Management methods and systems for automotive alternators

Abstract

A method and management system for an automotive alternator for a vehicle equipped with an engine (ICE) are described, wherein the alternator (1) is controlled by an ECU (23), the ECU facilitating the mechanical coupling of the alternator (1) to a toothed belt (5) and the electrical coupling of the alternator (1) to a battery (20), wherein the ECU (23) receives a signal from a battery charge sensor (22) to: determine the battery charge level from BC1 (corresponding to a fully charged state), BC2 (corresponding to a working charge level) and BC3 (corresponding to a low charge level); and act on the alternator to electrically and mechanically decouple the alternator (1) at the BC1 level; maintain the electrical and mechanical coupling of the alternator (1) at the BC3 level; and mechanically couple the alternator (1) at the BC2 level when the vehicle's displacement speed is greater than a predetermined value (VLim) and the engine (ICE) disengages to shift gears, and electrically couples the alternator (1) when the vehicle is being driven in a cut-off mode.

Description

[0001] This invention relates to a method and system for managing an automotive alternator, and more specifically to a method for managing an alternator capable of being electrically and / or mechanically coupled and decoupled from an internal combustion engine (ICE) or similar equipment. More specifically, the invention aims to manage the selective coupling or decoupling of the alternator depending on the state of the battery and in conjunction with the driving state of the vehicle. Background Technology

[0002] As is known in the art, systems for generating electrical power in a vehicle typically include an electric motor responsible for generating electrical power, which is driven by the vehicle's engine via a synchronous belt during ignition. An alternator supplies power to all electrical devices and recharges the battery during vehicle operation, and its name is a reference to the type of current generated. This device operates based on the fundamental principle of electromagnetic induction: current flowing through the rotor generates a magnetic field that induces the movement of electrons in the stator coils, thereby producing alternating current. When the vehicle operates using direct current, the automotive alternator also includes two basic components: a rectifier unit (or simply rectifier), which converts alternating current to direct current; and a voltage regulator, which controls the generated voltage.

[0003] However, and despite their widespread use in vehicles, these motors contribute to fuel consumption and carbon dioxide (CO2) emissions because they represent a source of mechanical energy consumption from the crankshaft. Since the engine derives its mechanical energy from the heat generated by fuel combustion, the alternator acts as a load on the system; this load, when the battery is charging, causes an increase in fuel consumption to compensate for the energy consumed by the alternator. Furthermore, even when the battery is at a sufficient charge level, the alternator continuously consumes mechanical energy from the crankshaft to power the vehicle systems, which become increasingly complex and thus consume more and more electrical energy.

[0004] Fuel consumption and carbon dioxide emissions are direct indicators of a vehicle's energy efficiency. The combustion of fuels, especially fossil fuels, produces high concentrations of carbon dioxide (CO2). High levels of CO2 emissions into the atmosphere contribute to harmful environmental effects such as the greenhouse effect and resulting global warming, which in turn means the likelihood of natural disasters (e.g., tsunamis) and climate change, often impacting daily life. Furthermore, fuel consumption is associated with carbon monoxide (CO) and hydrocarbon (HC) emissions, which have been shown to be harmful to human health.

[0005] To minimize the negative impact of the alternator on vehicle fuel consumption, several techniques have been designed and implemented. Typically, projects are based on increasing the alternator's (electrical or mechanical) efficiency and the possibility of strategic alternator operation dependent on the battery's energy needs. In recent developments, the so-called "intelligent alternator" (IA) deserves emphasis; it is designed to minimize the mechanical load on the crankshaft based on data collected by the alternator from the vehicle itself (e.g., the ECU). In alternators equipped with internal control systems, as described in cited documents DE 19638872 and US 7816893, strategies are described for electrically disconnecting the alternator from the vehicle's electrical load under specific conditions. In other cases, this electrical disconnection occurs when the battery has a sufficient charge level to supply the vehicle's electrical system, or when the alternator's operating conditions are insufficient. Electrical reconnection is performed when the battery reaches its minimum charge level and needs recharging. In this way, the mechanical load on the crankshaft is minimized during alternator electrical disconnection.

