Control device and method for vehicle air conditioner, vehicle air conditioner and vehicle

Abstract

The invention discloses a control device and method for a vehicle air conditioner, the vehicle air conditioner and a vehicle, and the device comprises an overcurrent protection switch which is arranged between a motor controller loop and an air conditioner loop; the detection unit is used for detecting the current flowing from the motor controller loop to the air conditioner loop to obtain a current detection signal under the conditions that the vehicle runs and the air conditioner runs; under the conditions that the vehicle runs and the air conditioner runs, the overcurrent protection switch is closed; the frequency converter determines whether the air conditioner loop needs overcurrent protection or not according to the current detection signal; if it is determined that the air conditioner loop needs over-current protection, an over-current protection switch is controlled to be switched off, so that the current flowing from the motor controller loop to the air conditioner loop is switched off, and an air conditioner protective tube is protected. According to the scheme, when the current flowing from the motor controller loop to the air conditioner loop is over-current, the motor controller loop and the air conditioner loop are controlled to be disconnected, so that the fuse of the air conditioner loop is prevented from being fused due to over-current, and the fuse of the air conditioner loop is protected.

Description

Technical Field

[0001] The present invention belongs to the field of vehicle technology, and specifically relates to a control device and method for a vehicle air conditioner, a vehicle air conditioner and a vehicle, and more particularly to a control device and method for a control circuit of a new energy vehicle air conditioner, a vehicle air conditioner and a vehicle. Background Art

[0002] In the field of new energy air-conditioned vehicles (such as new energy buses), the fuses of the air conditioners and the entire vehicle on pure electric buses serve as an overcurrent protection device in the circuit. When an abnormal situation such as a short circuit or overload occurs in the circuit, the fuse will quickly melt and cut off the power supply, thereby avoiding damage to the battery pack and other electrical components due to excessive current, and providing protection for passengers and vehicles.

[0003] The actual driving of new energy air-conditioned vehicles is complicated. The driver may experience various driving conditions such as sudden braking, sudden acceleration (sudden acceleration start of the vehicle during operation and sudden acceleration start after power failure during operation), uphill, downhill, etc. The voltage and current fluctuations of the high-voltage battery under different driving conditions are different. The air-conditioning system fuse is generally equipped with about 50A. Sudden acceleration will cause large fluctuations in the circuit current. When the current flowing to the air-conditioning fuse exceeds the configured maximum value, there will be a safety hazard of burning the air-conditioning fuse.

[0004] The above contents are only used to assist in understanding the technical solution of the present invention and do not constitute an admission that the above contents are prior art. Summary of the invention

[0005] The purpose of the present invention is to provide a control device and method for a vehicle air conditioner, a vehicle air conditioner and a vehicle, so as to solve the potential safety hazard of a new energy air-conditioned vehicle causing a fuse of the air conditioner to blow due to large current fluctuations under different road conditions and driving states, and to achieve the effect of protecting the fuse of the air conditioner circuit by controlling the connection between the motor controller circuit and the air conditioner circuit to be disconnected when the current flowing from the motor controller circuit to the air conditioner circuit overcurrents, so as to avoid the fuse of the air conditioner circuit from blowing due to overcurrent.

[0006] The present invention provides a control device for a vehicle air conditioner, wherein the vehicle air conditioner has a motor controller circuit and an air conditioning circuit; the air conditioning circuit has a frequency converter and an air conditioning fuse; the control device for the vehicle air conditioner comprises: a detection unit and an overcurrent protection switch; the overcurrent protection switch is arranged between the motor controller circuit and the air conditioning circuit; wherein the detection unit is used to detect the current flowing from the motor controller circuit to the air conditioning circuit when the vehicle is running and the air conditioning is running, so as to obtain a current detection signal; and transmit the current detection signal to the frequency converter; wherein when the vehicle is running and the air conditioning is running, the overcurrent protection switch is closed; the frequency converter is used to determine whether the air conditioning circuit needs overcurrent protection according to the current detection signal; if it is determined that the air conditioning circuit needs overcurrent protection, the overcurrent protection switch is controlled to be disconnected to disconnect the current flowing from the motor controller circuit to the air conditioning circuit to protect the air conditioning fuse.

[0007] In some embodiments, the air-conditioning circuit has a main DC contactor; in the direction from the motor controller circuit to the air-conditioning circuit, the overcurrent protection switch is located at the front end of the main DC contactor; the detection unit is specifically used to detect the current flowing from the motor controller circuit to the air-conditioning circuit from the front end of the overcurrent protection switch to obtain a current detection signal.

[0008] In some embodiments, the motor controller loop has a motor controller; in the direction from the motor controller loop to the air-conditioning loop, the overcurrent protection switch is located at the rear end of the motor controller; the detection unit is specifically used to detect the current flowing from the motor controller loop to the air-conditioning loop from the rear end of the motor controller to obtain a current detection signal.

[0009] Matching the above device, the present invention provides a vehicle air conditioner on another aspect, including: the control device of the vehicle air conditioner mentioned above.

[0010] Matching the above-mentioned device, the present invention further provides a vehicle on another aspect, comprising: the above-mentioned vehicle air-conditioning control device, or the above-mentioned vehicle air-conditioning.

[0011] To match the above-mentioned vehicle, another aspect of the present invention provides a method for controlling a vehicle air conditioner, comprising: using the detection unit, when the vehicle is running and the air conditioner is running, detecting the current flowing from the motor controller circuit to the air conditioning circuit to obtain a current detection signal; wherein, when the vehicle is running and the air conditioner is running, the overcurrent protection switch is closed; based on the current detection signal, determining whether the air conditioning circuit needs overcurrent protection; if it is determined that the air conditioning circuit needs overcurrent protection, controlling the overcurrent protection switch to open, so as to disconnect the current flowing from the motor controller circuit to the air conditioning circuit, and protect the air conditioning fuse.

[0012] In some embodiments, the current detection signal is a level signal that can be recognized by the main chip of the inverter; based on the current detection signal, determining whether the air-conditioning circuit needs overcurrent protection includes: when the vehicle accelerates during operation, recording the current detection signal as a first level signal; determining whether the first level signal is greater than a preset level signal, if it is determined that the first level signal is greater than the preset level signal, determining that the air-conditioning circuit needs overcurrent protection.

[0013] In some embodiments, the current detection signal is a level signal that can be recognized by the main chip of the inverter; when the vehicle accelerates during operation, the current detection signal is recorded as a first level signal; based on the current detection signal, it is determined whether the air-conditioning circuit needs overcurrent protection, and it also includes: when the vehicle accelerates after power failure, the current detection signal is recorded as a second level signal; it is determined whether the second level signal is greater than the first level signal, and the first level signal is greater than a preset level signal. If it is determined that the second level signal is greater than the first level signal, and the first level signal is greater than the preset level signal, it is determined that the air-conditioning circuit needs overcurrent protection.

[0014] In some embodiments, the current detection signal is a level signal that can be recognized by the main chip of the inverter; when the vehicle accelerates during operation, the current detection signal is recorded as a first level signal; based on the current detection signal, it is determined whether the air-conditioning circuit needs overcurrent protection, and it also includes: when the vehicle accelerates after turning during operation, the current detection signal is recorded as a third level signal; it is determined whether the third level signal is less than the first level signal and the third level signal is greater than the preset level signal. If it is determined that the third level signal is less than the first level signal and the third level signal is greater than the preset level signal, it is determined that the air-conditioning circuit does not need overcurrent protection.

