Control method for vehicle-mounted inverter of extended-range electric vehicle

Abstract

The invention relates to the technical field of extended-range electric vehicles, in particular to a method for controlling a vehicle-mounted inverter of an extended-range electric vehicle, which comprises the following steps of: setting a physical key in a passenger compartment, and when a driver presses down the physical key, outputting a high effective level to a VCU (Vehicle Control Unit) by a switch; after the VCU judges that the signal is valid, whether the DCAC is allowed to work in the current vehicle state or not is further judged, the DCAC allowed to be used mainly comprises two scenes, namely a whole vehicle read state and a whole vehicle gun insertion charging state, the whole vehicle read state refers to that a whole vehicle high-voltage system is closed, and a whole vehicle power system actually has a driving state, and the whole vehicle gun insertion charging state refers to a whole vehicle gun insertion charging state. According to the whole vehicle gun inserting charging state, a charging gun of a charging pile is used for being inserted into a whole vehicle end quick charging connector, and when the condition is met, a whole vehicle power battery starts to be charged. However, if the control strategy is not fully considered, certain potential safety hazards are possibly brought to the user.

Description

Technical Field

[0001] The present invention relates to the technical field of extended-range electric vehicles, and in particular to a method for controlling an on-board inverter of an extended-range electric vehicle. Background Art

[0002] Extended-range electric commercial vehicles are equipped with a range extender that can convert oil into electricity as a mobile power source, or can be used as a temporary fixed power station to power other electrical equipment. As the preferred technical route for new energy RVs, they have no range anxiety, run quietly with pure electric drive, and can be parked on the spot to generate electricity, making them suitable for self-driving travel and other purposes.

[0003] The on-board inverter DCAC can convert the vehicle's high-voltage direct current into 220V alternating current, which can facilitate the use of electricity for household appliances and other equipment, and meet the user's diversified on-board electricity needs in multiple scenarios, such as charging sprayers, charging drones, charging other new energy vehicles, boiling water and cooking, etc. The vehicle control unit VCU serves as the vehicle's power control center and the comprehensive management and control center for the vehicle's status. It needs to monitor the vehicle's status. For the DCAC function, VCU needs to make a comprehensive decision whether to allow DCAC to enable output. Although DCAC is convenient and practical, if the control strategy is not considered comprehensively, it may bring certain vehicle safety risks to users. Summary of the invention

[0004] The present invention provides a method for controlling an on-board inverter of a range-extended electric vehicle, which solves the problem that although the DCAC in the prior art is convenient and practical, it may bring certain potential safety hazards to users if the control strategy is not comprehensive enough.

[0005] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a control method for an on-board inverter of a range-extended electric vehicle, a physical button is set in the passenger compartment, when the driver presses the physical button, and the switch outputs a high effective level to the VCU, the VCU further determines whether the current vehicle state allows the DCAC to work after judging that the signal is valid, and the DCAC is allowed to be used in two main scenarios: one is the whole vehicle ready state, and the other is the whole vehicle plug-in charging state. The whole vehicle ready state means that the whole vehicle high-voltage system is closed, and the whole vehicle power system is actually in a driving state. The whole vehicle plug-in charging state The power status refers to the use of the charging gun provided by the charging pile to plug into the fast charging connector on the vehicle end. When the conditions are met, the vehicle power battery will start to be charged. After the high voltage is lowered, the VCU sends a DCAC enable signal through CAN, VCU_DCACEnable=0, the DCAC power is cleared, and the DCAC feedback DCAC_InverterWorkingSts=1 standby, and then the VCU requests the DCAC to lower the low voltage. After completing its own data storage, the DCAC feedback allows the low voltage to be lowered. The VCU disconnects the DCAC hard line to wake up, and the DCAC goes into sleep mode and enters low power consumption mode.

[0006] It is further defined that the physical button is a self-resetting and self-locking switch, which will automatically reset after being pressed. Self-locking means that when the switch is pressed, its current state is locked, and the state will only be switched when the switch is pressed again. When the entire vehicle is powered off, the switch output state is locked, and the state remains unchanged after powering on again, that is, the switch state is only related to the action of pressing the switch, and has nothing to do with the power on and off action.

[0007] It is further defined that the high-voltage system closure refers to that the main positive contactor and the main negative contactor of the high-voltage system are closed, the main positive contactor refers to the high-voltage bus positive circuit control contactor in the power battery pack or the all-in-one, and the main negative contactor refers to the main negative contactor in the power battery pack. The main positive contactor and the main negative contactor will be closed according to the VCU vehicle power-on process control, and the VCU interacts with the control unit where the main positive contactor and the main negative contactor are located to complete the power-on control. The plug-in charging state refers to the ordinary charging gun brought by the charging pile being plugged into the fast charging connector at the vehicle end. When the conditions are met, the power battery of the vehicle will be charged.

