Range-extended electric vehicle and fixed-point control method and apparatus therefor, and storage medium

Abstract

A range extender control method of a range-extended electric vehicle. The method is applied to the technical field of hybrid vehicle power supply, and comprises: when the speed of a range-extended electric vehicle is in a first speed interval, controlling a range extender to operate at a first preselected operating point, the first preselected operating point being adapted to the first speed interval; and if the speed of the range-extended electric vehicle increases from the first speed interval to a second speed interval, controlling the range extender to sequentially switch from the first preselected operating point to a transition operating point and a second preselected operating point adapted to the second speed interval to operate, the power generation power of the range extender at the transition operating point being the same as the power generation power at the first preselected operating point, and the engine rotating speed at the transition operating point being less than the engine rotating speed at the first preselected operating point. The range extender control method at least reduces the technical problem of large NVH noise caused by vehicle speed changes to a range extender. Also provided are an apparatus for implementing the range extender control method, and a storage medium.

Description

Extended-range electric vehicle and fixed-point control method, device and storage medium thereof Technical Field

[0001] The present invention relates to the technical field of hybrid vehicle power supply, and in particular to an extended-range electric vehicle and a fixed-point control method, device and storage medium thereof. Background Art

[0002] Electric vehicles (EVs) with extended-range powertrains are gaining popularity in the market. Compared to traditional vehicles, EVs significantly reduce fuel consumption and emissions by matching the engine's high-efficiency operating point. Compared to HEVs (Hybrid Electric Vehicles) and PHEVs (Plug-in Hybrid Electric Vehicles), EVs minimize range anxiety, while offering the range of traditional vehicles and the driving experience of pure electric vehicles.

[0003] In the REEV (Range Extended Electric Vehicle) architecture, the range extender (REEV) provides only electrical power; the engine does not directly drive the vehicle. This completely decouples the range extender from the vehicle's operation, and the range extender's operating point has no direct relationship to vehicle speed. Existing technologies that use fixed-point control strategies to control the range extender suffer from poor NVH (noise, vibration, and harshness) performance when switching between different operating points.

[0004] Summary of the Invention

[0005] The present invention provides a range-extended electric vehicle and its fixed-point control method, device, and storage medium. These methods address the technical issue of poor NVH performance when switching between different operating points in conventional fixed-point control strategies for controlling the range extender. These methods optimize NVH performance while also balancing affordability.

[0006] In a first aspect of the present invention, a fixed-point control method for a range extender is provided, comprising: when the speed of the extended-range electric vehicle is in a first speed range, controlling the range extender of the extended-range electric vehicle to operate at a first preselected operating point, the first preselected operating point being adapted to the first speed range; if the speed of the extended-range electric vehicle decreases from the first speed range to a second speed range, during the process of the speed decrease of the extended-range electric vehicle, controlling the range extender to switch sequentially from the first preselected operating point to a target transition operating point and a second preselected operating point adapted to the second speed range, wherein the power generation power of the range extender at the target transition operating point is the same as the power generation power at the first preselected operating point, and the engine speed at the target transition operating point is less than the engine speed at the first preselected operating point.

[0007] In combination with the first aspect, in some embodiments, during the process of the extended-range electric vehicle's speed decreasing, the range extender is controlled to switch from the first preselected operating point to the target transition operating point and the second preselected operating point adapted to the second speed range in sequence, including: when the range extender is operating at the first preselected operating point, if the speed of the extended-range electric vehicle drops to meet a first preset condition, the range extender is controlled to switch from the first preselected operating point to the target transition operating point; when the range extender is operating at the target transition operating point, if the speed of the extended-range electric vehicle drops to meet a second preset condition, the range extender is controlled to switch from the target transition operating point to the second preselected operating point; wherein, the first preset condition and the second preset condition at least define the upper limit of the speed of the extended-range electric vehicle, and the upper limit of the speed defined by the second preset condition is less than the upper limit of the speed defined by the first preset condition.

[0008] In combination with the first aspect, in some embodiments, before controlling the range extender of the extended-range electric vehicle to operate at a first preselected operating point, it also includes: when the range extender is in an off state, monitoring the remaining power of the power battery of the extended-range electric vehicle; if it is determined that the power battery enters a feeding state based on the remaining power of the power battery, starting the range extender and determining the first preselected operating point based on the current vehicle speed of the extended-range electric vehicle.

[0009] In combination with the first aspect, in some embodiments, determining the first preselected operating point based on the current speed of the extended-range electric vehicle includes: determining a first speed interval in which the current speed of the extended-range electric vehicle is located from M pre-divided speed intervals, and configuring M preselected operating points for the operation of the range extender in a one-to-one correspondence with the M speed intervals, where M is an integer greater than 1; and selecting the preselected operating point corresponding to the first speed interval as the first preselected operating point.

[0010] In combination with the first aspect, in some embodiments, it also includes: when the range extender is operating at the first preselected operating point, if the speed of the extended-range electric vehicle drops to a level less than the first speed threshold and not less than the second speed threshold and the maintenance time reaches a first time threshold, it is determined that the speed of the extended-range electric vehicle has dropped to meet the first preset condition; wherein, the second speed interval is adjacent to the first speed interval, the first speed threshold and the second speed threshold are within the second speed interval, and the second speed threshold is less than the first speed threshold.

[0011] In combination with the first aspect, in some embodiments, it also includes: when the range extender is operating at the target transition operating point, if the speed of the extended-range electric vehicle drops to a speed less than the second speed threshold and not less than the lower speed limit of the second speed range and the maintenance time reaches a second time threshold, it is determined that the speed of the extended-range electric vehicle has dropped to meet the second preset condition.

[0012] In combination with the first aspect, in some embodiments, it also includes: when the range extender is operating at the first preselected operating point, if the speed of the extended-range electric vehicle increases from the first speed range to a third speed range, selecting a third preselected operating point corresponding to the third speed range from the M preselected operating points, wherein the power generation power of the range extender at the third preselected operating point is greater than the power generation power at the first preselected operating point; controlling the range extender to switch from the first preselected operating point to the third preselected operating point.

