Control method, device and computer readable storage medium of range extender

Abstract

The application discloses a control method and device of a range extender and a computer readable storage medium, and the method comprises the following steps: when a shutdown condition is met, controlling the range extender to enter an idle mode; acquiring an engine coolant temperature in the idle mode; when the engine coolant temperature is greater than or equal to a preset temperature value, controlling a generator to drag the engine to rotate in a forward direction, so as to reduce the engine coolant temperature; and when the engine coolant temperature is less than the preset temperature value, controlling the range extender to perform a shutdown operation. In the idle mode, the engine coolant temperature is reduced by dragging the engine to rotate in the forward direction by the generator, the reduction efficiency of the coolant temperature in the idle mode is improved, and the damage of engine parts caused by the excessively high water temperature in the engine cylinder is avoided. Meanwhile, when the coolant temperature decreases to meet the requirement, the range extender is controlled to shut down, the problem of the increased fuel consumption caused by the long-time idle mode of the range extender is avoided, and the fuel economy of the range extender is improved.

Description

Technical Field

[0001] This invention relates to the field of new energy electric vehicle technology, and in particular to a control method, device and computer-readable storage medium for a range extender. Background Technology

[0002] Currently, range-extended electric vehicles (REEVs) use a range extender to generate electricity that charges the battery and drives the electric motor, thus increasing the vehicle's range. When the engine of a REEV is operating under load, the temperature of the engine cylinder components becomes very high. If the engine suddenly stops, the coolant cannot circulate and cool, causing the high temperature inside the engine cylinders to persist and potentially leading to damage to these components. Current technologies address overheating by controlling the range extender to idle. However, prolonged idling increases fuel consumption and negatively impacts fuel economy. Summary of the Invention

[0003] This application provides a control method, device, and computer-readable storage medium for a range extender, aiming to improve the fuel economy of the range extender.

[0004] This application provides a control method for a range extender, the control method for the range extender including:

[0005] When the shutdown conditions are met, the range extender is controlled to enter idle mode;

[0006] Obtain the engine coolant temperature in the idle mode;

[0007] When the engine coolant temperature is greater than or equal to a preset temperature value, the generator is controlled to drive the engine to rotate forward in order to reduce the engine coolant temperature.

[0008] When the engine coolant temperature is lower than the preset temperature value, the range extender is controlled to perform a shutdown operation.

[0009] Optionally, the method further includes:

[0010] Determine whether the range extender is enabled;

[0011] When the range extender is not allowed to be enabled, it is determined that the shutdown condition is met.

[0012] Optionally, after the step of determining whether the range extender is allowed to be enabled, the following steps are included:

[0013] When the range extender is enabled, it is determined whether the maximum defrost request range extender start strategy and the high and low idle speed request range extender start strategy are effective;

[0014] When both the maximum defrost request range extender start strategy and the high and low idle speed request range extender start strategy are invalid, determine whether the NVH condition shutdown strategy is effective and whether the vehicle is in a forced start mode.

[0015] When the NVH shutdown strategy is effective and the vehicle is in forced start mode, the shutdown conditions are determined to be met.

[0016] Optionally, after determining whether the maximum defrost request range extender start strategy and the high / low idle speed request range extender start strategy are effective when the range extender's enable condition is valid, the method further includes:

[0017] When both the maximum defrost request range extender start strategy and the high and low idle speed request range extender start strategy are ineffective, determine whether the vehicle's required power generation is less than the preset power generation.

[0018] When the required power generation of the entire vehicle is less than the preset power generation, the shutdown condition is determined to be met.

[0019] Optionally, the step of determining whether the range extender should be enabled includes:

[0020] When all enabling conditions are met, the range extender is determined to be enabled. These enabling conditions include:

[0021] The vehicle is in a state of readiness to start;

[0022] The fault levels of the vehicle, generator, and engine are all lower than the preset fault levels;

[0023] The current remaining charge of the power battery is less than the preset charge.

[0024] The fault flag for the range extender starting failure has expired.

[0025] Both the generator and the engine are communicating normally;

[0026] The current remaining fuel level is greater than or equal to the preset fuel level;

[0027] The generator's current feedback status indicates it is not in an active discharge state;

[0028] There have been no instances of shutdowns caused by generator overheating, engine coolant overheating, engine oil overheating, excessively high engine oil pressure, or excessively low engine oil pressure.

[0029] Optionally, controlling the range extender to enter idle mode includes:

[0030] Torque unloading requests are sent to the engine and the generator respectively to reduce the requested torque of the engine and the generator;

[0031] Obtain the first torque currently fed back by the generator and the second torque currently fed back by the engine;

[0032] The duration during which both the first torque and the second torque are less than a preset torque is obtained;

[0033] When the duration reaches the preset duration, it is determined that the range extender has entered the idle mode.

[0034] Optionally, the method further includes:

[0035] If the generator drives the engine to rotate forward for a period exceeding a preset driving time, the range extender is controlled to perform a shutdown operation.

