Series-parallel hybrid chemical battery system

Abstract

In an exemplary embodiment, a system for controlling power transfer includes a propulsion battery assembly configured to power an electric motor of a vehicle, the propulsion battery assembly having a first chemical, and a supplemental battery assembly selectively connected to the propulsion battery assembly, the supplemental battery assembly having a second chemical, the supplemental battery assembly has a second chemical different from the first chemical. The system also includes a controller configured to selectively connect the supplemental battery assembly to perform at least one of providing charge to the propulsion battery assembly and supplying electrical power to the electric motor.

Description

Technical Field

[0001] The present invention relates to the storage and delivery of energy or power and, more particularly, to systems including multiple battery chemistries and methods for controlling the operation of multi-chemistry energy storage systems. Background Art

[0002] Vehicles, including gasoline and diesel powered vehicles, as well as electric and hybrid electric vehicles, have battery storage devices for purposes such as powering electric motors, electronic devices, and other vehicle subsystems. Battery systems provide power to a variety of loads, including electric motors for propulsion, accessories, and components such as power control modules, heaters, and cooling systems. It would be desirable to provide systems that can improve energy storage for purposes such as increasing range and improving vehicle performance. Summary of the invention

[0003] In an exemplary embodiment, a system for controlling power transmission includes a propulsion battery assembly configured to supply power to an electric motor of a vehicle, the propulsion battery assembly having a first chemistry, and a supplemental battery assembly selectively connected to the propulsion battery assembly, the supplemental battery assembly having a second chemistry different from the first chemistry. The system also includes a controller configured to selectively connect the supplemental battery assembly to perform at least one of providing a charge to the propulsion battery assembly and supplying electric power to the electric motor.

[0004] In addition to one or more features described herein, the system includes a third battery assembly including battery cells having a third chemistry different than the first chemistry and the second chemistry, the battery cells connected in series to the propulsion battery assembly.

[0005] In addition to one or more features described herein, the supplemental battery assembly is a high energy battery assembly having an energy density greater than an energy density of the propulsion battery assembly.

[0006] In addition to one or more features described herein, the system includes a DC-DC converter connected in parallel to the propulsion battery assembly and the supplemental battery assembly, the DC-DC converter configured to regulate an output voltage of the supplemental battery assembly.

[0007] In addition to one or more features described herein, the controller is configured to connect the supplemental battery assembly in series with the propulsion battery assembly and provide charge to the propulsion battery assembly via the DC-DC converter during vehicle propulsion to extend the vehicle's driving range.

[0008] In addition to one or more features described herein, the controller is configured to connect the supplemental battery assembly based on the state of charge (SOC) of the propulsion battery assembly being below a SOC threshold and provide charge to maintain the SOC of the propulsion battery assembly at or above the SOC threshold.

[0009] In addition to one or more features described herein, the controller is configured to connect the supplemental battery assembly in parallel to the propulsion battery assembly and provide electrical power to the electric motor through the DC-DC converter, with the electrical power bypassing the propulsion battery assembly.

[0010] In addition to one or more features described herein, the vehicle is configured to be connected to a power source for charging the propulsion battery assembly, and the controller is configured to control the charging process to preferentially provide charging power to the propulsion battery assembly.

[0011] In addition to one or more features described herein, the charging process includes providing an amount of power to charge the propulsion battery assembly to a desired SOC and providing a remaining amount of power to charge the supplemental battery assembly.

[0012] In addition to one or more features described herein, the controller is configured to control the charging process based on a predictive control method that includes predicting a state of charge of the propulsion battery assembly and the supplemental battery assembly based on a quasi-steady-state model.

[0013] In another exemplary embodiment, a method of controlling power transfer includes monitoring, by a controller, a propulsion system of a vehicle, the propulsion system connected to a hybrid chemistry battery system, the hybrid chemistry battery system including a propulsion battery assembly configured to power an electric motor of the propulsion system, and a supplemental battery assembly selectively connected to the propulsion battery assembly, the propulsion battery assembly having a first chemistry and the supplemental battery assembly having a second chemistry different from the first chemistry. The method also includes, based on receiving a request for additional propulsion, connecting the supplemental battery assembly and supplying additional power to the electric motor, and based on a state of charge (SOC) of the propulsion battery assembly being below a SOC threshold, providing charge from the supplemental battery assembly to the propulsion battery assembly.

[0014] In addition to one or more features described herein, the hybrid chemistry battery system includes a third battery assembly including battery cells having a third chemistry different than the first chemistry and the second chemistry connected in series to the propulsion battery assembly.

[0015] In addition to one or more features described herein, the supplemental battery assembly is a high energy battery assembly having an energy density greater than an energy density of the propulsion battery assembly.

[0016] In addition to one or more features described herein, the hybrid chemistry battery system includes a DC-DC converter connected in parallel to the propulsion battery assembly and the supplemental battery assembly, the DC-DC converter configured to regulate an output voltage of the supplemental battery assembly.

[0017] In addition to one or more features described herein, providing charge to the propulsion battery assembly includes connecting the supplemental battery assembly in series to the propulsion battery assembly and providing charge to the propulsion battery assembly via a DC-DC converter during vehicle propulsion to extend the range of the vehicle.