[0013] In combination with the first aspect, in some embodiments, after starting the range extender, it also includes: when the range extender is in an operating state, monitoring the remaining power of the power battery; if the remaining power of the power battery is on a downward trend, determining the target speed range in which the current speed of the extended-range electric vehicle is located from the M speed ranges, wherein M high-efficiency operating points are configured one-to-one for the M speed ranges, and for the preselected operating point and the high-efficiency operating point configured for the same speed range, the power generation power of the range extender at the high-efficiency operating point is greater than the power generation power at the preselected operating point; obtaining the high-efficiency operating point configured corresponding to the target speed range, and controlling the range extender to switch from the current operating point to the high-efficiency operating point configured corresponding to the target speed range.

[0014] In combination with the first aspect, in some embodiments, after starting the range extender, the method further includes: when the range extender is in an operating state, monitoring the remaining power of the power battery; if it is monitored that the remaining power of the power battery rises to a target power, shutting down the range extender.

[0015] In combination with the first aspect, in some embodiments, the M preselected operating points are optimal efficiency points for the range extender to provide M types of power generation.

[0016] In combination with the first aspect, in some embodiments, for each of the M preselected operating points, one or more transition operating points adapted to the preselected operating point are respectively configured.

[0017] In a second aspect of the present invention, a range extender control device for an extended-range electric vehicle is provided, comprising: a control unit configured to, when the speed of the extended-range electric vehicle is in a first speed range, control the range extender of the extended-range electric vehicle to operate at a first preselected operating point, the first preselected operating point being adapted to the first speed range; an exit switching unit configured to, if the speed of the extended-range electric vehicle decreases from the first speed range to a second speed range, control the range extender to switch sequentially from the first preselected operating point to a target transition operating point and a second preselected operating point adapted to the second speed range during the process of the speed decrease of the extended-range electric vehicle, wherein the power generation power of the range extender at the target transition operating point is the same as the power generation power at the first preselected operating point, and the engine speed at the target transition operating point is less than the engine speed at the first preselected operating point.

[0018] In combination with the second aspect, in some embodiments, the exit switching unit includes: a first switching subunit, configured to control the range extender to switch from the first preselected operating point to the target transition operating point if the speed of the extended-range electric vehicle drops to satisfy a first preset condition when the range extender is operating at the first preselected operating point; a second switching subunit, configured to control the range extender to switch from the target transition operating point to the second preselected operating point if the speed of the extended-range electric vehicle drops to satisfy a second preset condition when the range extender is operating at the target transition operating point; wherein the first preset condition and the second preset condition at least limit the upper speed limit of the extended-range electric vehicle, and the upper speed limit defined by the second preset condition is less than the upper speed limit defined by the first preset condition.

[0019] In a third aspect of the present invention, there is provided an extended-range electric vehicle comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the steps of the method according to any one of the embodiments of the first aspect are implemented.

[0020] In a fourth aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored, and when the program is executed by a processor, the steps of the method described in any embodiment of the first aspect are implemented.

[0021] The one or more technical solutions provided by the embodiments of the present invention achieve at least the following technical effects or advantages:

[0022] In an embodiment of the present invention, when the speed of a range-extended electric vehicle decreases from a first speed range to a second speed range, the range extender is controlled to sequentially switch from a first preselected operating point corresponding to the first speed range to a target transition operating point and a second preselected operating point corresponding to the second speed range. The range extender's power generation at the target transition operating point is the same as that at the first preselected operating point, and the engine speed at the target transition operating point is lower than the engine speed at the first preselected operating point. This technical solution adds a transition operating point, so that after exiting the first preselected operating point, the range extender achieves the same power generation as in the first preselected operating condition by increasing engine torque and reducing engine speed during the speed reduction process. Since the lower the engine speed of the range extender, the better the NVH performance, reducing the engine speed can ensure NVH performance at higher speeds in the second speed range without reducing power generation, thereby optimizing NVH performance. As the vehicle speed continues to decrease, the range extender switches to the second preselected operating point corresponding to the second speed range, thereby also maintaining economic efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0024] FIG1 is a flow chart of a fixed-point control method for a range extender provided by an embodiment of the present invention;

[0025] FIG2 is a schematic diagram showing the relationship between the transition operating point and the preselected operating point in an embodiment of the present invention;

[0026] FIG3 is a functional module diagram of a fixed-point control device for a range extender provided by an embodiment of the present invention;

[0027] FIG4 is a schematic structural diagram of an extended-range electric vehicle provided by an embodiment of the present invention. DETAILED DESCRIPTION

[0028] According to an embodiment of the present invention, a range-extended electric vehicle and a fixed-point control method, device and storage medium thereof are provided to solve the technical problem of poor NVH performance when switching between different operating points when controlling the range extender using the fixed-point control strategy of the prior art.

[0029] The technical solution of the embodiment of the present invention is to solve the above technical problems, and the overall idea is as follows:

[0030] When the speed of the extended-range electric vehicle decreases from a first speed range to a second speed range, the range extender is controlled to switch from a first preselected operating point adapted to the first speed range to a target transition operating point and a second preselected operating point adapted to the second speed range in sequence, wherein the power generation power of the range extender at the target transition operating point is the same as the power generation power at the first preselected operating point, and the engine speed at the target transition operating point is less than the engine speed at the first preselected operating point.

[0031] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] First, the term "and / or" as used herein simply describes a relationship between associated objects, indicating that three possible relationships exist. For example, "A and / or B" can represent: A alone, A and B together, or B alone. Furthermore, the character " / " in this document generally indicates an "or" relationship between the associated objects.

