Control method, device and equipment of range extender

Abstract

The application discloses a control method, device and equipment of a range extender, wherein the range extender comprises an engine and a generator rigidly connected with the engine; the method comprises the following steps: predicting the combustion torque of the engine based on the ignition angle and the crank angle of the engine; determining the pulsation torque of the engine according to the combustion torque and the average combustion torque of the engine in a preset crank angle range; determining the target compensation torque opposite to the direction of the pulsation torque based on the pulsation torque; and compensating the torque of the generator based on the target compensation torque to suppress the speed fluctuation of the range extender. The application solves the technical problem of large speed fluctuation of the range extender.

Description

Technical Field

[0001] This invention belongs to the field of range extender control technology, and particularly relates to a control method, device and equipment for a range extender. Background Technology

[0002] To improve power density, reduce NVH transmission, and decrease axial dimensions, the highly integrated range extender adopts a structure with a direct rigid connection between the engine crankshaft and the generator rotor, eliminating the large-mass flywheel traditionally found in engines. Without the flywheel, the rotational inertia of the entire rotating system consisting of the engine crankshaft and generator rotor is significantly reduced, completely eliminating the inertia buffering and speed stabilization functions originally provided by the flywheel. During engine operation, the torque output from the crankshaft fluctuates significantly and periodically with the crankshaft angle due to the combined effects of periodic combustion impacts from single and multi-cylinder combustion and intake / exhaust pump resistance. In traditional flywheel-equipped designs, the large mass inertia of the flywheel can absorb and smooth these torque fluctuations, maintaining stable speed; however, in the flywheel-less design, the engine torque pulsation is not buffered and is directly converted into generator speed fluctuations, meaning the range extender's speed fluctuations increase.

[0003] Increased speed fluctuations in the range extender lead to unstable generator output voltage, affecting the charging safety of the power battery and the operational stability of the drive motor and on-board electrical loads. Simultaneously, it also causes vehicle vibration, reducing ride comfort. Therefore, large speed fluctuations in the range extender are a technical problem that urgently needs to be addressed. Summary of the Invention

[0004] This invention provides a control method, apparatus, and device for a range extender, which solves the technical problem of large speed fluctuations in the range extender.

[0005] In a first aspect, embodiments of the present invention provide a control method for a range extender, the range extender including an engine and a generator rigidly connected to the engine; the method includes: predicting the combustion torque of the engine based on the ignition angle and crankshaft angle of the engine; determining the pulsating torque of the engine based on the combustion torque and the average combustion torque of the engine within a preset crankshaft angle range; determining a target compensation torque opposite in direction to the pulsating torque based on the pulsating torque; and compensating the torque of the generator based on the target compensation torque to suppress speed fluctuations of the range extender.

[0006] In conjunction with the first aspect of the present invention, in some embodiments, predicting the combustion torque of the engine based on the ignition angle and crankshaft angle of the engine includes: determining a correction coefficient based on the engine speed, load, coolant temperature and intake air temperature; predicting the basic combustion torque of the engine based on the ignition angle and crankshaft angle of the engine; and correcting the basic combustion torque based on the correction coefficient to obtain the combustion torque.

[0007] In conjunction with the first aspect of the present invention, in some embodiments, determining the correction coefficient based on the engine speed, load, coolant temperature, and intake air temperature includes: determining a first correction coefficient based on the engine speed and load; determining a second correction coefficient based on the engine coolant temperature; and determining a third correction coefficient based on the engine intake air temperature; wherein the correction coefficient includes the first correction coefficient, the second correction coefficient, and the third correction coefficient.

[0008] In conjunction with the first aspect of the present invention, in some embodiments, the step of correcting the base combustion torque based on the correction coefficient to obtain the combustion torque includes: obtaining the combustion torque based on the product of the base combustion torque, the first correction coefficient, the second correction coefficient, and the third correction coefficient.

[0009] In conjunction with the first aspect of the present invention, in some embodiments, the value range of the first correction coefficient is 0.8 to 1.2; the value range of the second correction coefficient is 1 to 1.5, and the higher the coolant temperature of the engine, the smaller the second correction coefficient; the value range of the third correction coefficient is 0.8 to 1, and the higher the intake air temperature of the engine, the smaller the third correction coefficient.

[0010] In conjunction with the first aspect of the present invention, in some embodiments, determining the pulsating torque of the engine based on the combustion torque and the average combustion torque of the engine within a preset crankshaft angle range includes: determining the pulsating torque based on the difference between the combustion torque and the average combustion torque.

[0011] In conjunction with the first aspect of the present invention, in some embodiments, determining the target compensation torque opposite to the direction of the pulsating torque based on the pulsating torque includes: acquiring the original speed signal of the generator; determining the speed fluctuation parameter of the generator based on the original speed signal of the generator; determining the compensation gain coefficient based on the speed fluctuation parameter, wherein the larger the speed fluctuation parameter, the larger the compensation gain coefficient; and determining the target compensation torque based on the compensation gain coefficient and the pulsating torque.

[0012] In conjunction with the first aspect of the present invention, in some embodiments, determining the target compensation torque based on the compensation gain coefficient and the pulsating torque includes: multiplying the compensation gain coefficient by the pulsating torque and inverting the product to obtain the target compensation torque.

[0013] In conjunction with the first aspect of the present invention, in some embodiments, the step of compensating the torque of the generator based on the target compensation torque includes: obtaining the average torque required to maintain the rated power output of the generator; determining the target torque based on the sum of the average torque and the target compensation torque; and controlling the generator based on the target torque.

[0014] In conjunction with the first aspect of the present invention, in some embodiments, before predicting the combustion torque of the engine based on the ignition angle and crankshaft angle of the engine, the method further includes: acquiring the ignition angle and crankshaft angle of the engine according to a preset execution cycle, wherein the preset execution cycle includes 1ms to 50ms.