[0036] Optionally, controlling the range extender to perform a shutdown operation includes:

[0037] Upon receiving a request to stop the engine, control the engine to stop;

[0038] Obtain the current speed and torque of the generator;

[0039] When the current rotational speed is less than or equal to a preset rotational speed and the current torque is less than or equal to a preset torque, the generator is controlled to stop.

[0040] In addition, to achieve the above objectives, the present invention also provides a control device for a range extender, the control device for the range extender comprising: a memory and a processor, wherein the memory stores a control program for the range extender that can run on the processor, and when the control program for the range extender is executed by the processor, it implements the steps of the above-described control method for the range extender.

[0041] In addition, to achieve the above objectives, the present invention also provides a computer-readable storage medium having a control program for a range extender stored thereon, wherein the control program for the range extender, when executed by a processor, implements the steps of the above-described control method for the range extender.

[0042] This application provides a control method, device, and computer-readable storage medium for a range extender. When the range extender is in idle mode and stopped, the engine coolant temperature is acquired. When the engine coolant temperature is greater than or equal to a preset temperature value, the generator is controlled to drive the engine forward, thereby reducing the engine coolant temperature. Because the engine coolant temperature is reduced by driving the engine forward in idle mode, the efficiency of coolant temperature reduction in idle mode is improved, avoiding damage to engine components due to excessively high engine cylinder temperatures. Simultaneously, when the coolant temperature drops to the required level, the range extender is stopped, preventing the range extender from remaining in idle mode for extended periods, which would lead to increased fuel consumption and improve the fuel economy of the range extender. Attached Figure Description

[0043] Figure 1 This is a flowchart illustrating the first embodiment of the control method for the range extender of the present invention;

[0044] Figure 2 This is a schematic diagram illustrating the enable judgment of the range extender in this invention;

[0045] Figure 3 This is a schematic diagram of the control device for the range extender involved in an embodiment of the present invention.

[0046] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. The accompanying drawings are only one embodiment and not the entirety of the invention. Detailed Implementation

[0047] When a range-extended electric vehicle suddenly stops, the engine stops rotating, the coolant cannot circulate and cool, and the high temperature inside the engine cylinders persists, posing a risk of overheating and damage to engine components. This application proposes a control method for the range extender. When the range extender is in idle mode, the engine coolant temperature is acquired, and when the coolant temperature is greater than or equal to a preset value, the generator is controlled to drive the engine forward, thereby lowering the coolant temperature. Because the coolant temperature is lowered by driving the engine forward in idle mode via the generator, compared to natural cooling in idle mode, this application improves the efficiency of coolant temperature reduction, preventing damage to engine components from excessively high engine cylinder temperatures. Simultaneously, when the coolant temperature drops to a acceptable level, the range extender is shut down, avoiding the problem of increased fuel consumption caused by prolonged idling and improving the fuel economy of the range extender.

[0048] To better understand the above technical solutions, exemplary embodiments of this disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of this disclosure are shown in the drawings, it should be understood that this disclosure can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of this disclosure to those skilled in the art.

[0049] First embodiment.

[0050] like Figure 1 As shown, in the first embodiment of this application, the control method of the range extender of this application includes the following steps:

[0051] Step S110: When the shutdown conditions are met, control the range extender to enter idle mode.

[0052] In this embodiment, when the engine is running, a portion of the engine oil is supplied to the turbocharger rotor bearing for lubrication and cooling. When the running engine suddenly stops, the oil pressure drops rapidly to zero, interrupting lubrication. The heat inside the turbocharger cannot be carried away by the oil, and the high temperature of the turbine section is transferred to the center. The heat in the bearing support housing cannot be quickly dissipated, while the turbocharger rotor continues to rotate at high speed due to inertia. This can cause the turbocharger shaft and bushing to "seize," damaging the bearing and shaft. Furthermore, after the engine suddenly shuts off, the exhaust manifold temperature is very high, and this heat is absorbed onto the turbocharger housing, turning the oil inside the turbocharger into carbon deposits. As these carbon deposits accumulate, they can clog the oil inlet, leading to insufficient lubrication of the bushing and accelerating wear between the turbine shaft and bushing. Therefore, before performing the shutdown operation (i.e., shutting off the engine), the range extender is first controlled to idle, aiming to reduce the turbocharger rotor speed and lower the engine coolant temperature. The engine shutdown operation is only performed when the engine coolant temperature drops to the required level.

[0053] A range extender is a combination of an engine and a generator; that is, the range extender includes both an engine and a generator. When shutdown conditions are met, the range extender can be controlled to enter idle mode. This lowers the engine coolant temperature in idle mode. Once the engine coolant temperature has decreased to a suitable level, a shutdown operation is performed.

[0054] In one embodiment, controlling the range extender to enter idle mode when shutdown conditions are met includes two parts: requesting to enter idle mode and detecting whether idle mode has already been entered. By configuring these two parts, the range extender can be controlled to normally enter idle mode when shutdown conditions are met, so that the range extender can subsequently shut down normally.