[0033] In the fixed-point control strategy of the range extender, in order to prevent the range extender from frequently switching operating points or frequently starting and stopping the range extender, "hysteresis" control will be performed when the range extender exits the operating point. That is, when the vehicle speed is ≥ the target speed, the range extender enters the operating point to work, and exits the operating point when the vehicle speed is < the target speed - the hysteresis speed. Then, when the vehicle speed drops to a speed range that is less than the target speed but not less than the target speed - the hysteresis speed, the range extender continues to operate at the operating point, resulting in a higher speed of the range extender relative to the vehicle speed, which does not match the vehicle speed that has been reduced, resulting in a problem of large NVH noise. To this end, an embodiment of the present invention provides a fixed-point control method for a range extender to at least solve the above-mentioned technical problems.

[0034] FIG1 is a flow chart of a fixed-point control method for a range extender provided in an embodiment of the present invention. As shown in FIG1 , the fixed-point control method for a range extender includes steps S101 to S102 .

[0035] In step S101 , when the speed of the range-extended electric vehicle is in a first speed range, the range extender is controlled to operate at a first preselected operating point, which is adapted to the first speed range.

[0036] In some implementations, the speed range of the extended-range electric vehicle can be divided into M speed intervals based on actual control requirements, where M is an integer greater than 1, and there is no overlap between the M speed intervals, and the M speed intervals completely cover the entire speed range. Due to the driving scenario of the extended-range electric vehicle, the user's driving habits, and other factors, the speed of the extended-range electric vehicle will constantly change, and the speed intervals it is in will also change. Therefore, the first speed interval in S101 does not refer to a specific speed interval and can be any speed interval among the M speed intervals.

[0037] It is understood that the M speed intervals may be of equal or unequal lengths. The speed range may be divided into M speed intervals of equal length according to a preset step length. The M speed intervals may be semi-open intervals that include the lower speed limit but not the upper speed limit. For example, the preset step length may be 10 km / h, 20 km / h, or 30 km / h, etc.

[0038] In some embodiments, before entering step S101, the fixed-point control method of the range extender provided in the embodiment of the present invention may further include: when the range-extended electric vehicle is in the starting state, monitoring the remaining power of the power battery of the range-extended electric vehicle; if it is determined that the power battery has entered the feeding state based on the remaining power of the power battery, starting the range extender and determining the first preselected operating point based on the current speed of the range-extended electric vehicle. It is understandable that when the remaining power of the power battery is lower than a calibrated power threshold, it is determined that the power battery has entered the feeding state. The feeding state means that the power stored in the power battery is insufficient to drive the vehicle, and the range extender needs to intervene for the vehicle to operate normally. The power threshold for reaching the feeding state is different for hybrid vehicles of different models and brands, and the power threshold can be within the range of 10%-30%.

[0039] In other embodiments, before proceeding to step S101, the range extender fixed-point control method provided in embodiments of the present invention may further include: when the range-extended electric vehicle is in the startup state, monitoring the remaining power of the power battery, and determining whether the power battery has entered a feeding state based on the remaining power; if the power battery is monitored to have entered the feeding state and the speed of the range-extended electric vehicle reaches a preset lower speed limit, starting the range extender and determining a first preselected operating point based on the current speed of the range-extended electric vehicle. For example, the preset lower speed limit can be customized based on the usage scenario, such as being set to 20 km / h.

[0040] In some embodiments, determining the first preselected operating point based on the current speed of the extended-range electric vehicle may include: determining a first speed interval in which the current speed of the extended-range electric vehicle is located from M pre-divided speed intervals, and configuring M preselected operating points for operation of the range extender in a one-to-one correspondence with the M speed intervals, where M is an integer greater than 1; and selecting the preselected operating point configured corresponding to the first speed interval as the first preselected operating point.

[0041] In some embodiments, the M speed intervals are formed by dividing the speed range consisting of a preset lower speed limit and speeds above it. The speed range can be divided into two, three, four, or even more speed intervals. For example, if the preset lower speed limit is 20 km / h, the speed intervals divided are [20, 40), [40, 60), [60, 80), [80, 100), and [100, 120), etc. If the vehicle speed is less than 20 km / h, the range extender will not be activated.

[0042] It should be noted that, for each of the M preselected operating points, it is the optimal efficiency point for the range extender to provide the power generation required for the speed range corresponding to the preselected operating point. The power generation required for each speed range is the power that enables the power battery to maintain charge and discharge balance when the range-extended electric vehicle is traveling within the speed range. For each of the M speed ranges, the power generation required by the range extender in the speed range is determined based on the vehicle power demand of the range-extended electric vehicle in the speed range. More specifically, the power generation required by the range extender in the speed range has a certain redundancy over the vehicle power demand of the range-extended electric vehicle in the speed range, so that the power battery can maintain charge and discharge balance. Therefore, the preselected operating point adapted to each speed range needs to be obtained through pre-testing.

[0043] It is understandable that as the speed of the extended-range electric vehicle changes, the speed may rise to a second speed range that is higher than the first speed range, or may fall to a third speed range that is lower than the first speed range. The following describes these two changes respectively:

[0044] If the first speed interval is any speed interval among the M speed intervals except the speed interval with the minimum speed, step S102 can be executed: if the speed of the extended-range electric vehicle decreases from the first speed interval to the second speed interval, then during the process of the speed decrease of the extended-range electric vehicle, the range extender is controlled to switch from the first preselected operating point to the target transition operating point and the second preselected operating point adapted to the second speed interval in sequence, wherein the power generation power of the range extender at the target transition operating point is the same as the power generation power at the first preselected operating point, and the engine speed at the target transition operating point is less than the engine speed at the first preselected operating point.

