NL2023615B1

NL2023615B1 - Energy management system for a hybrid vehicle

Info

Publication number: NL2023615B1
Application number: NL2023615A
Authority: NL
Inventors: Theodorus Bernard Anna Kessels Johannes; Martinus Herman Wieland Albertus
Original assignee: Daf Trucks Nv
Priority date: 2019-08-07
Filing date: 2019-08-07
Publication date: 2021-02-16

Abstract

It is aimed to provide an energy management system for a hybrid vehicle comprising a hybrid electric powertrain consisting of a fuel combustion engine and an electric motor powered by a battery, said energy management system comprising a state of charge (SOC) setpoint controller, said SOC setpoint controller arranged to set the SOC setpoint to control a state of charge (SOC) of the (energy storage) battery said motor energy supply management system arranged for e-mode driving wherein the energy management system switches to electric power supply to the electric motor, independent of the SOC setpoint; wherein said SOC setpoint controller is arranged to calculating the SOC setpoint in a minimizing operation, wherein an inputted distance range data value is used as a minimum constraint value.

Description

P121923NL00 Title: Energy management system for a hybrid vehicle Field of invention The invention relates to a battery control device.

The invention also relates to a method of controlling a setpoint for a state of charge in a battery for a vehicle.

The invention further relates to a computer program product for putting into effect the method.

Description of the prior art Recently hybrid vehicles are becoming mainstream solutions to counter the emission effects of combustion engines, in particular in densely populated areas.

Even more so, hybrid vehicles, i.e. vehicles that are able to drive both electrically and by a combustion engine, are required to drive in e-mode (that is: all electric) in zones that are designated as emission free zones.

It 1s expected that such regulation may become a norm in for instance city centers or other places where air pollution is not acceptable.

In these areas, it is important to manage the state of charge of the battery, since it is undesired that the battery runs out of energy before reaching the end of the emission-free zone.

The driver will typically want to be on the safe side with available electrical power and will aim to keep the battery loaded.

However, this creates an efficiency problem and a lifetime problem since this implies that the electrical power stored in the battery is not optimally used.

There is thus an aim to maximize energy recovery and/or battery lifetime optimization and simultaneously respecting the required electric-driving range.

Summary of the invention In one aspect, it 1s aimed to provide an energy management system for a hybrid vehicle comprising a hybrid electric powertrain of a fuel combustion engine and an electric motor powered by an electric battery, said energy management system comprising a state of charge (SOC) setpoint controller, said SOC setpoint controller arranged to set the SOC setpoint to control a state of charge (SOC) of the electric battery; wherein, when the SOC setpoint controller detects a SOC below a SOC setpoint, the energy management system switches to fuel supply to the fuel combustion engine to keep the battery in a minimum preset charge; and wherein, when the SOC setpoint controller detects the SOC above the SOC setpoint, the energy management system switches to electric power supply to the electric motor; said motor energy supply management system further arranged for e-mode driving wherein the energy management system switches to electric power supply to the electric motor, independent of the SOC setpoint; wherein the energy management system further comprises; a data port for receiving a distance range data value for e-mode driving; wherein said SOC setpoint controller of the battery management system is coupled to the data port for receiving the distance range data value; said SOC setpoint controller arranged to calculating the SOC setpoint in a minimizing operation, wherein the distance range data value is used as a minimum constraint value.

In this way an electric driving distance range may be pre-set while at the same time maximizing energy recovery and/or battery lifetime optimization. A driver will no longer need to fully charge the battery when entering a zero-emission zone, as long as the pre-set distance range is received by the SOC setpoint controller so that the SOC setpoint controller may calculate the SOC setpoint based on the distance range data value used as a minimum constraint value. Current available automatic systems typically focus on maximum possible electric-driving range, this however limits the maximum amount of energy that can be recovered, e.g. from braking energy recovery or other recovery systems and also limits battery life time since a highly charged state is undesirable for battery life time. Recharging may also consume valuable time or energy by charging the battery at times when this is not necessary, as battery charging can be postponed after exiting the zero-emission zone, for instance, until when a driver reaches his final destination and low-cost efficient charging from the grid is available. By setting the required distance for e-mode driving, the energy management system will always keep the energy reserve available for the required distance to drive without the driver having to worry about recharging the batteries on time for so called last mile electric driving (emission free city centers).

