Simplified switching for state of charge balancing of battery strings and modules

Abstract

The battery system includes: at least two battery modules, each of the at least two battery modules including three battery cell strings; and a switch control module configured to: determine the state of charge (SOC) of each battery cell string; determine the time periods of each phase based on the SOC using model predictive control; and determine the time periods during which the strings will be connected to a second positive terminal and a second negative terminal during the phase, the determination of the time periods of the strings including: setting the time period of one string in one of the battery modules to end before the end of the phase; and setting the time periods of the other two strings in the battery module to end at the end of the phase.

Description

Technical Field

[0001] This disclosure relates to vehicles, and more particularly to the battery systems of vehicles. Background Technology

[0002] The information provided in this section is for the purpose of presenting the overall context of this disclosure. To the extent described in this section, the work of the currently attributed inventors and aspects that may not otherwise be described as prior art at the time of filing are neither explicitly nor implicitly considered to be prior art to this disclosure.

[0003] Some types of vehicles consist solely of an internal combustion engine that generates propulsive torque. Hybrid vehicles include both an internal combustion engine and one or more electric motors. Compared to using only an internal combustion engine, some types of hybrid vehicles utilize both an electric motor and an internal combustion engine in an attempt to achieve greater fuel efficiency. Some types of hybrid vehicles achieve a greater torque output than an internal combustion engine can achieve on its own.

[0004] Some example types of hybrid vehicles include parallel hybrid vehicles, series hybrid vehicles, and other types of hybrid vehicles. In a parallel hybrid vehicle, an electric motor operates in parallel with an engine to combine the power and range advantages of the engine with the efficiency and regenerative braking advantages of the electric motor. In a series hybrid vehicle, the engine drives a generator to produce electricity for the electric motor, and the electric motor drives a transmission. This allows the electric motor to take on some of the power responsibilities of the engine, which may permit the use of a smaller and potentially more efficient engine. This application applies to electric vehicles, hybrid vehicles, and other types of vehicles. Summary of the Invention

[0005] In one feature, a battery system includes: a first positive terminal, a second positive terminal, and a negative terminal; a switch; at least two battery modules, wherein each of the at least two battery modules includes three battery cell strings configured to be connected in series to the first positive terminal via a first switch in the switch; connected in parallel to the second positive terminal via a second switch in the switch; and disconnected from both the first and second positive terminals at different times; and a switch control module configured to: determine the state of charge (SOC) of each battery cell string; determine the time periods of each phase using model predictive control based on the SOC; determine the time periods during which the strings will be connected to the second positive terminal and the negative terminal during the phase using model predictive control based on the SOC, wherein determining the time periods of the strings includes: setting the time period of one of the strings in one of the battery modules to end before the end of the phase; setting the time periods of the other two strings in the one of the battery modules to end at the end of the phase; and selectively actuating the switch based on the time periods of the phase and the time periods of the battery cell strings.

[0006] In a further feature, the switch control module is configured to: use model predictive control to set a first time period of the first phase to one of (a) a second time period that is greater than and (b) less than the second phase.

[0007] In a further feature, the switch control module is configured to: use model predictive control to set a third time period of the third phase to: (a) a second time period that is greater than or (b) less than the second phase; and (a) a first time period that is greater than or (b) less than the first phase.

[0008] In a further feature, the switch control module is configured to use model predictive control to set the first, second, and third time periods of the first, second, and third phases to different values ​​from each other.

[0009] In a further feature, the switch control module is further configured to: set the time period of the second string in the second battery module to end before the end of the second phase; and set the time periods of the other two strings in the second battery module to end at the end of the second phase.

[0010] In a further feature, the switch control module is configured to actuate the switch and: during charging of one of the battery modules, based on the fact that the SOC of one of the strings in the battery module is greater than the SOC of the other strings in the battery module at the start of the phase, disconnect the string in the battery module before the end of the phase; and disconnect the other strings in the battery module at the end of the phase.

[0011] In a further feature, the switch control module is configured to actuate the switch and: during a discharge of one of the battery modules, based on the fact that the SOC of one of the strings in the battery module is less than the SOC of the other strings in the battery module at the start of the phase, disconnect the one string in the battery module before the end of the phase; and disconnect the other strings in the battery module at the end of the phase.

[0012] In a further feature, the switch control module is configured to determine the period of the phase and the period of the string based on minimizing the error between the SOCs of the battery cell strings.

[0013] In a further feature, the error is the squared error between the state of charge (SOC) of the battery cell strings.

[0014] In a further feature, each of the battery cell strings comprises multiple battery cells connected in series.

[0015] In a further feature, the plurality of battery cells includes four 3-volt battery cells.

[0016] In a further feature, the switch control module is configured to control a switch such that one of the battery cell strings is not simultaneously connected to both the first positive terminal and the second positive terminal.

[0017] In a further feature: the first positive terminal is configured to output a first reference potential; the second positive terminal is configured to output a second reference potential; and the first reference potential is greater than the second reference potential.

[0018] In one feature, a method for a battery includes: determining the state of charge (SOC) of battery cell strings of at least two battery modules, wherein each of the at least two battery modules includes three battery cell strings configured to be connected in series to a first positive terminal via a first switch in a switch; connected in parallel to a second positive terminal via a second switch in a switch; and disconnected from both the first and second positive terminals at different times; and determining time periods of a phase based on the SOC using model predictive control; determining time periods during which the strings will be connected to the second positive and negative terminals during the phase based on the SOC using model predictive control, the determination of the time periods of the strings including: setting the time period of one of the strings of one of the battery modules to end before the end of the phase; and setting the time periods of the other two strings of the one of the battery modules to end at the end of the phase; and selectively actuating switches based on the time periods of the phase and the time periods of the battery cell strings.

[0019] In a further feature, determining the time period of a phase includes: setting a first time period of the first phase as one of a second time period that is (a) greater than and (b) less than the second phase.

[0020] In a further feature, determining the time period of the phase further includes: setting the third time period of the third phase as: one of the second time periods that is (a) greater than and (b) less than the second phase; and one of the first time periods that is (a) greater than and (b) less than the first phase.

[0021] In a further feature, determining the time periods of the phase includes setting the first, second, and third time periods of the phase to different values ​​from each other.

[0022] In a further feature, determining the time period of the string includes: setting the time period of the second string in the second battery module to end before the end of the second phase; and setting the time periods of the other two strings in the second battery module to end at the end of the second phase.

[0023] In a further feature, selectively actuating the switch includes: actuating the switch and: during charging of one of the battery modules, based on the fact that the SOC of one of the strings in the battery module is greater than the SOC of the other strings in the battery module at the start of the phase, disconnecting the one string in the battery module before the end of the phase; and disconnecting the other strings in the battery module at the end of the phase.

[0024] In a further feature, selectively actuating the switch includes: actuating the switch and: during a discharge of one of the battery modules, based on the fact that the SOC of one of the strings in the battery module is less than the SOC of the other strings in the battery module at the start of the phase, disconnecting the one string in the battery module before the end of the phase; and disconnecting the other strings in the battery module at the end of the phase.

[0025] Option 1. A battery system, comprising:

[0026] First positive terminal, second positive terminal, and negative terminal;

[0027] switch;

[0028] At least two battery modules, wherein each of the at least two battery modules comprises three battery cell strings, the battery cell strings being configured to operate at different times:

[0029] It is connected in series with the first switch in the switch and connected to the first positive terminal;

[0030] Connected in parallel to the second positive terminal via the second switch in the switch; and

[0031] Disconnect from both the first positive terminal and the second positive terminal; and

[0032] The switch control module is configured to:

[0033] Determine the state of charge (SOC) of each battery cell string.

[0034] Based on SOC, model predictive control is used to determine the time periods of each stage.

[0035] Based on SOC, model predictive control is used to determine the time periods during which the string will be connected to the second positive and negative terminals, respectively, during the stated phase. The determination of these time periods includes:

[0036] Set the time period of one of the strings in one of the battery modules to end before the end of the phase; and

[0037] The time periods of the other two strings in one of the battery modules are set to end at the end of the phase; and

[0038] The switch is selectively actuated based on the time period of the phase and the time period of the battery cell string.

[0039] Option 2. The battery system according to Option 1, wherein the switch control module is configured to: use model predictive control to set a first time period of the first stage to one of (a) greater than and (b) less than a second time period of the second stage.