[0006] The invention described in US 10247265, authored by the inventors, relates to an alternator (E / MS) capable of being coupled to and / or decoupled from the crankshaft of a vehicle engine (ICE or similar device), wherein the coupling or mechanical decoupling is selectively performed in steps other than electrical connection or disconnection. Advantages of the described alternator include reduced vibrations caused by electrical and mechanical coupling, reduced fuel consumption, and thus reduced emissions from the vehicle engine.

[0007] Therefore, and although both using the aforementioned intelligent alternators and alternators with different electrical and mechanical couplings have advantages, subsequent research has promoted the development of new management strategies for vehicle alternators, thereby potentially increasing these advantages even further.

[0008] Purpose of the invention Therefore, a first objective of the present invention is to provide a method for managing an alternator capable of being coupled to or decoupled from the crankshaft of a vehicle engine, in order to reduce fuel consumption, carbon dioxide (CO2) emissions, and emissions of substances such as carbon monoxide (CO), hydrocarbons (HC), and nitrogen oxides (NOx). x In addition to reducing the levels of other polluting gas emissions, it also reduces crankshaft load and thus significantly reduces vibration.

[0009] Another object of the present invention is to provide a method for managing an alternator, the method being designed to facilitate selective coupling and decoupling of the alternator depending on a combination of battery charge levels and vehicle drive modes. Summary of the Invention

[0010] These and other objectives are achieved and satisfied by a method for managing an automotive alternator, the method comprising the following steps: - Determine the battery charge level from BC1 (corresponding to the battery's fully charged state), BC2 (corresponding to the working battery charge level), and BC3 (corresponding to the low battery charge level); in: - At BC1 level, the alternator remains electrically and mechanically decoupled; - At BC3 level, the alternator remains electrically and mechanically coupled; and - At BC2 level, the alternator is mechanically coupled when the vehicle's displacement speed is greater than a predetermined VLim and when the ICE engine disengages for shifting; and electrically coupled when the vehicle is being driven in cut-off mode.

[0011] In addition, the method further includes the following step: when the engine speed is lower than a predetermined limit value RLim, mechanically and electrically decouple the alternator.

[0012] Similarly, the object of the present invention is also achieved and satisfied by an automotive alternator management system comprising a vehicle equipped with an ICE engine, wherein rotation of the crankshaft is transmitted to an alternator via a toothed belt, wherein the vehicle further comprises a battery for supplying electrical systems to the vehicle and a battery charge sensor, the alternator being controlled by an ECU capable of facilitating mechanical coupling between the alternator and the toothed belt and facilitating electrical coupling between the alternator and the battery by applying action to a pulley, wherein the ECU receives a signal from the battery charge sensor so as to: - Determine the battery charge level from BC1 (corresponding to the battery's fully charged state), BC2 (corresponding to the working battery charge level), and BC3 (corresponding to the low battery charge level); And so that it can act on the alternator such that: - At BC1 level, the alternator remains electrically and mechanically decoupled; - At BC3 level, the alternator remains electrically and mechanically coupled; and - At BC2 level, the alternator is mechanically coupled when the vehicle's displacement speed is greater than a predetermined VLim and when the ICE engine disengages for shifting; and electrically coupled when the vehicle is being driven in cut-off mode.

[0013] In addition, the system also includes mechanically and electrically decoupling the alternator when the engine speed is below a predetermined limit value RLim. Attached Figure Description

[0014] The invention will be better understood through a detailed description of preferred embodiments, which are supported and illustrated by the accompanying drawings. The drawings are provided for illustrative and guiding purposes only and do not limit the scope of the invention. In the drawings: - Figure 1 This is a schematic diagram of the mechanical coupling between the alternator pulley and the crankshaft pulley; - Figure 2 This is a schematic diagram of the power supply and control system of an alternator; - Figure 3 The diagram illustrates the operating parameters of the ICE as a function of the driving time of a vehicle equipped with a manual transmission, and includes a graph indicating the timing of battery charging; and - Figure 4 The diagram illustrates the operating parameters of the ICE depending on the driving time of a vehicle equipped with an automatic or automated transmission, and includes a graph indicating when to charge the battery. Detailed Implementation

[0015] According to the appendix Figure 1 and 2 The number 1 indicates an alternator that includes a housing 2 in a known manner, within which a rotor (not shown) and a stator (not shown) are housed. The relative rotational motion of the rotor and stator results in the generation of an electromagnetic field for producing electrical energy. Specifically, alternator 1 is an alternator (E / MC) with a selective mechanical coupling and electrical connection system (according to US 10247265). Generally, alternator 1 is an alternator capable of being coupled and / or decoupled from the vehicle's drive system and electrically connected / disconnected from the vehicle's electrical system independently of each other. Specifically, and as will be apparent to those skilled in the art, the advantages of the alternator described above are realized when mechanical coupling precedes electrical connection.