BRIEF DESCRIPTION OF THE DRAWINGS The invention will be further elucidated in the figures: Figure 1 shows a conventional energy management system wherein a SOC setpoint controller has a fixed setpoint; Figure 2 shows an enhanced energy management system wherein a SOC setpoint controller has a controlled setpoint e.g. based on driver input; Figure 3 shows a further enhanced energy management system.

DETAILED DESCRIPTION Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs as read in the context of the description and drawings. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein. In some instances, detailed descriptions of well-known devices and methods may be omitted so as not to obscure the description of the present systems and methods. Terminology used for describing particular embodiments is not intended to be limiting of the invention. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The term "and/or" includes any and all combinations of one or more of the associated listed items. It will be further understood that the terms "comprises" and/or "comprising" specify the presence of stated features but do not preclude the presence or addition of one or more other features. All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control.

The term “circuit” is used in a conventional way to signify any structural hardware or software arrangement having a capability of executing program logic in order to provide a certain basic function. A skilled person is typically aware of how to operate or implement a circuit in the context of the description, with processor elements elucidated here below. The term “program logic” is used in a conventional way to signify the operating instructions, which may be embodied in hard-or software structures, that control a circuit to the designated functional behavior.

The term “signal line” is used in a conventional way to signify an information exchanged, which may be in the form of coded signals, in analog or digital fashion by any conventional communication device, where it is not excluded that other signal lines are available, but merely to signify that a certain connectivity is available. This may also indicate indirect connectivity, that is, a signal line may be provided by indirect signaling, for example, via another functional device.

The term “module” as in “storage module” or “receiver module” or “control module” is used to emphasize the modular character of these units, i.e. the functionality of the system may be separated into independent, interchangeable units. The term “user interface” may comprise one or more 5 hardware elements configured to perform operational acts in accordance with the present systems and methods, such as to provide control signals to the various other module components. The processor may be a dedicated processor for performing in accordance with the present system or may be a general-purpose processor wherein only one of many functions operate for performing in accordance with the present system. The processor may operate utilizing a program portion, multiple program segments, or may be a hardware device utilizing a dedicated or multi-purpose integrated circuit. Any type of processor may be used such as a dedicated or shared one. The processor may include micro-controllers, central processing units (CPUs), digital signal processors (DSPs), ASICs, or any other processor(s) or controller(s) such as digital optical devices, or analog electrical circuits that perform the same functions, and employ electronic techniques and architecture. The controller or processor may further comprise a memory that may be part of or operationally coupled to the controller. The memory may be any suitable type of memory where data is stored. Any medium known or developed that can store and/or transmit information suitable for use with the present systems and methods may be used as a memory. The memory may also store user preferences and/or application data accessible by the controller for configuring it to perform operational acts in accordance with the present systems and methods.

While example embodiments are shown for systems and methods, also alternative ways may be envisaged by those skilled in the art having the benefit of the present disclosure for achieving a similar function and result. E.g. some components may be combined or split up into one or more alternative components.

Finally, these embodiments are intended to be merely illustrative of the present system and should not be construed as limiting the appended claims to any particular embodiment or group of embodiments.

Thus, while the present system has been described in particular detail with reference to specific exemplary embodiments thereof, it should also be appreciated that numerous modifications and alternative embodiments may be devised by those having ordinary skill in the art without departing from the scope of the present systems and methods as set forth in the claims that follow.

The specification and drawings are accordingly to be regarded in an illustrative manner and are not intended to Limit the scope of the appended claims.

Turning to Figure 1 there is disclosed a conventional energy management system wherein a SOC setpoint controller has a fixed setpoint.

In such a system energy management system 100 for a hybrid vehicle 200 comprising a hybrid electric powertrain of a fuel combustion engine 300 and an electric motor 400 powered by an electric battery 500. The energy management system 100 has a state of charge (SOC) setpoint controller 600 that in this case controls the battery to a fixed setpoint for a state of charge (SOC) of the electric battery.

When the energy management system 100 receives from the SOC setpoint controller 600 an SOC setpoint which is higher than the actual SOC received from the battery 500, the energy management system 100 switches to power from the combustion engine 300. The energy management system 100 will bring the SOC of the battery 500 to the requested setpoint from the SOC setpoint controller 600. Next, the energy management system 100 secures that the actual SOC of the battery 500 will be maintained at a value which is at least equal or possibly higher than the requested setpoint from setpoint controller 600. This setpoint can be a value that is zero, or any other pre-set value.