[0008] Further, when the vehicle is ready or in the charging state, the DCAC is allowed to output after the following conditions are met: a. The vehicle is high voltage closed, and the key is in the On position or there is a gun insertion signal b. Battery SOC is greater than the threshold c. The available remaining discharge power of the system is greater than the threshold, and the power consumption priority is lower than AC power consumption d. The DCAC itself has no faults e. The vehicle is not in the intelligent charging state f. The vehicle is not in remote financial lock mode g. The vehicle is not in the remote air conditioning activation state Further defined, the battery SOC greater than the threshold means that the VCU will judge the power state of the power battery. When the battery power is too low, the DCAC is not allowed to be used to prevent the risk of the whole vehicle breaking down under extreme working conditions due to low power. The SOC judgment sets a hysteresis interval, and the calibrated hysteresis interval is 13%-15% to prevent the SOC fluctuation from causing the output state of the enable judgment to jitter. At the same time, the upper and lower limits of the hysteresis interval are calibrable variables, which can be adaptively calibrated and adjusted according to the actual situation such as the battery size; The system available remaining discharge power is greater than the threshold value, and the power priority is lower than AC power. The system available remaining discharge power refers to the discharge power available for DCAC in addition to the power used by the drive system and high-voltage accessories. DCAC, as the on-board power, has the lowest priority compared to the power used by the vehicle itself, so it is necessary to give priority to the power used by the drive and high-voltage accessories. When the available remaining discharge power is higher than the threshold value and other conditions are met, DCAC is allowed to enable output. Otherwise, in order to prevent over-discharge of the battery, when the available remaining discharge power is lower than the threshold value, DCAC is prohibited from enabling output. The threshold value is set to 7KW. The DCAC itself is free of faults, which means that the working state of the DCAC itself monitored by the control unit is normal, without over-temperature, over-current and other faults. The VCU determines whether the DCAC is in a fault state by monitoring the DCAC to send its own state signal DCAC_InverterWorkingSts. If DCAC_InverterWorkingSts=3, it means that the DCAC is faulty, and the VCU outputs the disable enable signal VCU_DCACEnable=0. DCAC_InverterWorkingSts≠3 means that the DCAC is in a normal state. The whole vehicle is not in the intelligent charging state means that the VCU dynamically monitors the charge state of the low-voltage battery. When the voltage of the low-voltage battery is lower than the threshold, the VCU will control the high voltage to close and charge the low voltage to prevent the low-voltage battery from running out of power and causing the whole vehicle to break down. The intelligent charging function is a remote automatic opening function, that is, the vehicle operator is not in the vehicle, and the high voltage will be closed at this time. If the DCAC is allowed to enable output, if the on-board electrical appliances use electricity, it may cause safety hazards. Therefore, when the intelligent charging function of the whole vehicle is in operation, the DCAC is prohibited from enabling output; For vehicles purchased through financial policies that are not in remote financial lock, when the vehicle purchaser fails to repay on time, the OEM will adopt soft restriction control of the vehicle in order to urge the loan purchaser to repay on time, that is, after the financial lock is triggered, the vehicle running speed is reduced and cannot be driven normally. At this time, in order to further promote the vehicle purchaser to repay on time, the vehicle purchaser is deprived of the right to use DCAC, which increases the discomfort of the vehicle purchaser and prompts him to repay as soon as possible; The whole vehicle is not in the remote air conditioning enabled state means that when the remote air conditioning is in operation, DCAC enable output is prohibited. When the remote air conditioning is turned on, the driver is also not in the vehicle, and the high voltage is closed. If DCAC enable output is allowed, if the on-board electrical appliances use electricity, it may cause safety hazards. Therefore, when the remote air conditioning is in operation, DCAC enable output is prohibited.

[0009] It is further defined that when all the above conditions are met, the VCU sends a DCAC enable signal VCU_DCACEnable=1 through CAN; if DCAC is not allowed to work, the VCU sends a DCAC disable enable signal VCU_DCACEnable=0. After receiving the enable signal sent by the VCU, the DCAC provides status feedback through CAN. DCAC_InverterWorkingSts=2 means that it is in operation and provides real-time feedback on its own input / output voltage, current, temperature and other information. The VCU thermal management module and energy management module need to monitor the temperature and actual power consumption of the DCAC in real time to perform thermal management control of the DCAC and energy management control of the entire vehicle.

[0010] It is further defined that the thermal management control means that the VCU needs to monitor the temperature of the DCAC in real time. When the temperature is higher than the threshold, it is necessary to control the operation of the thermal management loop water pump and fan to dissipate the heat of the DCAC to prevent it from overheating, reducing power or shutting down. The energy management control means that the use of the DCAC needs to avoid over-discharge of the battery and give priority to power consumption of high-priority equipment. If the power generation control state of the VCU is the power following mode after the APU is started, the VCU needs to compensate for the actual power consumption of the DCAC, that is, the power generation power requested by the APU needs to be added to the actual power consumption of the DCAC to ensure the power balance of the entire vehicle without affecting the power performance of the entire vehicle.