[0016] When the stator is fixedly mounted relative to the frame 2, the rotor occupies the central position of the alternator 1 and is supported in a freely rotatable manner about an axis 3 that protrudes beyond the volume defined by the frame 2 and is designed to receive the torque required to provide relative rotational motion between the rotor and the stator via pulley 4. It is also known that the belt 5 (typically a toothed belt) engages with both pulley 4 and pulley 6 of the crankshaft 7. It is also known that the belt 5 can engage with other mechanical devices, such as a tensioner 8 designed to maintain tension of the belt 5 within specific operating parameters, and guide pulleys, such as idler pulleys (not shown). Similarly, pulley 6 of the crankshaft 7 also drives other devices on the vehicle, such as pulley 28 of the power steering pump or pulley 9 of the air conditioning system via belt 29.

[0017] Regarding the electrical connections of the system (see...) Figure 2 Alternator 1 and battery 20 are electrically connected in parallel, and both are connected to supply the vehicle’s electrical loads 21, such as air conditioning system, radio, interior lights, exterior lights, etc.

[0018] In one embodiment, the battery 20 is further connected to a battery state of charge sensor 22, which has the ability to assess the charge stored in the battery cell and provides a signal indicating this charge to a control unit or ECU 23 via a data line 24.

[0019] Generally, the charge of battery 20 is determined by a system and / or apparatus for determining or detecting the charge of the battery. By way of example, and not limitation, the charge level of battery 20 may be detected or determined by an apparatus or system, such as those described in the applicant’s document WO 2017 / 027950, or documents US 8536872 or US 6674266.

[0020] In the specific case where alternator 1 is an alternator (E / MC), according to patent US 10247265, the mechanical coupling between the interference shaft 3 and pulley 4 is achieved by an electromagnetic clutch 10, which can couple and decouple shaft 3 relative to pulley 4. In this case, ECU 23 is still connected to alternator 1 via data line 25A and to clutch 10 via data line 25B, so as to be able to command the electrical behavior (connection or disconnection) of alternator 1 and the mechanical behavior of pulley 4 respectively. More specifically, in addition to the electrical connection with vehicle battery 20 and electrical load 21, alternator 1 also includes a logic connector (not shown), which interconnects alternator 1's voltage regulator (not shown) with ECU 23 via line 25A. It should be noted that, depending on the logic communication infrastructure of the vehicle in which this system is installed, lines 24 and / or 25A, 25B can be separate lines, or they can be part of a CAN network, an Ethernet network, or another network previously present in the vehicle.

[0021] Figure 3 The diagram illustrates a process flow according to the present invention, wherein the coupling and / or decoupling of the alternator 1 is a function of the combination of the charge level of the battery 20 and the driving state of the vehicle.

[0022] More specifically, the method of the present invention analyzes the battery charge level state and combines the battery charge level state with vehicle drive to indicate the appropriate timing for coupling or decoupling the alternator. The main focus of this method is to reduce fuel consumption and thus vehicle emissions. However, based on the claimed appropriate strategy, the driving feel of the vehicle can also be increased by selecting the optimal moment to couple and decouple the vehicle's alternator. In this way, alternator coupling can be controlled to avoid the inherent "vibration" caused by a sudden increase in load on the crankshaft of the vehicle's ICE. Specifically, this vibration can be defined as a sudden decrease in the vehicle's displacement velocity due to a sudden increase in load on the crankshaft.

[0023] Therefore, it is initially necessary to establish some operating levels for the battery (20), in which: -BC1: Corresponds to the battery's fully charged state - For example, a battery charge level greater than 99% relative to the total battery charge level can be defined as this fully charged level: -BC2: Corresponds to the working battery charge level, that is, the charge sufficient to drive the vehicle without risk of impairing the operation of the electrical system, even in a vehicle with several active electrical accessories, when the alternator cannot be used. For example, a battery charge level between 75% and 99% of the total battery charge level can be defined as this working charge level relative to the total battery charge level; and -BC3: Corresponds to a low battery charge level, that is, a battery charge level that is insufficient to maintain normal vehicle operation over the estimated time period. For example, a battery charge level that is less than 75% of the total battery charge level can be defined as this low charge level.