[0055] Optionally, a torque unloading request is sent to the engine and generator respectively to reduce the requested torque of the engine and generator. This process is called requesting to enter the idle mode. During this process, when the engine and generator receive the torque unloading request, they can unload torque according to a preset slope to achieve the purpose of reducing the requested torque of the engine and generator.

[0056] Optionally, after sending torque unloading requests to the engine and generator respectively, it is also necessary to check whether the range extender has entered the idle mode. The first torque currently fed back by the generator and the second torque currently fed back by the engine can be obtained, and the duration for which both the first torque and the second torque are less than a preset torque can be obtained. When the duration reaches the preset duration, it is determined that the range extender has entered the idle mode. Specifically, when both the first torque and the second torque are less than the preset torque, the start time and end time of the first torque and the second torque being less than the preset torque can be obtained, and the duration can be determined based on the start time and the end time. For example, assuming the preset torque is set to 5 N·m and the duration is set to 5 seconds, then if both the first torque fed back by the generator and the second torque fed back by the engine are less than 5 N·m within 5 seconds, then torque unloading is considered complete, and the range extender is determined to have entered the idle mode.

[0057] Step S120: Obtain the engine coolant temperature in the idle mode.

[0058] In this embodiment, the engine coolant temperature is measured by a coolant temperature sensor, which then sends the engine coolant temperature to the system to obtain the engine coolant temperature. It takes time for the coolant temperature to drop to the required level. If the range extender remains in idling mode during this period, it will increase the fuel consumption of the range-extended electric vehicle and reduce fuel economy. Therefore, to reduce the fuel consumption of range-extended electric vehicles, it is necessary to improve the efficiency of engine coolant temperature reduction.

[0059] Step S130: When the engine coolant temperature is greater than or equal to a preset temperature value, control the generator to drive the engine to rotate forward in order to reduce the engine coolant temperature.

[0060] In this embodiment, the preset temperature value is a set temperature threshold, which can be set according to actual conditions. The system's temperature judgment module compares the engine coolant temperature with the preset temperature value and sends the comparison result to the system. For example, if the engine coolant temperature is 130°C and the preset temperature value is 106°C, the comparison result is that the engine coolant temperature is higher than the preset temperature value. If the engine coolant temperature is higher than the preset temperature value, the generator drives the engine to rotate forward, causing the water pump to operate and the coolant in the range extender to circulate continuously, improving the engine coolant temperature reduction efficiency. This effectively improves the engine coolant temperature reduction efficiency without changing the component structure or vehicle cost. While controlling the generator to drive the engine to rotate forward, the engine coolant temperature in idle mode is acquired in real time for temperature judgment to determine whether the coolant temperature has dropped to the required level.

[0061] Step S140: When the engine coolant temperature is lower than the preset temperature value, control the range extender to perform a shutdown operation.

[0062] In this embodiment, when the engine coolant temperature is lower than a preset temperature value, the generator and engine are sequentially shut down, thereby achieving the purpose of shutting down the range extender. It should be noted that under normal circumstances, by driving the engine forward through the generator, the engine coolant temperature can drop below the target value within a certain period of time.

[0063] According to the above technical solution, this embodiment acquires the engine coolant temperature when the range extender is in idle mode. When the engine coolant temperature is greater than or equal to a preset temperature value, it controls the generator to drive the engine to rotate forward, thereby reducing the engine coolant temperature. Compared to natural cooling of the coolant temperature in idle mode, this application reduces the engine coolant temperature by driving the engine to rotate forward using the generator in idle mode, improving the efficiency of coolant temperature reduction and preventing damage to engine components due to excessively high engine cylinder temperatures. Simultaneously, when the coolant temperature drops to the required level, the range extender is shut down, preventing the range extender from remaining in idle mode for extended periods, which would lead to increased fuel consumption and improve the fuel economy of the range extender.

[0064] Second embodiment.

[0065] Before step S110 in the first embodiment of this application, the control method of the range extender in this application includes:

[0066] Step S210: Determine whether the range extender is allowed to be enabled.

[0067] In this embodiment, whether the range extender is enabled indicates whether the range extender can be started. Multiple enable / disable conditions can be preset according to actual conditions. When all enable conditions are met, the range extender is determined to be enabled, and an enable flag is sent, thus allowing the range extender to start.

[0068] Optionally, the enabling conditions set in this application include, but are not limited to, those provided in this application. Figure 2 The judgment conditions shown are as follows:

[0069] (1) The vehicle is in a state of readiness to start;

[0070] (2) The fault levels of the whole vehicle, generator and engine are all lower than the preset fault levels;

[0071] (3) The current remaining power of the power battery is less than the preset power;

[0072] (4) The fault flag for the range extender starting failure is invalid;

[0073] (5) Both the generator and the engine are communicating normally;

[0074] (6) The current remaining fuel level is greater than or equal to the preset fuel level;

[0075] (7) The current state fed back by the generator is not in an active discharge state;

[0076] (8) No shutdown failures have occurred due to generator overheating, generator overheating, engine water temperature overheating, engine oil overheating, engine oil pressure over-high or engine oil pressure over-low.