[0040] Option 3. The battery system according to Option 2, wherein the switching control module is configured to: use model predictive control to set the third time period of the third stage as:

[0041] (a) greater than and (b) less than the second of the said phases in the second time period; and

[0042] (a) greater than and (b) less than the first of the first time periods in the said phase.

[0043] Option 4. The battery system according to Option 1, wherein the switching control module is configured to: use model predictive control to set the first, second, and third time periods of the first, second, and third phases to different values ​​from each other.

[0044] Option 5. The battery system according to Option 1, wherein the switch control module is further configured to:

[0045] Set the second time period in the second string of the battery module to end before the end of the second phase; and

[0046] The time periods for the other two strings of the second battery module are set to end at the end of the second phase.

[0047] Option 6. The battery system according to Option 1, wherein the switch control module is configured to actuate the switch and:

[0048] During charging of one of the battery modules, if the State of Charge (SOC) of one of the strings in the battery module is greater than the SOC of the other strings in the battery module at the start of the phase, then that string in the battery module is disconnected before the end of the phase; and

[0049] The other strings in one of the battery modules are disconnected at the end of this phase.

[0050] Option 7. The battery system according to Option 1, wherein the switch control module is configured to actuate the switch and:

[0051] During a discharge phase in a battery module, if the State of Charge (SOC) of one string in the battery module is lower than the SOC of the other strings in the battery module at the start of the phase, then that string in the battery module is disconnected before the end of the phase; and

[0052] The other strings in one of the battery modules are disconnected at the end of this phase.

[0053] Option 8. The battery system according to Option 1, wherein the switch control module is configured to determine the time period of the phase and the time period of the string based on minimizing the error between the SOCs of the battery cell strings.

[0054] Option 9. The battery system according to Option 8, wherein the error is the squared error between the SOCs of the battery cell strings.

[0055] Option 10. The battery system according to Option 1, wherein each of the battery cell strings comprises a plurality of battery cells connected in series.

[0056] Option 11. The battery system according to Option 10, wherein the plurality of battery cells includes four 3-volt battery cells.

[0057] Option 12. The battery system according to Option 1, wherein the switch control module is configured to control a switch such that one of the battery cells in the string is not simultaneously connected to both the first positive terminal and the second positive terminal.

[0058] Option 13. The battery system according to Option 1, wherein:

[0059] The first positive terminal is configured to output the first reference potential;

[0060] The second positive terminal is configured to output a second reference potential; and

[0061] The first reference potential is greater than the second reference potential.

[0062] Option 14. A method for a battery, the method comprising:

[0063] The state of charge (SOC) of the battery cell strings of at least two battery modules is determined, wherein each of the at least two battery modules comprises three battery cell strings configured to operate at different times:

[0064] It is connected in series with the first switch in the switch and connected to the first positive terminal;

[0065] Connected in parallel to the second positive terminal via the second switch in the switch; and

[0066] Disconnect from both the first positive terminal and the second positive terminal; and

[0067] Based on SOC, model predictive control is used to determine the time periods of each stage.

[0068] Based on SOC, model predictive control is used to determine the time periods during which the string will be connected to the second positive and negative terminals, respectively, during the stated phase. The determination of these time periods includes:

[0069] Set the time period of one of the strings in one of the battery modules to end before the end of the phase; and

[0070] The time periods of the other two strings in one of the battery modules are set to end at the end of the phase; and

[0071] The switch is selectively actuated based on the time period of the phase and the time period of the battery cell string.

[0072] Option 15. The method according to Option 14, wherein determining the time period of the phase includes: setting a first time period of the first phase as one of (a) greater than and (b) less than a second time period of the second phase.

[0073] Option 16. The method according to Option 15, wherein determining the time period of the phase further includes: setting the third time period of the third phase as:

[0074] (a) greater than and (b) less than the second of the said phases in the second time period; and

[0075] (a) greater than and (b) less than the first of the first time periods in the said phase.

[0076] Option 17. The method according to Option 14, wherein determining the time period of the phase includes: setting the first time period, the second time period, and the third time period of the first, second, and third phases to different values ​​from each other.

[0077] Option 18. The method according to Option 14, wherein determining the time period of the string includes:

[0078] Set the second time period in the second string of the battery module to end before the end of the second phase; and

[0079] The time periods for the other two strings of the second battery module are set to end at the end of the second phase.

[0080] Option 19. The method according to Option 14, wherein selectively actuating the switch comprises: actuating the switch and:

[0081] During charging of one of the battery modules, if the State of Charge (SOC) of one of the strings in the battery module is greater than the SOC of the other strings in the battery module at the start of the phase, then that string in the battery module is disconnected before the end of the phase; and

[0082] The other strings in one of the battery modules are disconnected at the end of this phase.

[0083] Option 20. The method according to Option 14, wherein selectively actuating the switch comprises: actuating the switch and:

[0084] During a discharge phase in a battery module, if the State of Charge (SOC) of one string in the battery module is lower than the SOC of the other strings in the battery module at the start of the phase, then that string in the battery module is disconnected before the end of the phase; and

[0085] The other strings in one of the battery modules are disconnected at the end of this phase.

[0086] Other areas of application of this disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are intended for illustrative purposes only and are not intended to limit the scope of this disclosure. Attached Figure Description

[0087] This disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0088] Figure 1 This is a functional block diagram of an example engine control system;

[0089] Figure 2 This is a functional block diagram of an example battery system for a vehicle;

[0090] Figures 3A-3B This is a schematic diagram of an example implementation including a battery system;

[0091] Figure 4 This is a functional block diagram of an example implementation of a battery module in an open-circuit (X) configuration;

[0092] Figure 5 Example illustration of a battery module in a series (S) configuration;

[0093] Figure 6 Example illustrations include battery modules in a parallel (P) configuration;

[0094] Figure 7 This is a functional block diagram of an example switch control module;

[0095] Figure 8Includes example time series for operation in power mode during charging;

[0096] Figure 9 This is a flowchart illustrating an example method for a SOC (System-on-Chip) of balanced batteries, including battery strings and battery modules.

[0097] Figure 10 Includes example time series operating in power mode in cases where the string is disconnected in advance for balancing;

[0098] Figure 11 This is an example time series illustrating the state of charge (SOC) of a battery module string during charging by disconnecting one of the strings before the end of the phase; and

[0099] Figure 12 Example curves showing the SOC versus time for battery strings balanced with both string and module during discharge.

[0100] In the accompanying drawings, reference numerals may be used repeatedly to identify similar and / or identical elements. Detailed Implementation

[0101] The vehicle includes a battery having a first terminal on its casing for outputting a first operating voltage (e.g., 48 V) and a second output terminal on its casing for outputting a second operating voltage (e.g., 12 V). The battery includes multiple battery modules and multiple switches. Each battery module includes multiple battery strings, and each battery string includes multiple battery cells. The switches are configured to connect the strings together in series or independently to the terminals. The strings can also be disconnected from the first and second output terminals.

[0102] According to this application, the Model Predictive Control (MPC) module uses an estimate of the State of Charge (SOC) of the battery string and controls the switches to minimize the SOC error across the battery string and battery module. This ensures that each battery string is charged and discharged as uniformly as possible and maximizes battery life. As discussed further below, the MPC uses a simplified control strategy to balance the SOC of the battery string while also reducing computational workload and associated memory usage.

[0103] Now for reference Figure 1 The diagram presents a functional block diagram of an example powertrain 100. The vehicle's powertrain 100 includes an engine 102 that burns an air / fuel mixture to generate torque. The vehicle can be non-autonomous or autonomous.

[0104] Air is drawn into the engine 102 through the intake system 108. The intake system 108 may include an intake manifold 110 and a throttle valve 112. By way of example only, the throttle valve 112 may include a butterfly valve with rotatable vanes. The engine control module (ECM) 114 controls the throttle actuator module 116, and the throttle actuator module 116 regulates the opening of the throttle valve 112 to control the airflow into the intake manifold 110.

[0105] Air from the intake manifold 110 is drawn into the cylinders of the engine 102. Although the engine 102 includes multiple cylinders, a single representative cylinder 118 is shown for illustrative purposes. By way of example only, the engine 102 may include 2, 3, 4, 5, 6, 8, 10, and / or 12 cylinders. The ECM 114 may instruct the cylinder actuator module 120 to selectively deactivate some cylinders in certain situations, which can improve fuel efficiency.