When the energy management system 100 detects that the SOC of battery 500 is above the SOC setpoint, the energy management system 100 switches to electric power supply, from the battery 500 to the electric motor 400 and the combustion engine can be brought to a low power state, e.g. switched off.

The battery 500 may be charged by regeneration mechanisms that convert e.g. mechanical energy in the e-motor 400 to electrical energy provided to the battery 500 but also may be optionally charged by off board chargers, e.g. a plugin 700.

Figure 2 shows an enhanced energy management system wherein an SOC setpoint controller has a controlled setpoint e.g. based on driver input. Accordingly the setpoint is now variable, to which end a data port 610, 620 is available to the SOC setpoint controller 600, for receiving a distance range data value for e-mode driving and wherein said SOC setpoint controller 600 is arranged to calculating the SOC setpoint in a minimizing operation wherein the distance range data value is used as a minimum constraint value. An example of a minimizing operation is calculating the amount of electrical energy necessary for driving the distance range data value and keeping that as a new SOC setpoint for the energy management module 100. The minimizing operation may include other operations, such as calculating the amount of electrical energy based on preset estimations, or on actual data measurement, such as an heuristic calculation, that averages from a historic data collection 630 the amounts of energy needed for previously recorded distance ranges or from distance ranges associated with road profile information from GPS data 640.

The data port 610 1s associated with an input device 611 that receives the distance range data value as an input value input by a driver and to supply the distance range data value to data port for receiving the distance range data value. The data value may be input manually, verbally, or transmitted wirelessly or in any other suitable way of inputting the distance range and may be a momentary desired value by a truck driver, or may be an adjustable preset value, e.g. by a fleet owner.

The battery 500 of the hybrid electric vehicle 200 is thus controlled by receiving, by at least one SOC setpoint controller 600, an indication of desired electric driving range and generating, by the SOC setpoint controller 600, a minimum required energy storage level (state of charge setpoint) for the battery 500 i.e. a rechargeable electric energy source.

The data port 620 1s associated with a GPS controller 621 that may calculate a desired distance range data value dependent on a calculated travel route or destination.

The benefits of such input ports 610, 620 being available is that vehicle energy efficiency and battery lifetime is optimized, since the variable setpoint enables battery 500 to operate at a lower state of charge setpoint than a fixed preset setpoint.

This makes the battery 500 better available for regeneration purposes, i.e. regeneration of electrical energy from mechanical energy, e.g. brake energy, saving energy, while at the same time keeping available a minimum driving distance range, to enable a driver to continue driving in e-mode driving independent of the SOC setpoint, e.g. when in an emission free driving area.

Also, this may release the (cheaper/regenerated) electrical energy from battery 500 almost completely before arriving at a charging station, without a prior need to recharge the battery 500 with more expensive electrical energy, e.g. by fuel conversion.

In this basic embodiment an e-drive driving range value 1s received, e.g. for an entire trip.

The vehicle model of this basic algorithm does not necessarily rely on additional preview information, e.g. no forecast is made about the traffic situation nor environmental conditions.

Contrary to the embodiment shown in Figure 3 the e-drive driving range value may remain fixed for the entire route.

A basic vehicle model may be used to calculate the required SOC setpoint.

Figure 3 shows a further enhanced energy management system 100 wherein the state of charge setpoint controller 600 is provided with additional data that enables SOC setpoint controller 600 to further calculate the SOC setpoint as a function of e.g. an actual physical location, e.g. determined by GPS data of GPS controller 621 and enhanced physical location controller 640. Thus the setpoint controller 600 may control the setpoint in accordance with GPS data of a terrain, e.g. from road profile information controller 660, and thus take into account the extra or lesser amount of electrical power required, when driving along a preset route, wherein the physical location controller 640 may provide an electrical energy consumption parameter tied to a physical location. In another aspect, a vehicle state controller 650 may determine an actual vehicle state, that is supplied to the SOC setpoint controller 600; the actual vehicle state including parameters that influence the actual energy consumption of the battery. These may include the ambient temperature, weight of the vehicle, payload of the vehicle, and vehicle configuration (amount of tyres axles etc) but also may include an energy budget of additional non-motor electrical utilities (e-auxiliaries, e-power take off). Thus, the energy management system 100 may control additional electric power supply for powering additional non-motor electrical utilities such as an air conditioner, cooler heater, or other electrical devices. When determining the vehicle state by vehicle state controller 650, the SOC setpoint controller 600 may instruct the vehicle state controller 650, when the SOC setpoint controller detects a SOC below the SOC setpoint, to power down the additional electric power supply.