[0011] Further definition, after the driver presses the physical button, if the VCU determines that the vehicle status does not meet the requirements for DCAC output, the VCU will send a DCAC prohibition reason signal VCU_disableDCACreason to the gateway TBOX through CAN. TBOX will forward the signal to the instrument ICM for analysis and display. The signal definition is as follows: VCU_disableDCACreason=0 means that DCAC is allowed to be enabled, and no information is prompted after ICM analysis. VCU_disableDCACreason=1 means that the high voltage is not closed, and the instrument pops up a window prompting "High voltage is not closed and DCAC is unavailable", which will be closed after 10 seconds. If VCU_disableDCACreason=2, the battery power is too low, and the instrument pop-up window prompts "Battery SOC is low and DCAC is unavailable", and the pop-up window lasts for 10 seconds before the system exits. If VCU_disableDCACreason=3, the system's available remaining discharge capacity is insufficient, and the instrument pop-up window prompts "System discharge capacity is low and DCAC is unavailable", and the pop-up window lasts for 10 seconds before the system exits. If VCU_disableDCACreason=4, the DCAC is faulty, and the instrument pop-up window prompts "DCAC is faulty and DCAC is unavailable", and the pop-up window lasts for 10 seconds before the system exits. If VCU_disableDCACreason=5, the vehicle is under remote control. Since remote control is absolutely isolated from local control and the vehicle operator is not on the vehicle, the instrument does not need to prompt at this time. If VCU_disableDCACreason=6, the DCAC is unavailable due to other reasons of the vehicle, such as a high-level fault of the vehicle requiring the high voltage to be lowered or the high voltage to be prohibited, the instrument pop-up window prompts "Other faults and DCAC is unavailable", and the pop-up window lasts for 10 seconds before the system exits.

[0012] Further defined, the power priority lower than AC means that the power priority of the whole vehicle is ranked as follows: drive system> high-voltage accessories> thermal management> passenger compartment air conditioning power> DCAC. The drive system power priority is the highest, giving priority to ensuring the driving power of the whole vehicle. High-voltage accessories ensure the normal operation of the whole vehicle system, involving vehicle safety, etc. For example, the power consumption of high-voltage braking system components ensures braking safety, and the power consumption of the DC converter for low-voltage charging ensures the normal operation of each control unit. Thermal management protects the electric drive system, etc. If you want to have strong performance, the heat dissipation must be stable. The power consumption of the passenger compartment air conditioning directly affects the comfort experience of the driver and passengers, so it has a higher priority than DCAC, and the comfort function priority is lower than the power and safety priority. DCAC, as the vehicle's on-board power port, has the lowest relative priority. When the temperature is low and the battery SOC is low, it is necessary to give priority to the APU startup power consumption, that is, at this time, the APU startup power consumption priority is the highest, so as to ensure the success rate of the APU startup and prevent the battery from running out of power and causing the whole vehicle to break down. Further restrictions: for the DCAC enable control, in order to prevent the main positive relay from closing with load when the high voltage is powered on, causing the relay to ignite and stick, affecting the high voltage safety, the DCAC enable signal output by the VCU needs to be output after the main positive relay is closed for 500ms. For the DCAC shutdown enable control, before the high voltage is lowered, the VCU needs to send a shutdown enable to the DCAC first, and then the VCU needs to monitor the real-time output power of the DCAC. When the output power is lower than 0.1kW, the main positive relay is disconnected to prevent the main positive relay from disconnecting with load, causing the relay to ignite and stick. Even if the DCAC clears power quickly, it will not affect the control speed of the vehicle lowering the high voltage. When the vehicle is plugged in for charging, if the DCAC is outputting, it is necessary to compensate for the real-time output power of the DCAC, that is, to increase the real-time power output value of the DCAC on the basis of the normal charging request power, so as to ensure that the charging speed of the battery is not affected by the output of the DCAC. Otherwise, when the battery is charging, due to the real-time output of the DCAC, the actual charging power to the battery will become smaller, resulting in a longer charging time, especially at the end of charging. In extreme cases, it may take a long time to fully charge the battery or even fail to fully charge it.

[0013] The beneficial effects of adopting the above technical solution are: 1. The key being in the On position or there being a charging signal is used as a criterion for determining whether the vehicle is ready or in the charging state. The reason why only the charging state is determined here but not the charging state is to enable users to use DCAC faster and more conveniently. For example, when driving at a high speed to a service area to charge, if it is determined whether it is in the charging state, a certain amount of waiting time is required from charging to verification and then to starting charging. Therefore, in order to enable users to use DCAC as quickly as possible and without interruption as much as possible, only the charging state is determined.

[0014] 2. The advantage of using a self-locking switch is that when the vehicle is powered on or off, the output state of the DCAC power switch remains unchanged, which avoids the need for users to frequently press the switch to request DCAC enable due to key power on and off, simplifying user operations and providing a better functional experience.