[0024] It must be emphasized that the battery charge level percentages defined for BC1, BC2, and BC3 are merely illustrative and not limiting. As any person skilled in the art can infer, the values ​​of the battery charge level percentages can vary depending on the total battery charge level and the amount and type of equipment that must be powered by the vehicle's powertrain.

[0025] Therefore, the system initially tests the battery charge level to define the behavior of alternator 1 (E / MS) when driving the vehicle.

[0026] Therefore, when sensor 22 detects that the battery charge level is at BC1, indicating that battery 20 is fully charged, there is no need to actuate alternator 1. In this case, pulley 4 remains mechanically decoupled from alternator 1, thereby reducing the load on crankshaft 7.

[0027] In the completely opposite state, i.e., battery 20 stores a small amount of charge (BC3 level), the system understands that the battery charge level must be restored, therefore alternator 1 is mechanically and electrically coupled, regardless of the vehicle's operating conditions. This behavior is selected in this way to prevent the battery from damaging the vehicle's electrical system power supply. This state is maintained until the battery charge level reaches at least the BC2 charge level. Specifically, Figure 3 The diagram shows that when the battery charge level (red curve) is below the “operating range” (BC2), the alternator remains mechanically and electrically coupled (blue line under level 1) until the battery charge level returns to the operating range.

[0028] Ultimately, and when the load sensor 22 indicates the load status within the BC2 level, this allows the system to properly manage the performance of the alternator 1 in order to coordinate battery recharging with fuel economy and reduction of pollutant emissions.

[0029] For this purpose, and as Figure 3 As specifically shown in the figure, this diagram illustrates an example where the parameters controlled by the system of the present invention are a function of the route taken by the vehicle, which can define the operating conditions of the present invention.

[0030] At time t = 0, the vehicle is shut off, and alternator 1 is electrically and mechanically decoupled from crankshaft 7. In this way, the engine is started (according to the gray line in the figure, the speed increases), and this starting is easy because the starter motor (not shown) does not need to move the alternator.

[0031] After starting the engine and before engaging first gear, the alternator remains mechanically decoupled from the crankshaft. The alternator remains decoupled as the driver begins to move the vehicle – specifically, see the black line in the diagram, which illustrates the vehicle's displacement speed. Speed ​​increases and gears are continuously shifted until the vehicle reaches its maximum speed VLim, for example, at [specific speed value]. Figure 3 The speed is indicated as 40 km / h. From this moment on, the system waits for the next gear shift, which is configured to activate the mechanical coupling of alternator 1. During the period when the driver activates the clutch pedal (disengages the vehicle) and performs a shift from the current gear to the next gear (which lasts for a few seconds), the system detects this situation and takes this opportunity to activate the mechanical coupling of alternator 1; the blue line indicates the mechanical coupling state of the alternator, where level 1 is for coupling and level 0 is for decoupling.

[0032] It should be noted that the limiting speed VLim is preferably a value that varies depending on the battery's "health status" (SoH) and / or the battery's charge level (SoC). In this way, a higher battery charge level allows for delayed coupling, which is reflected in the coupling that occurs at a higher speed Vlim; on the other hand, batteries that have been used for some time (with reduced charge storage capacity) require more constant coupling, which is reflected in the reduction of the limiting speed VLim.

[0033] At this particular moment, which, in combination with other moments, defines the essential characteristics of the invention, the driver of the vehicle will not perceive the mechanical coupling because it occurs when the engine is disengaged relative to the powertrain. The vehicle maintains its normal displacement through inertia, and the alternator coupling vibration is directed only towards the engine, but is undetectable by the vehicle or the driver.

[0034] Once this mechanical coupling of the alternator is performed, the system waits for a second opportunity to finally perform the electrical connection of the alternator. According to the invention, this opportunity refers to the moment when the vehicle is being driven in a disengaged state (the internal combustion engine rotation is maintained by the powertrain without the accelerator pedal being used), that is, when the vehicle is moving downwards along a downward path (acceleration is defined only by the component of gravity), when the engine is engaged (a gear is engaged and the clutch and accelerator pedal are not actuated), and when the engine is rotating at a certain speed (in rpm) above a certain limit. For example, and Figure 3 In the figure, the limit is defined as 1200 rpm.