[0077] This application sets multiple enable conditions for the range extender, and starts the range extender when all enable conditions are met, thereby improving the judgment accuracy and making the start-stop control of the range extender more intelligent.

[0078] Optionally, if one of the above enabling conditions is not met, the range extender is determined not to be enabled, and an enable-disable flag is sent; in this case, the range extender does not start. That is, the range extender is determined not to be enabled when any of the following conditions are met:

[0079] (1) The vehicle is not in a state of readiness to start;

[0080] (2) The fault level of the vehicle, generator or engine is greater than or equal to the preset fault level.

[0081] (3) The current remaining power of the power battery is greater than or equal to the preset power;

[0082] (4) Range extender start failure fault flag is valid;

[0083] (5) The generator and engine cannot communicate normally;

[0084] (6) The current remaining fuel level is less than the preset fuel level;

[0085] (7) The current state of the generator feedback is in active discharge state;

[0086] (8) There have been shutdown failures caused by generator overheating, generator overheating, engine water temperature overheating, engine oil overheating, engine oil pressure overheating and engine oil pressure underheating.

[0087] This application sets multiple enable conditions for the range extender, and the range extender is not started when one of the enable conditions is not met, making the start-stop control of the range extender more intelligent.

[0088] Step S220: When the range extender is not allowed to be enabled, it is determined that the shutdown condition is met.

[0089] In this embodiment, before controlling the range extender to enter idle mode, it is necessary to determine whether the range extender's idle mode is the idle mode entered during startup or the idle mode entered during shutdown. That is, before controlling the range extender to enter idle mode, it is necessary to determine the conditions met by the range extender, and thus determine whether the range extender is currently shut down or running. For example, when the shutdown conditions are detected, this application determines that the range extender's idle mode is the idle mode entered during shutdown, and at this time, controls the range extender to enter idle mode.

[0090] There are many triggering conditions for meeting shutdown conditions. In one embodiment, one of them is influenced by the range extender's enable state. Whether the range extender meets the shutdown or startup conditions can be determined based on whether it is enabled. For example, if the range extender is not enabled, no range extender enable flag is issued, indicating that the shutdown condition is met. If the range extender is enabled, a range extender enable flag is issued, indicating that the startup condition is met.

[0091] When the range extender is not allowed to be enabled, a shutdown condition is determined to be met. When the shutdown condition is met, the range extender is controlled to enter idle mode; the engine coolant temperature in idle mode is acquired. When the engine coolant temperature is greater than or equal to a preset temperature value, the generator is controlled to drive the engine forward to reduce the engine coolant temperature. When the engine coolant temperature is less than the preset temperature value, the range extender is controlled to perform a shutdown operation. Through the above specific implementation, this application enables the range extender to reduce engine coolant temperature by controlling the generator to drive the engine in idle mode, thereby improving the efficiency of coolant temperature reduction and improving the fuel economy of electric vehicles.

[0092] In one embodiment, the triggering condition for the range extender to stop is also affected by the type of strategy currently activated by the vehicle and the enable state of the range extender.

[0093] Optionally, it is determined whether the range extender is allowed to be enabled. If the range extender is allowed to be enabled, it is determined whether the maximum defrost request range extender start strategy and the high / low idle speed request range extender start strategy are effective. If both the maximum defrost request range extender start strategy and the high / low idle speed request range extender start strategy are ineffective, it is further determined whether the NVH condition shutdown strategy is effective and whether the vehicle is in forced start mode. If the NVH condition shutdown strategy is effective and the vehicle is in forced start mode, it is determined that the shutdown condition is met. When the shutdown condition is met, the range extender is controlled to enter idle mode; the engine coolant temperature in idle mode is acquired. When the engine coolant temperature is greater than or equal to a preset temperature value, the generator is controlled to drive the engine to rotate forward to reduce the engine coolant temperature. When the engine coolant temperature is less than the preset temperature value, the range extender is controlled to perform a shutdown operation.

[0094] The system can also return to the step of determining whether the range extender should be enabled when both the maximum defrost request range extender start strategy and the high / low idle speed request range extender start strategy are effective. Optionally, the system can also return to the step of determining whether the range extender should be enabled when the NVH condition shutdown strategy is ineffective and the vehicle is not in forced start mode.

[0095] Optionally, it can also be determined whether the range extender is allowed to be enabled. If the range extender is allowed to be enabled, it is determined whether the maximum defrost request range extender start strategy and the high / low idle speed request range extender start strategy are effective. If both the maximum defrost request range extender start strategy and the high / low idle speed request range extender start strategy are ineffective, it is further determined whether the vehicle's required power generation is less than the preset power generation. If the vehicle's required power generation is less than the preset power generation, it is determined that the shutdown condition is met. When the shutdown condition is met, the range extender is controlled to enter idle mode; the engine coolant temperature in idle mode is acquired. When the engine coolant temperature is greater than or equal to the preset temperature value, the generator is controlled to drive the engine to rotate forward to reduce the engine coolant temperature. When the engine coolant temperature is less than the preset temperature value, the range extender is controlled to perform a shutdown operation.