[0015] 3. VCU determines the status of the DCAC power switch and the high-voltage status of the entire vehicle. When considering the actual power usage scenario, it makes decisions based on the principle of safety first. While providing convenience for users, it ensures functional safety and reliability, avoids high-voltage power safety risks, and takes into account the power safety of the entire vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is the overall control architecture diagram of the present invention; Figure 2 This is a flow chart of the control strategy of the present invention; Figure 3 This is a priority control architecture diagram of the present invention; Figure 4 This is a high voltage control flow chart of the present invention; Figure 5 This is a high-voltage control flow chart of the present invention; Figure 6 This is a flow chart of the charging power compensation control of the plug cavity of the present invention. DETAILED DESCRIPTION

[0017] The specific implementation methods of the present invention are further explained in detail below by describing the embodiments with reference to the accompanying drawings, with the aim of helping those skilled in the art to have a more complete, accurate and in-depth understanding of the concept and technical solution of the present invention and facilitating its implementation.

[0018] The present invention is a control method for an on-board inverter of an extended-range electric vehicle. The VCU judges the state of the DCAC power switch and the high-voltage state of the whole vehicle comprehensively. When considering the actual power usage scenario, it makes decisions based on the principle of safety first. While providing convenience for users, it ensures functional safety and reliability, avoids the safety risks of high-voltage power usage, and takes into account the power safety of the whole vehicle. This solves the problem that the DCAC in the prior art is convenient and practical, but if the control strategy is not considered comprehensively, it may bring certain potential safety hazards to users.

[0019] Specifically, Figure 1-Figure 6As shown, a physical button is set in the passenger compartment and marked as 220V to facilitate ordinary users to identify the switch function. When the driver presses the physical button and the switch outputs a high effective level to the VCU, the VCU further determines whether the current vehicle state allows DCAC to work after determining that the signal is valid. The VCU determines all relevant conditions of the vehicle and allows DCAC to enable output only when the vehicle is in a high-voltage state based on the principle of safety first, that is, DCAC is allowed to enable output only when the driver's subjective consciousness is that the vehicle is powered on or charging, to prevent other scenarios, such as the key off state, the on-board electrical appliances are in a working state, the DCAC is in output, and the person forgets that the on-board electrical appliances are in a running state after leaving the car, thereby causing safety hazards. In this way, the high-voltage safety of DCAC output is fully guaranteed, so DCAC is allowed to be There are two main usage scenarios: one is the vehicle ready state, and the other is the vehicle plug-in charging state. The vehicle ready state means that the vehicle high-voltage system is closed, and the vehicle power system is actually in the driving state. The high-voltage system closure means that the main positive contactor and the main negative contactor of the high-voltage system are closed. The main positive contactor refers to the high-voltage bus positive circuit control contactor in the power battery pack or the all-in-one, and the main negative contactor refers to the main negative contactor in the power battery pack. The main positive contactor and the main negative contactor will be closed according to the VCU vehicle power-on process control. The VCU interacts with the control unit where the main positive contactor and the main negative contactor are located to complete the power-on control. The vehicle plug-in charging state refers to the use of the charging gun brought by the charging pile to plug into the fast charging connector at the vehicle end. When the conditions are met, the vehicle power battery will start to be charged; The physical button is a self-resetting and self-locking switch, which will automatically reset after being pressed. Self-locking means that when the switch is pressed, its current state is locked, and the state will only switch when the switch is pressed again. When the vehicle is powered off, the switch output state is locked, and the state remains unchanged after powering on again. That is, the switch state is only related to the action of the switch being pressed, and has nothing to do with the power-on and power-off actions. When the vehicle is powered on and off, the output state of the DCAC power switch remains unchanged, which avoids the need for users to frequently press the switch to request DCAC enable due to key power on and off, simplifies user operation, and provides a better functional experience. After all the above conditions are met, that is, the following condition a is met, the high voltage closed state, the key is in the On gear or there is a gun plug signal as the judgment condition for the vehicle to be ready or in the whole vehicle plug-in charging state. The reason why only the gun plug-in state is judged here but not the charging state is to enable users to use DCAC faster and more conveniently. For example, if you drive at a high speed to a service area to plug in and charge, if you want to judge whether it is in the charging state, there is a certain waiting time from plugging in to checking and then starting charging. Therefore, in order to enable users to use DCAC as quickly as possible and as uninterrupted as possible, only the gun plug-in state is judged. After condition a is met and the following other conditions are met, DCAC is allowed to enable output. The conditions are as follows: a. The vehicle is high voltage closed, and the key is in the On position or there is a gun insertion signal b. Battery SOC is greater than the threshold c. The available remaining discharge power of the system is greater than the threshold, and the power consumption priority is lower than AC power consumption d. The DCAC itself has no faults e. The vehicle is not in the intelligent charging state f. The vehicle is not in remote financial lock mode g. The vehicle is not in the remote air conditioning activation state The battery SOC greater than the threshold value means that the VCU will judge the power state of the power battery. When the battery power is too low, DCAC is not allowed to be used to prevent the risk of the whole vehicle breaking down under extreme working conditions due to low power. The SOC judgment sets a hysteresis interval, and the calibrated hysteresis interval is 13%-15% to prevent SOC fluctuations from causing jitter in the output state of the enable judgment. At the same time, the upper and lower limits of the hysteresis interval are calibrable variables, which can be adaptively calibrated and adjusted according to actual conditions such as battery size; The system available remaining discharge power is greater than the threshold value, and the power priority is lower than AC power. The system available remaining discharge power refers to the discharge power available for DCAC in addition to the power used by the drive system and high-voltage accessories. DCAC, as the on-board power, has the lowest priority compared to the power used by the vehicle itself, so it is necessary to give priority to the power used by the drive and high-voltage accessories. When the available remaining discharge power is higher than the threshold value and other conditions are met, DCAC is allowed to enable output. Otherwise, in order to prevent over-discharge of the battery, when the available remaining discharge power is lower than the threshold value, DCAC is prohibited from enabling output. The threshold value is set to 7KW. The DCAC itself is free of faults, which means that the working state of the DCAC itself monitored by the control unit is normal, without over-temperature, over-current and other faults. The VCU determines whether the DCAC is in a fault state by monitoring the DCAC to send its own state signal DCAC_InverterWorkingSts. If DCAC_InverterWorkingSts=3, it means that the DCAC is faulty, and the VCU outputs the disable enable signal VCU_DCACEnable=0. DCAC_InverterWorkingSts≠3 means that the DCAC is in a normal state. The whole vehicle is not in the intelligent charging state means that the VCU dynamically monitors the charge state of the low-voltage battery. When the voltage of the low-voltage battery is lower than the threshold, the VCU will control the high voltage to close and charge the low voltage to prevent the low-voltage battery from running out of power and causing the whole vehicle to break down. The intelligent charging function is a remote automatic opening function, that is, the vehicle operator is not in the vehicle, and the high voltage will be closed at this time. If the DCAC is allowed to enable output, if the on-board electrical appliances use electricity, it may cause safety hazards. Therefore, when the intelligent charging function of the whole vehicle is in operation, the DCAC is prohibited from enabling output; For vehicles purchased through financial policies that are not in remote financial lock, when the vehicle purchaser fails to repay on time, the OEM will adopt soft restriction control of the vehicle in order to urge the loan purchaser to repay on time, that is, after the financial lock is triggered, the vehicle running speed is reduced and cannot be driven normally. At this time, in order to further promote the vehicle purchaser to repay on time, the vehicle purchaser is deprived of the right to use DCAC, which increases the discomfort of the vehicle purchaser and prompts him to repay as soon as possible; The whole vehicle is not in the remote air conditioning enabled state means that when the remote air conditioning is in operation, DCAC enable output is prohibited. When the remote air conditioning is turned on, the driver is also not in the vehicle, and the high voltage is closed. If DCAC enable output is allowed, if the on-board electrical appliances use electricity, it may cause safety hazards. Therefore, when the remote air conditioning is in operation, DCAC enable output is prohibited.