[0015] In some embodiments, the current detection signal is a level signal that can be recognized by the main chip of the inverter; when the vehicle accelerates during operation, the current detection signal is recorded as a first level signal; based on the current detection signal, it is determined whether the air-conditioning circuit needs overcurrent protection, and it also includes: when the vehicle accelerates after turning during operation, the current detection signal is recorded as a fourth level signal; it is determined whether the fourth level signal is less than the first level signal and the fourth level signal is greater than the preset level signal. If it is determined that the fourth level signal is less than the first level signal and the fourth level signal is greater than the preset level signal, it is determined that the air-conditioning circuit does not need overcurrent protection.

[0016] Therefore, the scheme of the present invention sets a detection unit (such as a current and voltage detection board) for the motor controller circuit and the air-conditioning circuit of the vehicle air conditioner, which is used to detect the current flowing from the motor controller circuit to the air-conditioning circuit to obtain a current detection signal; and sets an overcurrent protection switch (such as an overcurrent cut-off DC contactor KM5) between the motor controller circuit and the air-conditioning circuit. When the inverter of the air-conditioning circuit recognizes that the overcurrent signal detected by the detection unit meets the preset overcurrent condition, the overcurrent protection switch is controlled to be disconnected to protect the fuse of the air-conditioning circuit; thereby, when the current flowing from the motor controller circuit to the air-conditioning circuit overcurrents, the connection between the motor controller circuit and the air-conditioning circuit is controlled to be disconnected to avoid the fuse of the air-conditioning circuit from being blown due to overcurrent, thereby protecting the fuse of the air-conditioning circuit.

[0017] Other features and advantages of the present invention will be set forth in the description which follows, and in part will be apparent from the description, or may be learned by practice of the present invention.

[0018] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic structural diagram of an embodiment of a vehicle air conditioner control device of the present invention;

[0020] Figure 2 This is a schematic diagram of the battery power supply circuit for the new energy vehicle air conditioner;

[0021] Figure 3 A schematic diagram of the structure of the pre-charging circuit of the overall power supply system of the new energy vehicle air conditioner;

[0022] Figure 4 It is a structural schematic diagram of a control device for a pre-charging circuit of an air conditioner in a new energy vehicle;

[0023] Figure 5 It is a flow chart of the main circuit overcurrent sampling control method of the new energy vehicle air conditioner;

[0024] Figure 6 The figure is a flow chart of an embodiment of a method for controlling a vehicle air conditioner according to the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0026] Considering that the high-voltage power battery of the new energy air-conditioned vehicle connects a series of high-voltage components such as the motor controller of the drive and steering motor, the DC charger, the air conditioner, and the three-in-one controller together, the internal high-voltage relay or DC contactor is controlled by the external low-voltage control circuit, and the high-voltage DC power supply of the high-voltage power battery is distributed according to the internal design of the high-voltage power supply. When the high-voltage current is transmitted, the terminals are tightened by bolts to achieve the connection of various high-voltage systems. Among them, the power source of the air-conditioning system and the motor controller is the high-voltage power battery, and the strong power supply circuit will be equipped with a pre-charging circuit and a fuse to prevent the impact of the large current caused by the instantaneous charging of the capacitor by the motor controller and the air conditioner when starting to damage the capacitor or power electronic devices.

[0027] New energy air-conditioned vehicles may experience large current fluctuations under different road conditions and driving states, which may cause the air-conditioning fuse to melt. In addition, the air-conditioning system may fail to cool, affecting the user's riding comfort and experience.

[0028] Therefore, the scheme of the present invention proposes a control device for an automobile air conditioner, specifically a control device for a control circuit of an air conditioner of a new energy automobile. The device identifies the large current of the control circuit of the air conditioner of the new energy automobile, and selects a suitable control method according to the magnitude of the current impact fluctuation to eliminate the large current impact and fluctuation, thereby solving the safety hazard of the air conditioning fuse blowing during the driving of the new energy air-conditioned vehicle, improving the reliability and safety of the air conditioner of the new energy automobile during operation, and improving the riding comfort and experience of the passengers.

[0029] According to an embodiment of the present invention, a control device for a vehicle air conditioner is provided. Figure 1 The vehicle has a motor drive control pre-charging system (such as Figure 2 The system A shown is Figure 3 The motor drive control system shown in the figure has a motor controller circuit (such as Figure 3The vehicle air conditioner has an air conditioning control pre-charging system (such as Figure 2 The B system shown is Figure 3 The air conditioning control pre-charging system shown in FIG. 1 ) has an air conditioning circuit (such as Figure 3 The air conditioning control pre-charging system control loop shown in FIG. 1 ); that is, the vehicle air conditioning has a motor controller loop and an air conditioning loop; the air conditioning loop has a frequency converter (such as Figure 3 The inverter with integrated main control chip shown), and air conditioner fuse (such as Figure 3 Air conditioning fuse FU1 shown); Figure 2 This is a schematic diagram of the battery power supply circuit for new energy vehicle air conditioners. Figure 2 As shown, the battery power supply circuit of the new energy vehicle air conditioner includes: independent high-voltage battery 1 and independent high-voltage battery 2 that can be shared, and independent high-voltage battery 1 is connected to independent high-voltage battery 2; independent high-voltage battery 1 supplies power to the motor controller through system A, and independent high-voltage battery 2 supplies power to the air conditioner, three-in-one, electric auxiliary heating and other systems through system B. System A is connected in parallel with system B. System A is like the motor drive control pre-charging system, and system B is like the air conditioner control pre-charging system. Figure 2 From the schematic diagram of the power supply of the air-conditioning battery of the new energy vehicle shown, it can be seen that the power supply of the new energy vehicle mainly consists of two independent high-voltage batteries 1 and high-voltage battery 2, which can be shared and connected in parallel. When each high-voltage battery system is damaged, it will not affect the other system. The high-voltage battery 1 system mainly supplies power to the A system, which is mainly composed of a motor controller to control the power supply and functional logic; in addition, the high-voltage battery 2 system mainly supplies power to the B system, which is mainly composed of air conditioning, three-in-one, electric auxiliary heating, and other systems to control the power supply and functional logic; the A system and the B system are also connected in parallel, so when supplying power, there will be a situation where the same high-voltage battery 1 or high-voltage battery 2 is used together.

[0030] In the solution of the present invention, as shown in the figure, the control device of the vehicle air conditioner includes: a detection unit (such as Figure 3 Current and voltage detection board shown), and overcurrent protection switch (such as Figure 3 The overcurrent cut-off DC contactor KM5 shown in the figure); the overcurrent protection switch is arranged between the motor controller circuit and the air conditioning circuit.

[0031] Wherein, the detection unit is used to detect the current flowing from the motor controller circuit to the air conditioning circuit when the vehicle is running and the air conditioner is running, so as to obtain a current detection signal; and transmit the current detection signal to the inverter; wherein, when the vehicle is running and the air conditioner is running, the overcurrent protection switch is closed.

[0032] The frequency converter is used to determine whether the air-conditioning circuit needs overcurrent protection according to the current detection signal.

[0033] The inverter is also used to control the overcurrent protection switch to be opened if it is determined that the air conditioning circuit requires overcurrent protection, so as to disconnect the current flowing from the motor controller circuit to the air conditioning circuit and protect the air conditioning fuse. Of course, the inverter is also used to maintain the overcurrent protection switch closed if it is determined that the air conditioning circuit does not require overcurrent protection.