[0018] In addition to one or more features described herein, supplying additional power includes connecting a supplemental battery assembly in parallel to the propulsion battery assembly and providing electrical power to the electric motor through a DC-DC converter, the electrical power bypassing the propulsion battery assembly.

[0019] In yet another exemplary embodiment, a vehicle system includes a memory having computer-readable instructions and a processing device for executing the computer-readable instructions, the computer-readable instructions controlling the processing device to perform a method. The method includes monitoring a propulsion system of a vehicle by a controller, the propulsion system connected to a hybrid chemistry battery system, the hybrid chemistry battery system including a propulsion battery assembly configured to power an electric motor of the propulsion system, and a supplemental battery assembly selectively connected to the propulsion battery assembly, the propulsion battery assembly having a first chemistry, the supplemental battery assembly having a second chemistry different from the first chemistry. The method also includes, based on receiving a request for additional propulsion, connecting the supplemental battery assembly and supplying additional power to the electric motor, and based on a state of charge (SOC) of the propulsion battery assembly being below an SOC threshold, providing charge from the supplemental battery assembly to the propulsion battery assembly.

[0020] In addition to one or more features described herein, the hybrid chemistry battery system includes a third battery assembly including battery cells having a third chemistry different than the first chemistry and the second chemistry connected in series to the propulsion battery assembly.

[0021] In addition to one or more features described herein, the supplemental battery assembly is a high energy battery assembly having an energy density greater than an energy density of the propulsion battery assembly.

[0022] In addition to one or more features described herein, the hybrid chemistry battery system includes a DC-DC converter connected in parallel to the propulsion battery assembly and the supplemental battery assembly, the DC-DC converter configured to regulate an output voltage of the supplemental battery assembly.

[0023] The above features and advantages and other features and advantages of the present disclosure will become apparent from the following detailed description when taken in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Other features, advantages and details appear, by way of example only, in the following detailed description, which refers to the accompanying drawings, in which:

[0025] Figure 1 is a top view of a motor vehicle including a hybrid chemistry battery system including battery assemblies having different chemistries according to an exemplary embodiment;

[0026] Figure 2 depicts a hybrid chemistry battery system connected to a vehicle propulsion system according to an exemplary embodiment;

[0027] Figure 3A and 3B depicts operating states of a hybrid chemistry battery system according to an exemplary embodiment;

[0028] Figure 4 is a flow chart describing aspects of a method of controlling power transfer between battery systems during vehicle operation according to an exemplary embodiment;

[0029] Figure 5 Schematically illustrates components of a hybrid chemistry battery system according to an exemplary embodiment and depicts aspects of a charging method;

[0030] Figure 6 is a flow chart depicting aspects of a method of charging one or more components of a hybrid chemistry battery system according to an exemplary embodiment;

[0031] Figure 7 depicts an example of a battery assembly including battery cells having different chemistries according to an exemplary embodiment; and

[0032] Figure 8 A computer system according to an exemplary embodiment is depicted. DETAILED DESCRIPTION

[0033] The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application or use. It should be understood that in all figures, corresponding reference numerals represent the same or corresponding parts and features. As used herein, the term module refers to a processing circuit, which may include an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated or group) and memory that executes one or more software or firmware programs, a combinational logic circuit and / or other suitable components that provide the described functions.

[0034] According to exemplary embodiments, methods, devices, and systems for energy storage and / or energy transmission using a battery system having multiple chemistries are provided. An embodiment of a hybrid chemistry battery system for a vehicle includes a propulsion battery system having a first chemistry (e.g., lithium iron phosphate or LFP) and a supplemental battery system having a second chemistry. For example, the supplemental battery system includes a high energy density (compared to the propulsion battery system) battery assembly, such as a lithium metal battery (LMB) chemistry. The supplemental battery system is selectively connected in parallel to the propulsion battery system and is operable to perform functions such as providing additional power to the vehicle propulsion system and extending the vehicle's range.

[0035] In an embodiment, a propulsion battery system (e.g., one or more high voltage battery packs) is connected in series to a third battery system having a different chemistry than the propulsion battery system. For example, the third battery system includes one or more battery cells or modules having a nickel manganese cobalt (NCM) chemistry. Benefits provided by the third battery system include increased overall energy density, improved low temperature performance, and improved estimation of the state of charge of the propulsion battery system (e.g., LFP battery).

[0036] Embodiments also include systems and methods for controlling charging of components of a hybrid chemistry battery system. In an embodiment, a system includes a controller configured to control a charging process. The charging process distributes charge to a battery system based on a predictive control method that utilizes a model of the battery system to predict the state of charge and / or other parameters and controls the charging current to apply the charging current at an optimal level that improves or maximizes charging efficiency under selected constraints.

[0037] The embodiments described herein present numerous advantages and technical effects. These embodiments provide efficient use of advanced high energy density batteries to supplement existing battery storage devices and improve vehicle performance and range. These embodiments utilize the advantages of different chemistries to improve overall performance.