[0096] The system can also return to the step of determining whether the range extender should be enabled when the required power generation of the vehicle is greater than or equal to the preset power generation.

[0097] The aforementioned maximum defrost request range extender activation strategy effectively indicates that the vehicle is currently using the maximum defrost function, and requests the range extender to start when the maximum defrost function is activated. If the range extender allows enabling and the maximum defrost function is activated, then the range extender is determined to meet the activation conditions.

[0098] The aforementioned high and low idle speed request range extender start strategies include a high idle speed request range extender start strategy and a low idle speed request range extender start strategy. These strategies can be set according to actual conditions. Because the throttle valve controls the engine's intake air volume through the idle speed control valve, the vehicle's idle speed can be adjusted by changing the opening of the idle speed control valve. A valid high and low idle speed request range extender start strategy indicates that the vehicle is currently using either a high idle speed function or a low idle speed function, and requests the range extender to start when either function is activated. If the range extender is enabled and the high and low idle speed functions are activated, then the range extender is deemed to meet the start conditions.

[0099] The preset power generation capacity can be determined according to the actual situation. In this application, the preset power generation capacity can be set to 4KW.

[0100] In one embodiment, regarding the above-mentioned NVH shutdown strategy: In order to improve the overall vehicle NVH performance and reduce noise by shutting down the range extender when the vehicle is static or at low speed, the vehicle continuously monitors information such as remaining battery power, vehicle speed, and accelerator pedal depth. The vehicle enters the NVH shutdown strategy when the following conditions are met: the remaining battery power fed back by the power battery is greater than or equal to a first preset remaining battery power; the current vehicle speed is less than or equal to a first preset vehicle speed; the current accelerator pedal depth is less than or equal to a first preset accelerator pedal depth; the duration of the current accelerator pedal depth being less than or equal to the first preset accelerator pedal depth is greater than or equal to a first preset duration; and the vehicle is not currently in a forced start mode. For example, assuming the remaining charge of the power battery is 30% and the first preset remaining charge is 25%; the current vehicle speed is 15km / h and the first preset vehicle speed is 20km / h; the current throttle depth is 10% and the first preset throttle depth is 20%; the duration of the current throttle depth being less than or equal to the first preset throttle depth is 70s, and the first preset duration is 60s; and the vehicle is not currently in REC (Restart Control) mode. Since the remaining charge of the power battery is ≥25%, the current vehicle speed is ≤20km / h, the duration of the current throttle depth being ≤20% is ≥60s, and the vehicle is not currently in REC mode, the NVH (Noise, Vibration, and Harshness) shutdown strategy is initiated.

[0101] Optionally, the vehicle exits the NVH shutdown condition when any of the following conditions are met: the remaining charge fed back by the power battery is less than or equal to a second remaining charge; the current vehicle speed is greater than or equal to a second preset vehicle speed; the duration for which the current vehicle speed is greater than or equal to the second preset vehicle speed is greater than or equal to a second preset duration; the current throttle depth is greater than or equal to a second preset throttle depth; the duration for which the current throttle depth is greater than or equal to the second throttle depth is greater than or equal to a third preset duration; or the vehicle is currently in a forced start mode. For example, assuming the remaining charge of the power battery is 20%, the second preset remaining charge is 22%; the current vehicle speed is 35 km / h, the second preset vehicle speed is 30 km / h, the current vehicle speed is greater than or equal to the second preset vehicle speed for 25 seconds, and the second preset duration is 20 seconds; the current throttle depth is 80%, the second preset throttle depth is 70%; the current throttle depth is greater than or equal to the second preset throttle depth for 15 seconds, and the third preset duration is 12 seconds; the vehicle is currently in REC strong start mode. Because the remaining charge of the power battery is ≤22%, the current vehicle speed is ≥30 km / h for ≥20 seconds, the current throttle depth is ≥70% for ≥12 seconds, and the vehicle is currently in REC strong start mode, the NVH condition shutdown strategy is exited.

[0102] In one embodiment, the methods used to detect the effectiveness of the high and low idle speed request range extender start-up strategy include: the gasoline range extender dual idle speed method and the diesel range extender free acceleration method. Among these,

[0103] (1) Gasoline range extender dual idle speed method

[0104] Gasoline range extenders fall under the category of gasoline vehicles and are tested for emissions using the dual idle speed method in GB18285-2018. Before testing, the engine must be warmed up and the test should begin when the engine coolant temperature is ≥70℃.

[0105] The range extender continuously monitors the following conditions during operation:

[0106] 1) The current vehicle speed is ≤3km / h;

[0107] 2) The vehicle is currently in neutral (N) gear.

[0108] 3) The range extender enable condition is valid;

[0109] 4) Set the range extender idle speed switch to high or low idle speed;

[0110] When all of the above conditions are met, the high and low idle speed start-up range extender strategy is considered effective; when any of the above conditions are invalid, the range extender considers the high and low idle speed start-up range extender strategy to be invalid.