[0034] The scheme of the present invention proposes a control scheme for a control circuit of an air conditioner of a new energy vehicle. When a driver performs sudden braking, sudden acceleration (sudden acceleration start of the vehicle during operation and sudden acceleration start after power failure during operation), turning, going uphill, going downhill and the like in actual complex road conditions, the current fluctuation is too large, causing the air conditioner fuse to blow. The control method of converting the detected and sampled current fluctuation into a level recognizable by the chip is used to select whether to cut off the DC contactor to eliminate the abnormal current fluctuation, thereby avoiding the blowing of the air conditioner fuse, improving the safety and reliability of the air conditioner operation, and solving the problem of the driver's air conditioner fuse blowing due to large current fluctuations in actual complex road conditions and various driving states.

[0035] In some embodiments, the air conditioning circuit has a main DC contactor (such as Figure 3 The main DC contactor KM1 shown in FIG. 1 ). In the direction from the motor controller circuit to the air conditioning circuit, the overcurrent protection switch is located at the front end of the main DC contactor.

[0036] The detection unit is specifically used to detect the current flowing from the motor controller circuit to the air conditioning circuit from the front end of the overcurrent protection switch to obtain a current detection signal.

[0037] In the solution of the present invention, an appropriate control method is selected according to the detected and sampled current fluctuation level to eliminate abnormal current fluctuations, thereby avoiding the fuse of the air conditioner, thereby achieving safe and reliable operation of the air conditioner of the new energy vehicle. Thus, the problem of the driver's air conditioner fuse fusing due to abnormal large impact current fluctuations under actual complex road conditions and various driving conditions is solved, which makes the air conditioner unable to cool normally. The fuse can be prevented from fusing in advance and the air conditioner can operate normally.

[0038] In some embodiments, the motor controller circuit has a motor controller. In the direction from the motor controller circuit to the air conditioning circuit, the overcurrent protection switch is located at the rear end of the motor controller.

[0039] The detection unit is specifically used to detect the current flowing from the motor controller circuit to the air conditioning circuit from the rear end of the motor controller to obtain a current detection signal.

[0040] Figure 3 This is a schematic diagram of the pre-charging circuit structure of the overall power supply system for new energy vehicle air conditioners. Figure 3 As shown, the overall power supply system of the air conditioner of a new energy vehicle includes: a high-voltage battery pack such as a battery pack that can provide 400V-6300VDC, a motor drive control pre-charging system A, and an air conditioning control pre-charging system B. Among them, the motor drive control pre-charging system A has a main DC contactor KM3, a vehicle fuse FU2, a pre-charging cement resistor R1, a pre-charging DC contactor KM4, a motor capacitor C2, and a motor controller. The air conditioning control pre-charging system B has an overcurrent cut-off DC contactor KM5, a main DC contactor KM1, a current and voltage detection board, an air conditioning fuse FU1, a pre-charging cement resistor R, a pre-charging DC contactor KM2, a capacitor C1, an inverter with an integrated main control chip, and a compressor.

[0041] Among them, the positive electrode of the high-voltage battery pack is connected to the first connection end of the inverter integrated with the main control chip through the contact of the main DC contactor KM3, the vehicle fuse FU2, the contact of the overcurrent cut-off DC contactor KM5, the contact of the main DC contactor KM1, and the air-conditioning fuse FU1. The positive electrode of the high-voltage battery pack is also connected to the common end of the main DC contactor KM3 and the vehicle fuse FU2 through the contact of the pre-charged DC contactor KM4 and the pre-charged cement resistor R1; the common end of the vehicle fuse FU2 and the overcurrent cut-off DC contactor KM5 is connected to the negative electrode of the high-voltage battery pack through the capacitor C2; the common end of the vehicle fuse FU2 and the overcurrent cut-off DC contactor KM5 is also connected to the negative electrode of the high-voltage battery pack through the motor controller. The common end of the overcurrent cut-off DC contactor KM5 and the main DC contactor KM1 is connected to the contact of the main DC contactor KM1 and the common end of the air-conditioning fuse FU1 through the pre-charged DC contactor KM2 and the pre-charged cement resistor R; the common end of the air-conditioning fuse FU1 and the inverter with integrated main control chip is connected to the negative pole of the high-voltage battery pack through the capacitor C1. The current and voltage detection board is used to detect the current and voltage at the common end of the motor controller and the overcurrent cut-off DC contactor KM5. The current and voltage detection board is connected to the inverter with integrated main control chip through CAN communication. CAN communication is a serial communication protocol bus for real-time applications. The current and voltage detection board refers to the main board that detects and collects abnormal impact large currents and converts them into voltage signals that can be recognized by the inverter main chip. It belongs to the automotive air-conditioning control circuit and communicates with the inverter main board through CAN.

[0042] Among them, the specific structure of the current and voltage detection board can include a flyback switching power supply, a buck conversion (BUCK) power supply chip or an LDO power supply, a comparator, an operational amplifier and its main chip, an indicator light and a CAN communication circuit. Since the input of the current and voltage detection board is strong electricity, the current and voltage detection board with a flyback switching power supply is first isolated and stepped down to a DC weak current of +24V or +12V and filtered, and the weak current is converted into a +3.3V or +5V voltage for the comparator, the operational amplifier and its main chip to work through a BUCK power supply chip or a low dropout regulator (Low Dropout Regulator, LDO) power supply, and another power supply is used to supply power to the indicator light and the CAN communication circuit. The indicator light is used to display the working status and fault status of the current and voltage detection board. The voltage detection part mainly uses resistor voltage division to collect the analog IO port of the main chip. The current detection part is mainly composed of an operational amplifier, a comparator and a sampling resistor. The operational amplifier model can be OPA4374AID, the comparator model can be LM293ADR, the main chip model can be TI's G-MatrikII-A (FLASH), and the sampling resistor can be a chip resistor 4527 0.005Ω±1% / 5W (variable frequency).

[0043] Depend on Figure 4 From the control device of the new energy vehicle air-conditioning pre-charging circuit shown, it can be known that the pre-charging DC contactor KM2 is matched with the pre-charging cement resistor to complete the strong power-on to pre-charge the circuit to prevent high current from damaging the controller mainboard; the main DC contactor KM1 is always energized after the pre-charging is completed, and the device is always working when the air-conditioning is working. The air-conditioning fuse FU1 is blown in time to prevent high current from damaging the rear-end mainboard. The capacitor C1 is generally a metalized polypropylene film capacitor, which is used to stabilize the bus voltage and smooth the bus voltage. At the moment the unit is powered on, it is equivalent to charging the C1 capacitor. There will be a momentary impact of high current during the charging process. In this way, KM2 is matched with the pre-charging cement resistor to eliminate the high current generated at this moment. After pre-charging, the 6 IGBT tubes at the rear end start to send drive signals to inverter drive the compressor motor M when the main chip detection logic functions of the unit are normal and there is no short circuit in the mainboard.