[0038] For example, lithium-based battery cells such as LFP cells are low cost and have relatively high cycle life, but have relatively low energy density and are affected by low temperatures. Lithium metal battery cells such as NCM battery cells or other advanced battery chemistries have relatively high energy density but generally have shorter life cycles and lower charging performance (e.g., charging rate) compared to typical propulsion battery chemistries. Embodiments address these limitations by combining battery chemistries to improve overall energy density, cycle life, and charging performance.

[0039] Furthermore, estimating the state of charge (SOC) of LFP battery cells is also challenging. Including a third battery system connected in series as described herein can significantly improve the ability to accurately estimate SOC.

[0040] Embodiments are not limited to use with any particular vehicle and may be applicable in a variety of environments. For example, embodiments may be used with automobiles, trucks, aircraft, construction equipment, farm equipment, automated factory equipment, and / or any other equipment or system for which additional thermal control may be required to augment existing thermal control capabilities or features of the equipment or system.

[0041] Figure 1 An embodiment of a motor vehicle 10 is shown that includes a body 12 that at least partially defines an occupant compartment 14. The body 12 also supports various vehicle subsystems, including a propulsion system 16 and other subsystems to support the functions of the propulsion system 16 and other vehicle components, such as a braking subsystem, a suspension system, a steering subsystem, and if the vehicle is a hybrid electric vehicle, a fuel injection subsystem, an exhaust subsystem, etc.

[0042] The vehicle 10 may be an electric vehicle (EV), a hybrid vehicle, or any other vehicle. In an embodiment, the vehicle 10 is an electric vehicle that includes one or more motors and one or more drive systems. For example, the propulsion system 16 is a multi-drive system that includes a first drive unit 20 and a second drive unit 30. The first drive unit 20 includes a first electric motor 22 and a first inverter 24, as well as other components such as a cooling system 26. The second drive unit 30 includes a second electric motor 32 and a second inverter 34, as well as other components such as a cooling system 36. Inverters 24 and 34 (e.g., traction power inverter units or TPIMs) each convert direct current (DC) power from a high voltage (HV) battery system into multi-phase (e.g., two-phase, three-phase, six-phase, etc.) alternating current (AC) power to drive motors 22 and 32.

[0043] In propulsion system 16, drive unit 20 and drive unit 30 are electrically connected to a hybrid chemistry battery system 40. Battery system 40 or components thereof may be configured as a rechargeable energy storage system (RESS).

[0044] The hybrid chemistry battery system 40 includes one or more battery assemblies. For example, the battery system 40 includes one or more high voltage battery packs, such as a first battery pack 44 connected to the inverter 24 and a second battery pack 46 connected to the inverter 34. The battery packs 44 and 46 (and associated components such as a RESS or battery management system (BMS) controller) are the primary power source for the propulsion system 16 and are referred to as a propulsion battery system.

[0045] The battery pack 44 includes a plurality of battery modules 48 and the battery pack 46 includes a plurality of battery modules 50. Each module 48, 50 includes a plurality of individual battery cells (not shown). In an embodiment, the battery packs 44 and 46 can be charged independently and can be used to independently provide power for propulsion, power supply and / or charging.

[0046] Each battery module 48, 50 includes a plurality of battery cells (not shown) having a selected chemistry. In an embodiment, each battery cell is a lithium-ion battery, such as a lithium iron phosphate (LFP) battery. The battery packs 44 and 46 are not limited thereto and may have any suitable chemistry. Other examples include nickel metal hydride and lead acid chemistries.

[0047] The hybrid chemical battery system 40 can be configured to provide different output voltage levels. For example, a battery switching device 52 is included to selectively connect the battery pack 44 in series to the battery pack 46 to provide a relatively high voltage. The battery switching device 52 can also be operated to connect the battery packs in parallel to provide a relatively low voltage.

[0048] The vehicle 10 includes a plurality of additional battery components (e.g., one or more additional battery cells, modules, battery packs, etc.). In an embodiment, the hybrid chemistry battery system 40 includes a supplemental battery system 60 that is connected in parallel or selectively connectable to the battery packs 44 and 46. The supplemental battery system 60 is provided to supplement the battery packs 44 and 46, for example, by providing additional power to the propulsion system 16 and / or providing energy to the battery packs 44 and / or 46 to increase the range of the vehicle 10. The supplemental battery system 60 includes at least one supplemental battery pack 62, which may have the same rated voltage as the battery packs 44 and 46 (e.g., 400V), but is not limited thereto.

[0049] The supplemental battery pack 62 is connected to the battery system 40 via a conversion device, such as a DC-DC converter 64. Control of the DC-DC converter 64 and / or the supplemental battery system 60 may be performed using any suitable processing device or processor, such as a battery management system (BMS) controller or other controller associated with the battery packs 44 and 46, a charge controller, a motor controller, etc.

[0050] In an embodiment, the supplemental battery system 60 is a high energy density system (i.e., has a higher energy density than the battery packs 44 and 46). For example, the battery pack 62 includes a plurality of high energy density battery cells. Such battery cells have high energy density chemistries, such as lithium metal battery cells (e.g., LMB battery cells), silicon anode battery cells (lithium ion battery cells with silicon-based anodes), etc.