[0035] Therefore, when the disconnected state is detected, the system takes this opportunity to perform electrical connection of alternator 1, that is, to rotate the alternator by the displacement of the vehicle in gear (sequence: wheels, gearbox, engine, alternator), so that the mechanical energy converted into electricity by the alternator comes only from the "inertial" displacement of the vehicle.

[0036] As those skilled in the art will understand, because fuel injection is prohibited in the cut-off state, this state allows battery 20 to be charged relative to fuel at "zero cost" and with zero pollution emissions. Figure 3 In the diagram, the red line indicates the time period when the alternator is charging the battery (level 1) and the time period when it is not charging battery 20 (level 0).

[0037] On the other hand, this form of battery charge is maintained as long as the cut-off state continues. The speed limit (rpm) defining this cut-off state depends primarily on the alternator 1, that is, on the minimum speed at which it causes significant electrical energy generation, and on the characteristics of the ICE that allow it to maintain operation within a certain speed range without fuel injection. In other words, for other vehicle systems (e.g., water pump, oil pump, air conditioning system, etc.) to function fully, the engine must be at a certain speed, in which case the speed must be maintained by the displacement of the vehicle.

[0038] In this way, once the engine speed drops below this functional limit (RLim), the system is used to mechanically and electrically decouple the alternator. Figure 3 In the diagram, the moment when the vehicle speed decreases from approximately 50 km / h to a complete stop (where t is approximately 120 seconds) can be identified. At a point on this curve in the diagram, at approximately 20 km / h, the engine speed drops below the minimum speed limit (RLim), thus facilitating the complete decoupling of alternator 1. When the vehicle resumes motion, the alternator is recoupled, first mechanically and then electrically, provided that the aforementioned conditions are met.

[0039] For vehicles equipped with automated transmissions, the proposed system performs identically because each gear shift is performed only after the driver has been instructed to do so via actuation of the gear lever. Alternatively, vehicles with automated transmission systems can follow the coupling procedure described below for vehicles with automated transmissions, since in these automated systems, clutch actuation is performed by the actuator commanded by the TCU, rather than by the driver.

[0040] In the case of a so-called automatic transmission engine, the coupling and decoupling states strictly adhere to the parameters described above. The essential difference in this case is that the TCU is the entity that manages each gear shift, and therefore, there must be communication (not shown) between the proposed system (i.e., between the processors responsible for managing the system of the present invention) and the TCU via a CAN network or similar means, such that the system of the present invention informs the TCU that coupling needs to be performed, wherein the TCU informs the system that the vehicle is disengaged.

[0041] Alternatively, Figure 4 The invention demonstrates the diverse possibilities for actuation of the system, namely, mechanical and electrical coupling in continuous time. This is possible provided that both the mechanical coupling state and the electrical coupling state (as described above) are satisfied, and based on the delay of the TCU's shift time (if necessary), since automatic shifting may require a very short time, thereby preventing or damaging the mechanical and / or electrical coupling of the alternator, as is known.

[0042] Alternatively, and even more advantageously, for both vehicles with automatic and automated transmissions, mechanical and electrical coupling can be performed already in the off state (checking the alternator's coupling status), and sequentially, for example, at intervals of a fraction of a second between each coupling. In this case, and while the TCU itself controls the transmission clutch (engagement time and duration), mechanical and electrical coupling can be compressed in a timely manner in the off state to reduce the rotational load of the alternator on the crankshaft (7) to its maximum.

[0043] According to tests conducted by the inventors, the systems and methods proposed in this invention can achieve a 3% to 4% reduction in fuel consumption, and thus a reduction in pollutant emissions, compared to vehicles whose alternators are of a conventional type (always mechanically and electrically coupled to the vehicle).

[0044] Among other things, this advantage stems from the following characteristics of the proposed system.

[0045] Initially, it may be possible to start the vehicle engine and begin moving the vehicle without a coupled alternator. This reduces the mechanical load on the engine, thereby reducing the need for injected fuel.

[0046] Shifting the battery charging period to a state where the vehicle is off allows the battery to charge without consuming any fuel, instead utilizing the geographical conditions of the displaced terrain.