[0106] Engine 102 can be operated using a four-stroke cycle or another suitable engine cycle. The four strokes of the four-stroke cycle described below will be referred to as the intake stroke, compression stroke, combustion stroke, and exhaust stroke. During each revolution of the crankshaft (not shown), two of these four strokes occur within cylinder 118. Therefore, cylinder 118 requires two revolutions of the crankshaft to complete all four strokes. For a four-stroke engine, one engine cycle corresponds to two revolutions of the crankshaft.

[0107] When cylinder 118 is activated, air from intake manifold 110 is drawn into cylinder 118 through intake valve 122 during the intake stroke. ECM 114 controls fuel actuator module 124, which adjusts fuel injection to achieve a desired air / fuel ratio. Fuel may be injected into intake manifold 110 at a central location or at multiple locations (e.g., near intake valve 122 of each cylinder). In various embodiments (not shown), fuel may be injected directly into the cylinder or into a mixing chamber / port associated with the cylinder. Fuel actuator module 124 may interrupt fuel injection to the deactivated cylinder.

[0108] The injected fuel mixes with air in cylinder 118 to create an air / fuel mixture. During the compression stroke, a piston (not shown) within cylinder 118 compresses the air / fuel mixture. Engine 102 can be a compression ignition engine, in which case compression causes ignition of the air / fuel mixture. Alternatively, engine 102 can be a spark ignition engine, in which case spark actuator module 126 actuates spark plug 128 in cylinder 118 based on a signal from ECM 114, which ignites the air / fuel mixture. Some types of engines, such as homogeneous charge compression ignition (HCCI) engines, can perform both compression ignition and spark ignition. The timing of the spark can be defined relative to the time when the piston is in its highest position (which will be referred to as top dead center (TDC)).

[0109] The spark actuator module 126 can be controlled by a timing signal that specifies how far before or after the TDC (Temperature Directional Control) the spark is generated. Because the piston position is directly related to the crankshaft rotation, the operation of the spark actuator module 126 can be synchronized with the crankshaft position. The spark actuator module 126 can disable the spark supply to the deactivated cylinder or provide a spark to the deactivated cylinder.

[0110] During the combustion stroke, the combustion of the air / fuel mixture drives the piston downward, which in turn drives the crankshaft. The combustion stroke can be defined as the time between when the piston reaches TDC and when it returns to its lowest position (which will be called bottom dead center (BDC)).

[0111] During the exhaust stroke, the piston moves upward from the BDC and discharges combustion byproducts through exhaust valve 130. The combustion byproducts are discharged from the vehicle via exhaust system 134.

[0112] Intake valve 122 can be controlled by intake camshaft 140, while exhaust valve 130 can be controlled by exhaust camshaft 142. In various embodiments, multiple intake camshafts (including intake camshaft 140) can control multiple intake valves (including intake valve 122) of cylinder 118 and / or can control intake valves (including intake valve 122) of multiple exhaust cylinders (including cylinder 118). Similarly, multiple exhaust camshafts (including exhaust camshaft 142) can control multiple exhaust valves of cylinder 118 and / or can control exhaust valves (including exhaust valve 130) of multiple exhaust cylinders (including cylinder 118). Although camshaft-based valve actuation has been shown and discussed, camless valve actuators can be implemented. Although separate intake and exhaust camshafts are shown, a single camshaft with convex angles for both intake and exhaust valves can be used.

[0113] Cylinder actuator module 120 can deactivate cylinder 118 by preventing the opening of intake valve 122 and / or exhaust valve 130. The timing of intake valve 122 opening can be changed relative to piston TDC by intake cam phaser 148. The timing of exhaust valve 130 opening can be changed relative to piston TDC by exhaust cam phaser 150. Phaser actuator module 158 can control intake cam phaser 148 and exhaust cam phaser 150 based on signals from ECM 114. In various embodiments, cam phasing can be omitted. Variable valve lift (not shown) can also be controlled by phaser actuator module 158. In various other embodiments, intake valve 122 and / or exhaust valve 130 can be controlled by actuators other than the camshaft, such as electromechanical actuators, electrohydraulic actuators, electromagnetic actuators, etc.

[0114] Engine 102 may include one, one, or more supercharging devices that supply pressurized air to intake manifold 110. For example, Figure 1 A turbocharger is shown, comprising a turbocharger turbine 160-1 driven by exhaust gas flowing through an exhaust system 134. A supercharger is another type of boosting device.

[0115] The turbocharger also includes a turbocharger compressor 160-2, which is driven by the turbocharger turbine 160-1 and compresses the air leading to the throttle valve 112. A wastegate (WG) 162 controls the exhaust flow through and bypasses the turbocharger turbine 160-1. The wastegate may also be referred to as a (turbocharger) turbine bypass valve. The wastegate 162 allows exhaust bypass of the turbocharger turbine 160-1 to reduce the compression of the intake air supplied by the turbocharger. The ECM 114 can control the turbocharger via a wastegate actuator module 164. The wastegate actuator module 164 can regulate the turbocharger boost by controlling the opening of the wastegate 162.

[0116] A cooler (e.g., a booster air cooler or intercooler) dissipates some of the heat contained in the compressed air charge, which is generated as the air is compressed. Although shown separately for illustrative purposes, the turbocharger turbine 160-1 and turbocharger compressor 160-2 are mechanically linked to each other, thereby placing the intake air in close proximity to the hot exhaust. The compressed air charge can absorb heat from components of the exhaust system 134.

[0117] Engine 102 may include an exhaust gas recirculation (EGR) valve 170 that selectively redirects exhaust gas back to intake manifold 110. EGR valve 170 may receive exhaust gas upstream of turbocharger turbine 160-1 in exhaust system 134. EGR valve 170 may be controlled by EGR actuator module 172.

[0118] The crankshaft position can be measured using a crankshaft position sensor 180. The engine speed can be determined based on the crankshaft position measured using the crankshaft position sensor 180. The engine coolant temperature (ECT) sensor 182 can be used to measure the temperature of the engine coolant. The ECT sensor 182 can be located within the engine 102 or at other locations along the coolant circulation path, such as the radiator (not shown).

[0119] A manifold absolute pressure (MAP) sensor 184 can be used to measure the pressure within the intake manifold 110. In various embodiments, engine vacuum, which is the difference between ambient air pressure and the pressure within the intake manifold 110, can be measured. An air mass flow (MAF) sensor 186 can be used to measure the mass flow rate of air flowing into the intake manifold 110. In various embodiments, the MAF sensor 186 may be located in a housing that also includes a throttle valve 112.

[0120] One or more throttle position sensors (TPS) 190 can be used to measure the position of the throttle valve 112. Intake air temperature (IAT) sensor 192 can be used to measure the temperature of the air drawn into the engine 102. One or more other sensors 193 may also be implemented. These other sensors 193 include an accelerator pedal position (APP) sensor, a brake pedal position (BPP) sensor, and may include a clutch pedal position (CPP) sensor (e.g., in the case of a manual transmission), and may include one or more other types of sensors. The APP sensor measures the position of the accelerator pedal within the passenger compartment of the vehicle. The BPP sensor measures the position of the brake pedal within the passenger compartment of the vehicle. The CPP sensor measures the position of the clutch pedal within the passenger compartment of the vehicle. Other sensors 193 may also include one or more acceleration sensors that measure the longitudinal (e.g., front / rear) acceleration and the lateral (latitudinal) acceleration of the vehicle. An accelerometer is an example type of acceleration sensor, but other types of acceleration sensors may be used. The ECM 114 can use the signals from the sensors to make control decisions for the engine 102.

[0121] ECM 114 can communicate with transmission control module 194, for example, to coordinate engine operation using gear shifting in transmission 195. ECM 114 can communicate with hybrid power control module 196, for example, to coordinate the operation of engine 102 and electric motor 198. While an example of an electric motor is provided, multiple electric motors can be implemented. Electric motor 198 can be a permanent magnet electric motor or another suitable type of electric motor that outputs voltage based on anti-electromagnetic force (EMF) when freely rotating, such as a direct current (DC) electric motor or a synchronous electric motor. In various embodiments, the various functions of ECM 114, transmission control module 194, and hybrid power control module 196 can be integrated into one or more modules.

[0122] Each system that alters engine parameters can be referred to as an engine actuator. Each engine actuator has associated actuator values. For example, the throttle actuator module 116 can be referred to as an engine actuator, and the throttle opening area can be referred to as an actuator value. Figure 1 In the example, the throttle actuator module 116 adjusts the throttle opening area by adjusting the angle of the blades of the throttle valve 112.