[0051] In an embodiment, the vehicle 10 includes one or more additional battery cells 54 that are connected in series with the battery cells of the battery pack 46 (and may also be connected in series with the battery pack 44 when the battery switching device 52 is closed). Although the battery cells 54 are shown as being connected to the battery pack 46, one or more battery cells 54 may also be connected in series with the battery pack 44. Note that the embodiments are not limited to Figure 1 The number or configuration of battery cells 54 is shown.

[0052] In an embodiment, battery cell 54 has a different battery chemistry than battery packs 44 and / or 46. For example, battery cell 54 is an NCM battery cell and battery packs 44 and 46 have a lithium-ion chemistry, such as LFP.

[0053] The battery cells 54 may have various uses and functions. The battery cells 54 provide improvements in low temperature performance and may be used as a "virtual sensor" to facilitate estimating the SOC of the battery pack 46. The SOC estimation may be performed by estimating the SOC of the battery cells 54 and estimating the SOC of the battery pack 46, via known techniques such as coulomb counting. These estimates are combined to reduce the error in the SOC estimation of the battery pack 46 (e.g., to 3% or less).

[0054] The vehicle 10 also includes a charging system that can be used to charge the battery packs 44 and 46 (and the battery cells 54), charge the supplemental battery system 60, and / or provide power to charge another energy storage system (e.g., vehicle-to-vehicle (V2V) and / or vehicle-to-everything (V2X) charging). The charging system includes one or more conversion devices for controlling aspects of charging and / or discharging. For example, at least one conversion device provides conversion between AC current and DC current and / or voltage control. The conversion device can be a bidirectional conversion device that allows the charging port to be used for charging or discharging.

[0055] In an embodiment, the charging system includes a charging control device 66, such as an on-board charging module (OBCM). The charging control device 66 includes a conversion device in the form of a charger (charging circuit), which includes devices for alternating current (AC)-DC conversion and DC-DC conversion. For example, the charging control device 66 allows charging and discharging to and from an external power storage device (such as a battery system of another vehicle) (V2V charging). The charging control device 66 connects the battery system 40 to the charging port 68 for charging the vehicle battery system and / or providing charge to the external storage system.

[0056] The vehicle 10 also includes a computer system 70 that includes one or more processing devices 72 and a user interface 74. The various processing devices and units may communicate with each other via a communication device or system, such as a controller area network (CAN) or transmission control protocol (TCP) bus.

[0057] Figure 2 An embodiment of a hybrid chemistry battery system 40 is depicted. A battery pack 62 of a supplemental battery system 60 is connected in parallel to a DC-DC converter 64 and the battery pack 44. The system 40 has a topology that allows for different modes of operation.

[0058] Battery pack 62 and a propulsion battery system (including, for example, battery pack 44 and / or battery pack 46) are connected in parallel via a supplemental power bus 80. Figure 2 Only battery pack 44 is shown, but it should be understood that battery pack 46 may be similarly connected.

[0059] The supplemental battery pack 62 is selectively connected to the DC-DC converter 64 and the bus 80 through a circuit including a resistor 82 and a pre-charge switch 84 (K1), an inductor Linput and a capacitor Cin. The supplemental battery pack 62 and the circuit can be connected and disconnected through a negative side switch 86 and a positive side switch 88 (switch K2).

[0060] The battery pack 44 can be selectively connected to the DC-DC converter 64 and the bus 80 through the inductor Lout and the pre-charge circuit including the switch 90 (K3) and the resistor 92. The battery pack 44 can be connected and disconnected from the bus 80 through the negative side switch 94 and the positive side switch 96 (switch k4).

[0061] The DC-DC converter 64 is configured to step up or step down the voltage, for example, when the supplemental battery pack 62 is charged or when the supplemental battery pack 62 provides power for propulsion. The DC-DC converter 64 can transfer power bidirectionally. In an embodiment, the DC-DC converter includes a half-bridge circuit including switches dp1, d1, dp2, d2, dp3, and d3.

[0062] Any switch described may be any suitable type of switch, such as a mechanical contactor, an electronic switch, or a solid-state switching device. Any suitable solid-state or electronic device may be used as a switch. For example, the switch may include a solid-state relay or a transistor, such as a silicon (Si) insulated gate bipolar transistor (IGBT) and a field effect transistor (FET). Examples of FETs include metal oxide semiconductor FETs (MOSFETs), Si MOSFETs, silicon carbide (Sic) MOSFETs, gallium nitride (GaN) high electron mobility transistors (HEMTs), and SiC junction gate FETs (JFETs). Other examples of switches that may be used include diamond, gallium oxide, and other power switching devices based on wide bandgap (WBG) semiconductors.

[0063] As described above, the hybrid chemistry battery system 40 is configured to operate according to various operating modes. The operating modes include, for example, a normal propulsion mode, a range assist mode, and a power assist mode.