[0015] Secondly, embodiments of the present invention provide a control device for a range extender, the range extender including an engine and a generator rigidly connected to the engine; the device includes: an integrated engine control unit and a generator control unit; the engine control unit is used to predict the combustion torque of the engine based on the ignition angle and crankshaft angle of the engine; and to determine the pulsating torque of the engine based on the combustion torque and the average combustion torque of the engine within a preset crankshaft angle range; the generator control unit is used to determine a target compensation torque opposite to the direction of the pulsating torque based on the pulsating torque; and to compensate the torque of the generator based on the target compensation torque to suppress the speed fluctuation of the range extender.

[0016] Thirdly, embodiments of the present invention provide an electronic device, including: a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the computer program to implement the method described in any of the first aspects.

[0017] The one or more technical solutions provided in the embodiments of the present invention achieve at least the following technical effects or advantages: This invention predicts the engine's combustion torque based on the engine's ignition angle and crankshaft angle; determines the engine's pulsating torque based on the combustion torque and the engine's average combustion torque within a preset crankshaft angle range; determines a target compensation torque in the opposite direction to the pulsating torque based on the pulsating torque; and compensates the generator's torque based on the target compensation torque to suppress range extender speed fluctuations. Compensating the generator's torque based on the target compensation torque suppresses the engine's pulsating torque, thus reducing engine torque fluctuations and, to some extent, preventing engine torque pulsations from translating into generator speed fluctuations. Therefore, it reduces the range extender's speed fluctuations. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a flowchart of the control method for the range extender in an embodiment of the present invention; Figure 2 This is a functional block diagram of the control device for the range extender in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of an electronic device in an embodiment of the present invention. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0021] In this invention, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of that feature. Furthermore, the technical solutions of the various embodiments can be combined with each other, but only on the basis of being achievable by those skilled in the art. If the combination of technical solutions is contradictory or impossible to implement, such a combination of technical solutions should be considered non-existent and not within the scope of protection claimed by this invention.

[0022] This invention provides a control method for a range extender, the range extender including an engine and a generator rigidly directly connected to the engine; see reference. Figure 1 As shown, the method includes the following steps S101 to S104: S101: Predicts engine combustion torque based on engine ignition angle and crankshaft angle.

[0023] In some implementations, the combustion torque of the engine is predicted based on the engine's ignition angle and crankshaft angle, including the following steps S1011 to S1013: S1011: Determine the correction factor based on engine speed, load, coolant temperature, and intake air temperature.

[0024] It's important to note that engine load is a physical quantity that describes the extent to which the engine is currently exerting its output capacity. Simply put, it's "how much effort the engine is putting in," representing the intensity of combustion work. Additionally, engine load can be determined by the amount of air entering the engine. Specifically, the throttle valve controls the amount of air entering the engine; more air intake corresponds to more fuel injection, resulting in stronger combustion work and a higher load.

[0025] In some implementations, the correction factor is determined based on the engine speed, load, coolant temperature, and intake air temperature, including: determining a first correction factor based on the engine speed and load; determining a second correction factor based on the engine coolant temperature; and determining a third correction factor based on the engine intake air temperature; the correction factor includes the first correction factor, the second correction factor, and the third correction factor.

[0026] In some implementations, determining a first correction coefficient based on engine speed and load can be achieved by inputting the engine speed and load into a first correspondence to obtain the first correction coefficient; wherein the first correspondence is the relationship between engine speed, load, and the first correction coefficient. Determining a second correction coefficient based on engine coolant temperature can be achieved by inputting the engine coolant temperature into a second correspondence to obtain the second correction coefficient; wherein the second correspondence is the relationship between engine coolant temperature and the second correction coefficient. Determining a third correction coefficient based on engine intake air temperature can be achieved by inputting the engine intake air temperature into a third correspondence to obtain the third correction coefficient; wherein the third correspondence is the relationship between engine intake air temperature and the third correction coefficient.

[0027] It should be noted that the above-mentioned first, second, and third correction coefficients, derived based on the first, second, and third correspondence relationships, are obtained by first testing corresponding data and then determining them through a table lookup. Besides using a table lookup method, they can also be determined through mathematical formulas, as follows: In other embodiments, determining a first correction coefficient based on engine speed and load can be achieved by inputting the engine speed and load into a first mathematical expression to obtain the first correction coefficient; wherein the first mathematical expression is a mathematical relationship between engine speed, load, and the first correction coefficient. Determining a second correction coefficient based on engine coolant temperature can be achieved by inputting the engine coolant temperature into a second mathematical expression to obtain the second correction coefficient; wherein the second mathematical expression is a mathematical relationship between engine coolant temperature and the second correction coefficient. Determining a third correction coefficient based on engine intake air temperature can be achieved by inputting the engine intake air temperature into a third mathematical expression to obtain the third correction coefficient; wherein the third mathematical expression is a mathematical relationship between engine intake air temperature and the third correction coefficient.

[0028] In some implementations, the first correction factor ranges from 0.8 to 1.2; the second correction factor ranges from 1 to 1.5, with the second correction factor being smaller as the engine coolant temperature increases; and the third correction factor ranges from 0.8 to 1, with the third correction factor being smaller as the engine intake air temperature increases.

[0029] Regarding the first correction coefficient, its core function is to correct for differences in pulsation amplitude under different speeds and loads, based on the torque pulsation waveform under preset operating conditions. It is the main correction term that determines the adaptability of the prediction model to different operating conditions. In terms of physical mechanisms, speed determines the combustion time window and pump resistance characteristics; load determines the amount of charge in the cylinder and the peak combustion pressure. These two are the core variables affecting the torque pulsation amplitude and are coupled together, jointly determining the pulsation intensity under the current power generation conditions. By independently representing the most critical operating condition variables as a two-dimensional table, the pulsation characteristics across the entire load and speed range can be accurately matched, ensuring the basic accuracy of torque prediction under different power generation demands.

