigeration"; if Tmeas - Tsetstd < ΔTh, no operation is performed.

4. The method for controlling the power of an on-board compressor according to claim 1, characterized in that, When performing the heating mode switching control, including: When receiving the heating mode signal and the bus voltage is between the undervoltage threshold and the overvoltage threshold, enter the heating mode switching process: Sampling the current bus voltage Vbus, the compressor current Icom and the temperature sensor signal Tmeas, calculating the compressor power Pcom = Vbus × Icom. If the compressor power Pcom > 10W, perform the smooth mode switching strategy: Gradually reducing the duty cycle DUT so that it linearly decays to zero within tdec = 3s; After the compressor is turned off, delay tfan = 30s, and then turn off the large fan.

5. The method for controlling the power of an on-board compressor according to claim 1, characterized in that, When the compressor power Pcom ≥ 0.9Plim is detected, the power dynamic limiting logic is activated: Adjusting the duty cycle of the DUT, power reduction is achieved according to the linear derating DUTnew formula: Wherein, DUTcur is the duty cycle, and kp is the power derating factor, which ranges from 0.1 to 0.3 and is used to control the derating rate. When the compressor power continuously exceeds the limit, the duty cycle adjustment is calculated according to a fixed cycle to achieve derating control.

6. The vehicle-mounted compressor power control method according to claim 1, characterized in that, When the power recovers to the safe range Pcom < 0.8Plim and the temperature sensor detects that the cooling demand still exists, duty cycle recovery control is executed according to the recovery function DUTrec: Where kr is the power recovery coefficient, Tset is the set temperature, and Tcur is the current temperature.

7. The method for controlling the power of an on-board compressor according to claim 1, characterized in that, The logic for determining safe shutdown and recovery includes: When the bus voltage Vbus is detected to be lower than the undervoltage threshold VUV=10.5V or higher than the overvoltage threshold VOV=16.0V, the duty cycle DUTcur will be reduced to less than 50% by a linear derating ratio; if it continues for more than the set duration tabn=3s, the PWM drive signal will be turned off and the compressor enable signal ENA will be shut down, and a shutdown will be executed. When the compressor current Icom is detected to exceed the current threshold Ilim=5A or the continuous upward trend exceeds the set change rate ΔIcom / Δt>0.5A / s, it is determined to be overload operation, and the duty cycle step decay control logic is executed. When the temperature of the power device Tcom exceeds the temperature threshold Tlim=85℃, the compressor output power is gradually reduced to 70% of the rated power. If the temperature continues to rise to Tshut=95℃, an emergency shutdown is triggered, shutting down the compressor drive output and fan control signal.

8. The vehicle-mounted compressor power control method according to claim 1, characterized in that, Limiting compressor power includes: When the compressor enters the oiling stage, a high-load operation control link is triggered when the compressor power Pcom > 60W. If the high load lasts for more than 1 minute and the fan voltage FAN ≥ 12V, a secondary power determination is performed. When the compressor power Pcom > 60W and lasts for more than 15 minutes, the compressor speed RPM is reduced by 100 rpm, but not lower than 2700 rpm, to reduce the load. If the power is still > 60W after the reduction and lasts for more than 1 minute, the load reduction is performed again. If the power drops to ≤60W or the fan voltage does not reach 12V at any stage, a steady-state control strategy will be implemented.

9. A method for controlling the power of an on-board compressor according to claim 8, characterized in that, The steady-state control strategy includes: When the compressor power Pcom ≤ 60W and the fan voltage drops below 9.3V, it enters the low-voltage protection mode. When the compressor power Pcom < 50W and remains so for more than 1 minute, it performs steady-state maintenance. If the compressor power Pcom ≥ 50W, it continues to run and waits for the fan voltage to recover. When the voltage does not drop to 9.3V, it judges the consistency between the actual speed RPM and the set speed RPMset. If the actual speed reaches the set value, it increases the speed by 100rpm.

10. A method for controlling the power of an on-board compressor according to claim 8, characterized in that, The limitation of compressor power also includes: monitoring the panel setting status SET, compressor power Pcom, and real-time speed RPM during any operation phase of the compressor; if it is detected that the compressor power is not set on the panel and the compressor power Pcom ≥ 90W lasts for more than 30 seconds, the compressor speed is reduced from 400r / s to 2700rpm and maintained for 3 seconds; if the compressor power is set on the panel but the actual speed is detected as failing to reduce from 400r / s to 2700rpm and maintain for 3 seconds within the preset time window, the fan is delayed for 3 minutes to perform heat dissipation protection.

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