[0044] Figure 4 This is a structural schematic diagram of the control device of the pre-charging circuit of the air conditioner of a new energy vehicle. Figure 4 Can display Figure 2 The working principle of the air conditioning module's pre-charge control circuit and inverter to drive the compressor. Figure 4As shown, the positive electrode of the high-voltage battery pack E is connected to the first connection end of the capacitor C1 through the contact of the main DC contactor KM1 and the air-conditioning fuse FU1; the positive electrode of the high-voltage battery pack E is connected to the common end of the contact of the main DC contactor KM1 and the air-conditioning fuse FU1 through the pre-charged DC contactor KM2 and the pre-charged cement resistor R; the negative electrode of the high-voltage battery pack E is connected to the second connection end of the capacitor C1. The first connection end of the capacitor C1 is connected to the first connection end of the input end of the inverter; the second connection end of the capacitor C1 is connected to the second connection end of the input end of the inverter; the output end of the inverter is connected to the three-phase winding of the motor M.

[0045] exist Figure 2 , Figure 3 and Figure 4 In the example shown, a current and voltage detection board and an overcurrent cut-off DC contactor KM5 are set up. The current and voltage detection board detects and collects abnormally large currents. The detected and sampled current fluctuations are converted into a level that can be recognized by the main chip to select whether to control the overcurrent cut-off DC contactor KM5 to cut off the control mode of the DC contactor to eliminate abnormal current fluctuations and avoid the fuse of the air conditioner from blowing. Figure 3 From the example shown, it can be seen that the current and voltage detection board specifically samples the current on the same branch from the high-voltage circuit at the rear end of the motor controller power supply to the middle of the front end of the air conditioner pre-charging. The motor controller and the air conditioner are connected in parallel, so the power between them comes from the shared independent high-voltage battery 1 or the independent high-voltage battery 2 power high-voltage direct current.

[0046] from Figure 3 and Figure 4 From the example shown, it can be seen that the large capacitor (such as capacitor C1) and the main DC contactor KM1 and the auxiliary pre-charging DC contactor KM2 of the air conditioner of the new energy vehicle are connected in parallel with the capacitor C2 of the motor controller on the high-voltage power line. According to the different power-on priorities: the car will first power on and pre-charge the motor controller, that is, the pre-charging DC contactor KM4 is closed first, the main DC contactor KM3 is disconnected, and the pre-charging DC contactor KM4 is opened after the pre-charging is completed, and then the main DC contactor KM3 is closed; then a start command is issued to the air conditioner. Since the air conditioner control end is weak current to control strong current, the battery 24V first supplies power to the main control part of the main board of the air conditioner inverter, and the air conditioner control board issues a weak current command to control the auxiliary DC contactor of the air conditioner (pre-charging DC contactor KM2) to close, and charge the capacitor on the air conditioner controller board. After the pre-charging is completed, the pre-charging DC contactor KM2 is controlled to pop open, and then the main DC contactor KM1 of the air conditioner is closed to supply power to the drive part. After the main chip detects that the air conditioner load is operating normally, the compressor is started for cooling, and the air conditioner operates normally.

[0047] In the scheme of the present invention, according to the risk of abnormal impact of large current that may cause the driver to melt the fuse under different road conditions and driving states, the large current identified in the circuit is detected and sampled, and the large current impact and fluctuation are eliminated by selecting a suitable control method according to the size level of the current impact fluctuation, thereby solving the problem of frequent burning of the air-conditioning fuse in related schemes, allowing the driver to avoid blowing the fuse in the face of complex road conditions and driving states, and improving the reliability, comfort and safety of the car air conditioner.

[0048] When a new energy air-conditioned vehicle is running, the sudden acceleration start of the vehicle during operation and the sudden acceleration start after power failure during operation are two different driving states, both of which will cause the current and voltage flowing from the motor controller circuit to the air-conditioning circuit to fluctuate. According to the priority and actual situation, these two situations are assumed: when the motor controller is powered on, the driver then turns on the vehicle hand operator to turn on the air-conditioning. In addition, the air-conditioning is assumed to be turned on all the time during the operation of the vehicle; Figure 2 From the example shown, it can be seen that system A is mainly powered by an independent high-voltage battery 1 and controls the motor controller; system B is mainly powered by an independent high-voltage battery 2 and controls the air-conditioning system, three-in-one system, electric auxiliary heating system and other systems. The parallel connection of system A and system B is efficient and will not cause the entire system to be paralyzed due to a failure in a certain system. At the same time, since the high-voltage batteries that power system A and system B can be shared, if the voltage and current of the high-voltage battery of system A fluctuate, it will directly cause corresponding fluctuations in the voltage and current of the system B circuit.

[0049] According to the actual situation, the air conditioner is always on by default before the vehicle is accelerated during operation. When the vehicle is accelerated during operation, the output power required by the motor controller becomes larger, the discharge current of the high-voltage battery pack increases, and the current and voltage fluctuations of the high-voltage battery pack become larger. The large current fluctuations flow from the motor controller circuit to the main circuit of the air conditioner. When the air conditioner is cooling normally, the main DC contactor KM1 of the air conditioner is always in a closed state. The large current caused by the high-voltage battery fluctuations will impact the fuse FU1 at the rear end of the air conditioner's strong main circuit. In addition, in the hot summer weather, the heating of the fuse will be more serious than usual. The long-term heat accumulation of the fuse will cause the battery current fluctuation to flow back to the main circuit of the air conditioner due to the hot summer and the sudden acceleration start, indirectly causing the air conditioner fuse FU1 to melt. Therefore, the melting and burning of the fuse FU1 is mainly caused by overcurrent. The solution and control method are to install an overcurrent cut-off DC contactor KM5 and a control board with strong current filtering effect, strong current voltage, and current detection protection at the front end of the air conditioner main and auxiliary DC contactors KM1 and KM2 to sample the fluctuating strong current voltage and current and cut off the abnormally large current in time, so as to Figure 3From the example shown, it can be seen that the current and voltage detection board communicates with the inverter of the integrated main control chip through CAN. When the driver accelerates and starts the vehicle suddenly, the fluctuating current due to the discharge of the high-voltage battery will be much larger than the current in other driving states, recorded as current I1, and the voltage will be lowered. When the fluctuating voltage and current are supplied to the main chip on the board through strong electric filtering and step-down power supply, the sampled voltage and current signals are converted into level signals recognizable by the main chip on the inverter through CAN communication, recorded as voltage U2. Voltage U2 is mainly the level of the sampled fluctuating current converted into voltage; the software is set in the main chip program of the inverter The value of the normal sampling current converted into a voltage is recorded as U0. When U2>U0, the inverter main chip of the integrated main control chip recognizes that the current flowing into the air-conditioning main circuit fluctuates and overcurrent occurs during the rapid acceleration of the vehicle at this time, and sends an overcurrent cut-off signal to the detection board to cut off the DC contactor KM5, thereby protecting the air-conditioning fuse FU1 from overcurrent melting. The scheme of the present invention mainly detects the situation where the air-conditioning fuse melts due to the abnormally large current flowing into the air-conditioning main circuit through sampling. The voltage in the circuit generally fluctuates very little or is pulled down by more than ten volts or dozens of volts. Therefore, the fuse directly caused by the voltage fluctuation and pull-down in the circuit is not considered.

[0050] Only when the vehicle is started by sudden acceleration will the current flowing to the main circuit of the air conditioner fluctuate greatly and overcurrent will occur. The abnormal overcurrent signal sampled by the current and voltage detection board will be converted into a level signal recognizable by the inverter, and then compared with the voltage U0 converted from the sampled current value set by the software. When the sampled voltage level satisfies U2>U0, the contactor KM5 will cut off the main circuit of the air conditioner to protect the fuse FU1 at the rear end of the air conditioner.