[0030] Regarding the second correction factor, its core function is to correct for the difference in frictional torque caused by changes in engine coolant temperature, compensating for the amplitude deviation of net output torque under cold and warm engine conditions. From a physical mechanism perspective, coolant temperature directly determines engine oil viscosity. At low temperatures, engine oil viscosity is high, significantly increasing the frictional resistance of moving parts such as the piston, crankshaft, and valve train. Under the same combustion intensity, more torque is consumed through friction, resulting in a corresponding decrease in the final output net torque and pulsation amplitude. Coolant temperature is a slowly changing thermal state variable, existing as an independent one-dimensional table. It does not need to be coupled with speed or load dimensions, requiring only a few single-point tests for calibration, significantly reducing calibration workload. It accurately covers the compensation needs during cold starts and warm-up processes, avoiding inaccurate compensation due to frictional deviations under cold engine conditions, while not increasing the complexity of the main operating condition table.

[0031] Regarding the third correction factor, its core function is to correct the impact of intake air temperature changes on combustion intensity, compensating for the torque pulsation amplitude deviation caused by differences in in-cylinder charge density and combustion rate under different intake air temperatures. From a physical mechanism perspective, higher intake air temperatures result in lower air density, smaller in-cylinder charge mass for the same intake volume, and lower peak combustion pressure and pulsation amplitude; conversely, lower intake temperatures increase charge density and amplify pulsation amplitude. Intake air temperature is a slow-moving, environment-dependent variable. The primary correction structure is simple, computationally minimal, and can quickly adapt to different ambient temperatures and intake heating states. It eliminates the need to expand the dimensions of the main operating condition table, improving the model's adaptability to all environments with extremely low calibration costs, while also accommodating extreme usage scenarios such as high altitudes, high temperatures, and low temperatures.

[0032] S1012: Predicts the engine's base combustion torque based on the engine's ignition angle and crankshaft angle.

[0033] In some implementations, predicting the engine's base combustion torque based on the engine's ignition angle and crankshaft angle includes: inputting the engine's ignition angle and crankshaft angle into a fourth correspondence to obtain the engine's base combustion torque; wherein the fourth correspondence is the correspondence between the engine's ignition angle, crankshaft angle, and base combustion torque.

[0034] In some implementations, the fourth correspondence includes multiple corresponding data points, each of which is established through the following steps: when the test engine is in a preset operating condition, the ignition angle of the test engine is controlled as the test ignition angle, and the crankshaft angle of the test engine is controlled as the test crankshaft angle; when the ignition angle and crankshaft angle of the test engine are both the test ignition angle and the test crankshaft angle, the cylinder pressure and speed of the test engine are obtained; based on the cylinder pressure and cylinder volume of the test engine, the power of the test engine is determined; based on the power and speed of the test engine, the test baseline combustion torque of the test engine is determined; and based on the test ignition angle, the test crankshaft angle, and the test baseline combustion torque, the corresponding data is obtained.

[0035] It should be noted that the preset operating conditions can be that the test engine speed is a preset speed and the average combustion torque of the test engine is a preset combustion torque; the preset speed can be 3000 rpm and the preset combustion torque can be 100 Nm. In addition, based on the power and speed of the test engine, the test basis combustion torque of the test engine can be determined by referring to the following formula (1): T(θ)=p(θ)·9550 / n (1); Where T(θ) is the test baseline combustion torque of the test engine, p(θ) is the power of the test engine, and n is the speed of the test engine.

[0036] It should be noted that the above method of inputting the engine's ignition angle and crankshaft angle into the fourth correspondence to obtain the engine's basic combustion torque works by determining the engine's basic combustion torque through a lookup table. Alternatively, the engine's basic combustion torque can also be determined using mathematical relationships, as follows: In other embodiments, the engine's base combustion torque is predicted based on the engine's ignition angle and crankshaft angle, including: inputting the engine's ignition angle and crankshaft angle into a fourth mathematical relation to obtain the engine's base combustion torque; wherein the fourth mathematical relation is a mathematical relation between the engine's ignition angle, crankshaft angle, and base combustion torque.

[0037] S1013: The basic combustion torque is corrected based on the correction factor to obtain the combustion torque.

[0038] It should be noted that the correction factor can include a first correction factor, a second correction factor, and a third correction factor, or it can only include the first correction factor and the second correction factor, or it can only include the first correction factor, etc. The steps in step S1013 will also be different depending on the correction factor. An example is given below: Example 1: In some implementations, the correction coefficients include a first correction coefficient, a second correction coefficient, and a third correction coefficient; the basic combustion torque is corrected based on the correction coefficients to obtain the combustion torque, including obtaining the combustion torque based on the product of the basic combustion torque, the first correction coefficient, the second correction coefficient, and the third correction coefficient.

[0039] It should be noted that the multiplication order of the base combustion torque, the first correction factor, the second correction factor, and the third correction factor can be implemented in various ways, as illustrated below: In some implementations, the combustion torque is obtained based on the product of the base combustion torque, the first correction factor, the second correction factor, and the third correction factor. This can be achieved by: using the product of the base combustion torque and the first correction factor as the first value; using the product of the first value and the second correction factor as the second value; and using the product of the second value and the third correction factor as the combustion torque.

[0040] In other embodiments, the combustion torque is obtained based on the product of the base combustion torque, the first correction factor, the second correction factor, and the third correction factor. This can be achieved by: using the product of the base combustion torque and the second correction factor as the first value; using the product of the first value and the first correction factor as the second value; and using the product of the second value and the third correction factor as the combustion torque.

[0041] In some other implementations, the combustion torque is obtained based on the product of the base combustion torque, the first correction factor, the second correction factor, and the third correction factor. This can be achieved by: using the product of the base combustion torque and the third correction factor as the first value; using the product of the first value and the first correction factor as the second value; and using the product of the second value and the second correction factor as the combustion torque.