[0047] The establishment of three battery charge levels (BC1, BC2, and BC3) and the corresponding specific operating procedures allow for safe vehicle operation without the risk of battery discharge, which could damage the vehicle's electrical system. It should be noted that, according to the system of the present invention, the vehicle system's power supply is primarily provided by the battery, unlike in conventional vehicles where it is provided by an alternator.

[0048] Another advantage of the proposed system is reduced engine load, for example, under conditions of higher electrical demand. Therefore, if the driver indicates an overtaking maneuver (accelerator pedal fully depressed and eventually downshifted), the alternator can be completely decoupled.

[0049] During periods of idling (e.g., when the vehicle is stationary or disengaged) and when the battery is charging while in operation, the alternator remains decoupled, which means that fuel consumption is significantly reduced (from 30% to 40%) under these conditions.

Claims

1. A management method of an automobile alternator, characterized by, The method includes the following steps: - The battery state of charge level is determined to be within the range of BC1, BC2, or BC3, wherein the BC1 range corresponds to the fully charged state of the battery when the battery state of charge is higher than a first predetermined threshold; the BC2 range corresponds to the working battery charge level when the battery state of charge is between the first predetermined threshold and a lower second predetermined threshold; and the BC3 range corresponds to the low battery charge level when the battery state of charge is lower than the second predetermined threshold. in: - Within the BC1 range, the alternator (1) remains electrically decoupled from the vehicle's electrical system and mechanically decoupled from the crankshaft of the vehicle's engine; - Within the BC3 range, the alternator (1) remains electrically and mechanically coupled; and Its features - Within the BC2 range, when the vehicle's displacement speed is greater than a predetermined value (VLim) and the vehicle engine is disengaged for shifting, the alternator (1) is mechanically coupled; and when the vehicle is driven in a cut-off mode, i.e., when the vehicle engine is engaged and the clutch and accelerator pedal are not actuated, the alternator (1) is electrically coupled.

2. The method according to claim 1, characterized in that, The method further includes the following steps: when the engine speed is lower than a predetermined limit value (RLim), mechanically and electrically decouple the alternator (1).

3. The method according to claim 1, characterized in that, The maximum speed (VLim) varies depending on the health condition of the battery and / or the amount of charge in the battery.

4. A management system for an automotive alternator, the management system being used to implement the method according to claim 1, characterized in that, The management system includes a vehicle equipped with an engine, wherein rotation of the crankshaft (7) is transmitted to the alternator (1) via a toothed belt (5), wherein the vehicle also includes a battery (20) for supplying the vehicle's electrical system and a battery charge sensor (22), wherein the alternator (1) is controlled by an ECU (23), which is capable of promoting mechanical coupling of the alternator (1) to the toothed belt (5) and electrical coupling of the alternator (1) to the battery (20) by applying an action to a pulley (4), wherein the ECU (23) receives a signal from the battery charge sensor (22) so that: - The battery state of charge level is determined to be within the range of BC1, BC2, or BC3, wherein the BC1 range corresponds to the fully charged state of the battery when the battery state of charge is above a first predetermined threshold; the BC2 range corresponds to the working battery charge level when the battery state of charge is between the first predetermined threshold and a lower second predetermined threshold; and the BC3 range corresponds to the low battery charge level when the battery state of charge is below the second predetermined threshold; and in order to apply an action to the alternator (1), in: - Within the BC1 range, the alternator (1) remains electrically decoupled from the vehicle's electrical system and mechanically decoupled from the crankshaft of the vehicle's engine; - Within the BC3 range, the alternator (1) remains electrically and mechanically coupled; and - Within the BC2 range, when the vehicle's displacement speed is greater than a predetermined value (VLim) and the vehicle engine is disengaged for shifting, the alternator (1) is mechanically coupled; and when the vehicle is being driven in a cut-off mode, i.e., when the vehicle engine is engaged and the clutch and accelerator pedal are not actuated, the alternator (1) is electrically coupled.

5. The system according to claim 4, characterized in that, When the engine speed is below a predetermined limit (RLim), the ECU (23) mechanically and electrically decouples the alternator (1).

6. The system according to claim 4, characterized in that, The maximum speed (VLim) varies depending on the health condition of the battery (20) and / or the amount of charge on the battery (20).

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