[0064] In normal propulsion mode, switches 86 and 88 are open, and battery pack 44 (and / or battery pack 46) operates normally to provide propulsion power and / or power vehicle components (loads). For example, in normal propulsion mode, battery system 40 provides three-phase AC current to the vehicle propulsion system via propulsion bus 98 (and conversion devices such as DC-DC converters and inverters (not shown)). The various motors, components, propulsion buses, and chargers are connected to the vehicle in a manner that is consistent with the vehicle's propulsion system. Figure 3A and 3B In the figure, they are collectively represented by element 99.

[0065] In power assist mode, both battery pack 44 and supplemental battery pack 62 are connected to bus 80 (switches K2 and K4 are closed). Battery pack 62 provides additional energy for propulsion, such as when the driver requires additional power.

[0066] For example, Figure 3A As schematically shown, in the power assist mode, the propulsion battery pack 44 provides current to the motors 22 and / or 32 through the inverter 24 and / or the inverter 34 (represented by element 99). Current from the supplemental battery pack 62 flows through the DC-DC converter 64, which can be controlled in this mode to adjust the output voltage as needed, such as to equalize the voltage of the battery pack 44 and the battery 62. The current flowing from the DC-DC converter 64 bypasses the battery pack 44 and is provided to the propulsion bus 98 (represented by element 99).

[0067] In the range assist mode, the supplemental battery pack 62 is connected in series to the battery pack 44 and operates during propulsion to provide charge to the battery pack 44 to maintain the battery pack 44 at or above the desired SOC. In the range assist mode, the supplemental battery pack 62 provides energy to the battery pack 44 through the DC-DC converter 64 to maintain the SOC of the battery pack 44 at a certain level. Current flows from the supplemental battery pack 62 through the DC-DC converter 64 into the battery pack 44.

[0068] like Figure 3B As shown schematically, in the range assist mode, the propulsion battery pack 44 provides current to the propulsion bus 98, and the supplemental battery pack 62 is connected in series with the battery pack 44 to provide charge thereto when needed or requested. For example, when the control device 66 detects that the SOC of the battery pack 44 is below a certain threshold charge level, or when a request is received, the current from the supplemental battery pack 62 is caused to flow through the DC-DC converter 64, which can be controlled in this mode to regulate the output voltage, as described herein. The current from the DC-DC converter flows to the battery pack 44 and charges the battery pack 44.

[0069] Figure 4An embodiment of a method 100 for transferring power between and / or from battery systems having different chemistries is depicted. Aspects of the method 100 may be performed by one or more processors disposed in a vehicle, such as the control device 66. Note that the method 100 is not limited thereto and may be performed by any suitable processing device or system or combination of processing devices.

[0070] Method 100 includes a number of steps or phases represented by blocks 101-108. Method 100 is not limited to the number or order of steps therein, as some steps represented by blocks 101-108 may be performed in a different order than described below, or less than all steps may be performed in an order.

[0071] For the purpose of illustration, Figure 1 Vehicle 10 and Figure 5 The method 100 is described with reference to a topology of FIG. The method 100 is not limited thereto and may be used with any suitable vehicle battery system and any suitable hybrid chemistry battery system.

[0072] At box 101, the processing device monitors the vehicle 10 and the amount of power requested by the driver. At box 102, the processing device determines whether the power demand exceeds a threshold. The power demand threshold may be related to the maximum power output or power limit of the battery pack 44 and / or the battery pack 46.

[0073] At box 103, if the requested power exceeds the power demand threshold, the processing device determines the SOC of the supplemental battery pack 62. If the supplemental battery pack SOC is above the minimum SOC or SOC threshold, then at box 104, the processing device sets the hybrid chemistry battery system 40 to a power assist mode as described above, and both battery packs 44 and 64 provide power for propulsion. If the supplemental battery pack SOC is equal to or below the minimum SOC or SOC threshold, the method returns to box 101.

[0074] At box 105, if the requested power does not exceed the power demand threshold, the processing device determines the SOC of the battery pack 44. At box 106, the SOC of the battery pack 44 is compared to the SOC threshold. If the SOC is at or above the SOC threshold, the method returns to box 101.

[0075] At box 107 , if the SOC of battery pack 44 is below the SOC threshold, the processing device compares the SOC of battery pack 62 to a selected threshold level. If the SOC of battery pack 62 is below the selected threshold level, the method returns to box 101 .

[0076] At box 108, if the SOC of the battery pack 62 is at or above the selected threshold level, the processing device sets the hybrid chemistry battery system 40 to the range assist mode as described above, wherein the supplemental battery pack 62 is connected in series to the battery pack. Energy is then transferred to the battery pack 44 until the battery pack reaches the desired SOC and / or remains at or above the target SOC of the battery pack 44.

[0077] As previously mentioned, the hybrid chemistry battery system described herein can be used to facilitate the charging process. Figure 5 The energy flow between vehicle components during a charging operation is shown. The charging operation is performed using a control method or algorithm that allows the propulsion battery system and the supplemental battery system to be charged simultaneously or concurrently.