[0045] It can be understood that each operating point for the range extender is jointly determined by the engine speed and engine torque of the range extender. In order to make the power generation achieved by the range extender at the target transition operating point and the first pre-selected operating point the same, and the engine speed of the range extender at the target transition operating point is lower than the engine speed at the first pre-selected operating point, it is necessary to sacrifice fuel consumption to increase the engine torque of the range extender, so that the engine torque at the target transition operating point is greater than the engine torque at the first pre-selected operating point, thereby reducing the engine speed. Since the greater the engine torque of the range extender, the higher the fuel consumption, the lower the engine speed of the range extender, the better the NVH performance of the vehicle, therefore, the target transition operating point is used to optimize the NVH noise performance of the extended-range electric vehicle when the speed is reduced to a higher speed point in the first speed range.

[0046] In some embodiments, for each of the M preselected operating points, one or more transition operating points adapted to the preselected operating point are respectively provided. For each preselected operating point, the range extender has the same power generation power at the preselected operating point and the transition operating point adapted thereto, wherein, relative to the preselected operating point, the engine torque of the transition operating point adapted thereto is greater and the engine speed is less. The transition operating point is used to transition when the speed of the extended-range electric vehicle drops from the larger speed interval to the smaller speed interval in two adjacent speed intervals. Therefore, when the range extender exits the preselected operating point adapted to the larger speed interval, it will not directly switch to another preselected operating point adapted to the smaller speed interval.

[0047] If only one transition operating point is set for the same preselected operating point, as shown in Figure 2, the vehicle speed range is divided into three speed intervals for example, and preselected operating points 1, 2, and 3 are configured accordingly. Preselected operating point 1 is configured with transition operating point 1N for transitioning when exiting preselected operating point 1, preselected operating point 2 is configured with transition operating point 2N for transitioning when exiting preselected operating point 2, and preselected operating point 3 is configured with transition operating point 3N for transitioning when exiting preselected operating point 3. In Figure 2, the contour lines represent the fuel consumption of the range extender, and the dotted line represents the power generation power of the range extender. Preselected operating point 1 and transition operating point 1N correspond to the same power generation power of the range extender.

[0048] If multiple different transition operating points are configured for the same preselected operating point, each transition operating point configured for the same preselected operating point and the generated power at that preselected operating point are identical, and the engine torque and engine speed are different. For example, if the vehicle speed range is divided into three speed intervals and each preselected operating point is configured with two transition operating points, preselected operating points 1, 2, and 3 are configured in a one-to-one correspondence across the three speed intervals. Preselected operating point 1 is adapted to transition to transition out of preselected operating point 1 using transition points 1N and 1N'; preselected operating point 2 is adapted to transition to transition out of preselected operating point 2 using transition points 2N and 2N'; and preselected operating point 3 is adapted to transition to transition out of preselected operating point 3 using transition points 3N and 3N'.

[0049] In some embodiments, step S102 may include: when the range extender is operating at a first preselected operating point, if the speed of the range-extended electric vehicle drops to a point that satisfies a first preset condition, controlling the range extender to switch from the first preselected operating point to a target transition operating point; when the range extender is operating at the target transition operating point, if the speed of the range-extended electric vehicle drops to a point that satisfies a second preset condition, controlling the range extender to switch from the target transition operating point to a second preselected operating point, wherein the first preset condition and the second preset condition define at least an upper speed limit of the range-extended electric vehicle, and the upper speed limit defined by the second preset condition is less than the upper speed limit defined by the first preset condition. Furthermore, it should be noted that the target transition operating point is a transition operating point that is compatible with the first preselected operating point.

[0050] In some embodiments, when the range extender is operating at a first preselected operating point, if the speed of the range-extended electric vehicle drops to a level less than a first speed threshold and not less than a second speed threshold for a period of time that reaches a first time threshold, it is determined that the speed of the range-extended electric vehicle has dropped to meet a first preset condition; wherein the second speed interval is adjacent to the first speed interval, the first speed threshold and the second speed threshold are both within the second speed interval, and the second speed threshold is less than the first speed threshold. By setting the range extender to switch to the target transition operating point only after the maintenance time reaches the first time threshold, frequent switching of the operating point of the range extender is avoided, thereby improving the operating stability of the range extender. In other embodiments, when the speed of the range-extended electric vehicle drops to a level less than the first speed threshold and not less than the second speed threshold, it is directly determined that the speed of the range-extended electric vehicle has dropped to meet the first preset condition.

[0051] In other embodiments, if there are N transition operating points compatible with the first preselected operating point, where N can be a value within the range of 2 to 5, and the N transition operating points correspond one-to-one to N first vehicle speed thresholds, wherein the transition operating point with greater engine torque corresponds to a smaller first vehicle speed threshold, when the range extender is operating at the first preselected operating point and the speed of the extended-range electric vehicle decreases, a target transition operating point is determined from the N transition operating points based on the speed decrease, and the range extender is controlled to switch to the target transition operating point. Specifically, if the vehicle speed of any of the N transition operating points, other than the transition operating point with the highest engine torque, decreases below the first vehicle speed threshold corresponding to that transition operating point and not below the first vehicle speed threshold corresponding to the next transition operating point for a period of time that exceeds a first duration threshold, then that transition operating point is determined as the target transition operating point. The transition operating point with the largest engine torque among the N transition operating points is determined as the target transition operating point when the vehicle speed drops below the first vehicle speed threshold corresponding to the transition operating point and is not lower than the second vehicle speed threshold for a period of time that reaches a first time threshold.

[0052] In some embodiments, when the range extender is operating at a target transition operating point that matches the first preselected operating point, if the vehicle speed of the range-extended electric vehicle drops below a second speed threshold but not below the lower speed limit of the second speed interval for a period of time that reaches a second time threshold, the vehicle speed of the range-extended electric vehicle is determined to have dropped to meet the second preset condition. In other embodiments, when the vehicle speed of the range-extended electric vehicle drops below the second speed threshold but not below the lower speed limit of the second speed interval, the vehicle speed of the range-extended electric vehicle is directly determined to have dropped to meet the second preset condition.

[0053] In some embodiments, when the range extender is operating at a target transition operating point that is adapted to the first preselected operating point, if the speed of the extended-range electric vehicle rises to a value not less than the first speed threshold and is maintained for a time period that reaches a third time period threshold, the range extender is controlled to switch from the target transition operating point back to the first preselected operating point.