FURTHER EMBODIMENTS In further embodiments state of charge setpoint controller 600 collects information from multiple inputs about the desired electric driving range.

These inputs can include driver operated dashboard buttons / steering wheel logics or driver routing programs wherein e-drive distance range data value may be associated for a specific trip or multiple trips during that day/week/month/year.

Further inputs to the enhanced physical location controller can be provided e.g. by a battery state controller 680, that measures a battery state 680, e.g. size, temperature capacity, chemistry and/or kWh available.

For example: o Driver programs may provide additional parameters that provide insight in expected vehicle energy consumption (kWh/km). Some examples are urban/highway road; hilly/flat environment. o Feedback by means of driver information display (covering historical data, see explanation below) o Default e-drive distance range data value as well as (kWh/km) values (for propulsion and optionally for PTO application) may be programmed; this may be done remotely by a backend system, e.g. owned by a fleet owner o Such back end programs may provide e-drive distance range data values depending on the planned route along the day/week/month.

Also the availability of plug-in charging after an e-drive operation may be taken into account (e.g. by controller 670). To maximize benefit from plug-in, the hybrid truck should not recharge the battery in case a plug-in charging moment is foreseen after e-drive. o Backend programs may also provide key performance indicators for the planned route: average energy consumption for propulsion (kWh/km) and average energy consumption for PTO (kWh/km). These values may be calculated by the back office from fleet data and input by back office input 635.

History data collection 630 may support a driver in programming an optimal e-drive distance range, e.g. a driver may receive advice on how well the input e-drive distance range matches with an expected required e- range.

A driver may receive feedback on the optimality of the programmed e-range distance.

After a trip, checkmarks may be shown to the driver (e.g. ranging from v to vvv’) on how well the programmed e-range matched the real required e-range.

Energy consumption histogram The vehicle may record information on actual energy consumption and may visualize from this information a histogram.

This histogram may provide the driver and back-office insight in the historical/average consumed energy for electric driving per trip/day/week/month/year.

A histogram is available for the total energy request (kWh/km) as well as the energy request for the propulsion part (kWh/km) and the PTO part (kWh/km). For advanced data analysis, the information in the histogram is augmented by extra measurement values (vehicle parameters, traffic conditions, GPS location and environmental aspects). SOC setpoint controller 600 may execute an algorithm for translating a requested e-drive distance range into an actual SOC setpoint.

To this, a vehicle model may be used by a physical location controller 640 to estimate the required battery energy (kWh) for the requested e-range.

Many information sources which provide insight in the actual energy consumption of the vehicle may be used here: - Static vehicle parameters (vehicle weight, number of axles; tyres; aero parameters) - Dynamic vehicle parameters (directly measured by sensors, like temperature; or indirectly measured by state estimators, like payload)

- Historical data on vehicle energy consumption (kWh/km) - Power consumption of electrified auxiliaries (in particular cabin climate and Electric Power Take Off consume substantial power which needs to be taken into account) A further enhancement may include an e-drive distance range request via port 610 to SOC setpoint controller 600, which depends on the actual GPS position of the planned route, as e.g. received from GPS controller 621 via port 620. For example starting with a relative high value, and decreasing to zero when driving to a plug-in charging station. This means that the advanced version of the algorithm provides an SOC setpoint which depends on the actual GPS position of the vehicle. Moreover, the advanced version further improves the accuracy of the requires battery energy by calculating a forecast on the expected traffic and environmental conditions. Altogether, the advanced algorithm may comprise following steps: Step 1: The algorithm receives the requested e-range for each part of the trip. Also information about plug-in charging opportunities is included here.

Step 2: Based on actual traffic and environmental data, the algorithm prepares a forecast on vehicle parameters (planned pay-load), traffic conditions (free flow or conjected traffic) and environmental aspects (ambient temperature, expected wind & rain) for each part of the trip.

Step 3: The algorithm calculates an accurate prediction of the vehicle energy consumption (kWh for each part of the trip) using a vehicle model with parameters mentioned above.