[0042] Specifically, the combustion torque is obtained by multiplying the base combustion torque, the first correction factor, the second correction factor, and the third correction factor, as shown in the following formula (2): T_comb(θ) =q(sprk_ang, θ)·f(n, load)·β1·β2(2); Where T_comb(θ) is the engine's combustion torque, q(sprk_ang, θ) is the engine's base combustion torque, f(n, load) is the first correction coefficient, β1 is the second correction coefficient, β2 is the third correction coefficient, θ is the engine's crankshaft angle, sprk_ang is the engine's ignition angle, n is the engine's speed, and load is the engine's load.

[0043] It should be noted that the factors affecting the combustion torque pulsation of the engine belong to three completely independent physical dimensions: operating condition intensity, thermal state, and environmental state. Their influencing mechanisms, rates of change, and coupling characteristics are all different. If combined into a single correction coefficient, problems such as an exponential increase in calibration workload, ambiguous physical meaning, difficulty in debugging and positioning, and poor real-time performance would arise. Therefore, this embodiment of the invention distinguishes different correction coefficients. First, it achieves physical decoupling and precise debugging and positioning: each correction coefficient corresponds to a single type of physical influencing factor, allowing for precise location of parameter adjustments and fault diagnosis. For cold-start compensation anomalies, the second correction coefficient is adjusted first; for operating condition adaptation anomalies, the first correction coefficient is adjusted first, avoiding the shortcomings of a single correction coefficient in locating problems. Second, it achieves better prediction accuracy: the influence patterns of different factors (linear, nonlinear, and magnitude of influence) vary. Dimensional correction can match their respective changing characteristics, more accurately compensating for various deviations compared to a single correction coefficient, improving the overall accuracy of torque prediction, and ultimately ensuring the effectiveness of torque compensation.

[0044] Example 2: In some implementations, the correction factor includes a first correction factor and a second correction factor; the basic combustion torque is corrected based on the correction factor to obtain the combustion torque, including: obtaining the combustion torque based on the product of the basic combustion torque, the first correction factor and the second correction factor.

[0045] It should be noted that the order in which the base combustion torque, the first correction factor, and the second correction factor are multiplied can be implemented in various ways, as illustrated below: In some implementations, the combustion torque is obtained based on the product of the base combustion torque, the first correction factor, and the second correction factor. This can be achieved by multiplying the base combustion torque by the first correction factor as the first value, and multiplying the first value by the second correction factor as the combustion torque.

[0046] In other embodiments, the combustion torque is obtained based on the product of the base combustion torque, the first correction factor, and the second correction factor. This can be achieved by: using the product of the base combustion torque and the second correction factor as the first value; and using the product of the first value and the first correction factor as the combustion torque.

[0047] Example 3: In some implementations, the correction factor includes a first correction factor; correcting the base combustion torque based on the correction factor to obtain the combustion torque includes: multiplying the base combustion torque by the first correction factor as the combustion torque.

[0048] Example 4: In some implementations, the correction factor includes a second correction factor; correcting the base combustion torque based on the correction factor to obtain the combustion torque includes: multiplying the base combustion torque by the second correction factor as the combustion torque.

[0049] Example 5: In some implementations, the correction factor includes a third correction factor; correcting the base combustion torque based on the correction factor to obtain the combustion torque includes: multiplying the base combustion torque by the third correction factor as the combustion torque.

[0050] S102: Determine the engine's pulsating torque based on the combustion torque and the engine's average combustion torque within a preset crankshaft angle range.

[0051] It should be noted that the pulsating torque of the engine varies periodically with the crankshaft angle, resulting from instantaneous torque deviations caused by factors such as uneven combustion and intake fluctuations. The greater the pulsating torque of the engine, the greater the speed fluctuation of the range extender. The preset crankshaft angle range can be 0° to 720°CA. For the engine to complete one full intake-compression-power-exhaust cycle, the crankshaft needs to rotate 2 revolutions, corresponding to the crankshaft angle range of 0° to 720°CA. Within this complete cycle, the engine's combustion torque fluctuates dramatically with the crankshaft angle: during the power stroke, the cylinder pressure surges, and the instantaneous torque reaches its peak value; during the compression and exhaust strokes, pumping resistance exists, causing the instantaneous torque to decrease or even become negative. The average combustion torque is the arithmetic mean of all instantaneous combustion torques within a complete cycle. It represents the steady-state component of the engine's output torque under that operating condition, reflecting only the overall power output level under the current condition, stripping away the periodic pulsating components, and serves as the basic torque for maintaining the current power generation.

[0052] In some implementations, the pulsating torque of the engine is determined based on the combustion torque and the average combustion torque of the engine within a preset crankshaft angle range, including: determining the pulsating torque based on the difference between the combustion torque and the average combustion torque.

[0053] In some implementations, the pulsating torque is determined based on the difference between the combustion torque and the average combustion torque. This can be achieved by subtracting the average combustion torque from the combustion torque and using the difference as the engine's pulsating torque. Specifically, refer to the following formula (3): ΔT(θ) = T_comb(θ) T_avg_eng(3); Where ΔT(θ) is the engine's pulsating torque, and T_avg_eng is the average combustion torque.

[0054] In other implementations, the pulsating torque is determined based on the difference between the combustion torque and the average combustion torque. This can be achieved by: determining a first difference between the combustion torque and the average combustion torque; and multiplying the first difference by a fourth correction factor as the engine's pulsating torque.

[0055] S103: Based on the pulsating torque, determine the target compensation torque that is opposite to the direction of the pulsating torque.

[0056] In some implementations, determining a target compensation torque opposite to the direction of the pulsating torque based on the pulsating torque includes: acquiring the original speed signal of the generator; determining the speed fluctuation parameter of the generator based on the original speed signal of the generator; determining the compensation gain coefficient based on the speed fluctuation parameter, wherein the larger the speed fluctuation parameter, the larger the compensation gain coefficient; and determining the target compensation torque based on the compensation gain coefficient and the pulsating torque.