[0123] Spark actuator module 126 can also be referred to as an engine actuator, and the corresponding actuator value can be the spark advance relative to the cylinder TDC. Other engine actuators may include cylinder actuator module 120, fuel actuator module 124, phaser actuator module 158, wastegate actuator module 164, and EGR actuator module 172. For these engine actuators, the actuator values ​​can correspond to the cylinder activation / deactivation sequence, fuel injection rate, intake and exhaust cam phaser angles, target wastegate opening, and EGR valve opening, respectively.

[0124] ECM 114 can control actuator values ​​to cause engine 102 to output torque based on a torque request. ECM 114 can determine the torque request, for example, based on one or more driver inputs (e.g., APP, BPP, CPP, and / or one or more other suitable driver inputs). ECM 114 can determine the torque request, for example, using one or more functions or lookup tables that associate driver inputs with the torque request.

[0125] In some cases, the hybrid power control module 196 controls the electric motor 198 to output torque, for example, to supplement the engine torque output. The hybrid power control module 196 can also control the electric motor 198 to output torque for vehicle propulsion during periods when the engine 102 is shut off.

[0126] The hybrid power control module 196 applies electrical power from the battery 208 to the electric motor 198 to cause the electric motor 198 to output positive torque. The battery is discussed further below. The electric motor 198 can output torque to, for example, the input shaft of the transmission 195, the output shaft of the transmission 195, or another component. The clutch 200 can be implemented to engage the electric motor 198 with the transmission 195 and disengage the electric motor 198 from the transmission 195. One or more transmissions can be implemented between the output of the electric motor 198 and the input of the transmission 195 to provide one or more predetermined gear ratios between the rotation of the electric motor 198 and the rotation of the input of the transmission 195. In various embodiments, the electric motor 198 may be omitted. In vehicles (e.g., electric vehicles and autonomous vehicles), the battery 208 can be used to supply its own redundant power to various systems, such as Automotive Safety Integrity Level (ASIL) systems and Advanced Driver Assistance Systems (ADAS), and to provide multiple output voltages (e.g., 12 volts and 48 volts).

[0127] ECM 114 starts engine 102 via starter motor 202. ECM 114 or another suitable module of the vehicle engages starter motor 202 with engine 102 for engine starting events. For example, ECM 114 may engage starter motor 202 with engine 102 upon receiving a key ON command. For instance, a driver may enter a key ON command via one or more ignition keys, buttons, and / or switches that actuate the vehicle or its remote key. Starter motor 202 may engage a flywheel coupled to the crankshaft or one or more other suitable components that drive the rotation of the crankshaft.

[0128] ECM 114 can also start the engine in response to an automatic start command during an automatic stop / start event or an engine start command in response to a sailing event. Automatic stop / start events include shutting off the engine 102 when the vehicle is stopped, the driver has depressed the brake pedal, and the driver has not yet entered the key OFF command. An automatic start command can be generated when the engine 102 is shut off in response to an automatic stop / start event, for example, when the driver releases the brake pedal and / or depresses the accelerator pedal.

[0129] A coasting event may include the ECM 114 shutting off the engine 102 when the vehicle is moving (e.g., the vehicle speed is greater than a predetermined speed, such as 50 mph), the driver does not apply pressure to the accelerator pedal, and the driver has not yet entered a key OFF command. An engine start command may be generated when the engine 102 is shut off in response to a coasting event, for example, when the driver depresses the accelerator pedal. The driver may enter a key OFF command, for example, via actuating one or more ignition keys, buttons, and / or switches, as discussed above.

[0130] A starter motor actuator (e.g., a solenoid) actuates the starter motor 202 to engage with the engine 102. For example only, the starter motor actuator may engage a starter pinion with a flywheel coupled to the crankshaft. In various embodiments, the starter pinion may be coupled to the starter motor 202 via a drive shaft and a one-way clutch. The starter actuator module 204 controls the starter motor actuator and the starter motor 202 based on signals from the starter control module, as discussed further below. In various embodiments, the starter motor 202 may remain engaged with the engine 102.

[0131] In response to a command to start the engine 102 (e.g., an automatic start command, an engine start command to end a coasting event, or when a key ON command is received), the starter actuator module 204 supplies current to the starter motor 202 to start the engine 102. The starter actuator module 204 may also actuate the starter motor actuator to engage the starter motor 202 with the engine 102. After engaging the starter motor 202 with the engine 102, for example, to allow gear engagement, the starter actuator module 204 may supply current to the starter motor 202.

[0132] Applying an electric current to the starter motor 202 drives the rotation of the starter motor 202, which in turn drives the rotation of the crankshaft (e.g., via a flywheel). The period during which the starter motor 202 drives the crankshaft to start the engine 102 may be referred to as engine cranking.

[0133] The starter motor 202 draws power from the battery 208 to start the engine 102. Once the engine 102 is running after an engine starting event, the starter motor 202 is disengaged from or disconnected from the engine 102, and the current flow to the starter motor 202 may be interrupted. For example, the engine 102 may be considered to be running when the engine speed exceeds a predetermined speed (e.g., a predetermined idle speed). For example only, the predetermined idle speed could be approximately 700 revolutions per minute (rpm) or another suitable speed. When the engine 102 is running, engine crank starting may be considered complete.

[0134] Generator 206 converts the mechanical energy of engine 102 into alternating current (AC) power. For example, generator 206 may be coupled to a crankshaft (e.g., via gears or belts) and convert the mechanical energy of engine 102 into AC power by applying a load to the crankshaft. Generator 206 rectifies the AC power into DC power and stores the DC power in battery 208. Alternatively, a rectifier external to generator 206 may be implemented to convert AC power into DC power. Generator 206 may be, for example, an alternator. In various embodiments, such as in the case of a belt-driven alternator starter (BAS), starter motor 202 and generator 206 may be implemented together. In various embodiments, one or more direct current (DC) to direct current (DC) converters may be implemented.

[0135] Figure 2 This is a functional block diagram of an example battery system for a vehicle. Battery 208 has at least two (positive) output terminals and one negative terminal to provide at least two direct current (DC) operating voltages. By way of example only, battery 208 may have a first positive (e.g., 48 volts (V) nominal) terminal 210, a negative terminal 212, and a second positive (e.g., 12 V nominal) terminal 214. While an example of battery 208 with a 48 V nominal operating voltage and a 12 V nominal operating voltage is provided, battery 208 may have one or more other operating voltages.

[0136] Battery 208 includes multiple battery modules, such as first battery module 224-1, ..., and Nth battery module 224-N (“battery module 224”), where N is an integer greater than or equal to 2. In various embodiments, N may be equal to 2, 3, 4, 5, 6, 8, 10, 12 or another suitable number.

[0137] The following text is about Figure 4 As discussed further, each of the battery modules 224 includes multiple battery strings. Each battery string can be independently replaceable. The ability to independently replace battery strings allows the battery 208 to include a shorter warranty period and lower warranty costs. The battery strings can also be independently isolated, for example, in the event of a failure within a battery string. In various embodiments, the battery 208 may have the form factor of a standard automotive-grade 12V battery.

[0138] Battery 208 includes multiple switches, such as first switch 232-1, ..., Nth switch 232-N (collectively referred to as "switch 232"). Switch 232 enables the battery strings of battery module 224 to be connected in series, in parallel, or in a combination of series and parallel to provide a target output voltage and capacity at the output terminals.

[0139] The switch control module 240 controls the switch 232 to provide the desired output voltage and capacity at the output terminals. As discussed further below, the switch control module 240 uses model predictive control (MPC) to control the switch 232 to balance the state of charge (SOC) of the battery string as closely as possible.

[0140] Figures 3A-3B This is a schematic diagram including an example battery system comprising battery 208. A group of battery strings can be connected in series (via a switch in switch 232) to a first positive terminal 210 and a negative terminal 212 to provide a first nominal output voltage (e.g., 48 V) via the first positive terminal 210. Individual battery strings in the battery group can be connected (via a switch in switch 232) to a second positive terminal 214 and a negative terminal 212 to provide a second nominal output voltage (e.g., 12 V) via the second positive terminal 214. The number of battery strings connected to the first positive terminal 210 and the second positive terminal 214 determines the portion of the total capacity of battery 208 available at each of the positive terminals.