[0051] During the operation of the new energy air-conditioned vehicle, it is accelerated suddenly after power failure. At this time, if the electric vehicle is powered on again after power failure, and then the air conditioner is also powered on, due to the short time interval of the pre-charging capacitor of the motor controller and the large capacitor C2 of the motor controller, it does not have the active discharge function. The sudden acceleration at the moment of power failure, the high voltage on the capacitor C2 of the motor controller has no time to change suddenly, and the capacitor C2 of the motor controller will immediately charge the capacitor C1 of the air conditioning controller. Since the resistance value of the air conditioning fuse FU1 is very small, the recharge current in the circuit is too large to cause the air conditioning fuse FU1 to fuse and burn. The solution and control method are also to install the overcurrent cut-off DC contactor KM5 and the control board with strong current filtering effect, strong current voltage and current detection protection at the front end of the main and auxiliary DC contactors KM1 and KM2 of the air conditioner to sample the fluctuating strong current voltage and current and cut off the abnormally large current in time. When the driver accelerates suddenly after power failure during operation, the motor controller capacitor C2 will immediately charge the air-conditioning controller capacitor C1, and the current will be very large, recorded as current I2, and the voltage will also be slightly lowered. When the fluctuating voltage and current are filtered by strong electricity and powered by step-down power supply to the main chip on the board, the sampled current signal is converted into a level signal recognizable by the main chip on the inverter through CAN communication, recorded as voltage U3. Voltage U3 is mainly the level of the sampled fluctuating current converted into a voltage. When voltage U3 ≥ voltage U2 > voltage U0, the inverter main chip with integrated main control chip recognizes that the current flowing into the air-conditioning main circuit during the rapid acceleration start after power failure during operation of the vehicle has an overcurrent condition, and sends an overcurrent cut-off signal to the detection board to cut off the DC contactor KM5. The detection board controls KM5 to send a disconnect signal, thereby protecting the air-conditioning fuse FU1 from overcurrent.

[0052] When the vehicle brakes suddenly, the vehicle slows down, and the voltage and current flowing to the air-conditioning main circuit are both lowered. At this time, the sampled fluctuating current is converted into a voltage recorded as voltage U4<U0, the air-conditioning fuse FU1 does not blow, and the overcurrent cut-off DC contactor KM5 does not operate.

[0053] When the vehicle is turning, due to the slight deceleration of the braking action, the current flowing to the main circuit of the air conditioner becomes smaller and the voltage fluctuation is smaller. At this time, the sampled fluctuating current is converted into a voltage and recorded as voltage U5<U0. The air conditioner fuse FU1 does not melt, and the overcurrent cut-off DC contactor KM5 does not operate.

[0054] When the vehicle accelerates after turning, the acceleration will increase the current flowing to the main circuit of the air conditioner and lower the voltage. In practice, the acceleration current of the turn will not cause the air conditioner fuse to blow. At this time, the sampled fluctuating current is converted into a voltage and recorded as voltage U6. Voltage U6>U0, the air conditioner fuse FU1 does not blow, and the overcurrent cut-off DC contactor KM5 does not operate.

[0055] When the vehicle is traveling uphill, it will accelerate, which will increase the current flowing to the main circuit of the air conditioner and lower the voltage. In practice, the current will not cause the air conditioner fuse to blow when the vehicle is traveling uphill. At this time, the sampled fluctuating current is converted into a voltage recorded as U7. The voltage U7>U0, the air conditioner fuse FU1 does not blow, and the overcurrent cut-off DC contactor KM5 does not operate.

[0056] When the vehicle is traveling downhill, the battery will be charged due to the regenerative braking of the motor, which will cause the battery voltage to rise slightly. But overall, the fluctuation of the battery voltage is relatively small, because the battery management system (BMS) will maintain the voltage stability by adjusting the balance of charging and discharging. When going downhill, the corresponding braking and deceleration action will be performed, which will reduce the current flowing to the main circuit of the air conditioner. At this time, the sampled fluctuating current is converted into a voltage and recorded as voltage U1. Voltage U1<U0, the air conditioner fuse FU1 does not melt, so the overcurrent cut-off DC contactor KM5 does not operate.

[0057] In the scheme of the present invention, the current flowing to the main circuit of the air conditioner will fluctuate greatly and overcurrent will occur only when the vehicle is started by sudden acceleration or after power failure during operation. The abnormal overcurrent signal is sampled by the current and voltage detection board and converted into a level signal recognizable by the inverter. The voltage U0 converted by the sampled current value is compared with the software setting value. When the sampled voltage level satisfies U3≥U2>U0, the contactor KM5 will cut off the main circuit of the air conditioner to protect the fuse FU1 at the rear end of the air conditioner.

[0058] In the scheme of the present invention, the air conditioner of the new energy vehicle is mainly detected under various complex driving conditions and combined with the actual situation, and the overcurrent DC contactor KM5 is timely cut off to protect the air conditioner fuse FU1 by detecting the abnormal large current flowing into the main circuit of the air conditioner, which causes the air conditioner fuse to blow. Since the air conditioner fuse FU1 is mainly directly caused by excessive current, the voltage is too high or too low, which may also indirectly cause the current flowing into the main circuit of the air conditioner to increase, thereby causing the air conditioner fuse FU1 to burn out, but these situations are rare. The scheme of the present invention solves the safety hazard of the air conditioner fuse blowing during the driving of the new energy air-conditioned vehicle, is conducive to the safe and efficient operation of the air conditioner, ensures the performance and service life of the air conditioner, reduces the maintenance cost and the whole vehicle operation cost; improves the reliability and safety of the air conditioner of the new energy vehicle during operation, and improves the riding comfort and experience of passengers.

[0059] By adopting the technical solution of the present invention, a detection unit (such as a current and voltage detection board) is set for the motor controller circuit and the air-conditioning circuit of the vehicle air conditioner to detect the current flowing from the motor controller circuit to the air-conditioning circuit to obtain a current detection signal; and an overcurrent protection switch (such as an overcurrent cut-off DC contactor KM5) is set between the motor controller circuit and the air-conditioning circuit. When the frequency converter of the air-conditioning circuit recognizes that the overcurrent signal detected by the detection unit meets the preset overcurrent condition, the overcurrent protection switch is controlled to be disconnected to protect the fuse of the air-conditioning circuit; thus, when the current flowing from the motor controller circuit to the air-conditioning circuit overcurrents, the connection between the motor controller circuit and the air-conditioning circuit is controlled to be disconnected to avoid the fuse of the air-conditioning circuit from being blown due to overcurrent, thereby protecting the fuse of the air-conditioning circuit.

[0060] According to an embodiment of the present invention, a vehicle air conditioner corresponding to the control device of the vehicle air conditioner is also provided. The vehicle air conditioner may include: the control device of the vehicle air conditioner described above.

[0061] Since the processing and functions implemented by the vehicle air conditioner of this embodiment basically correspond to the embodiments, principles and examples of the device, for the details not described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0062] According to an embodiment of the present invention, a vehicle corresponding to the control device of the vehicle air conditioner is also provided. The vehicle may include: the control device of the vehicle air conditioner described above.

[0063] Since the processing and functions implemented by the vehicle of this embodiment basically correspond to the embodiments, principles and examples of the device, for the details not described in this embodiment, please refer to the relevant descriptions in the aforementioned embodiments and will not be repeated here.