Step 4: The algorithm sends the energy consumption (kWh) as a sequence depending on GPS location to the vehicle energy manager.

Claims

Conclusions

A hybrid vehicle energy management system comprising a hybrid electric powertrain of a combustion engine and an electric motor powered by an electric battery, the energy management system comprising a state of charge controller (SOC), which SOC setpoint controller is configured to Set SOC set point to control a state of charge (SOC) of the electric battery; wherein, when the power management system 100 receives from the SOC setpoint controller 600 a SOC setpoint higher than an actual SOC, power management system 100 switches to fuel supply to the combustion engine to maintain the battery in a minimum preset charge; and wherein when the power management system 100 receives from the SOC setpoint controller 600 an SOC setpoint that is lower than an actual SOC, the power management system 100 switches to electrical power to the electric motor; - wherein the energy management system is further arranged for e-mode driving, wherein the energy management system switches the electric motor to electric power supply, independent of the SOC set point; wherein the SOC setpoint controller further comprises; - a data port for receiving a distance range data value for e-mode driving; and wherein - said SOC setpoint controller is arranged to calculate the SOC setpoint in a minimize operation, using the remote range data value as a minimum constraint value.

The power management system of claim 1, further comprising a driving route calculator arranged to provide the distance range data value to a gate for receiving the distance range designated to e-mode driving when a user has programmed a route in the driving route calculator. .

The power management system of any preceding claim, further comprising an input device configured to receive the remote range data value as an input value entered by a user and to provide the remote range data value to a data port to receive the remote range data value.

The energy management system of any preceding claim, further configured to manage additional electrical power supply to provide additional non-motor electrical supplies such as an air conditioner, cooler, heater or other electrical appliances, wherein when the SOC setpoint controller has a SOC below the SOC set point, which is calculated in the minimize operation, to turn off the additional electrical power supply.

The power management system of any preceding claim, wherein the SOC set point controller further calculates the SOC set point as a function of a current physical location determined by a physical location controller.

The energy management system of any preceding claim, wherein the SOC set point controller further calculates the SOC set point as a function of an actual vehicle status determined by a vehicle status controller including an indication of ambient temperature, weather conditions, vehicle weight, vehicle load capacity. vehicle, vehicle configuration, rolling resistance, air resistance, expected vehicle speed, expected insertion time, expected GPS trajectory, expected locations of green zones, expected locations for insertion charging stations, expected road type, expected road conditions or other characteristics related to road characterization and the charging station; indication of usable energy capacity of rechargeable energy source, data on charging and discharging power capabilities of energy rechargeable energy source, efficiency data for charging / discharging of rechargeable energy source, temperature of rechargeable energy source or other characteristics related to the characterization of the rechargeable energy source.

The energy management system of claim 6, further configured to control an energy budget of additional non-motor electrical supplies, including any of an electrical control system, electrical air compressor, cabin heating / cooling system, pumps and fans of a vehicle thermal system, or energy consumption of other ancillary equipment that also address optional electrical loads for specific vehicle purposes, such as refrigerated transport refrigeration unit and waste collection units.

The power management system of any preceding claim, wherein the SOC setpoint controller further calculates the SOC setpoint as a function of historical setpoint values stored in a history database.

The energy management system of claim 8, wherein historical set points are based on historical data for the vehicle, historical data for trailer, historical data for the driver of the vehicle, historical data for other drivers, or historical data for other vehicles or trailer.

A hybrid vehicle power management method comprising a hybrid electric powertrain of a combustion engine and an electric motor powered by an electric battery, comprising: setting a state of charge (SOC) set point to a state of charge (SOC) of the electric battery. to arrange; wherein], when a SOC setpoint higher than an actual SOC is received, fuel is supplied to the combustion engine to keep the battery at a minimum preset charge; and wherein, when a SOC setpoint lower than an actual SOC is received, electrical power is supplied to the trolling motor; which method further comprises the steps of

- receive a distance range data value for driving e-mode in which mode electrical power is supplied to the electric motor, independent of the SOC setpoint; and - calculate the SOC setpoint in a minimize operation, using the remote range data value as a minimum constraint value.

A computer program product with computer program logic configured to run on a data logging system comprising a control module, a storage and a plurality of data sources registered in the control module and arranged to perform the method of claim 10.