[0141] like Figure 3B As shown, the first group of vehicle electrical components operates using one of two or more operating voltages from battery 208. For example, this first group of vehicle electrical components may be connected to a second positive terminal 214. This first group of vehicle electrical components may include, but is not limited to, ECM 114 and other vehicle control modules, starter motor 202, and / or other electrical loads, such as a first 12V load 304, a second 12V load 308, other control modules 312, a third 12V load 316, and a fourth 12V load 320. In various embodiments, a switching device 324 may be implemented.

[0142] like Figure 3A As shown, the second set of vehicle electrical components operates using another of the two or more operating voltages of battery 208. For example, this second set of vehicle electrical components may be connected to the first positive terminal 210. This second set of vehicle electrical components may include, for example, but not limited to, a generator 206 and various electrical loads, such as a 48 V load 328. The generator 206 may be controlled to charge battery 208.

[0143] Each of the switches 232 can be an insulated gate bipolar transistor (IGBT), a field-effect transistor (FET) (e.g., a metal-oxide-semiconductor FET (MOSFET)), or another suitable type of switch.

[0144] Figure 4 This is a functional block diagram of an example implementation of one of the battery modules 224 (numbered battery module 404) and a set of switches 232. Each of the battery modules 224 may be the same as 404, and each set of switches 232 may be the same.

[0145] Battery module 404 includes three battery strings 408, 412, and 416. Battery strings 408-416 are identical, and each includes four battery cells 420, 424, 428, and 432. Battery cells 420-432 are connected in series to provide a second operating voltage (e.g., 12 V). Each of battery cells 420-432 may be, for example, a 3 V battery cell or have another suitable voltage to provide the second operating voltage when battery cells 420-432 are connected in series. Battery cells 420-432 may be, for example, lithium iron phosphate (LFP) battery cells or have another suitable chemistry.

[0146] The negative terminals of battery strings 408-416 are connected to negative terminal 212. When switches 436 and 440 are closed, the negative terminals of battery strings 408 and 412 are connected to negative terminal 212 via switches 436 and 440, respectively. Switches 436 and 440 can be opened to disconnect the negative terminals of battery strings 408 and 412 from negative terminal 212. The negative terminal of battery string 416 can be directly connected to negative terminal 212.

[0147] The positive terminal of battery string 416 is connected to the negative terminal of battery string 412, such that battery strings 412 and 416 are connected in series when switch 444 is closed. Switch 444 can be opened to disconnect the positive terminal of battery string 416 from the negative terminal of battery string 412. The positive terminal of battery string 412 is connected to the negative terminal of battery string 408, such that battery strings 412 and 408 are connected in series when switch 448 is closed. Switch 448 can be opened to disconnect the positive terminal of battery string 412 from the negative terminal of battery string 408.

[0148] Switches 452, 456, and 460 connect and disconnect the positive terminals of battery strings 408, 412, and 416 from a first bus (e.g., a 12V bus), which is connected to a second positive terminal 214. Switch 464 connects and disconnects the positive terminal of battery string 408 from a second bus (e.g., a 48V bus), which is connected to a first positive terminal 210.

[0149] The switch control module 240 controls the switching of the switches (switch groups) of each of the battery modules 224. At any given time, the switch control module 240 can actuate the switches associated with the battery modules, such that the battery modules are in an open-circuit (X) configuration, a series (S) configuration, or a parallel (P) configuration. Figure 4 An example illustration includes a battery module 404 in an open-circuit (X) configuration. When the battery module is in the open-circuit (X) configuration, all battery strings of the battery module are disconnected from both the first positive terminal 210 and the second positive terminal 214.

[0150] Figure 5 An example illustration includes a battery module 404 in a series (S) configuration. When the battery module is in a series (S) configuration, all the battery strings of the battery module are connected in series and connected to the first positive terminal 210. This is accomplished by closing switches 444, 448, and 464 and opening all other switches 436, 440, 452, 456, and 460. When the battery module is in a series (S) configuration, none of the battery strings are connected to the second positive terminal 214.

[0151] Figure 6 An example illustration includes a battery module 404 in a parallel (P) configuration. When the battery module is in the parallel (P) configuration, all the battery strings of the battery module are connected in parallel to the second positive terminal 214. This is accomplished by closing switches 452, 456, 460, 436, and 440 and opening all other switches 444, 448, and 464. When the battery module is in the parallel (P) configuration, none of the battery strings are connected to the first positive terminal 210.

[0152] Figure 7 This is a functional block diagram of an example embodiment of the switch control module 240. The switching module 704 applies signals to the switches 232 (switch group) of the battery module 224 (e.g., the gate terminals) to control the actuation of the switches 232 and control whether each of the battery modules 224 is in an open circuit (X) state, a series (S) state, or a parallel (P) state.

[0153] The switching module 704 applies signals based on inputs from the model predictive control (MPC) module 708. The MPC module 708 determines the current power mode, phase duration, and string and module disconnection times based on one or more operating parameters, and generates an output to the switching module 704 based on the current power mode. The MPC module 708 further generates the output based on constraints 712 set by the constraint module 716. Examples of constraints 712 include, for example: when its battery module is in an X-connection, the battery string cannot be connected to either the first positive terminal 210 or the second positive terminal 214. The battery string cannot be connected to both the first positive terminal 210 and the second positive terminal 214 simultaneously. When the battery module is to be connected in parallel (P) mode, the battery string cannot be connected to the second positive terminal 214 multiple times. The phase duration can be constrained to meet the requirements at the first positive terminal 210. The connection duration of each string can be limited (constrained) until the end of the phase. The number of channels (battery strings) for each battery module can be constrained to meet the requirements at the second positive terminal 210. Another constraint is that only one battery string of a battery module can be disconnected from the second positive terminal 214 before the end of the phase during which the battery module operates in parallel mode, in order to better balance the SOC of the battery module string. The other two battery strings of this battery module are connected to the positive terminal until the end of the phase in which the battery module operates in parallel mode. This constraint can minimize the computational workload associated with switching. Moreover, the phase duration can be left unconstrained (via constraint 712) to a fixed length or the same length. Therefore, the MPC module 708 can better and faster balance the SOC of the battery strings and the battery module.

[0154] One, more, or all of the constraints 712 may be fixed. In various implementations, one or more of the constraints 712 may be variable. The constraint module 716 may set variable constraints based on one or more operating parameters 714. Examples of operating parameters 714 include, for example, the current power mode, the prediction duration of the current power mode, and other example operating parameters.

[0155] The State of Charge (SOC) module 718 determines the current SOC 720 of each of the battery strings. In other words, the SOC module 718 determines the current SOC 720 of each battery string individually. The SOC module 718 may determine the current SOC of the battery string based, for example, on at least one of the voltage across the battery string and the current flowing into and out of the battery string. The SOC module 718 may use at least one of the equations and lookup tables that relate voltage and / or current to SOC to determine the current SOC of the battery string. In various embodiments, the SOC module 718 may determine the SOC of the battery string based on the impedance of the battery string, for example, to more accurately correlate voltage and current with SOC. The SOC module 718 performs this operation for each battery string. Voltage and current sensors may be used separately to measure the voltage and current of the battery string 724.

[0156] MPC module 708 controls the switching (via switching module 704) to minimize the error (e.g., sum of squared errors) between the state of charge (SOC) of the battery strings for the current power mode. MPC module 708 can further control the switching based on the current output demand via the first positive terminal 210 and the second positive terminal 214, and the predicted output demand from the first positive terminal 210 and the second positive terminal 214. The current output demand and the predicted output demand are illustrated by 728. Due to constraint 712, MPC module 708 allows only one battery string to be disconnected before the end of a phase during charging or discharging. This simplifies the control of the switching and reduces the computational workload associated with the switching control.

[0157] To balance the SOC of string 720, MPC is used. MPC module 708 sets the duration of each of the three phases (Phase 1, Phase 2, and Phase 3), the number of battery strings connected when in P mode, and the duration for which each battery string is connected in P mode. The duration of the phases can be set to different lengths based on string and / or module balancing. Each power mode has an associated set of configurations (X mode, P mode, or S mode) for the battery modules 224 used in that power mode. A table illustrating the power modes and battery module modes for each phase is provided below. MPC module 708 repeatedly cycles through the phases (Phase 1, Phase 2, Phase 3, then back to Phase 1, etc.) until the power mode is changed.