[0054] It is understandable that the first, second, and third duration thresholds can all be customized based on the user's usage scenario. Specifically, they can all be set within the range of 1 to 2 minutes and can use the same duration value. The first and second speed thresholds can be set based on the lower speed limit of the first speed range and the preset hysteresis speed. If only one transition operating point is configured to match the first preselected operating point, the first speed threshold can be set to the lower speed limit of the first speed range, and the second speed threshold can be set to the difference between the lower speed limit of the first speed range and the hysteresis speed, where the hysteresis speed is less than the step size for dividing the speed range. For example, the first speed range is [v1, v2), and the hysteresis speed is represented by v0. It needs to satisfy v0<v2-v1. In some embodiments, it can be limited to v0≤1 / 2(v2-v1). On this basis, the first speed threshold is set to v1, and the second speed threshold is set to v1-v0. If the speed of the extended-range electric vehicle drops to the point where v1-v0≤speed<v1 and the duration is greater than or equal to the first duration threshold, the range extender is controlled to switch from the first preselected operating point to the target transition operating point. If the speed of the extended-range electric vehicle continues to drop, and drops to the point where v3≤speed<v1-v0 is satisfied and the duration is greater than or equal to the second duration threshold, V3 is the lower speed limit of the second speed interval, the range extender is controlled to switch from the target transition operating point to the second preselected operating point adapted to the second speed interval.

[0055] If there are N transition operating points adapted to the first preselected operating point, unlike the above embodiment in which only one transition operating point is configured, there are N first speed thresholds, where the first speed threshold corresponding to the transition operating point with maximum engine torque is the lower speed limit of the first speed range, and the N-1 first speed thresholds corresponding to the other N-1 transition operating points are all less than the lower speed limit of the first speed range and greater than the difference between the lower speed limit of the first speed range and the hysteresis speed. For example, if the first speed range is [v1, v2), and the hysteresis speed is v0, and taking the first preselected operating point as an example with two transition operating points configured, the corresponding two first speed thresholds are v1 and v1-0.5v0, respectively, and the second speed threshold is v1-v0.

[0056] In some embodiments, if the first speed interval is the speed interval with the lowest speed among the M speed intervals, then when the power battery is in the feeding state, if the speed of the range-extended electric vehicle drops to the lower speed limit of the speed interval with the lowest speed and the duration of maintenance reaches the fourth duration threshold, the range extender is turned off. Taking the speed interval with the lowest speed as [20,40) as an example, the range extender is turned off when the speed of the range-extended electric vehicle is lower than 20 km / h and the duration of maintenance reaches the fourth duration threshold. In other embodiments, the range extender is turned off when the speed of the range-extended electric vehicle drops to a difference between the lower speed limit of the speed interval with the lowest speed and the hysteresis speed and the duration reaches the fourth duration threshold, thereby avoiding frequent starts and stops of the range extender.

[0057] In some embodiments, the fixed-point control method of the range extender provided in the embodiments of the present invention may further include: when the range extender is operating at the first preselected operating point, if the speed of the extended-range electric vehicle increases from the first speed range to the third speed range, selecting a third preselected operating point corresponding to the third speed range from the M preselected operating points, wherein the power generated by the range extender at the third preselected operating point is greater than the power generated at the first preselected operating point; and controlling the range extender to switch from the first preselected operating point to the third preselected operating point.

[0058] In other embodiments, if the speed of the extended-range electric vehicle increases from the first speed range to the third speed range, and the duration of the maintenance in the third speed range reaches a first duration threshold, the range extender is controlled to switch from the first preselected operating point to the third preselected operating point, thereby avoiding frequent switching of the range extender's operating points. Specifically, the range extender can be controlled to switch from the first preselected operating point to the third preselected operating point when the speed of the extended-range electric vehicle increases to a speed lower limit of the third speed range or higher and the duration of the maintenance in the third speed range reaches a fifth duration threshold.

[0059] In some embodiments, after starting the range extender, the fixed-point control method for the range extender provided in the embodiments of the present invention may further include: monitoring the remaining power of the power battery while the range extender is in operation; if the remaining power of the power battery is monitored to be on a downward trend, determining a target speed range for the current speed of the range-extended electric vehicle from M speed ranges, each of the M speed ranges being further configured with a high-efficiency operating point, and for the high-efficiency operating point and preselected operating point configured for the same speed range, the power generated by the range extender at the high-efficiency operating point is greater than the power generated at the preselected operating point; obtaining the high-efficiency operating point configured for the target speed range; and controlling the range extender to switch from the current operating point to the high-efficiency operating point configured for the target speed range. This further prevents the power battery from continuing to lose power during the operation of the range extender, thereby improving reliability.

[0060] In some embodiments, the fixed-point control method of the range extender provided in the embodiment of the present invention may further include: when the range extender is in an operating state, monitoring the remaining power of the power battery; if it is monitored that the remaining power of the power battery reaches the target power, shutting down the range extender.

[0061] The following uses only two speed intervals [v1, v2) and [v2, +∞) and a hysteresis speed v0 as an example to provide a control logic of a fixed-point control method for a range extender provided by an embodiment of the present invention, but this is not intended to limit the present invention.

[0062] S1: During the driving process of the extended-range electric vehicle, monitoring whether the power battery of the extended-range electric vehicle enters the feeding state, if it is monitored that the power battery enters the feeding state, triggering the execution of step S2;

[0063] S2: Detect the speed V of the extended-range electric vehicle in real time and proceed to step S3;

[0064] S3: Determine whether V≥v2 is satisfied. If so, the range extender is started and operates at the preselected operating point 2 after starting, and then proceeds to step S5. If not, proceeds to step S4.