[0057] In some implementations, determining the generator speed fluctuation parameters based on the generator's original speed signal includes: determining the generator's instantaneous maximum speed and instantaneous minimum speed within a complete working cycle based on the generator's original speed signal; and using the difference between the instantaneous maximum speed and the instantaneous minimum speed as the speed fluctuation parameter.

[0058] In other embodiments, the generator speed fluctuation parameters are determined based on the generator's original speed signal, including: determining the generator's instantaneous maximum speed and instantaneous minimum speed within a complete working cycle, as well as the generator's average speed within a complete working cycle, based on the generator's original speed signal; taking the difference between the instantaneous maximum speed and the instantaneous minimum speed as the peak-to-peak value of the speed fluctuation; and taking the quotient of the peak-to-peak value of the speed fluctuation divided by the generator's average speed within a complete working cycle as the speed fluctuation parameter.

[0059] In some implementations, the target compensation torque is determined based on the compensation gain coefficient and the pulsating torque, including: multiplying the compensation gain coefficient by the pulsating torque and inverting the product to obtain the target compensation torque. Specifically, refer to the following formula (4): T_comp(θ) = K · ΔT(θ)(4; Where K is the compensation gain coefficient and T_comp(θ) is the target compensation torque.

[0060] It should be noted that the compensation gain coefficient can range from 0 to 1. When the generator speed fluctuates significantly, the compensation gain coefficient approaches 1 to increase the compensation intensity; when the generator speed is stable, the compensation gain coefficient approaches 0. This setting aims to avoid overcompensation oscillations and improve system stability. Specifically, if K=1 is fixed to completely eliminate torque pulsations, factors such as combustion prediction model errors, sensor noise, and actuator delays can easily lead to compensation phase or amplitude deviations, which may trigger secondary speed oscillations. Furthermore, flywheel-less, low-inertia systems are more sensitive to disturbances, and the negative impact of overcompensation will be further amplified. K is adaptively adjusted according to the degree of fluctuation. High gain enhances the suppression effect during large fluctuations, while low gain avoids excessive intervention during small fluctuations. This eliminates the risk of overcompensation oscillations from the control logic perspective, significantly improving system robustness and operational reliability.

[0061] S104: Based on the target compensation torque, compensate the generator torque to suppress the speed fluctuation of the range extender.

[0062] In some implementations, the torque of the generator is compensated based on a target compensation torque, including: obtaining the average torque required to maintain the rated power output of the generator; determining a target torque based on the sum of the average torque and the target compensation torque; and controlling the generator based on the target torque.

[0063] It should be noted that the average torque required to maintain the rated power output of the generator can be the torque generated by the VCU (Vehicle Control Unit) and executed by the generator. Its value can be obtained by inverting the average combustion torque of the engine within a preset crankshaft angle range.

[0064] In some implementations, the target torque is determined based on the sum of the average torque and the target compensation torque. This can be achieved by using the sum of the average torque and the target compensation torque as the target torque.

[0065] In other implementations, the target torque is determined based on the sum of the average torque and the target compensation torque. This can be achieved by: determining a first sum of the average torque and the target compensation torque; and multiplying the first sum by a fifth correction coefficient as the target torque.

[0066] In some implementations, controlling the generator based on the target torque can be achieved by using the target torque as the generator's output torque.

[0067] In some implementations, before step S101, the method may further include: acquiring the engine's ignition angle and crankshaft angle according to a preset execution cycle, wherein the preset execution cycle includes 1ms to 50ms.

[0068] It should be noted that after obtaining the engine's ignition angle and crankshaft angle each time according to the preset execution cycle, steps S101 to S104 need to be executed again to redetermine the latest target compensation torque, thereby compensating the generator's torque in real time. This enables rapid tracking of torque command changes, providing hardware support for real-time offsetting of combustion pulsation, and ultimately achieving real-time suppression of the range extender's speed fluctuations.

[0069] It should be noted that in hybrid vehicle control, the VCU (Vehicle Control Unit) calculates the vehicle's power demand. Based on the engine's specific fuel consumption parameters, it selects the optimal engine speed and torque point, then sends the required torque to the ECU (Engine Control Unit) and the required speed to the GCU (Generator Control Unit). The GCU adjusts the generator torque to achieve closed-loop speed control, converting mechanical power into electrical power. The electrical energy is then output to the drive motor and other electrical loads, enabling vehicle operation and the normal operation of peripheral devices. The highly integrated range extender features a direct rigid connection between the engine crankshaft and the generator rotor. To improve power density, reduce NVH transmission, and decrease axial dimensions, the traditional large-mass flywheel of the engine is eliminated, and the engine and generator controllers are integrated. This embodiment of the invention pertains to the control of a range extender system for new energy vehicles. By predicting the relationship between engine combustion torque and crankshaft angle, the generator performs real-time torque phase compensation, achieving highly stable range extender speed under flywheel-less conditions.