[0158] Power mode Phase 1 Phase 2 Phase 3 Condition 1 (XXX mode) XXX XXX XXX OFF 2 (XXP mode) XXP PXX XPX 12V Sleep Mode 3 (XXS mode) XXS SXX XSX 48V Low Power Mode with Diagnostics 4 (XPP mode) XPP PXP PPX 12V Medium Power Mode with Diagnostics 5 (SXP mode) SXP PSX XPS Low-power 2-voltage mode with diagnostics 6 (XSS mode) XSS SXS SSX 48V medium power with diagnostics 7 (PPP model) PPP PPP PPP 12V high-power crank start mode 8 (PPS mode) PPS SPP PSP Normal 2-voltage mode 9 (PSS mode) PSS SPS SSP Normal 2-voltage mode 10 (SSS Mode) SSS SSS SSS 48V High Power Mode

[0159] The example table above provides the battery module modes for each stage. For example, in Power Mode 5 (SXP mode), during the first stage (Stage 1), the first battery module operates in series (S) mode, the second battery module operates in open circuit (X) mode, and the third battery module operates in parallel (P) mode. Before the end of the first stage, only one string of the third battery module (operating in P mode) can be disconnected to better balance the strings of the third battery module. During the second stage (Stage 2) of Power Mode 5, the first battery module operates in parallel (P) mode, the second battery module operates in series (S) mode, and the third battery module operates in open circuit (X) mode. Before the end of the second stage, only one string of the first battery module (operating in P mode) can be disconnected to better balance the strings of the first battery module. During the third stage (Stage 3) of Power Mode 5, the first battery module operates in open circuit (X) mode, the second battery module operates in parallel (P) mode, and the third battery module operates in series (S) mode. Before the end of the third phase, only one string of the second battery module (operating in P mode) can be disconnected to better balance the strings of the second battery module.

[0160] The MPC module 708 sets the duration (length) of each of the first, second, and third stages based on the balance of the State of Charge (SOC) of each battery string and each battery module. For example, if the battery string of one battery module (e.g., on average) has a lower SOC than the other two battery modules, during charging, the MPC module 708 can set one or more stages of the one battery module operating in parallel (P) mode to be longer than one or more stages of the other two battery modules. This will result in the SOC of the other two battery modules increasing less than the SOC of the one battery module, making the SOC more balanced across the battery modules. During discharging, if the battery string of one battery module (e.g., on average) has a lower SOC than the other two battery modules, the MPC module 708 can set one or more stages of the one battery module operating in parallel (P) mode to be shorter than one or more stages of the other two battery modules. This will result in the SOC of the other two battery modules decreasing more than the SOC of the one battery module, making the SOC more balanced across the battery modules.

[0161] The MPC module 708 also sets the duration (length / period) of each battery string connected to the second positive terminal 214 for each phase to balance the individual SOCs of the battery strings in each module. For example, during charging, when one battery string of a battery module has a lower SOC than the other battery strings in the same module, the MPC module 708 can set the duration of connection of said one battery string to the second positive terminal 214 to be longer than the duration of connection of said one battery string to the second positive terminal 214. This will cause the SOC of said one battery string to increase more than the SOC of the other battery strings in the same module, resulting in a more balanced SOC within the battery module. The MPC module 708 performs this operation for each battery module. During discharging, when one battery string of a battery module has a lower SOC than the other battery strings in the same module, the MPC module 708 can set the duration of connection of said one battery string to the second positive terminal 214 to be shorter than the duration of connection of connection of said one battery string to the second positive terminal 214. This will cause the SOC of said one battery string to decrease less than the SOC of connection of said one battery string in the same module, resulting in a more balanced SOC within the battery module. MPC module 708 performs this operation for each battery module.

[0162] As another example, during charging, when one battery string of a battery module has a higher SOC than the other battery strings of the same module, the MPC module 708 can set the duration for which said one battery string is connected to the second positive terminal 214 such that said one battery string is disconnected before the end of the phase (i.e., shorter than the phase) and the other two battery strings are connected to the second positive terminal 214 for the entire phase (i.e., the length of the phase). This will result in the SOC of said one battery string of the battery module increasing by less than the SOC of the other battery strings of the battery module, making the SOC more balanced within the battery module. The MPC module 708 performs this operation for each battery module. During discharging, when one battery string of a battery module has a lower SOC than the other battery strings of the same module, the MPC module 708 can set the duration for which said one battery string is disconnected before the end of the phase (i.e., shorter than the phase) and the other two battery strings are connected to the second positive terminal 214 for the entire phase (i.e., the length of the phase). This will result in the SOC of one battery string in the battery module being less reduced than the SOC of the other battery strings in the battery module, making the SOC more balanced within the battery module. The MPC module 708 performs this operation for each battery module.

[0163] Figure 8This includes an example time series for operation in Power Mode 5 (SXP) when battery 208 is charged through the second positive terminal 214 while simultaneously being charged or discharged (e.g., with a small current) through the first positive terminal 210. 804 is the first stage (stage 1), 808 is the second stage (stage 2), and 812 is the third stage (stage 3). As used herein, MNO mode may mean that the first battery module operates in mode M, the second battery module operates in mode N, and the third battery module operates in mode O, where M, N, and O are all one of parallel (P), series (S), or open circuit (X). For example, the first stage includes SXP mode, where the first battery module operates in series (S) mode, the second battery module operates in open circuit (X) mode, and the third battery module operates in parallel (P) mode. The second stage includes operation in PSX mode, where the first battery module operates in parallel (P) mode, the second battery module operates in series (S) mode, and the third battery module operates in open circuit (X) mode. The third stage includes operation in XPS mode, in which the first battery module operates in open circuit (X) mode, the second battery module operates in parallel (P) mode, and the third battery module operates in series (S) mode.

[0164] exist Figure 8 In the example, MPC module 708 sets the duration of the second stage to be longer than the duration of the third stage and sets the duration of the third stage to be shorter than the duration of the first stage. Through the second positive terminal 214, more charging is allowed for the battery string of the first battery module (which is connected in parallel (P) mode in the second stage) than for the other battery modules, and less charging is allowed for the battery string of the second battery module (which is connected in parallel (P) mode in the third stage) than for the battery string of the third battery module. The third battery module operates in parallel (P) mode in the first stage.

[0165] During the first phase 804, the MPC module 708 connects the third battery string 824 of the third battery module to the second positive terminal 214 for a total duration less than that of the first battery string 816 and the second battery string 820 of the third battery module. This allows the first battery string 816 and the second battery string 820 of the third battery module to charge more than the third battery string 824 of the third battery module, in order to balance the SOC of the first battery string 816, the second battery string 820 and the third battery string 824 of the third battery module.

[0166] During the second phase 808, the MPC module 708 connects the first battery string 828 of the first battery module to the second positive terminal 214 for a total duration shorter than that of the second battery string 832 and the third battery string 836 of the first battery module. This allows the second battery string 832 and the third battery string 836 of the first battery module to charge more than the first battery string 828 of the first battery module, in order to balance the SOC of the first battery string 828, the second battery string 832, and the third battery string 836 of the first battery module.

[0167] During the third phase 812, the MPC module 708 connects the second battery string 844 of the second battery module to the second positive terminal 214 for a total duration shorter than that of the first battery string 840 and the third battery string 848 of the second battery module. This allows the first battery string 840 and the third battery string 848 of the second battery module to charge more than the second battery string 844 of the second battery module, in order to balance the SOC of the first battery string 840, the second battery string 844, and the third battery string 848 of the second battery module.

[0168] Assuming the power mode remains unchanged, control then returns to stage one. In other words, control continues from stage 1 to stage 2 to stage 3, and then repeats stages 1-3 in the same order.

[0169] Although discussed in the diagram of charging Figure 8 However, similar principles apply to discharge scenarios. For example, if the SOC of the third string of the first, second, and third battery modules is lower than the SOC of the first and second strings of the first to third battery modules, respectively, the MPC module 708 can connect the third string of the first to third battery modules to the second positive terminal 214 during the corresponding period, with a total duration shorter than that of the first and second strings. This results in the third string discharging less than the first and second strings and balances the SOC of the battery strings.

[0170] Figure 9 This is a flowchart illustrating an example method for determining the State of Charge (SOC) of the battery strings in the battery modules of the balancing battery 208. Control begins at 904, where the SOC module 718 determines the SOC of the battery strings (first, second, and third) of each of the battery modules 224 (first, second, and third) of the battery 208.