[0020] When all the above conditions are met, VCU sends a DCAC enable signal VCU_DCACEnable=1 through CAN; if DCAC is not allowed to work, VCU sends a DCAC disable enable signal VCU_DCACEnable=0. After receiving the enable signal sent by VCU, DCAC provides status feedback through CAN. DCAC_InverterWorkingSts=2 means that it is in operation and provides real-time feedback on its own input / output voltage, current, and temperature information. The VCU thermal management module and energy management module need to monitor the temperature and actual power consumption of DCAC in real time to perform thermal management control of DCAC and energy management control of the entire vehicle.

[0021] Thermal management control means that VCU needs to monitor the temperature of DCAC in real time. When the temperature is higher than the threshold, it needs to control the operation of the thermal management loop water pump and fan to dissipate the heat of DCAC to prevent it from overheating, reducing power or shutting down. The energy management control means that the use of DCAC needs to avoid over-discharge of the battery and give priority to high-priority equipment. If the power generation control state of VCU is power following mode after starting APU, VCU needs to compensate the actual power consumption of DCAC, that is, the power generation power requested by APU needs to be added to the actual power consumption of DCAC to ensure the balance of the whole vehicle power without affecting the performance of the whole vehicle power. The priority of electricity consumption is lower than AC, which means that the priority of electricity consumption for the whole vehicle is as follows: drive system > high-voltage accessories > thermal management > passenger compartment air conditioning power > DCAC. The drive system has the highest priority, which gives priority to ensuring the driving dynamics of the whole vehicle. High-voltage accessories ensure the normal operation of the whole vehicle system, involving vehicle safety, etc. For example, the power consumption of high-voltage braking system components ensures braking safety, and the power consumption of DC converters for charging low voltage ensures the normal operation of each control unit. Thermal management protects the electric drive system, etc. For strong performance, heat dissipation must be stable. The power consumption of passenger compartment air conditioning directly affects the comfort experience of drivers and passengers, so its priority is higher than DCAC, while the priority of comfort functions is lower than that of power and safety. DCAC, as the vehicle's on-board power port, has the lowest relative priority. When the temperature is low and the battery SOC is low, it is necessary to give priority to the power consumption of APU startup, that is, at this time, the power consumption of APU startup has the highest priority to ensure the success rate of APU startup and prevent the whole vehicle from breaking down due to battery power loss. For the DCAC enable control, in order to prevent the main positive relay from closing with load when the high voltage is powered on, causing the relay to ignite and stick, affecting the high voltage safety, the DCAC enable signal output by the VCU needs to be output after the main positive relay is closed for 500ms. For the DCAC shutdown enable control, before the high voltage is lowered, the VCU needs to send a shutdown enable to the DCAC first, and then the VCU needs to monitor the real-time output power of the DCAC. When the output power is lower than 0.1kW, the main positive relay is disconnected to prevent the main positive relay from disconnecting with load, causing the relay to ignite and stick. Even if the DCAC clears power quickly, it will not affect the control speed of the vehicle to lower the high voltage. When the vehicle is plugged in for charging, if the DCAC is outputting, it is necessary to compensate for the real-time output power of the DCAC, that is, to increase the real-time power output value of the DCAC on the basis of the normal charging request power, so as to ensure that the charging speed of the battery is not affected by the output of the DCAC. Otherwise, when the battery is charging, due to the real-time output of the DCAC, the actual charging power to the battery will become smaller, resulting in a longer charging time, especially at the end of charging. In extreme cases, it may take a long time to fully charge the battery or even fail to fully charge it.