[0070] It's important to note that speed fluctuations trigger a chain reaction of performance degradation. High-frequency, periodic fluctuations in speed directly impact generator output and overall vehicle performance. Specifically, this results in unstable generator voltage: the generator's output voltage is directly related to rotor speed; continuous high-frequency fluctuations in speed lead to significant ripple in the output voltage, reducing stability and affecting battery charging safety, as well as the operational stability of the drive motor and onboard electrical loads. Vehicle vibration and NVH (Noise, Vibration, and Harshness) performance deterioration: the impact of torque and speed is transmitted to the entire vehicle through structural paths, causing continuous vibration and abnormal noises, reducing ride comfort. Decreased power generation efficiency of the range extender system: on one hand, speed fluctuations cause the generator to deviate from its rated high-efficiency operating range, increasing electromagnetic losses; on the other hand, unstable speed interferes with engine combustion control, making it difficult to operate stably at the optimal fuel consumption point, ultimately leading to a reduction in the overall fuel-generating efficiency of the range extender. To address the aforementioned issues, conventional PI speed closed-loop control in existing technologies suffers from inherent response lag, failing to provide real-time and accurate responses to high-frequency periodic torque fluctuations strongly tied to crankshaft angle. Consequently, it cannot effectively suppress speed fluctuations without a flywheel range extender, becoming a core technical obstacle to the implementation of this highly integrated solution. To resolve these problems, this invention proposes an embodiment. Regarding mechanical connections, the engine and generator employ a rigid direct connection, eliminating the traditional flywheel structure, resulting in a simpler structure and lower cost. Regarding sensors, the engine controller connects to crankshaft position (60-2 signal disk) and camshaft position sensor signals (cylinder detection), enabling real-time acquisition of engine crankshaft angle and speed, providing core input signals for subsequent torque prediction and phase synchronization compensation. After synchronization, GCU resolver position sensor signals can be used to directly calculate the engine angle via electrical angle, resulting in higher control accuracy and faster operation (1ms). Regarding the controller configuration, the engine control unit and generator control unit are integrated into a single controller design, reducing signal transmission delay and enabling coordinated control of the engine and generator. Regarding the generator operating mode, the generator employs a fast torque control mode, with an execution module cycle of up to 1ms, enabling rapid tracking of torque command changes and providing hardware support for real-time cancellation of combustion pulsations. Regarding the controller's built-in modules, the integrated controller incorporates three core modules: a combustion torque prediction module, a steering angle phase compensation module, and a generator torque control module. These three modules work together to achieve precise suppression of torque pulsations and stable system operation. Regarding engine control, the engine is only responsible for maintaining average operating conditions, controlling intake air volume, ignition, and fuel injection timing through the ECU to ensure stable average combustion torque. It does not participate in suppressing high-frequency torque pulsations, avoiding pulsation suppression failure caused by engine response lag.

[0071] This invention, through a generator reverse compensation control scheme that synchronizes combustion torque feedforward prediction with crankshaft angle, achieves multiple optimizations in smoothness, reliability, economy, and cost within a highly integrated range extender architecture that eliminates the flywheel. Specific benefits are as follows: First, speed stability is significantly improved, overcoming the control bottleneck of flywheel-less architectures. This invention replaces the physical inertia buffering effect of the traditional flywheel with active torque compensation, effectively offsetting speed disturbances caused by periodic combustion torque pulsations in the engine. This solves the defect of traditional PI closed-loop control in responding to high-frequency angle-related fluctuations. Even with the elimination of the flywheel and a significant reduction in system rotational inertia, the range extender speed remains highly stable, with speed fluctuations reduced by more than 50%, providing core control support for the practical application of flywheel-less highly integrated range extenders. Secondly, the power generation quality is significantly optimized, extending the service life of the electrical system. The highly stable speed of the range extender directly ensures the stability of the generator output voltage, greatly reducing output current ripple and preventing the power battery from being subjected to impact charging and discharging. At the same time, it reduces the electrical stress and heat loss of electronic control devices such as the generator controller and high-voltage power distribution, effectively improving the operational reliability and service life of the power battery and core electronic control components. Thirdly, NVH performance is comprehensively improved, offsetting combustion impact at the source. The periodic torque impact generated by single-cylinder and multi-cylinder combustion in the engine is directly offset within the rotating shaft system by the reverse compensation torque synchronously output by the generator. This blocks the transmission path of torque impact to the vehicle body, suspension, and cabin from the source, significantly reducing overall vibration and abnormal noise. The engine combustion impact is effectively offset, greatly improving driving comfort. Fourthly, the system boasts a compact and lightweight structure, reducing overall costs. This invention replaces the flywheel's buffering function with a control algorithm, completely eliminating the traditional flywheel, flywheel housing, and connecting components. This effectively shortens the range extender's axial dimension, reduces overall weight, and achieves a more compact and lighter design. Simultaneously, it reduces the number of parts and assembly steps, lowering material and manufacturing costs and improving the flexibility of the vehicle's powertrain layout. Fifthly, improved fuel economy and reduced operating fuel consumption are achieved. Stable speed control allows the engine to operate stably at its optimal efficiency point for extended periods, preventing deviations from the high-efficiency operating range due to frequent speed fluctuations. Simultaneously, the generator can also maintain its high-efficiency power generation range, reducing unnecessary electromagnetic losses. Ultimately, this improves the overall power generation efficiency of the range extender, effectively reducing overall vehicle fuel consumption.