[0064] According to an embodiment of the present invention, a vehicle air conditioner control method corresponding to a vehicle is also provided. Figure 6 The flowchart of an embodiment of the method of the present invention is shown in FIG. The vehicle air conditioner control method may include: steps S110 to S130.

[0065] At step S110, the detection unit detects the current flowing from the motor controller circuit to the air conditioning circuit when the vehicle is running and the air conditioner is running, and obtains a current detection signal; wherein, when the vehicle is running and the air conditioner is running, the overcurrent protection switch is closed.

[0066] In step S120, the frequency converter determines whether the air conditioning circuit requires overcurrent protection according to the current detection signal.

[0067] At step S130, if the inverter determines that the air conditioning circuit requires overcurrent protection, the overcurrent protection switch is controlled to be opened to disconnect the current flowing from the motor controller circuit to the air conditioning circuit to protect the air conditioning fuse. Of course, if the inverter determines that the air conditioning circuit does not require overcurrent protection, the overcurrent protection switch is maintained closed.

[0068] The scheme of the present invention proposes a control scheme for a control circuit of an air conditioner of a new energy vehicle. When a driver performs sudden braking, sudden acceleration (sudden acceleration start of the vehicle during operation and sudden acceleration start after power failure during operation), turning, going uphill, going downhill and the like in actual complex road conditions, the current fluctuation is too large, causing the air conditioner fuse to blow. The control method of converting the detected and sampled current fluctuation into a level recognizable by the chip is used to select whether to cut off the DC contactor to eliminate the abnormal current fluctuation, thereby avoiding the blowing of the air conditioner fuse, improving the safety and reliability of the air conditioner operation, and solving the problem of the driver's air conditioner fuse blowing due to large current fluctuations in actual complex road conditions and various driving states.

[0069] In some embodiments, the current detection signal is a level signal that can be recognized by the main chip of the inverter. In step S120, the inverter determines whether the air conditioning circuit needs overcurrent protection according to the current detection signal, including: when the vehicle accelerates during operation, the current detection signal is recorded as a first level signal (such as voltage U2); determine whether the first level signal is greater than a preset level signal, and if it is determined that the first level signal is greater than the preset level signal, it is determined that the air conditioning circuit needs overcurrent protection. The preset level signal is such as voltage U0.

[0070] In the scheme of the present invention, when the new energy air-conditioned vehicle is running, the sudden acceleration start of the vehicle during operation and the sudden acceleration start after power failure during operation are two different driving states, both of which will cause the current and voltage flowing from the motor controller circuit to the air-conditioning circuit to fluctuate. According to the priority and actual situation, these two situations are defaulted: when the motor controller is powered on, the driver then turns on the vehicle hand operator to control the air-conditioning to turn on. In addition, the air-conditioning is always turned on by default during the operation of the vehicle; Figure 2 From the example shown, it can be seen that system A is mainly powered by an independent high-voltage battery 1 and controls the motor controller; system B is mainly powered by an independent high-voltage battery 2 and controls the air-conditioning system, three-in-one system, electric auxiliary heating system and other systems. The parallel connection of system A and system B is efficient and will not cause the entire system to be paralyzed due to a failure in a certain system. At the same time, since the high-voltage batteries that power system A and system B can be shared, if the voltage and current of the high-voltage battery of system A fluctuate, it will directly cause corresponding fluctuations in the voltage and current of the system B circuit.

[0071] According to the actual situation, the air conditioner is always on by default before the vehicle is accelerated during operation. When the vehicle is accelerated during operation, the output power required by the motor controller becomes larger, the discharge current of the high-voltage battery pack increases, and the current and voltage fluctuations of the high-voltage battery pack become larger. The large current fluctuations flow from the motor controller circuit to the main circuit of the air conditioner. When the air conditioner is cooling normally, the main DC contactor KM1 of the air conditioner is always in a closed state. The large current caused by the high-voltage battery fluctuations will impact the fuse FU1 at the rear end of the air conditioner's strong main circuit. In addition, in the hot summer weather, the heating of the fuse will be more serious than usual. The long-term heat accumulation of the fuse will cause the battery current fluctuation to flow back to the main circuit of the air conditioner due to the hot summer and the sudden acceleration start, indirectly causing the air conditioner fuse FU1 to melt. Therefore, the melting and burning of the fuse FU1 is mainly caused by overcurrent. The solution and control method are to install an overcurrent cut-off DC contactor KM5 and a control board with strong current filtering effect, strong current voltage, and current detection protection at the front end of the air conditioner main and auxiliary DC contactors KM1 and KM2 to sample the fluctuating strong current voltage and current and cut off the abnormally large current in time, so as to Figure 3 From the example shown, it can be seen that the current and voltage detection board communicates with the inverter of the integrated main control chip through CAN. When the driver accelerates and starts the vehicle suddenly, the fluctuating current due to the discharge of the high-voltage battery will be much larger than the current in other driving states, recorded as current I1, and the voltage will be lowered. When the fluctuating voltage and current are supplied to the main chip on the board through strong electric filtering and step-down power supply, the sampled voltage and current signals are converted into level signals recognizable by the main chip on the inverter through CAN communication, recorded as voltage U2. Voltage U2 is mainly the level of the sampled fluctuating current converted into voltage; the software is set in the main chip program of the inverter The value of the normal sampling current converted into a voltage is recorded as U0. When U2>U0, the inverter main chip of the integrated main control chip recognizes that the current flowing into the air-conditioning main circuit fluctuates and overcurrent occurs during the rapid acceleration of the vehicle at this time, and sends an overcurrent cut-off signal to the detection board to cut off the DC contactor KM5, thereby protecting the air-conditioning fuse FU1 from overcurrent melting. The scheme of the present invention mainly detects the situation where the air-conditioning fuse melts due to the abnormally large current flowing into the air-conditioning main circuit through sampling. The voltage in the circuit generally fluctuates very little or is pulled down by more than ten volts or dozens of volts. Therefore, the fuse directly caused by the voltage fluctuation and pull-down in the circuit is not considered.

[0072] In the scheme of the present invention, the current flowing to the main circuit of the air conditioner will fluctuate greatly and overcurrent will occur only when the vehicle is started by sudden acceleration. The abnormal overcurrent signal is sampled by the current and voltage detection board and converted into a level signal recognizable by the inverter. The voltage U0 converted by the sampled current value is compared with the software set value. When the sampled voltage level satisfies U2>U0, the contactor KM5 will cut off the main circuit of the air conditioner to protect the fuse FU1 at the rear end of the air conditioner.

[0073] In some embodiments, the current detection signal is a level signal that can be recognized by the main chip of the inverter; when the vehicle accelerates during operation, the current detection signal is recorded as a first level signal (such as voltage U2). In step S120, the inverter is used to determine whether the air-conditioning circuit needs overcurrent protection based on the current detection signal, and it also includes: when the vehicle is accelerated after power failure, the current detection signal is recorded as a second level signal (such as voltage U3); determine whether the second level signal is greater than the first level signal, and the first level signal is greater than the preset level signal. If it is determined that the second level signal is greater than the first level signal, and the first level signal is greater than the preset level signal, it is determined that the air-conditioning circuit needs overcurrent protection. Among them, the preset level signal is such as voltage U0.