[0111] (2) Free acceleration method of diesel range extender

[0112] Diesel range extenders fall under the category of diesel vehicles and are tested for emissions using the free acceleration method in GB3847-2018. Before testing, the engine must be warmed up and the test should begin when the engine coolant temperature is ≥70℃.

[0113] The range extender continuously monitors the following conditions during operation:

[0114] 1) The current vehicle speed is ≤3km / h;

[0115] 2) The vehicle is currently in neutral (N) gear.

[0116] 3) The range extender enable condition is valid;

[0117] 4) Set the range extender idle speed switch to high or low idle speed;

[0118] When the range extender detects that the above conditions are met simultaneously, the range extender considers the high and low idle speed start-up strategy to be effective; when any of the above conditions are invalid, the range extender considers the high and low idle speed start-up strategy to be invalid.

[0119] In one embodiment, the range extender continuously monitors the shutdown requirements of various strategies during operation, and strategy or mode conflicts may exist. For strategies that require the range extender to shut down, the range extender prioritizes the strategies in the following order: range extender emission detection function strategy > battery heating start range extender strategy > forced start mode > NVH condition shutdown strategy > intelligent mode > pure electric mode > maximum defrost request range extender start strategy.

[0120] Regarding the range extender start strategy for the aforementioned emissions testing request: when a vehicle is registered or undergoes its annual inspection, the engine needs to run continuously at a fixed speed for a certain period of time when the vehicle passes through the testing line for emissions testing. The emissions testing function strategy varies depending on the vehicle model and fuel.

[0121] This application uses the above method to determine whether the range extender meets the shutdown conditions in different scenarios, so that the range extender can achieve normal shutdown in different scenarios.

[0122] Third embodiment.

[0123] Based on the first embodiment, in the third embodiment of this application, the control method of the range extender includes the following steps:

[0124] Step S110: When the shutdown conditions are met, control the range extender to enter idle mode;

[0125] Step S120: Obtain the engine coolant temperature in the idle mode;

[0126] Step S130: When the engine coolant temperature is greater than or equal to a preset temperature value, control the generator to drive the engine to rotate forward in order to reduce the engine coolant temperature.

[0127] Step S310: If the duration during which the generator drives the engine to rotate forward exceeds a preset driving duration, control the range extender to perform a shutdown operation.

[0128] In this embodiment, the duration for which the generator drives the engine in forward rotation can also be set. If the duration exceeds a preset duration, the range extender will be shut down. If, after the generator has driven the engine for the preset duration, the coolant temperature of the range extender engine is still greater than or equal to a preset temperature value, the range extender will be shut down to prevent the range extender from running for an extended period without stopping if the coolant temperature fails to drop to the target value after the shutdown command is issued. This function is an additional redundant protection feature to prevent extreme situations from occurring.

[0129] In one embodiment, the range extender is controlled to shut down after the engine coolant temperature falls below a preset temperature value, or after the generator has been driving the engine forward for a preset duration. Specifically, controlling the range extender to shut down includes the following steps:

[0130] Step S141: Upon receiving a shutdown request for the engine, control the engine to shut down;

[0131] In this embodiment, a request to stop the engine is sent when the engine coolant temperature is lower than a preset temperature value or when the generator drives the engine to rotate forward for a duration exceeding a preset duration. Upon receiving the request to stop the engine, the system controls the engine to stop.

[0132] In this embodiment, after controlling the engine to stop, it can be further determined whether the engine has stopped successfully. At this time, the range extender obtains the current state feedback from the engine and starts timing; if the current state feedback from the engine is detected as a stopped state, it indicates that the engine has stopped. The range extender further obtains the current speed and current torque feedback from the generator.

[0133] Step S142: Obtain the current speed and current torque of the generator;

[0134] Step S143: When the current speed is less than or equal to the preset speed and the current torque is less than or equal to the preset torque, control the generator to stop.

[0135] Optionally, the system can also acquire the duration for which the current rotational speed is less than or equal to a preset rotational speed and the current torque is less than or equal to a preset torque. If this duration is less than the preset duration, the system will control the generator to shut down. For example, if the system detects that the current rotational speed is less than or equal to 100 rpm and the current torque is less than or equal to 5 N·m within 5 seconds, the system will control the generator to shut down. If the timeout period is exceeded, the system will consider the generator speed reduction timeout to have occurred.

[0136] Optionally, after controlling the generator to stop, it can be further determined whether the generator has stopped successfully. At this time, the range extender obtains the current status feedback from the generator and starts timing; if the current status feedback from the generator is detected as a stop state, it means that the generator has stopped. For example, if the current status feedback from the generator is a stop state within 500ms, it is considered that the generator has been shut down; if the timeout occurs, it is considered that the shutdown timeout has occurred.

[0137] This invention provides an embodiment of a control method for a range extender. It should be noted that although the logical order is shown in the flowchart, in some cases, the steps shown or described may be performed in a different order than that shown here.