[0078] In an embodiment, the charging operation is performed based on the priority charging of the propulsion battery system, so that the available power is provided to the propulsion battery subject to the charging constraints for protecting the propulsion battery pack. Any remaining power (ie, power not required to charge the propulsion battery) is provided to charge the supplemental battery system.

[0079] exist Figure 5 , power flows and communications are schematically shown. The propulsion battery system is configured as a power module 110, which includes a propulsion battery assembly, such as a battery pack 44 and at least one battery cell 54. An energy module 112 includes a supplemental battery assembly, such as a supplemental battery pack 62. At least one bidirectional DC-DC converter 114 (isolated or non-isolated) is connected between the power module 110 and the energy module 112.

[0080] The control device 66 controls the power flow during charging. In an embodiment, the control device 66 is a predictive controller that implements a model predictive control (MPC) method. MPC is based on models of the propulsion system and the supplementary battery system and is selected to allow the control device 66 to simulate the parameters of the system and make predictions for controlling the charging process.

[0081] During charging, battery pack 62 and battery pack 44 are connected to charging bus 80 and the charging current i c The charging current is provided to the charging bus 80. The charging current is regulated based on a control signal provided from the control device 66.

[0082] In an embodiment, a heat source is used to allow heating of the energy module 112 to improve charging performance. This is very useful in low temperature environments or seasons, etc. For example, when the battery cells are warm (e.g., at or above about 50 degrees Celsius), chemistries such as LMB are more likely to accept higher charging rates. The power module 110 can be used to provide energy to heat the battery cells in the energy module 112, or a separate heating device can be used to heat the energy module 112.

[0083] In an embodiment, the power module 110 is configured to heat the power module 110 by applying an AC heating current i h to heat the energy module 112. The heating current is controlled by the controller 118. The heating current i h It can be used to increase the temperature of the energy module 112 so that the battery cells therein can be charged at a higher charging rate.

[0084] During charging, measurements of current, voltage, and temperature are obtained from modules 110 and 112. The control device 66 generates or obtains an estimate of the SOC (denoted as SOCe) and the state of power (SOP) of the energy module 112, and also generates or obtains an estimate of the SOC (denoted as SOCp) and the state of power (SOP) of the power module 110. These estimates are based on the charging current, the measured voltage, and the temperature.

[0085] In an embodiment, the estimates of SOC and SOP are predictions used in real time by the controller 116 to determine the desired charging current i c The predictions are obtained by applying the measurements to a mathematical model that simulates the parameters of the energy module 112 and the power module 110. A controller using model predictive control (MPC) uses these predictions to determine an optimal value for the charging current. The optimal value is the value produced by minimizing a cost function while satisfying the constraints.

[0086] In an embodiment, the mathematical model is a quasi-steady-state model that simulates the SOC and temperature of the module. The embodiment is not limited thereto, as other types of models may be utilized. Examples of such models include steady-state models and models based on lookup tables.

[0087] The following equation represents an example of a quasi-steady-state model:

[0088]

[0089]

[0090]

[0091] In the above equation, t is time and ΔT is the change in temperature of the energy module 112 compared to the previous time step or the previous prediction. c is the charging current, i L is the current through the inductor Linput, i h is the heating current. q e is the SOC of the energy module 112, and T is the temperature of the energy module 112. e and Q p are the respective capacities of the energy module 112 and the power module 110 .

[0092] p is a variable associated with each phase of the AC current provided for propulsion and is defined as the number of DC-DC converters 114 connected in parallel. mb is the mass of the energy module 112. Cp b is the specific heat, h is the heat transfer coefficient, and A is the surface area. e and V p are the voltages of the energy module 112 and the power module 110 , respectively.

[0093] q e (t) represents q at a given time step or time e , qe(t+ΔT) represents the change in q when a given temperature changes e Similarly, q p (t) represents q at time t p ,q e (t+ΔT) represents q p , T(t+ΔT) represents the prediction of the temperature of the energy module 112 .

[0094] The control device 66 controls the charging current, the inductor current and the heating current (if used) to keep these currents within the following constraints:

[0095] 0≤i L (t),0≤i h (t),0≤i c (t)

[0096]

[0097]

[0098] Among them, i max energy (T) and i min energy (T) is the maximum allowable current and the minimum current through the energy module 112 at temperature T. max power and i min power are the maximum and minimum currents allowed through the power module 110 .

[0099] In order to keep the performance of the system within these constraints, the control device 66 determines the current value that minimizes the cost function J:

[0100] in,

[0101] y(k)=w1(q w (k)-1) 2 +w2(q p (k)-1) 2

[0102]

[0103] In the above, k is the time step or control interval, and N is the selected finite range (e.g., the number of consecutive intervals k). w1 and w2 are q e and q p The weighting coefficients of L ,i h and i c When optimizing various currents, weights can be selected to adjust the importance or weight given to the corresponding parameters.

[0104] Figure 6 An embodiment of a method 120 for charging a battery system of a vehicle is shown. Aspects of the method 120 may be performed by one or more processors disposed in the vehicle, such as a BMS controller. Note that the method 120 is not limited thereto and may be performed by any suitable processing device or system or combination of processing devices.