[0022] After the driver presses the physical button, if the VCU determines that the vehicle status does not meet the requirements for DCAC output, the VCU will send a DCAC prohibition reason signal VCU_disableDCACreason to the gateway TBOX through CAN. TBOX will forward the signal to the instrument ICM for analysis and display. The signal definition is as follows: VCU_disableDCACreason=0 means that DCAC is allowed to be enabled, and no information is prompted after ICM analysis. VCU_disableDCACreason=1 means that the high voltage is not closed, and the instrument pops up a window prompting "High voltage is not closed and DCAC is unavailable", which will be closed after 10 seconds. If VCU_disableDCACreason=2, the battery power is too low, and the instrument pop-up window prompts "Battery SOC is low and DCAC is unavailable", and the pop-up window lasts for 10 seconds before the system exits. If VCU_disableDCACreason=3, the system's available remaining discharge capacity is insufficient, and the instrument pop-up window prompts "System discharge capacity is low and DCAC is unavailable", and the pop-up window lasts for 10 seconds before the system exits. If VCU_disableDCACreason=4, the DCAC is faulty, and the instrument pop-up window prompts "DCAC is faulty and DCAC is unavailable", and the pop-up window lasts for 10 seconds before the system exits. If VCU_disableDCACreason=5, the vehicle is under remote control. Since remote control is absolutely isolated from local control and the vehicle operator is not on the vehicle, the instrument does not need to prompt at this time. If VCU_disableDCACreason=6, the DCAC is unavailable due to other reasons of the vehicle, such as a high-level fault of the vehicle requiring the high voltage to be lowered or the high voltage to be prohibited, the instrument pop-up window prompts "Other faults and DCAC is unavailable", and the pop-up window lasts for 10 seconds before the system exits.

[0023] The present invention is described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention; or the above-mentioned concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the protection scope of the present invention.

Claims

1. A method for controlling an onboard inverter of a range-extended electric vehicle, characterized in that: A physical button is set in the passenger compartment. When the driver presses the physical button and the switch outputs a high effective level to the VCU, the VCU determines that the signal is valid and further determines whether the current vehicle state allows DCAC to work. There are mainly two scenarios in which DCAC is allowed to be used: one is the ready state of the whole vehicle, and the other is the plug-in charging state of the whole vehicle. The ready state of the whole vehicle means that the high-voltage system of the whole vehicle is closed, and the power system of the whole vehicle is actually in a driving state. The plug-in charging state of the whole vehicle means that the charging gun brought by the charging pile is plugged into the fast charging connector at the end of the whole vehicle. When the conditions are met, the power battery of the whole vehicle starts to be charged. After the high voltage is lowered, the VCU sends a DCAC enable signal through CAN, VCU_DCACEnable=0, the DCAC power is cleared, and the DCAC feedbacks DCAC_InverterWorkingSts=1 to standby, and then the VCU requests DCAC to lower the low voltage. After completing its own data storage, DCAC feedbacks that it allows low voltage to be lowered. The VCU disconnects the DCAC hard line to wake up, and the DCAC sleeps and enters low power consumption mode.

2. The on-board inverter control method of the range-extended electric vehicle according to claim 1, characterized in that: The physical button is a self-resetting and self-locking switch, which will automatically reset after being pressed. Self-locking means that when the switch is pressed, its current state is locked, and the state will only be switched when the switch is pressed again. When the vehicle is powered off, the switch output state is locked, and the state remains unchanged after powering on again. That is, the switch state is only related to the action of pressing the switch, and has nothing to do with the power on and off action.