[0138] Reference Figure 3 , Figure 3This is a schematic diagram of the control device for a range extender according to an embodiment of the present invention. This application discloses a control device for a range extender, comprising: a memory 1002, a processor 1001, and a control program for the range extender stored in the memory 1002 and executable on the processor 1001. When the control program is executed by the processor 1001, it implements the steps of a control method for the range extender.

[0139] The memory 1002 can be used to store software programs and modules. The processor 1001 executes various functional applications and data processing by running the software programs and modules stored in the memory 1002. The memory 1002 may mainly include a program storage area and a data storage area. The program storage area may store the operating system, application programs required for functions, etc.; the data storage area may store data created according to the use of the terminal, etc. In addition, the memory 1002 may include a high-speed random access memory 1002, and may also include non-volatile memory 1002, such as at least one disk storage device 1002, flash memory device, or other volatile solid-state memory 1002. Accordingly, the memory 1002 may also include a memory 1002 controller to provide the processor 1001 with access to the memory 1002.

[0140] In one embodiment, when processor 1001 calls the control program for the range extender stored in memory 1002, it performs the following operations:

[0141] When the shutdown conditions are met, the range extender is controlled to enter idle mode;

[0142] Obtain the engine coolant temperature in the idle mode;

[0143] When the engine coolant temperature is greater than or equal to a preset temperature value, the generator is controlled to drive the engine to rotate forward in order to reduce the engine coolant temperature.

[0144] When the engine coolant temperature is lower than the preset temperature value, the range extender is controlled to perform a shutdown operation.

[0145] In one embodiment, when processor 1001 calls the control program for the range extender stored in memory 1002, it performs the following operations:

[0146] Determine whether the range extender is enabled;

[0147] When the range extender is not allowed to be enabled, it is determined that the shutdown condition is met.

[0148] In one embodiment, when processor 1001 calls the control program for the range extender stored in memory 1002, it performs the following operations:

[0149] When the range extender is enabled, it is determined whether the maximum defrost request range extender start strategy and the high and low idle speed request range extender start strategy are effective;

[0150] When both the maximum defrost request range extender start strategy and the high and low idle speed request range extender start strategy are invalid, determine whether the NVH condition shutdown strategy is effective and whether the vehicle is in a forced start mode.

[0151] When the NVH shutdown strategy is effective and the vehicle is in forced start mode, the shutdown conditions are determined to be met.

[0152] In one embodiment, when processor 1001 calls the control program for the range extender stored in memory 1002, it performs the following operations:

[0153] When both the maximum defrost request range extender start strategy and the high and low idle speed request range extender start strategy are ineffective, determine whether the vehicle's required power generation is less than the preset power generation.

[0154] When the required power generation of the entire vehicle is less than the preset power generation, the shutdown condition is determined to be met.

[0155] In one embodiment, when processor 1001 calls the control program for the range extender stored in memory 1002, it performs the following operations:

[0156] When all enabling conditions are met, the range extender is determined to be enabled. These enabling conditions include:

[0157] The vehicle is in a state of readiness to start;

[0158] The fault levels of the vehicle, generator, and engine are all lower than the preset fault levels;

[0159] The current remaining charge of the power battery is less than the preset charge.

[0160] The fault flag for the range extender starting failure has expired.

[0161] Both the generator and the engine are communicating normally;

[0162] The current remaining fuel level is greater than or equal to the preset fuel level;

[0163] The generator's current feedback status indicates it is not in an active discharge state;

[0164] There have been no instances of shutdowns caused by generator overheating, engine coolant overheating, engine oil overheating, excessively high engine oil pressure, or excessively low engine oil pressure.

[0165] In one embodiment, when processor 1001 calls the control program for the range extender stored in memory 1002, it performs the following operations:

[0166] Torque unloading requests are sent to the engine and the generator respectively to reduce the requested torque of the engine and the generator;

[0167] Obtain the first torque currently fed back by the generator and the second torque currently fed back by the engine;

[0168] The duration during which both the first torque and the second torque are less than a preset torque is obtained;

[0169] When the duration reaches the preset duration, it is determined that the range extender has entered the idle mode.

[0170] In one embodiment, when processor 1001 calls the control program for the range extender stored in memory 1002, it performs the following operations:

[0171] If the generator drives the engine to rotate forward for a period exceeding a preset driving time, the range extender is controlled to perform a shutdown operation.

[0172] In one embodiment, when processor 1001 calls the control program for the range extender stored in memory 1002, it performs the following operations:

[0173] Upon receiving a request to stop the engine, control the engine to stop;

[0174] Obtain the current speed and torque of the generator;

[0175] When the current rotational speed is less than or equal to a preset rotational speed and the current torque is less than or equal to a preset torque, the generator is controlled to stop.

[0176] Based on the same inventive concept, this application also provides a computer-readable storage medium storing a control program for a range extender. When the control program for the range extender is executed by the processor 1001, it implements the various steps of the control method for the range extender as described above and achieves the same technical effect. To avoid repetition, it will not be described again here.