[0074] In the scheme of the present invention, during the operation of the new energy air-conditioned vehicle, the vehicle is rapidly accelerated after power failure. At this time, if the electric vehicle is powered on again after power failure, the air conditioner is also powered on subsequently. Since the pre-charging time interval of the motor controller capacitor is short, and since the capacitor C2 of the motor controller is large and does not have an active discharge function, the vehicle is rapidly accelerated at the moment of power failure, and the high voltage on the motor controller capacitor C2 has no time to suddenly change. The motor controller capacitor C2 will immediately charge the capacitor C1 of the air-conditioning controller. Since the resistance value of the air-conditioning fuse FU1 is very small, the recharge current in the circuit is too large to cause the air-conditioning fuse FU1 to fuse and burn. The solution and control method are also to install a DC contactor KM5 with overcurrent cutoff and a control board with strong electric filtering effect, strong electric voltage, and current detection protection at the front end of the main and auxiliary DC contactors KM1 and KM2 of the air-conditioning to sample the fluctuating strong electric voltage and current and the abnormally large current Cut off in time. When the driver accelerates and starts suddenly after power failure during operation, the motor controller capacitor C2 will immediately charge the air-conditioning controller capacitor C1. The current will be very large, recorded as current I2, and the voltage will be slightly lowered. When the fluctuating voltage and current are supplied to the main chip on the board through strong electric filtering and step-down power supply, the sampled current signal is converted into a level signal recognizable by the main chip on the inverter through CAN communication, recorded as voltage U3. Voltage U3 is mainly the level of the sampled fluctuating current converted into a voltage. When voltage U3 ≥ voltage U2 > voltage U0, the inverter main chip with integrated main control chip recognizes that the current flowing into the air-conditioning main circuit during the rapid acceleration and starting after power failure during operation of the vehicle has an overcurrent condition, and sends an overcurrent cut-off signal to the detection board to cut off the DC contactor KM5. The detection board controls KM5 to send a disconnect signal, thereby protecting the air-conditioning fuse FU1 from overcurrent melting.

[0075] When the vehicle brakes suddenly, the vehicle slows down, and the voltage and current flowing to the air-conditioning main circuit are both lowered. At this time, the sampled fluctuating current is converted into a voltage recorded as voltage U4<U0, the air-conditioning fuse FU1 does not blow, and the overcurrent cut-off DC contactor KM5 does not operate.

[0076] When the vehicle is turning, due to the slight deceleration of the braking action, the current flowing to the main circuit of the air conditioner becomes smaller and the voltage fluctuation is smaller. At this time, the sampled fluctuating current is converted into a voltage and recorded as voltage U5<U0. The air conditioner fuse FU1 does not melt, and the overcurrent cut-off DC contactor KM5 does not operate.

[0077] In the scheme of the present invention, the current flowing to the main circuit of the air conditioner will fluctuate greatly and overcurrent will occur only when the vehicle is started up suddenly after power failure during operation. The abnormal overcurrent signal is sampled by the current and voltage detection board and converted into a level signal recognizable by the inverter. The signal is then compared with the voltage U0 converted from the sampled current value according to the software setting value. When the sampled voltage level satisfies U3>U0, the contactor KM5 will cut off the main circuit of the air conditioner to protect the fuse FU1 at the rear end of the air conditioner.

[0078] In some embodiments, the current detection signal is a level signal that can be recognized by the main chip of the inverter; when the vehicle accelerates during operation, the current detection signal is recorded as a first level signal (such as voltage U2). In step S120, the inverter is used to determine whether the air-conditioning circuit needs overcurrent protection according to the current detection signal, and it also includes: when the vehicle accelerates after turning during operation, the current detection signal is recorded as a third level signal (such as voltage U6); determine whether the third level signal is less than the first level signal and the third level signal is greater than the preset level signal. If it is determined that the third level signal is less than the first level signal and the third level signal is greater than the preset level signal, it is determined that the air-conditioning circuit does not need overcurrent protection. Wherein, the preset level signal is such as voltage U0.

[0079] In the solution of the present invention, when the vehicle accelerates after turning, the acceleration will increase the current flowing to the main circuit of the air conditioner and lower the voltage. Practically speaking, the acceleration current of the turn will not cause the air conditioner fuse to blow. At this time, the sampled fluctuating current is converted into a voltage and recorded as voltage U6. Voltage U6>U0, the air conditioner fuse FU1 will not blow, and the overcurrent cut-off DC contactor KM5 will not operate.

[0080] In the scheme of the present invention, when the vehicle accelerates after turning, the abnormal overcurrent signal sampled by the current and voltage detection board will be converted into a level signal recognizable by the inverter, and then compared with the voltage U0 converted from the sampled current value according to the software setting value. When the sampled voltage level satisfies U6>U0, the contactor KM5 will not cut off the main circuit of the air conditioner to protect the rear end fuse FU1 of the air conditioner.

[0081] In some embodiments, the current detection signal is a level signal that can be recognized by the main chip of the inverter; when the vehicle accelerates during operation, the current detection signal is recorded as a first level signal (such as voltage U2). In step S120, the inverter is used to determine whether the air-conditioning circuit needs overcurrent protection according to the current detection signal, and it also includes: when the vehicle accelerates after turning during operation, the current detection signal is recorded as a fourth level signal (such as voltage U7); determine whether the fourth level signal is less than the first level signal and the fourth level signal is greater than the preset level signal. If it is determined that the fourth level signal is less than the first level signal and the fourth level signal is greater than the preset level signal, it is determined that the air-conditioning circuit does not need overcurrent protection. Wherein, the preset level signal is such as voltage U0.

[0082] In the solution of the present invention, when the vehicle is traveling uphill, it will accelerate, which will increase the current flowing to the main circuit of the air conditioner and lower the voltage. From a practical point of view, the current will not cause the air conditioner fuse to blow when the vehicle is traveling uphill. At this time, the sampled fluctuating current is converted into a voltage recorded as U7. The voltage U7>U0, the air conditioner fuse FU1 does not blow, and the overcurrent cut-off DC contactor KM5 does not operate.

[0083] When the vehicle is traveling downhill, the battery will be charged due to the regenerative braking of the motor, which will cause the battery voltage to rise slightly. But overall, the fluctuation of the battery voltage is relatively small, because the battery management system (BMS) will maintain the voltage stability by adjusting the balance of charging and discharging. When going downhill, the corresponding braking and deceleration action will be performed, which will reduce the current flowing to the main circuit of the air conditioner. At this time, the sampled fluctuating current is converted into a voltage and recorded as voltage U1. Voltage U1<U0, the air conditioner fuse FU1 does not melt, so the overcurrent cut-off DC contactor KM5 does not operate.

[0084] Figure 5 The figure is a flow chart of the main circuit overcurrent sampling control method of the new energy vehicle air conditioner. Figure 5 As shown, the main circuit overcurrent sampling control method of the new energy vehicle air conditioner includes:

[0085] Step 1: The current and voltage detection board samples the overcurrent signal, and then executes step 2.

[0086] Step 2: convert the overcurrent signal into a level signal Un (n=1, 2, 3, 4, 5, 6, 7) recognized by the inverter chip, where n is a positive integer and represents different driving states, and then execute step 3.

[0087] Step 3, compare the level signal Un with the voltage value U0 converted from the normal current set by the software to determine whether U3≥U2>U0 is satisfied: if so, execute step 4; otherwise, determine that the air conditioner fuse FU1 is normal.

[0088] Step 4: The inverter and the current and voltage detection board recognize overcurrent through CAN communication. The current and voltage detection board sends a control signal to cut off the overcurrent DC contactor KM5 to ensure that the air conditioner fuse FU1 is normal.