3. The on-board inverter control method of the range-extended electric vehicle according to claim 1, characterized in that: The high-voltage system closure refers to the fact that the main positive contactor and the main negative contactor of the high-voltage system are closed. The main positive contactor refers to the high-voltage bus positive circuit control contactor in the power battery pack or the all-in-one, and the main negative contactor refers to the main negative contactor in the power battery pack. The main positive contactor and the main negative contactor will be closed according to the VCU vehicle power-on process control. The VCU interacts with the control unit where the main positive contactor and the main negative contactor are located to complete the power-on control. The plug-in charging state refers to the ordinary charging gun brought by the charging pile being plugged into the fast charging connector at the vehicle end. When the conditions are met, the power battery of the vehicle will be charged.

4. The method for controlling an on-board inverter of a range-extended electric vehicle according to claim 1, characterized in that: When the vehicle is ready or in the charging state, DCAC is allowed to output after the following conditions are met: a. The vehicle is high voltage closed, and the key is in the On position or there is a gun insertion signal b. Battery SOC is greater than the threshold c. The available remaining discharge power of the system is greater than the threshold, and the power consumption priority is lower than AC power consumption d. The DCAC itself has no faults e. The vehicle is not in the intelligent charging state f. The vehicle is not in remote financial lock mode g. The vehicle is not in the remote air conditioning activation state.

5. The on-board inverter control method of the range-extended electric vehicle according to claim 4, characterized in that: The battery SOC greater than the threshold value means that the VCU will judge the power state of the power battery. When the battery power is too low, DCAC is not allowed to be used to prevent the risk of the whole vehicle breaking down under extreme working conditions due to low power. The SOC judgment sets a hysteresis interval, and the calibrated hysteresis interval is 13%-15% to prevent SOC fluctuations from causing jitter in the output state of the enable judgment. At the same time, the upper and lower limits of the hysteresis interval are calibrable variables, which can be adaptively calibrated and adjusted according to actual conditions such as battery size; The system available remaining discharge power is greater than the threshold value, and the power priority is lower than AC power. The system available remaining discharge power refers to the discharge power available for DCAC in addition to the power used by the drive system and high-voltage accessories. DCAC, as the on-board power, has the lowest priority compared to the power used by the vehicle itself, so it is necessary to give priority to the power used by the drive and high-voltage accessories. When the available remaining discharge power is higher than the threshold value and other conditions are met, DCAC is allowed to enable output. Otherwise, in order to prevent over-discharge of the battery, when the available remaining discharge power is lower than the threshold value, DCAC is prohibited from enabling output. The threshold value is set to 7KW. The DCAC itself is free of faults, which means that the working state of the DCAC itself monitored by the control unit is normal, without over-temperature, over-current and other faults. The VCU determines whether the DCAC is in a fault state by monitoring the DCAC to send its own state signal DCAC_InverterWorkingSts. If DCAC_InverterWorkingSts=3, it means that the DCAC is faulty, and the VCU outputs the disable enable signal VCU_DCACEnable=0. DCAC_InverterWorkingSts≠3 means that the DCAC is in a normal state. The whole vehicle is not in the intelligent charging state means that the VCU dynamically monitors the charge state of the low-voltage battery. When the voltage of the low-voltage battery is lower than the threshold, the VCU will control the high voltage to close and charge the low voltage to prevent the low-voltage battery from running out of power and causing the whole vehicle to break down. The intelligent charging function is a remote automatic opening function, that is, the vehicle operator is not in the vehicle, and the high voltage will be closed at this time. If the DCAC is allowed to enable output, if the on-board electrical appliances use electricity, it may cause safety hazards. Therefore, when the intelligent charging function of the whole vehicle is in operation, the DCAC is prohibited from enabling output; For vehicles purchased through financial policies that are not in remote financial lock, when the vehicle purchaser fails to repay on time, the OEM will adopt soft restriction control of the vehicle in order to urge the loan purchaser to repay on time, that is, after the financial lock is triggered, the vehicle running speed is reduced and cannot be driven normally. At this time, in order to further promote the vehicle purchaser to repay on time, the vehicle purchaser is deprived of the right to use DCAC, which increases the discomfort of the vehicle purchaser and prompts him to repay as soon as possible; The whole vehicle is not in the remote air conditioning enabled state means that when the remote air conditioning is in operation, DCAC enable output is prohibited. When the remote air conditioning is turned on, the driver is also not in the vehicle, and the high voltage is closed. If DCAC enable output is allowed, if the on-board electrical appliances use electricity, it may cause safety hazards. Therefore, when the remote air conditioning is in operation, DCAC enable output is prohibited.

6. The on-board inverter control method of the range-extended electric vehicle according to claim 4, characterized in that: When all the above conditions are met, VCU sends a DCAC enable signal VCU_DCACEnable=1 through CAN; if DCAC is not allowed to work, VCU sends a DCAC disable enable signal VCU_DCACEnable=0. After receiving the enable signal sent by VCU, DCAC provides status feedback through CAN. DCAC_InverterWorkingSts=2 means that it is in operation and provides real-time feedback on its own input / output voltage, current, and temperature information. The VCU thermal management module and energy management module need to monitor the temperature and actual power consumption of DCAC in real time to perform thermal management control of DCAC and energy management control of the entire vehicle.