[0177] Since the computer-readable storage medium provided in the embodiments of this application is a computer-readable storage medium used to implement the methods of the embodiments of this application, those skilled in the art can understand the specific structure and variations of the computer-readable storage medium based on the methods described in the embodiments of this application, and therefore will not be repeated here. All computer-readable storage media used in the methods of the embodiments of this application fall within the scope of protection of this application.

[0178] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or system that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or system. Unless otherwise specified, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or system that includes that element.

[0179] The sequence numbers of the above embodiments of the present invention are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0180] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes several instructions to cause a terminal device (which may be a mobile phone, computer, server, television, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0181] The above are merely preferred embodiments of the present invention and do not limit the scope of the patent. Any equivalent structural or procedural transformations made based on the description and drawings of the present invention, or direct or indirect applications in other related technical fields, are similarly included within the scope of patent protection of the present invention.

Claims

1. A control method for a range extender, characterized in that, The method includes: Determine whether the range extender is enabled; When the range extender is enabled, it is determined whether the maximum defrost request range extender start strategy and the high / low idle speed request range extender start strategy are valid. The valid maximum defrost request range extender start strategy indicates that the vehicle is currently using the maximum defrost function, and the range extender is requested to start when the maximum defrost function is used. The valid high / low idle speed request range extender start strategy indicates that the vehicle is currently using the high idle speed function or the low idle speed function, and the range extender is requested to start when the high idle speed function or the low idle speed function is used. When both the maximum defrost request range extender start strategy and the high and low idle speed request range extender start strategy are invalid, determine whether the NVH condition shutdown strategy is effective and whether the vehicle is currently in a forced start mode. When the NVH shutdown strategy is effective and the vehicle is not currently in forced start mode, the shutdown conditions are determined to be met. When the shutdown conditions are met, the range extender is controlled to enter idle mode; Obtain the engine coolant temperature in the idle mode; When the engine coolant temperature is greater than or equal to a preset temperature value, the generator is controlled to drive the engine to rotate forward in order to reduce the engine coolant temperature. When the engine coolant temperature is lower than the preset temperature value, the range extender is controlled to perform a shutdown operation; The effective judgment conditions of the NVH working condition shutdown strategy include: the remaining power of the power battery is greater than or equal to the first preset remaining power, the current vehicle speed is less than or equal to the first preset vehicle speed, the current throttle depth is less than or equal to the first preset throttle depth, and the duration of the current throttle depth being less than or equal to the first preset throttle depth is greater than or equal to the first preset duration.

2. The method as described in claim 1, characterized in that, The method further includes: When the range extender is not allowed to be enabled, it is determined that the shutdown condition is met.

3. The method as described in claim 1, characterized in that, After determining whether the maximum defrost request range extender start strategy and the high / low idle speed request range extender start strategy are effective when the range extender is enabled, the method further includes: When both the maximum defrost request range extender start strategy and the high and low idle speed request range extender start strategy are ineffective, determine whether the vehicle's required power generation is less than the preset power generation. When the required power generation of the entire vehicle is less than the preset power generation, the shutdown condition is determined to be met.

4. The method as described in claim 1, characterized in that, The step of determining whether the range extender should be enabled includes: When all enabling conditions are met, the range extender is determined to be enabled. These enabling conditions include: The vehicle is in a state of readiness to start; The fault levels of the vehicle, generator, and engine are all lower than the preset fault levels; The current remaining charge of the power battery is less than the preset charge. The fault flag for the range extender starting failure has expired. Both the generator and the engine are communicating normally; The current remaining fuel level is greater than or equal to the preset fuel level; The generator's current feedback status indicates it is not in an active discharge state; There have been no instances of shutdowns caused by generator overheating, engine coolant overheating, engine oil overheating, excessively high engine oil pressure, or excessively low engine oil pressure.

5. The method as described in claim 1, characterized in that, The process of controlling the range extender to enter idle mode includes: Torque unloading requests are sent to the engine and the generator respectively to reduce the requested torque of the engine and the generator; Obtain the first torque currently fed back by the generator and the second torque currently fed back by the engine; The duration during which both the first torque and the second torque are less than a preset torque is obtained; When the duration reaches the preset duration, it is determined that the range extender has entered the idle mode.

6. The method as described in claim 1, characterized in that, The method further includes: If the generator drives the engine to rotate forward for a period exceeding a preset driving time, the range extender is controlled to perform a shutdown operation.

7. The method according to any one of claims 1-6, characterized in that, The process of controlling the range extender to perform a shutdown operation includes: Upon receiving a request to stop the engine, control the engine to stop; Obtain the current speed and torque of the generator; When the current rotational speed is less than or equal to a preset rotational speed and the current torque is less than or equal to a preset torque, the generator is controlled to stop.

8. A control device for a range extender, characterized in that, The control device for the range extender includes a memory and a processor. The memory stores a control program for the range extender that can run on the processor. When the control program for the range extender is executed by the processor, it implements the steps of the control method for the range extender as described in any one of claims 1-7.

9. A computer-readable storage medium, characterized in that, The computer-readable storage medium stores a control program for the range extender, which, when executed by a processor, implements the steps of the control method for the range extender according to any one of claims 1-7.

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