[0065] S4: Determine whether V≥v1 is satisfied. If so, the range extender is started and operates at the preselected operating point 1 after starting, and then proceeds to step S7; if not, returns to step S3;

[0066] S5: Determine whether the vehicle speed drops to a value that satisfies v2-v0≤V<v2. If so, determine whether the duration T of v2-v0≤V<v2 satisfies T≥T1. If so, the range extender switches from the preselected operating point 2 to the transition operating point 2N, and then proceeds to step S6. If not, also proceeds to step S6.

[0067] S6: Determine whether the vehicle speed drops to a value that satisfies v1≤V<v2-v0. If so, determine whether the duration T of v1≤V<v2-v0 satisfies T≥T2. If so, the range extender switches from the transition operating point 2N to the preselected operating point 1.

[0068] S7: Determine whether the vehicle speed rises to satisfy V≥v2. If so, the range extender switches from preselected operating point 1 to preselected operating point 2. If not, proceed to step S8.

[0069] S8: Determine whether the vehicle speed drops to a value that satisfies v1-v0≤V<v1. If so, determine whether the duration T of v1-v0≤V<v1 satisfies T≥T1. If so, the range extender switches from the preselected operating point 1 to the transition operating point 1N, and then proceeds to step S9. If not, also proceeds to step S9.

[0070] S9: Determine whether the vehicle speed has dropped to a value that satisfies V<v1-v0. If so, determine whether the duration T of V<v1-v0 satisfies T≥T2. If so, turn off the range extender and return to step S2.

[0071] The range extender is controlled in fixed-point manner according to the logic of S2 to S9 above until the remaining power of the power battery reaches the target power, at which time the range extender is turned off and the process returns to step S1.

[0072] Based on the same inventive concept, an embodiment of the present invention provides a fixed-point control device for a range extender, as shown in FIG3 . The fixed-point control device includes:

[0073] The control unit 301 is configured to control the range extender of the extended-range electric vehicle to operate at a first preselected operating point when the speed of the extended-range electric vehicle is in a first speed range, wherein the first preselected operating point is adapted to the first speed range;

[0074] The exit switching unit 302 is configured to control the range extender to switch from the first preselected operating point to the target transition operating point and the second preselected operating point adapted to the second speed range in sequence during the speed reduction process of the extended-range electric vehicle if the speed of the extended-range electric vehicle drops from the first speed range to the second speed range, wherein the power generation power of the range extender at the target transition operating point is the same as the power generation power at the first preselected operating point, and the engine speed of the target transition operating point is less than the engine speed of the first preselected operating point.

[0075] In some embodiments, the exit switching unit 302 includes: a first switching subunit, configured to control the range extender to switch from the first preselected operating point to the target transition operating point if the speed of the extended-range electric vehicle drops to satisfy a first preset condition when the range extender is operating at the first preselected operating point; a second switching subunit, configured to control the range extender to switch from the target transition operating point to the second preselected operating point if the speed of the extended-range electric vehicle drops to satisfy a second preset condition when the range extender is operating at the target transition operating point; wherein the first preset condition and the second preset condition at least define an upper speed limit of the extended-range electric vehicle, and the upper speed limit defined by the second preset condition is less than the upper speed limit defined by the first preset condition.

[0076] In some embodiments, the fixed-point control device may further include: a power monitoring unit configured to monitor the remaining power of the power battery of the extended-range electric vehicle when the range extender is in the off state; a starting unit configured to start the range extender if it is determined that the power battery enters the feeding state based on the remaining power of the power battery; and a determination unit configured to determine the first preselected operating point based on the current vehicle speed of the extended-range electric vehicle.

[0077] In some embodiments, the determination unit can be configured to: determine a first speed interval in which the current speed of the extended-range electric vehicle is located from M pre-divided speed intervals, and configure M preselected operating points for the operation of the range extender in a one-to-one correspondence with the M speed intervals, where M is an integer greater than 1; and select the preselected operating point corresponding to the first speed interval as the first preselected operating point.

[0078] In some embodiments, the fixed-point control device may further include: a first condition judgment unit, configured to determine that the speed of the extended-range electric vehicle has dropped to meet the first preset condition if the speed of the extended-range electric vehicle drops to a level less than a first speed threshold and not less than a second speed threshold and the maintenance time reaches a first time threshold when the range extender is operating at a first preselected operating point; wherein the second speed interval is adjacent to the first speed interval, the first speed threshold and the second speed threshold are within the second speed interval, and the second speed threshold is less than the first speed threshold.

[0079] In some embodiments, the fixed-point control device may further include: a second condition judgment unit, configured to determine that the speed of the extended-range electric vehicle has dropped to meet the second preset condition if the speed of the extended-range electric vehicle drops to a level less than the second speed threshold and not less than the lower speed limit of the second speed range and the maintenance time reaches a second time threshold when the range extender is operating at the target transition operating point.

[0080] In some embodiments, the fixed-point control unit may further include an entry switching unit, which is configured to: when the range extender is operating at the first preselected operating point, if the speed of the extended-range electric vehicle increases from the first speed range to a third speed range, select a third preselected operating point corresponding to the third speed range from the M preselected operating points, wherein the power generation power of the range extender at the third preselected operating point is greater than the power generation power at the first preselected operating point; and control the range extender to switch from the first preselected operating point to the third preselected operating point.

[0081] In some embodiments, the fixed-point control device may further include: a power monitoring unit, configured to monitor the remaining power of the power battery when the range extender is in operation; an interval determination unit, configured to determine, if the remaining power of the power battery is on a downward trend, a target speed interval in which the current speed of the extended-range electric vehicle is located from the M speed intervals, wherein M high-efficiency operating points are configured one-to-one for the M speed intervals, and for the preselected operating point and the high-efficiency operating point configured for the same speed interval, the power generation power of the range extender at the high-efficiency operating point is greater than the power generation power at the preselected operating point; an operating point determination unit, configured to obtain the high-efficiency operating point configured corresponding to the target speed interval, and control the range extender to switch from the current operating point to the high-efficiency operating point configured corresponding to the target speed interval.