[0072] It should be noted that the engine control unit and generator control unit are integrated. This integrated controller design is the core hardware support for achieving high-frequency angle synchronous torque compensation in this solution. By integrating the engine control unit and generator control unit, benefits are brought in multiple dimensions such as real-time performance, synchronization accuracy, system cost, and reliability. The specific benefits are as follows: First, it eliminates cross-controller transmission delay, ensuring the real-time performance of high-frequency compensation. Specifically, in the split architecture, the independent ECU and GCU need to exchange crankshaft angle, speed, combustion status, and other signals through the vehicle bus, resulting in a transmission delay of several milliseconds. This is difficult to adapt to the millisecond-level angle synchronous torque compensation requirements of this solution, and can easily lead to compensation phase misalignment and reduced torque cancellation effect. Under the integrated design, the two types of control units share internal data channels. Signals such as crankshaft angle and combustion status on the engine side can be directly called by the generator control logic. The signal transmission delay is close to zero, ensuring that the compensation torque command matches the engine pulsating torque in real time, providing a key hardware foundation for suppressing speed fluctuations. Second, it unifies the clock and control reference, achieving precise collaborative control. Specifically, independent controllers, with their own independent clock sources and control cycles, naturally suffer from phase synchronization errors. This can lead to phase misalignment between the generator's compensation torque and the engine's combustion pulsations, weakening the cancellation effect and even causing secondary speed oscillations. Integrated controllers, on the other hand, employ a unified clock reference and synchronous scheduling logic. The engine's crankshaft angle phase, ignition timing, and generator torque output commands are strictly synchronized in time, ensuring precise phase alignment between the reverse compensation torque and the engine's pulsating torque. This maximizes the torque cancellation effect and further improves speed stability. Thirdly, the hardware architecture is simplified, reducing costs and failure rates. Specifically, by merging the power modules, main control chips, and housing connectors of the dual independent controllers, the number of parts and assembly processes are reduced, directly lowering material and manufacturing costs. Simultaneously, the communication harnesses and interfaces across controllers are eliminated, removing potential fault points such as bus interference and poor connector contact. This improves the overall reliability of the range extender's electronic control system and allows for a more compact layout, aligning with the miniaturization and integration goals of flywheel-less range extenders. Fourthly, it supports global optimization strategies, enhancing overall system performance. Specifically, the integrated architecture enables global coordinated scheduling of engine control and generator control, deeply integrating the combustion torque prediction model, operating condition correction logic, and generator torque execution logic without requiring cross-controller command interaction or parameter compromise. Based on this, more refined adaptive gain adjustment and fault collaborative handling functions can be achieved, further optimizing speed fluctuation suppression and power generation efficiency, and improving the overall robustness of the system.

[0073] This invention predicts the engine's combustion torque based on the engine's ignition angle and crankshaft angle; determines the engine's pulsating torque based on the combustion torque and the engine's average combustion torque within a preset crankshaft angle range; determines a target compensation torque in the opposite direction to the pulsating torque based on the pulsating torque; and compensates the generator's torque based on the target compensation torque to suppress range extender speed fluctuations. Compensating the generator's torque based on the target compensation torque suppresses the engine's pulsating torque, thus reducing engine torque fluctuations and, to some extent, preventing engine torque pulsations from translating into generator speed fluctuations. Therefore, it reduces the range extender's speed fluctuations.

[0074] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

[0075] Based on the same inventive concept, and referring to Figure 2 As shown, this embodiment of the invention provides a control device 10 for a range extender. The range extender includes an engine and a generator rigidly connected to the engine. The control device 10 includes an integrated engine control unit 110 and a generator control unit 120. The engine control unit 110 is used to predict the combustion torque of the engine based on the engine's ignition angle and crankshaft angle; and to determine the engine's pulsating torque based on the combustion torque and the engine's average combustion torque within a preset crankshaft angle range. The generator control unit 120 is used to determine a target compensation torque opposite to the direction of the pulsating torque based on the pulsating torque; and to compensate the generator's torque based on the target compensation torque to suppress the range extender's speed fluctuations.

[0076] The engine control unit 110 includes: a prediction subunit, used to determine correction coefficients based on engine speed, load, coolant temperature, and intake air temperature; predict the engine's basic combustion torque based on the engine's ignition angle and crankshaft angle; and correct the basic combustion torque based on the correction coefficients to obtain the combustion torque. Specifically, determining the correction coefficients based on engine speed, load, coolant temperature, and intake air temperature includes: determining a first correction coefficient based on engine speed and load; determining a second correction coefficient based on engine coolant temperature; and determining a third correction coefficient based on engine intake air temperature. The correction coefficients include the first, second, and third correction coefficients. Correcting the basic combustion torque based on the correction coefficients to obtain the combustion torque includes: obtaining the combustion torque based on the product of the basic combustion torque, the first correction coefficient, the second correction coefficient, and the third correction coefficient. The first correction factor ranges from 0.8 to 1.2; the second correction factor ranges from 1 to 1.5, with the second correction factor being smaller as the engine coolant temperature increases; the third correction factor ranges from 0.8 to 1, with the third correction factor being smaller as the engine intake air temperature increases.

[0077] The engine control unit 110 further includes a pulsation determination subunit for determining the pulsation torque based on the difference between the combustion torque and the average combustion torque.

[0078] The generator control unit 120 includes: a compensation determination subunit, used to acquire the generator's original speed signal; determine the generator's speed fluctuation parameters based on the original speed signal; determine a compensation gain coefficient based on the speed fluctuation parameters, wherein the larger the speed fluctuation parameters, the larger the compensation gain coefficient; and determine a target compensation torque based on the compensation gain coefficient and the pulsating torque. Specifically, determining the target compensation torque based on the compensation gain coefficient and the pulsating torque includes: multiplying the compensation gain coefficient by the pulsating torque and inverting the product to obtain the target compensation torque.

[0079] The generator control unit 120 further includes a compensation subunit for: obtaining the average torque required to maintain the rated power output of the generator; determining a target torque based on the sum of the average torque and the target compensation torque; and controlling the generator based on the target torque.

[0080] The range extender control device 10 further includes: a periodic execution unit, used to acquire the engine's ignition angle and crankshaft angle according to a preset execution cycle before predicting the engine's combustion torque based on the engine's ignition angle and crankshaft angle, wherein the preset execution cycle includes 1ms to 50ms.

[0081] It should be understood that further implementation details of the control device 10 of the range extender in the embodiments of the present invention are described in the aforementioned control method of the range extender, and will not be repeated here for the sake of brevity.

[0082] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

[0083] Based on the same inventive concept, embodiments of the present invention also provide an electronic device, such as... Figure 3 As shown, it includes a memory 304, a processor 302, and a computer program stored in the memory 304 and executable on the processor 302. The processor 302 executes the program to implement the steps described in any embodiment of the control method for the range extender.