[0105] Method 120 includes a number of steps or phases represented by blocks 121 - 125. Method 120 is not limited to the number or order of steps therein, as some steps represented by blocks 121 - 125 may be performed in a different order than described below, or less than all steps may be performed in an order.

[0106] For the purpose of illustration, Figure 1 Vehicles 10. Figure 2 Hybrid chemistry battery system 40 and Figure 5 The method 120 is described with reference to a schematic diagram of FIG. The method 120 is not limited thereto and may be used with any suitable vehicle battery system and any suitable charging system.

[0107] At box 121, the charging process is initiated. The charging process can be initiated by placing the vehicle 10 in a charging mode and connecting the charging port 68 to a power source. The power source can be a charging station, an electrical grid, another vehicle, or other suitable energy source. The controller can communicate with the power source, for example, via a charging cable or wirelessly.

[0108] The controller determines various charging parameters, such as nominal battery voltage, initial temperature, maximum allowed charging current, and desired charging energy for the power module 110 and the energy module 112 .

[0109] At block 122, the controller inputs the charging parameters into a mathematical model of the components used in the charging process. In one example, the mathematical model is a quasi-steady-state model as described above, or any other suitable model that allows simulation, prediction, estimation of the state of charge, temperature, and / or other parameters or conditions of the module.

[0110] At block 123, the charging current i c is applied to the power module 110. During charging, the current, voltage and temperature of the module are measured and provided to the model. The measurements may be performed continuously or periodically at a number of consecutive sampling times or time steps.

[0111] At block 124, the controller applies the measurements to the model at each time step to predict the state of charge of the power module 110. The controller then determines an optimal charging current that remains within selected constraints and minimizes a cost function, as described herein.

[0112] The controller periodically controls the charging current to meet the optimal charging current.

[0113] At box 125, when the predicted or estimated state of charge reaches the desired level, the controller disconnects the power module 110 from the charging bus 80, or stops providing energy to charge the power module 110. The energy module 112 is then charged for a selected amount of time, or until the energy module 112 reaches the desired SOC. During the charging of the energy module 112, the controller continues to measure battery parameters and determines the optimal charging current by minimizing a cost function, as described herein.

[0114] In an embodiment, the power module 110 and the energy module 112 are charged simultaneously. For example, the DC-DC converter 64 is a partial power processor, or the hybrid chemistry battery system additionally includes components that allow a portion of the total charging power to be distributed between the energy module and the power module. In this embodiment, the controller determines the amount of power required to charge the power module 110 and directs that amount of power to the power module 110. Any remaining power is directed to the energy module 112.

[0115] The various battery systems described herein may be packaged or arranged in any suitable manner. In an embodiment, the battery system is arranged (eg, as part of a battery module or power module) such that the temperature is distributed so that the temperature of a given battery or module does not exceed a desired threshold.

[0116] Figure 7 An example of a hybrid battery pack 130 including multiple battery cells having different chemistries is depicted. In this example, the hybrid battery pack includes LFP battery cells 132 (e.g., battery cells of battery packs 44 and / or 46) and NCM battery cells 134 (e.g., Figure 1 The battery pack also includes a LMB battery cell 136, which may be Figure 1 The battery pack 62 has battery cells.

[0117] In this example, the temperature is distributed according to a pattern that evenly distributes the different chemistries. In an embodiment, the pattern is selected so that individual battery cells with the same chemistry are not adjacent to each other. Figure 7 The pattern shown is an example, as other patterns for distributing different battery chemistries can be used. In some cases, it is better to add a thermal barrier.

[0118] Figure 8 Aspects of an embodiment of a computer system 140 are shown that can perform various aspects of the embodiments described herein. The computer system 140 includes at least one processing device 142, which typically includes one or more processors, for performing various aspects of the image acquisition and analysis methods described herein.

[0119] Components of the computer system 140 include a processing device 142 (such as one or more processors or processing units), a memory 144, and a bus 146 that couples various system components including the system memory 144 to the processing device 142. The system memory 144 may be a non-transitory computer-readable medium and may include various computer system-readable media. Such media may be any available media that can be accessed by the processing device 142 and includes both volatile and non-volatile media, as well as removable and non-removable media.

[0120] For example, system memory 144 includes nonvolatile memory 148, such as a hard drive, and may also include volatile memory 150, such as random access memory (RAM) and / or cache memory. Computer system 140 may also include other removable / non-removable, volatile / nonvolatile computer system storage media.

[0121] The system memory 144 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments described herein. For example, the system memory 144 stores various program modules that generally perform the functions and / or methods of the embodiments described herein. One or more modules 152 may be included to perform functions related to the power transmission control described herein. The system 140 is not limited thereto, as other modules may be included. As used herein, the term "module" refers to a processing circuit, which may include an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and / or other suitable components that provide the functions.

[0122] System memory 144 may include at least one program product having a set (e.g., at least one) of program modules configured to perform the functions of the embodiments described herein. For example, system memory 144 stores various program modules that typically perform the functions and / or methods of the embodiments described herein. System 140 is not limited thereto, as other modules may be included. As used herein, the term "module" refers to a processing circuit, which may include an application specific integrated circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group) and memory that executes one or more software or firmware programs, a combinational logic circuit, and / or other suitable components that provide the functions.