7. The method for controlling the on-board inverter of a range-extended electric vehicle according to claim 6, characterized in that: The thermal management control means that the VCU needs to monitor the temperature of the DCAC in real time. When the temperature is higher than the threshold, it is necessary to control the operation of the thermal management loop water pump and fan to dissipate the heat of the DCAC to prevent it from overheating, reducing power or shutting down. The energy management control means that the use of the DCAC needs to avoid over-discharge of the battery and give priority to power consumption of high-priority equipment. If the power generation control state of the VCU is the power following mode after the APU is started, the VCU needs to compensate for the actual power consumption of the DCAC, that is, the power generation power requested by the APU needs to be added to the actual power consumption of the DCAC to ensure the power balance of the entire vehicle without affecting the power performance of the entire vehicle.

8. The on-board inverter control method of the range-extended electric vehicle according to claim 1, characterized in that: After the driver presses the physical button, if the VCU determines that the vehicle status does not meet the requirements for DCAC output, the VCU will send a DCAC prohibition reason signal VCU_disableDCACreason to the gateway TBOX through CAN. TBOX will forward the signal to the instrument ICM for analysis and display. The signal definition is as follows: VCU_disableDCACreason=0 means that DCAC is allowed to be enabled, and no information is prompted after ICM analysis. VCU_disableDCACreason=1 means that the high voltage is not closed, and the instrument pops up a window prompting "High voltage is not closed and DCAC is unavailable". The pop-up window lasts for 10 seconds and then exits; VCU_disableDCACreason=2 means the battery power is too low, and the instrument pop-up window prompts "Battery SOC is low and DCAC is unavailable", which will last for 10 seconds before exiting; VCU_disableDCACreason=3 means that the system's available remaining discharge capacity is insufficient, and the instrument pops up a window prompting "System discharge capacity is low and DCAC is unavailable". The pop-up window lasts for 10 seconds before exiting; VCU_disableDCACreason=4 indicates a DCAC failure. The instrument pops up a window prompting "DCAC failure, DCAC unavailable". The pop-up window lasts for 10 seconds before exiting. VCU_disableDCACreason=5 means the vehicle is under remote control. Since remote control is absolutely isolated from local control and the operator is not on board, the instrument does not need to prompt at this time. VCU_disableDCACreason=6 means DCAC is unavailable due to other reasons. For example, if a high-level fault occurs in the vehicle and high voltage needs to be lowered or high voltage is prohibited, the instrument will pop up a window to prompt "DCAC is unavailable due to other faults". The pop-up window will last for 10 seconds before exiting.

9. The method for controlling an on-board inverter of a range-extended electric vehicle according to claim 4, characterized in that: The power priority lower than AC means that the power priority of the whole vehicle is ranked as follows: drive system>high-voltage accessories>thermal management>passenger compartment air conditioning power>DCAC. The drive system power priority is the highest, and the driving dynamics of the whole vehicle are guaranteed first. The high-voltage accessories ensure the normal operation of the whole vehicle system, involving vehicle safety, etc. For example, the power consumption of high-voltage braking system components ensures braking safety, and the power consumption of the DC converter for low-voltage charging ensures the normal operation of each control unit. Thermal management protects the electric drive system, etc. For strong performance, heat dissipation must be stable. The passenger compartment air conditioning power consumption directly affects the comfort experience of the driver and passengers, so its priority is higher than DCAC, and the comfort function priority is lower than the power and safety priorities. DCAC, as the vehicle's on-board power port, has the lowest relative priority. When the temperature is low and the battery SOC is low, it is necessary to prioritize the APU startup power consumption, that is, at this time, the APU startup power consumption priority is the highest, so as to ensure the APU startup success rate and prevent the battery from running out of power and causing the whole vehicle to break down.

10. The method for controlling an onboard inverter of a range-extended electric vehicle according to claim 3, characterized in that: For the DCAC enable control, in order to prevent the main positive relay from closing with load when the high voltage is powered on, causing the relay to ignite and stick, affecting the high voltage safety, the DCAC enable signal output by the VCU needs to be output after the main positive relay is closed for 500ms. For the DCAC shutdown enable control, before the high voltage is lowered, the VCU needs to send a shutdown enable to the DCAC first, and then the VCU needs to monitor the real-time output power of the DCAC. When the output power is lower than 0.1kW, the main positive relay is disconnected to prevent the main positive relay from disconnecting with load, causing the relay to ignite and stick. Even if the DCAC clears power quickly, it will not affect the control speed of the vehicle to lower the high voltage. When the vehicle is plugged in for charging, if the DCAC is outputting, it is necessary to compensate for the real-time output power of the DCAC, that is, to increase the real-time power output value of the DCAC on the basis of the normal charging request power, so as to ensure that the charging speed of the battery is not affected by the output of the DCAC. Otherwise, when the battery is charging, due to the real-time output of the DCAC, the actual charging power to the battery will become smaller, resulting in a longer charging time, especially at the end of charging. In extreme cases, it may take a long time to fully charge the battery or even fail to fully charge it.

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