[0082] In some embodiments, the fixed-point control device further includes: a power monitoring unit configured to monitor the remaining power of the power battery when the range extender is in operation; and a shutdown unit configured to shut down the range extender if it is monitored that the remaining power of the power battery rises to a target power.

[0083] In some embodiments, the M preselected operating points are optimal efficiency points for the range extender to provide M types of power generation.

[0084] In some embodiments, for each of the M preselected operating points, one or more transition operating points adapted to the preselected operating point are respectively configured.

[0085] Since the device described in this embodiment is the device used to implement the fixed-point control method for a range extender in the embodiment of the present invention, those skilled in the art will be able to understand the specific implementation and various variations of the device of this embodiment based on the fixed-point control method for a range extender described in the embodiment of the present invention. Therefore, how the electronic device implements the method in the embodiment of the present invention will not be described in detail here. As long as those skilled in the art can implement the device used in the fixed-point control method for a range extender in the embodiment of the present invention, it falls within the scope of protection of the present invention.

[0086] Based on the same inventive concept, an embodiment of the present invention provides an extended-range electric vehicle, as shown in Figure 4. The extended-range electric vehicle includes a memory 404, a processor 402, and a computer program stored in the memory 404 and executable on the processor 402. When the processor 402 executes the program, the above-mentioned fixed-point control method of the range extender is implemented.

[0087] In FIG4 , a bus architecture (represented by bus 400) is shown. Bus 400 may include any number of interconnected buses and bridges. Bus 400 links various circuits together, including one or more processors represented by processor 402 and memory represented by memory 404. Bus 400 may also link various other circuits together, such as peripherals, voltage regulators, and power management circuits, all of which are well known in the art and, therefore, will not be described further herein. Bus interface 405 provides an interface between bus 400 and receiver 401 and transmitter 403. Receiver 401 and transmitter 403 may be the same component, namely a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 402 is responsible for managing bus 400 and general processing, while memory 404 may be used to store data used by processor 402 when performing operations.

[0088] Based on the same inventive concept, an embodiment of the present invention provides a computer-readable storage medium having a computer program stored thereon, which implements the above-mentioned fixed-point control method of the range extender when executed by a processor.

[0089] According to the technical solutions of one or more of the above-described embodiments of the present invention, at least the following technical effects or advantages are achieved: when the speed of a range-extended electric vehicle decreases from a first speed range to a second speed range, the range extender is controlled to sequentially switch from a first preselected operating point adapted to the first speed range to a target transition operating point and a second preselected operating point adapted to the second speed range, wherein the power generated by the range extender at the target transition operating point is the same as the power generated at the first preselected operating point, and the engine speed at the target transition operating point is lower than the engine speed at the first preselected operating point. The above-described technical solution adds a transition operating point, so that after the range extender exits the first preselected operating point, the speed decreases by first increasing the engine torque and reducing the engine speed to achieve the same power generated as the first preselected operating condition. Since the lower the engine speed of the range extender, the better the NVH performance, reducing the engine speed can ensure that the NVH performance meets the requirements of the higher speed points in the second speed range without reducing the power generated. As the vehicle speed continues to decrease, it switches to the second preselected operating point that is adapted to the second vehicle speed range, thereby also taking economy into account at the same time.

[0090] Those skilled in the art will appreciate that embodiments of the present invention may be provided as methods, systems, or computer program products. Thus, the present invention may take the form of an entirely hardware embodiment, an entirely software embodiment, or an embodiment combining software and hardware aspects. Furthermore, the present invention may take the form of a computer program product implemented on one or more computer-usable storage media (including but not limited to magnetic disk storage, CD-ROM, optical storage, etc.) containing computer-usable program code.

[0091] The present invention is described with reference to the flowcharts and / or block diagrams of the methods, devices (systems), and computer program products according to embodiments of the present invention. It should be understood that each process and / or box in the flowchart and / or block diagram, as well as the combination of processes and / or boxes in the flowchart and / or block diagram, can be implemented by computer program instructions. These computer program instructions can be provided to a processor of a general-purpose computer, a special-purpose computer, an embedded processor, or other programmable data processing device to produce a machine, so that the instructions executed by the processor of the computer or other programmable data processing device produce a device for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0092] These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing device to operate in a specific manner, so that the instructions stored in the computer-readable memory produce a product including an instruction device that implements the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0093] These computer program instructions can also be loaded onto a computer or other programmable data processing device so that a series of operating steps are executed on the computer or other programmable device to produce a computer-implemented process, so that the instructions executed on the computer or other programmable device provide steps for implementing the functions specified in one or more processes in the flowchart and / or one or more boxes in the block diagram.

[0094] Although the preferred embodiments of the present invention have been described, those skilled in the art may make additional changes and modifications to these embodiments once they have learned the basic creative concept. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments and all changes and modifications that fall within the scope of the present invention.

[0095] Obviously, those skilled in the art may make various changes and modifications to the present invention without departing from the spirit and scope of the present invention. Thus, if such changes and modifications fall within the scope of the claims and their equivalents, the present invention is intended to include such changes and modifications.

Claims

1. A fixed-point control method for a range extender, characterized in that: include: When the speed of the extended-range electric vehicle is in a first speed interval, controlling the range extender of the extended-range electric vehicle to operate at a first preselected operating point, wherein the first preselected operating point is adapted to the first speed interval; If the speed of the extended-range electric vehicle decreases from the first speed interval to the second speed interval, during the speed decrease process of the extended-range electric vehicle, the range extender is controlled to switch from the first preselected operating point to the target transition operating point and the second preselected operating point adapted to the second speed interval in sequence, wherein the power generation power of the range extender at the target transition operating point is the same as the power generation power at the first preselected operating point, and the engine speed at the target transition operating point is less than the engine speed at the first preselected operating point.