[0123] Processing device 142 may also communicate with one or more external devices 156, which may be a keyboard, a pointing device, and / or any device that enables processing device 142 to communicate with one or more other computing devices (e.g., a network card, a modem, etc.). Communications with various devices may occur through input / output (I / O) interfaces 164 and 165.

[0124] The processing device 142 may also communicate with one or more networks 166, such as a local area network (LAN), a general wide area network (WAN), a bus network, and / or a public network (e.g., the Internet) via a network adapter 168. It should be understood that, although not shown, other hardware and / or software components may be used in conjunction with the computer system 140. Examples include, but are not limited to, microcode, device drivers, redundant processing units, external disk drive arrays, RAID systems, and data archival storage systems, etc.

[0125] The terms "one" and "an" do not indicate a limitation of quantity, but rather indicate the presence of at least one of the referenced items. The term "or" means "and / or", unless the context clearly indicates otherwise. References to "an aspect" throughout the specification mean that a particular element (e.g., feature, structure, step, or characteristic) described in conjunction with that aspect is included in at least one aspect described herein, and may or may not be present in other aspects. In addition, it should be understood that the described elements may be combined in any suitable manner in various aspects.

[0126] When an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.

[0127] Unless otherwise indicated herein, all test standards are the most recent standards in effect as of the filing date of the present application or, if priority is claimed, the filing date of the earliest priority application in which the test standards appear.

[0128] Unless defined otherwise, 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.

[0129] Although the above disclosure has been described with reference to exemplary embodiments, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted for its elements without departing from the scope thereof. In addition, many modifications may be made to adapt specific situations or materials to the teachings of the disclosure without departing from the essential scope of the disclosure. Therefore, it is intended that the disclosure is not limited to the specific embodiments disclosed, but will include all embodiments falling within its scope.

Claims

1. A system for controlling power transmission, comprising: a propulsion battery assembly configured to power an electric motor of a vehicle, the propulsion battery assembly having a first chemistry; a supplemental battery assembly selectively connected to the propulsion battery assembly, the supplemental battery assembly having a second chemistry different than the first chemistry; and A controller is configured to selectively connect the supplemental battery assembly to at least one of: provide an electrical charge to the propulsion battery assembly, and supply electrical power to the electric motor.

2. The system of claim 1 further comprising a third battery assembly comprising battery cells having a third chemistry different from the first and second chemistry, the battery cells being connected in series to the propulsion battery assembly.

3. The system according to claim 1, wherein: The supplemental battery assembly is a high energy battery assembly having an energy density greater than that of the propulsion battery assembly.

4. The system of claim 1 , further comprising a DC-DC converter connected in parallel to the propulsion battery assembly and the supplemental battery assembly, the DC-DC converter configured to regulate an output voltage of the supplemental battery assembly, wherein: The controller is configured to connect the supplemental battery assembly in series with the propulsion battery assembly and to provide charge to the propulsion battery assembly via the DC-DC converter during vehicle propulsion to extend the vehicle's driving range.

5. The system according to claim 4, wherein: The controller is configured to connect the supplemental battery assembly based on a state of charge (SOC) of the propulsion battery assembly being below a SOC threshold and provide charge to maintain the SOC of the propulsion battery assembly at or above the SOC threshold.

6. The system of claim 1, further comprising a DC-DC converter connected in parallel to the propulsion battery assembly and the supplemental battery assembly, the DC-DC converter configured to regulate an output voltage of the supplemental battery assembly, wherein: The controller is configured to connect the supplemental battery assembly in parallel to the propulsion battery assembly and to provide electrical power to the electric motor through the DC-DC converter, the electrical power bypassing the propulsion battery assembly.

7. The system according to claim 1, wherein: The vehicle is configured to be connected to a power source for charging the propulsion battery assembly, and the controller is configured to control a charging process that preferentially provides charging power to the propulsion battery assembly.

8. The system according to claim 7, wherein: The charging process includes providing an amount of power to charge the propulsion battery assembly to a desired SOC and providing a remaining amount of power to charge the supplemental battery assembly.

9. The system according to claim 7, wherein: The controller is configured to control the charging process based on a predictive control method, which includes predicting the charge state of the propulsion battery assembly and the supplemental battery assembly based on a quasi-steady-state model.

10. A method of controlling power transmission, comprising: monitoring, by a controller, a propulsion system of a vehicle, the propulsion system coupled to a hybrid chemistry battery system, the hybrid chemistry battery system including a propulsion battery assembly configured to power an electric motor of the propulsion system, and a supplemental battery assembly selectively coupled to the propulsion battery assembly, the propulsion battery assembly having a first chemistry, the supplemental battery assembly having a second chemistry different from the first chemistry; upon receiving a request for additional propulsion, connecting a supplemental battery assembly and supplying additional power to the electric motor; as well as Based on a state of charge (SOC) of the propulsion battery assembly being below a SOC threshold, charge is provided from the supplemental battery assembly to the propulsion battery assembly.

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