[0089] In the scheme of the present invention, the current flowing to the main circuit of the air conditioner will fluctuate greatly and overcurrent will occur only when the vehicle is started by sudden acceleration or after power failure during operation. The abnormal overcurrent signal is sampled by the current and voltage detection board and converted into a level signal recognizable by the inverter. The voltage U0 converted by the sampled current value is compared with the software setting value. When the sampled voltage level satisfies U3≥U2>U0, the contactor KM5 will cut off the main circuit of the air conditioner to protect the fuse FU1 at the rear end of the air conditioner.

[0090] In the scheme of the present invention, the air conditioner of the new energy vehicle is mainly detected under various complex driving conditions and combined with the actual situation, and the overcurrent DC contactor KM5 is timely cut off to protect the air conditioner fuse FU1 by detecting the abnormal large current flowing into the main circuit of the air conditioner, which causes the air conditioner fuse to blow. Since the air conditioner fuse FU1 is mainly directly caused by excessive current, the voltage is too high or too low, which may also indirectly cause the current flowing into the main circuit of the air conditioner to increase, thereby causing the air conditioner fuse FU1 to burn out, but these situations are rare. Of course, it is also possible to start from this rare situation and compare the voltage fluctuation under the condition of fuse blowing with the normal situation to judge, and the control method is similar to the above. Thereby, the safety hazard of the air conditioner fuse blowing during the driving of the new energy air-conditioned vehicle is solved, which is conducive to the safe and efficient operation of the air conditioner, ensures the performance and service life of the air conditioner, and reduces the maintenance cost and the whole vehicle operation cost; improves the reliability and safety of the air conditioner of the new energy vehicle during operation, and improves the riding comfort and experience of passengers.

[0091] Since the processing and functions implemented by the method of this embodiment basically correspond to the embodiments, principles and examples of the aforementioned vehicle, for the details not exhaustive in the description of this embodiment, please refer to the relevant descriptions in the aforementioned embodiments, and no further elaboration will be made here.

[0092] In summary, it is easy for those skilled in the art to understand that, under the premise of no conflict, the above-mentioned advantageous methods can be freely combined and superimposed.

[0093] The above description is only an embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent substitution, improvement, etc. made within the spirit and principle of the present invention shall be included in the scope of the claims of the present invention.

Claims

1. A vehicle air conditioner control device, characterized in that: The vehicle air conditioner has a motor controller circuit and an air conditioning circuit; the air conditioning circuit has a frequency converter and an air conditioning fuse; the vehicle air conditioner control device includes: a detection unit and an overcurrent protection switch; the overcurrent protection switch is arranged between the motor controller circuit and the air conditioning circuit; wherein, The detection unit is used to detect the current flowing from the motor controller circuit to the air conditioning circuit when the vehicle is running and the air conditioner is running, and obtain a current detection signal; and transmit the current detection signal to the inverter; wherein, when the vehicle is running and the air conditioner is running, the overcurrent protection switch is closed; The frequency converter is used to determine whether the air conditioning circuit needs overcurrent protection according to the current detection signal; If it is determined that the air-conditioning circuit requires overcurrent protection, the overcurrent protection switch is controlled to be disconnected to disconnect the current flowing from the motor controller circuit to the air-conditioning circuit, thereby protecting the air-conditioning fuse.

2. The vehicle air conditioner control device according to claim 1, characterized in that: The air conditioning circuit has a main DC contactor; In the direction from the motor controller circuit to the air conditioning circuit, the overcurrent protection switch is located at the front end of the main DC contactor; The detection unit is specifically used to detect the current flowing from the motor controller circuit to the air conditioning circuit from the front end of the overcurrent protection switch to obtain a current detection signal.

3. The vehicle air conditioner control device according to claim 1 or 2, characterized in that: The motor controller circuit comprises a motor controller; In the direction from the motor controller circuit to the air conditioning circuit, the overcurrent protection switch is located at the rear end of the motor controller; The detection unit is specifically used to detect the current flowing from the motor controller circuit to the air conditioning circuit from the rear end of the motor controller to obtain a current detection signal.

4. A vehicle air conditioner, characterized in that: include: A vehicle air conditioner control device as claimed in any one of claims 1 to 3.

5. A vehicle, characterized in that: include: The control device for the vehicle air conditioner according to any one of claims 1 to 3, or the vehicle air conditioner according to claim 4.

6. A method for controlling a vehicle air conditioner corresponding to the vehicle air conditioner control device according to any one of claims 1 to 3, characterized in that: include: By means of the detection unit, when the vehicle is running and the air conditioner is running, the current flowing from the motor controller circuit to the air conditioner circuit is detected to obtain a current detection signal; wherein, when the vehicle is running and the air conditioner is running, the overcurrent protection switch is closed; Determining whether the air conditioning circuit requires overcurrent protection according to the current detection signal; If it is determined that the air-conditioning circuit requires overcurrent protection, the overcurrent protection switch is controlled to be disconnected to disconnect the current flowing from the motor controller circuit to the air-conditioning circuit, thereby protecting the air-conditioning fuse.

7. The vehicle air conditioner control method according to claim 6, characterized in that: The current detection signal is a level signal that can be recognized by the main chip of the inverter; Determining whether the air conditioning circuit requires overcurrent protection according to the current detection signal includes: When the vehicle is accelerating during operation, recording the current detection signal as a first level signal; It is determined whether the first level signal is greater than a preset level signal. If it is determined that the first level signal is greater than the preset level signal, it is determined that the air-conditioning circuit requires overcurrent protection.

8. The vehicle air conditioner control method according to claim 6, characterized in that: The current detection signal is a level signal that can be recognized by the main chip of the inverter; when the vehicle accelerates during operation, the current detection signal is recorded as a first level signal; Determining whether the air conditioning circuit requires overcurrent protection according to the current detection signal further includes: In the case where the vehicle is accelerated after power failure, the current detection signal is recorded as a second level signal; Determine whether the second level signal is greater than the first level signal, and the first level signal is greater than a preset level signal. If it is determined that the second level signal is greater than the first level signal, and the first level signal is greater than the preset level signal, it is determined that the air-conditioning circuit requires overcurrent protection.

9. The vehicle air conditioner control method according to claim 6, characterized in that: The current detection signal is a level signal that can be recognized by the main chip of the inverter; when the vehicle accelerates during operation, the current detection signal is recorded as a first level signal; Determining whether the air conditioning circuit requires overcurrent protection according to the current detection signal further includes: When the vehicle accelerates after turning during operation, the current detection signal is recorded as a third level signal; Determine whether the third level signal is less than the first level signal and the third level signal is greater than the preset level signal. If it is determined that the third level signal is less than the first level signal and the third level signal is greater than the preset level signal, it is determined that the air-conditioning circuit does not require overcurrent protection.

10. The vehicle air conditioner control method according to claim 6, characterized in that: The current detection signal is a level signal that can be recognized by the main chip of the inverter; when the vehicle accelerates during operation, the current detection signal is recorded as a first level signal; Determining whether the air conditioning circuit requires overcurrent protection according to the current detection signal further includes: When the vehicle accelerates after turning during operation, the current detection signal is recorded as a fourth level signal; Determine whether the fourth level signal is less than the first level signal and the fourth level signal is greater than the preset level signal. If it is determined that the fourth level signal is less than the first level signal and the fourth level signal is greater than the preset level signal, it is determined that the air-conditioning circuit does not require overcurrent protection.

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