2. The method according to claim 1, characterized in that During the process of the vehicle speed of the extended-range electric vehicle decreasing, controlling the range extender to sequentially switch from the first preselected operating point to a target transition operating point and a second preselected operating point adapted to the second vehicle speed range, comprising: When the range extender is operating at the first preselected operating point, if the speed of the extended-range electric vehicle drops to meet a first preset condition, the range extender is controlled to switch from the first preselected operating point to the target transition operating point; When the range extender is operating at the target transition operating point, if the speed of the extended-range electric vehicle drops to meet a second preset condition, the range extender is controlled to switch from the target transition operating point to the second preselected operating point; Among them, the first preset condition and the second preset condition at least define the upper speed limit of the extended-range electric vehicle, and the upper speed limit defined by the second preset condition is smaller than the upper speed limit defined by the first preset condition.

3. The method according to claim 2, characterized in that Before controlling the range extender of the extended-range electric vehicle to operate at the first preselected operating point, the method further includes: When the range extender is in an off state, monitoring the remaining power of the power battery of the range-extended electric vehicle; If it is determined that the power battery enters a feeding state according to the remaining power of the power battery, the range extender is started and the first preselected operating point is determined according to the current vehicle speed of the extended-range electric vehicle.

4. The method according to claim 3, characterized in that The determining the first preselected operating point according to the current vehicle speed of the extended-range electric vehicle comprises: Determine a first speed interval in which the current speed of the range-extended electric vehicle is located from among the pre-divided M speed intervals, and configure M pre-selected operating points for the range extender in one-to-one correspondence with the M speed intervals, where M is an integer greater than 1; A preselected operating point configured corresponding to the first vehicle speed range is selected as the first preselected operating point.

5. The method according to claim 4, characterized in that Also includes: When the range extender is operating at the first preselected operating point, if the vehicle speed of the extended-range electric vehicle drops to a level less than a first vehicle speed threshold and not less than a second vehicle speed threshold for a period of time that reaches a first time threshold, it is determined that the vehicle speed of the extended-range electric vehicle drops to meet the first preset condition; The second vehicle speed interval is adjacent to the first vehicle speed interval, the first vehicle speed threshold and the second vehicle speed threshold are within the second vehicle speed interval, and the second vehicle speed threshold is less than the first vehicle speed threshold.

6. The method according to claim 5, characterized in that Also includes: When the range extender is operating at the target transition operating point, if the vehicle speed of the extended-range electric vehicle drops to a level less than the second speed threshold and not less than the lower speed limit of the second speed interval and the maintenance time reaches a second time threshold, it is determined that the vehicle speed of the extended-range electric vehicle has dropped to meet the second preset condition.

7. The method according to claim 4, characterized in that Also includes: When the range extender is operating at the first preselected operating point, if the speed of the extended-range electric vehicle increases from the first speed interval to a third speed interval, a third preselected operating point corresponding to the third speed interval is selected from the M preselected operating points, wherein the power generation of the range extender at the third preselected operating point is greater than the power generation at the first preselected operating point; The range extender is controlled to switch from the first preselected operating point to the third preselected operating point.

8. The method according to claim 4, characterized in that After starting the range extender, the method further includes: When the range extender is in operation, the remaining power of the power battery is monitored; If the remaining power of the power battery is in a downward trend, a target speed interval in which the current speed of the extended-range electric vehicle is located is determined from the M speed intervals, wherein M high-efficiency operating points are configured one by one for the M speed intervals, and pre-selected operating points are configured for the same speed interval. A condition point and a high-efficiency condition point, the power generation power of the range extender at the high-efficiency condition point is greater than the power generation power at the preselected condition point; An efficient operating point configured corresponding to the target vehicle speed interval is obtained, and the range extender is controlled to switch from the current operating point to the efficient operating point configured corresponding to the target vehicle speed interval.

9. The method according to claim 4 or 8, characterized in that After starting the range extender, the method further includes: When the range extender is in operation, the remaining power of the power battery is monitored; If it is monitored that the remaining power of the power battery rises to the target power, the range extender is turned off.

10. The method according to claim 4, characterized in that The M preselected operating points are the optimal efficiency points for the range extender to provide M types of power generation.

11. The method according to claim 4, characterized in that For each of the M preselected operating points, one or more transition operating points adapted to the preselected operating point are respectively configured.

12. A fixed-point control device for a range extender, characterized in that: include: A control unit is configured to control the range extender of the extended-range electric vehicle to operate at a first preselected operating point when the vehicle speed of the extended-range electric vehicle is in a first vehicle speed interval, wherein the first preselected operating point is adapted to the first vehicle speed interval; The exit switching unit is configured to control the range extender to switch from the first preselected operating point to the target transition operating point and the second preselected operating point adapted to the second speed range in sequence during the speed reduction process of the extended-range electric vehicle if the speed of the extended-range electric vehicle decreases from the first speed range to the second speed range, wherein the power generation power of the range extender at the target transition operating point is the same as the power generation power at the first preselected operating point, and the engine speed of the target transition operating point is less than the engine speed of the first preselected operating point.

13. The device according to claim 12, characterized in that The exit switching unit includes: A first switching subunit is configured to control the range extender to switch from the first preselected operating point to the target transition operating point when the speed of the extended-range electric vehicle drops to meet a first preset condition when the range extender is operating at the first preselected operating point; A second switching subunit is configured to control the range extender to switch from the target transition operating point to the second preselected operating point when the speed of the extended-range electric vehicle drops to meet a second preset condition when the range extender is operating at the target transition operating point; Among them, the first preset condition and the second preset condition at least define the upper speed limit of the extended-range electric vehicle, and the upper speed limit defined by the second preset condition is smaller than the upper speed limit defined by the first preset condition.

14. An extended-range electric vehicle, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein the steps of the method according to any one of claims 1 to 11 are implemented when the processor executes the program.

15. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the program is executed by a processor, the steps of the method described in any one of claims 1 to 11 are implemented.

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