[0171] At 908, the SOC module 718 can determine the SOC of the battery modules (first, second, and third) based on the battery strings of the battery modules respectively. For example, the SOC module 718 can determine the SOC of the first battery module based on the average SOC of the battery strings (first, second, and third) of the first battery module. The SOC module 718 can determine the SOC of the second battery module based on the average SOC of the battery strings (first, second, and third) of the second battery module. The SOC module 718 can determine the SOC of the third battery module based on the average SOC of the battery strings (first, second, and third) of the third battery module.

[0172] At 912, the MPC module 708 determines the power mode, as described above. The MPC module 708 can select one of the above power modes, such as SXP mode, XPP mode, XXP mode, or another of the above modes.

[0173] At 916, the MPC module 708 determines the stage duration (the time period of the first, second, and third stages) based on the power mode and the SOC of the battery module. For example, for discharge, when the SOC of the battery module is lower than that of other battery modules, the MPC module 708 may set the duration of the stage when the battery module is connected in parallel (P) mode to be shorter than the duration of other stages. The MPC module 708 uses MPC to determine the stage duration, and the stage durations may differ. In other words, the stage durations are not constrained (via constraint 712) to be the same.

[0174] At 920, the MPC module 708 determines the duration for which each string of each battery module is connected within the phase. As discussed above, only one string of a battery module that will operate in P mode during a phase can be disconnected before the end of that phase. For example, during charging, when two battery strings have a lower SOC than another battery string, the MPC module 708 can charge these two battery strings for a longer period (until the end of the phase) than the other battery string (which is disconnected before the end of the phase). During discharging, when a battery string has a higher SOC than another battery string, the MPC module 708 can discharge the battery string for a longer period than the other battery string. The MPC module 708 uses MPC to determine the duration of the battery string connection and can, via constraint 712, set only one of the battery strings of a battery module to be disconnected before the end of the phase (during which the battery module will operate in P mode).

[0175] In various implementations, 912 and 916 can be executed simultaneously by MPC module 708. The optimization cost criterion can be zero when all string SOCs are equal, and it can become larger as the difference between SOCs increases. One possible formula for this cost criterion is a weighted sum of the squared differences between adjacent pairs of SOCs in a cyclic chain including all strings, obtained within the planning scope consisting of one or more complete cycles through three stages. To avoid overheating any string, an additional penalty, such as the cost in the total connection time of the strings, can be added. The variables in the optimization are the stage duration and the duration of connection of each string configured with P. Minimization of the cost criterion is subject to constraint 712. Violating the constraint increases the cost of the possibility and thus prevents that possibility from being selected and used. Given the output requirements and prediction 728, the cost criterion can be evaluated by MPC module 708 for any set of connection durations. The solution to the minimization problem is to balance the set of stage durations and string connection durations of the string SOCs as close as possible within the planning scope, subject to constraint 712 and taking into account any additional penalty terms.

[0176] At 924, switching module 704 actuates switch 232 based on power mode, phase duration, and battery string duration. Control returns to 904 for the next cycle.

[0177] Figure 10 This includes an example curve showing the change over time 1002 when battery 208 is charging in power mode 8 (PPS). 1004 is the first stage (stage 1), 1008 is the second stage (stage 2), and 1012 is the third stage (stage 3). Row 1016 represents the first battery module, row 1020 represents the second battery module, and row 1024 represents the third battery module. The 1, 2, and 3 in the rows represent the first, second, and third strings of that battery module.

[0178] As illustrated, during the first phase 1004, the first and second battery modules 1016 and 1020 operate in P mode, and the third module 1024 operates in S mode. During the first phase 1004, only the third string (3) of the first battery module 1016 is disconnected before the end of the first phase 1004. The end of the first phase 1004 is... Figure 10 The diagram is composed of 1028.

[0179] During the second phase 1008, the second and third battery modules 1020 and 1024 operate in P mode, and the first module 1016 operates in S mode. During the second phase 1008, only the first string (1) of the second battery module 1020 is disconnected before the end of the second phase 1008. The end of the second phase 1008 is... Figure 10 The diagram is illustrated in 1032.

[0180] During the third phase 1012, the first and third battery modules 1016 and 1024 operate in P mode, and the second module 1020 operates in S mode. During the third phase 1012, only the second string (2) of the third battery module 1024 is disconnected before the end of the third phase 1012. The end of the third phase 1012 is... Figure 10 The diagram is composed of 1036.

[0181] Figure 11 This is an example time series illustrating the State of Charge (SOC) of a battery module string during charging by disconnecting one of the strings before the end of a phase. Allowing disconnection of one string before the end of a phase simplifies control and reduces the computational workload of the MPC module 708.

[0182] Initially, at time 1104, the first and third battery strings (A1 and A3) of the battery module have a lower SOC than the second battery string (A2). At 1108, at the beginning of a phase during which the battery module operates in P mode, the first, second, and third battery strings (A1, A2, and A3) are connected to the second positive terminal 214, thereby charging the first, second, and third battery strings.

[0183] At 1112, before the end of the phase, the switch control module 240 disconnects the second string (A2) from the second positive terminal 214 to balance the SOC of the first, second, and third strings. The first and third strings (A1 and A3) continue charging during 1112. At 1116, the switch control module 240 has disconnected all the first, second, and third strings (A1, A2, and A3) from the second positive terminal 214. As illustrated, the SOC of the strings is more balanced than it was initially at 1104.

[0184] The example charging amplitude is shown for illustrative purposes only, and the charging amplitude may differ from that shown.

[0185] Figure 12 Includes example curves showing the change of SOC 1204 of the battery string over time 1208 during discharge, based on the string and module balancing discussed above. As illustrated, although the SOCs are initially different, they become approximately equal relatively quickly. Higher currents can lead to string and module balancing being achieved even faster. The 10,000-second timescale is... Figure 12 The example provided is for illustrative purposes only and should not imply that string and / or module balancing will take that long.

[0186] The foregoing description is illustrative in nature and is in no way intended to limit this disclosure, its application, or use. The broad teachings of this disclosure can be implemented in various forms. Therefore, while this disclosure includes specific examples, its true scope should not be so limited, as other modifications will become apparent upon examination of the drawings, specification, and appended claims. It should be understood that one or more steps within a method may be performed in a different order (or simultaneously) without altering the principles of this disclosure. Furthermore, while each of the embodiments described above is described as having certain features, any one or more of those features described with reference to any embodiment of this disclosure may be implemented in and / or combined with features of any other embodiment, even if such combinations are not explicitly described. In other words, the described embodiments are not mutually exclusive, and substitutions of one or more embodiments for each other remain within the scope of this disclosure.

[0187] Various terms are used to describe spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.), including “connected,” “joined,” “linked,” “adjacent,” “next to,” “on top,” “above,” “below,” and “set.” Unless explicitly described as “direct,” when describing the relationship between first and second elements in the above disclosure, the relationship can be a direct relationship in which no other intermediate elements exist between the first and second elements, or an indirect relationship in which one or more intermediate elements exist between the first and second elements (spatially or functionally). As used herein, the phrase “at least one of A, B, and C” should be interpreted as meaning the logic of using the non-exclusive logic “OR” (A or B or C) and should not be interpreted as meaning “at least one of A, at least one of B, and at least one of C.”

[0188] In a diagram, the direction of the arrows typically indicates the flow of information (e.g., data or instructions) of interest. For example, when components A and B exchange various types of information, but the information transmitted from component A to component B is relevant to the diagram, the arrow may point from component A to component B. This unidirectional arrow does not imply that no other information is transmitted from component B to component A. Furthermore, for information sent from component A to component B, component B may send a request for the information or an acknowledgment of receipt of the information to component A.

[0189] In this application, including the following definitions, the term "module" or "controller" may be replaced by the term "circuit". The term "module" may refer to, be part of, or include the following: application-specific integrated circuit (ASIC); digital, analog, or mixed-signal analog / digital discrete circuit; digital, analog, or mixed-signal analog / digital integrated circuit; combinational logic circuit; field-programmable gate array (FPGA); processor circuitry (shared, dedicated, or grouped) that executes code; memory circuitry (shared, dedicated, or grouped) that stores code executed by the processor circuitry; other suitable hardware components that provide the aforementioned functionality; or some or all of the above, such as in a system-on-a-chip.

[0190] A module may include one or more interface circuits. In some examples, the interface circuits may include wired or wireless interfaces connected to a local area network (LAN), the Internet, a wide area network (WAN), or a combination thereof. The functionality of any given module disclosed herein may be distributed across multiple modules connected via the interface circuits. For example, multiple modules may allow for load balancing. In another example, a server (also referred to as a remote or cloud) module may perform some functions on behalf of a client module.