[0084] Among them, Figure 3 In this document, a bus architecture (represented by bus 300) is used. Bus 300 may include any number of interconnected buses and bridges, linking various circuits including one or more processors represented by processor 302 and memory represented by memory 304. Bus 300 may also link various other circuits such as peripheral devices, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further herein. Bus interface 305 provides an interface between bus 300 and receiver 301 and transmitter 303. Receiver 301 and transmitter 303 may be the same element, i.e., a transceiver, providing a unit for communicating with various other devices over a transmission medium. Processor 302 is responsible for managing bus 300 and general processing, while memory 304 can be used to store data used by processor 302 during operation.

[0085] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored as one or more instructions or codes on or transmitted via a computer-readable medium. Other examples and embodiments are within the scope and spirit of this invention and the appended claims. For example, due to the nature of software, the functions described above can be implemented using software executed by a processor, hardware, firmware, hardwired, or any combination thereof. Furthermore, the functional units can be integrated into a single processing unit, or each unit can exist physically separately, or two or more units can be integrated into a single unit.

[0086] In the several embodiments provided in this application, it should be understood that the disclosed technical content can be implemented in other ways. The device embodiments described above are merely illustrative; for example, the division of units can be a logical functional division, and in actual implementation, there may be other division methods. For instance, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. Furthermore, the displayed or discussed mutual coupling, direct coupling, or communication connection may be through some interfaces; the indirect coupling or communication connection between units or modules may be electrical or other forms.

[0087] The units described as separate components may or may not be physically separate. Similarly, the components of the control device may or may not be physical units; they may be located in one place or distributed across multiple units. Some or all of the units can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0088] If the integrated unit is implemented as a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes several instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes various media capable of storing program code, such as USB flash drives, read-only memory (ROM), random access memory (RAM), portable hard drives, magnetic disks, or optical disks.

[0089] The above description is merely an embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of the claims of the present invention.

Claims

1. A control method for a range extender, characterized in that, The range extender includes an engine and a generator rigidly directly connected to the engine; the method includes: Based on the engine's ignition angle and crankshaft angle, the engine's combustion torque is predicted; The pulsating torque of the engine is determined based on the combustion torque and the average combustion torque of the engine within a preset crankshaft angle range. Based on the pulsating torque, a target compensation torque opposite to the direction of the pulsating torque is determined; Based on the target compensation torque, the torque of the generator is compensated to suppress the speed fluctuation of the range extender.

2. The control method for the range extender according to claim 1, characterized in that, The prediction of the combustion torque of the engine based on the engine's ignition angle and crankshaft angle includes: Based on the engine's speed, load, coolant temperature, and intake air temperature, a correction factor is determined; Based on the engine's ignition angle and crankshaft angle, the engine's base combustion torque is predicted; The base combustion torque is corrected based on the correction factor to obtain the combustion torque.

3. The control method for the range extender according to claim 2, characterized in that, The determination of correction factors based on the engine's speed, load, coolant temperature, and intake air temperature includes: Based on the engine speed and load, a first correction factor is determined; A second correction factor is determined based on the engine's coolant temperature; A third correction factor is determined based on the engine's intake air temperature; the correction factor includes the first correction factor, the second correction factor, and the third correction factor.

4. The control method for the range extender according to claim 3, characterized in that, The step of correcting the base combustion torque based on the correction coefficient to obtain the combustion torque includes: The combustion torque is obtained by multiplying the base combustion torque, the first correction factor, the second correction factor, and the third correction factor.

5. The control method for the range extender according to claim 3, characterized in that, The first correction factor ranges from 0.8 to 1.2; The value of the second correction factor ranges from 1 to 1.

5. The higher the coolant temperature of the engine, the smaller the second correction factor. The value of the third correction factor ranges from 0.8 to 1, and the higher the intake air temperature of the engine, the smaller the third correction factor.

6. The control method for the range extender according to claim 1, characterized in that, Determining the pulsating torque of the engine based on the combustion torque and the average combustion torque of the engine within a preset crankshaft angle range includes: The pulsating torque is determined based on the difference between the combustion torque and the average combustion torque.

7. The control method for the range extender according to claim 1, characterized in that, The step of determining a target compensation torque opposite in direction to the pulsating torque based on the pulsating torque includes: Obtain the original speed signal of the generator; Based on the original speed signal of the generator, the speed fluctuation parameters of the generator are determined; Based on the speed fluctuation parameter, a compensation gain coefficient is determined, wherein the larger the speed fluctuation parameter, the larger the compensation gain coefficient. The target compensation torque is determined based on the compensation gain coefficient and the pulsating torque.

8. The control method for the range extender according to claim 7, characterized in that, Determining the target compensation torque based on the compensation gain coefficient and the pulsating torque includes: The target compensation torque is obtained by multiplying the compensation gain coefficient by the pulsating torque and then inverting the product.

9. The control method for the range extender according to claim 1, characterized in that, The compensation of the generator torque based on the target compensation torque includes: To obtain the average torque required to maintain the rated power output of the generator; The target torque is determined based on the sum of the average torque and the target compensated torque; The generator is controlled based on the target torque.

10. The control method for the range extender according to claims 1-9, characterized in that, Before predicting the combustion torque of the engine based on the engine's ignition angle and crankshaft angle, the method further includes: The ignition angle and crankshaft angle of the engine are obtained according to a preset execution cycle, wherein the preset execution cycle includes 1ms to 50ms.

11. A control device for a range extender, characterized in that, The range extender includes an engine and a generator rigidly connected to the engine; the device includes an integrated engine control unit and a generator control unit; The engine control unit is used to predict the combustion torque of the engine based on the ignition angle and crankshaft angle of the engine; and to determine the pulsating torque of the engine based on the combustion torque and the average combustion torque of the engine within a preset crankshaft angle range. The generator control unit is configured to determine a target compensation torque opposite to the direction of the pulsating torque based on the pulsating torque; and to compensate the torque of the generator based on the target compensation torque to suppress the speed fluctuation of the range extender.

12. An electronic device, characterized in that, include: A memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor, when executing the computer program, implements the method of any one of claims 1-10.

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