[0191] As used above, the term "code" can include software, firmware, and / or microcode, and can refer to programs, routines, functions, classes, data structures, and / or objects. The term "shared processor circuitry" covers a single processor circuitry that executes some or all of the code from multiple modules. The term "group processor circuitry" covers a processor circuitry that, in combination with additional processor circuitry, executes some or all of the code from one or more modules. References to multiple processor circuitry cover multiple processor circuitry on discrete dies, multiple processor circuitry on a single die, multiple cores of a single processor circuitry, multiple threads of a single processor circuitry, or a combination thereof. The term "shared memory circuitry" covers a single memory circuitry that stores some or all of the code from multiple modules. The term "group memory circuitry" covers a memory circuitry that, in combination with additional memory, stores some or all of the code from one or more modules.

[0192] The term "memory circuit" is a subset of the term "computer-readable medium." As used herein, the term "computer-readable medium" does not cover transient electrical or electromagnetic signals propagating through a medium (e.g., on a carrier wave); the term "computer-readable medium" can therefore be considered tangible and non-transient. Non-limiting examples of non-transient tangible computer-readable media are non-volatile memory circuits (e.g., flash memory circuits, erasable programmable read-only memory circuits, or masked read-only memory circuits), volatile memory circuits (e.g., static random access memory circuits or dynamic random access memory circuits), magnetic storage media (e.g., analog or digital magnetic tape or hard disk drives), and optical storage media (e.g., CDs, DVDs, or Blu-ray discs).

[0193] The apparatus and methods described in this application can be implemented, in part or in whole, by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions implemented in a computer program. The aforementioned function blocks, flowchart components, and other elements serve as software specifications that can be routinely converted into computer programs by skilled technicians or programmers.

[0194] A computer program includes processor-executable instructions stored on at least one non-transitory tangible computer-readable medium. A computer program may also include or depend on stored data. A computer program may encompass a basic input / output system (BIOS) for interacting with the hardware of a special-purpose computer, device drivers for interacting with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0195] Computer programs may include: (i) descriptive text to be parsed, such as HTML (Hypertext Markup Language), XML (Extensible Markup Language), or JSON (JavaScript Object Symbolization); (ii) assembly code; (iii) object code generated from source code by a compiler; (iv) source code executed by an interpreter; (v) source code compiled and executed by a just-in-time compiler; and so on. As an example only, source code can be written using syntax from languages ​​including C, C++, C#, Objective-C, Swift, Haskell, Go, SQL, R, Lisp, Java®, Fortran, Perl, Pascal, Curl, OCaml, Javascript®, HTML5 (Hypertext Markup Language 5th Revision), Ada, ASP (Active Server Pages), PHP (PHP: Hypertext Preprocessor), Scala, Eiffel, Smalltalk, Erlang, Ruby, Flash®, Visual Basic®, Lua, MATLAB, SIMULINK, and Python®.

Claims

1. A battery system, comprising: First positive terminal, second positive terminal, and negative terminal; switch; At least two battery modules, wherein each of the at least two battery modules comprises three battery cell strings, the battery cell strings being configured to operate at different times: It is connected in series with the first switch in the switch and connected to the first positive terminal; Connected in parallel to the second positive terminal via the second switch in the switch; and Disconnect from both the first positive terminal and the second positive terminal; and The switch control module is configured to: Determine the state of charge (SOC) of each battery cell string; Based on SOC, model predictive control is used to determine the time periods of each stage. Based on SOC, model predictive control is used to determine the time periods during which the string will be connected to the second positive and negative terminals, respectively, during the stated phase. The determination of these time periods includes: Set the time period of one of the strings in one of the battery modules to end before the end of the phase; and The time periods of the other two strings in one of the battery modules are set to end at the end of the phase; and The switch is selectively actuated based on the time period of the phase and the time period of the battery cell string. The switch control module is configured to use model predictive control to set the first time period of the first stage to one of the second time periods that is (a) greater than and (b) less than the second stage.

2. The battery system according to claim 1, wherein, The switch control module is configured to use model predictive control to set the third time period of the third stage as follows: (a) greater than and (b) less than the second of the said phases in the second time period; and (a) greater than and (b) less than the first of the first time periods in the said phase.

3. The battery system according to claim 1, wherein, The switch control module is configured to use model predictive control to set the first, second, and third time periods of the first, second, and third phases to different values ​​from each other.

4. The battery system according to claim 1, wherein, The switch control module is further configured to: Set the second time period in the second string of the battery module to end before the end of the second phase; and The time periods for the other two strings of the second battery module are set to end at the end of the second phase.

5. The battery system according to claim 1, wherein, The switch control module is configured to actuate the switch and: If, during a charging process in a battery module, the SOC of one of the strings in that battery module is greater than the SOC of the other strings in that battery module at the start of the phase, that string in that battery module is disconnected before the end of the phase. as well as The other strings in one of the battery modules are disconnected at the end of this phase.

6. The battery system according to claim 1, wherein, The switch control module is configured to actuate the switch and: During a discharge in a battery module, if the SOC of one of the strings in the battery module is less than the SOC of the other strings in the battery module at the start of the phase, the string in the battery module is disconnected before the end of the phase. as well as The other strings in one of the battery modules are disconnected at the end of this phase.

7. The battery system according to claim 1, wherein, The switch control module is configured to determine the time period of the phase and the time period of the string based on minimizing the error between the SOCs of the battery cell strings.

8. The battery system according to claim 7, wherein, The error is the squared error between the state of charge (SOC) of the battery cell strings.

9. The battery system according to claim 1, wherein, Each of the battery cell strings comprises multiple battery cells connected in series.

10. The battery system according to claim 9, wherein, The plurality of battery cells includes four 3-volt battery cells.

11. The battery system according to claim 1, wherein, The switch control module is configured to control a switch such that one of the battery cells in the battery cell string is not simultaneously connected to both the first positive terminal and the second positive terminal.

12. The battery system according to claim 1, wherein: The first positive terminal is configured to output the first reference potential; The second positive terminal is configured to output a second reference potential; and The first reference potential is greater than the second reference potential.

13. A method for using a battery, the method comprising: The state of charge (SOC) of the battery cell strings in at least two battery modules is determined, wherein each of the at least two battery modules comprises three battery cell strings configured to operate at different times: It is connected in series with the first switch in the switch and connected to the first positive terminal; Connected in parallel to the second positive terminal via the second switch in the switch; and Disconnect from both the first positive terminal and the second positive terminal; and Based on SOC, model predictive control is used to determine the time periods of each stage. Based on SOC, model predictive control is used to determine the time periods during which the string will be connected to the second positive and negative terminals, respectively, during the stated phase. The determination of these time periods includes: Set the time period of one of the strings in one of the battery modules to end before the end of the phase; and The time periods of the other two strings in one of the battery modules are set to end at the end of the phase; and The switch is selectively actuated based on the time period of the phase and the time period of the battery cell string. The time period for determining the stage includes: setting the first time period of the first stage as one of the second time periods that is (a) greater than and (b) less than the second stage.

14. The method according to claim 13, wherein, The determination of the time period of the phase further includes: setting the third time period of the third phase as: (a) greater than and (b) less than the second of the said phases in the second time period; and (a) greater than and (b) less than the first of the first time periods in the said phase.

15. The method according to claim 13, wherein, The time periods for determining the phase include setting the first, second, and third time periods of the phase to different values ​​from each other.

16. The method according to claim 13, wherein, The time period for determining the string includes: Set the second time period in the second string of the battery module to end before the end of the second phase; and The time periods for the other two strings of the second battery module are set to end at the end of the second phase.

17. The method according to claim 13, wherein, Selectively actuating the switch includes: an actuating switch and: During charging of one of the battery modules, if the State of Charge (SOC) of one of the strings in the battery module is greater than the SOC of the other strings in the battery module at the start of the phase, then that string in the battery module is disconnected before the end of the phase; and The other strings in one of the battery modules are disconnected at the end of this phase.

18. The method according to claim 13, wherein, Selectively actuating the switch includes: an actuating switch and: During a discharge phase in a battery module, if the State of Charge (SOC) of one string in the battery module is lower than the SOC of the other strings in the battery module at the start of the phase, then that string in the battery module is disconnected before the end of the phase; and The other strings in one of the battery modules are disconnected at the end of this phase.

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