Equalizing the charge state of a battery string with phase splitting

Abstract

Battery system, including: a first positive terminal a second positive terminal a negative terminal, Switch, two battery modules, each of which comprises three strings of battery cells designed to: to be connected in series and via the first of the switches to the first positive terminal, to be connected in parallel and via the second of the switches to the second positive terminal, and to be disconnected from both the first and second positive terminals, and a switching control module that is designed to to determine the state of charge (SOC) of each string of battery cells, To determine phase periods or to balance the SOCs of the battery modules using model predictive control, to determine periods for the strands using model predictive control, including setting one of the periods for one of the strands, which must be included in at least two of the phases, and to selectively actuate the switches based on the phase periods and the periods for the strings of battery cells.

Description

INTRODUCTION

[0001] The information contained in this section serves to provide a general context for the disclosure. Works by the presently named inventors, to the extent described in this introduction, as well as aspects of the description that cannot otherwise be considered prior art at the time of application, are neither expressly nor implicitly acknowledged as prior art with respect to this disclosure.

[0002] The present disclosure relates to vehicles and, more particularly, to vehicle battery systems.

[0003] Some vehicle types have only an internal combustion engine to generate drive torque. Hybrid vehicles have both an internal combustion engine and one or more electric motors. Some hybrid vehicle types use the electric motor and internal combustion engine to achieve greater fuel efficiency than using only the internal combustion engine. Some hybrid vehicle types use the electric motor and internal combustion engine to achieve higher torque output than the internal combustion engine could achieve alone.

[0004] Some types of hybrid vehicles include parallel hybrid vehicles, series hybrid vehicles, and other types of hybrid vehicles. In a parallel hybrid vehicle, the electric motor operates in parallel with the prime mover to combine the power and range advantages of the prime mover with the efficiency and regenerative braking advantages of the electric motor. In a series hybrid vehicle, the prime mover drives a generator to produce electricity for the electric motor, and the electric motor drives a transmission. This allows the electric motor to take over some of the power of the prime mover, allowing the use of a smaller and potentially more efficient prime mover. This application applies to electric vehicles, hybrid vehicles, and other types of vehicles.

[0005] Document DE 10 2020 102 806 A1 discloses a modular, dynamically allocated capacitance storage system comprising a housing and a control module, wherein the housing includes source terminals, switches, cells, and sensor modules. Source terminals supply power at a first voltage potential to a plurality of first loads and at a second voltage potential to a plurality of second loads. The control module can receive a power request signal and, based thereon, determine a connected configuration for the cells relative to each other and for the plurality of source terminals.

[0006] Document DE 10 2020 102 727 A1 discloses switching control systems and methods for batteries with adjustable capacity, including a plurality of individually housed batteries and a plurality of switches, wherein the switches are configured to connect one of the individually housed batteries to a first and second terminal. A switching control module is configured to vary a voltage applied to a gate of one of the switches at a frequency and to diagnose whether a fault exists based on a voltage across one of the switches. SUMMARY

[0007] In one feature, a battery system comprises: a first positive terminal, a second positive terminal, a negative terminal, switches, two battery modules each having three strings of battery cells configured to be connected in series and via a first of the switches to the first positive terminal, in parallel and via a second of the switches to the second positive terminal, and disconnected from both the first and second positive terminals at different times, and a switching control module configured to respectively determine states of charge (SOCs) of the strings of battery cells, to determine phase periods using a model predictive controller, and toto balance the SOCs of the battery modules, to determine periods for the strings using a model predictive controller, including setting one of the periods for one of the strings, which must be included in at least two of the phases, and to selectively operate the switches based on the phase periods and the periods for the strings of battery cells.

[0008] In further features, a first part of one of the periods for one of the strands lies in a first part of a first of the phases and a second part of one of the periods for one of the strands lies in a second part of a second of the phases.

[0009] In further features, a first part of a second of the periods for a second of the strands lies in a third part of the second of the phases and a second part of the second of the periods for the second of the strands lies in a fourth part of a third of the phases.

[0010] In further features, the switching control module is configured to set the one of the periods for the one of the strings to be included in at least two of the phases based on a first SOC of the one of the strings and a second SOC of a second of the strings.

[0011] In further features, the switching control module is configured to set the one of the periods for one of the strings to be included in the at least two of the phases during charging of the strings.

[0012] In further features, the switching control module is configured to adjust the one of the periods for one of the strings to be included in the at least two of the phases during discharging of the strings.

[0013] In further features, the switching control module is configured to set one of the periods longer than the longest of the phase periods.

[0014] In further features, the switching control module is configured to set a first period for a first of the strings of one of the battery modules to be longer than a second period for a second of the strings of the one of the battery modules during the charging process when a first SOC of the first of the strings is less than a second SOC of the second of the strings.

[0015] In further features, the switching control module is configured to set a first period for a first of the strings of one of the battery modules to be longer than a second period for a second of the strings of the one of the battery modules during the discharge process when a first SOC of the first of the strings is greater than a second SOC of the second of the strings.

[0016] In further features, the switching control module is configured to selectively set a first period for a first of the phases to be longer than a second period for a second of the phases during the charging process based on the SOCs of the strings.

[0017] In further features, the switching control module is configured to selectively set a first period for a first of the phases to be longer than a second period for a second of the phases during the discharge operation based on the SOCs of the strings.

[0018] In further features, each of the strings of battery cells comprises several battery cells connected in series.

[0019] In further features, the multiple battery cells include four three-volt battery cells.

[0020] In further features, the switch control module is configured to control the switches such that one of the strings of battery cells is not connected to the first positive terminal and the second positive terminal at the same time.

[0021] In further features, the first positive pole is configured to output a first reference potential, the second positive pole is configured to output a second reference potential, and the first reference potential is greater than the second reference potential.

[0022] In further features, a method for a battery comprises: determining states of charge (SOCs) of strings of battery cells and of a battery, the battery comprising: a first positive terminal, a second positive terminal, a negative terminal, switches, two battery modules, each of the two battery modules comprising three strings of the battery cells configured to be connected in series and to the first positive terminal at different times via first ones of the switches, connected in parallel and to the second positive terminal at different times via second ones of the switches, and disconnected from both the first and second positive terminals, determining phase periods and / orto balance the SOCs of the battery modules, to determine periods for the strings using a model predictive controller, including setting one of the periods for one of the strings, which must be included in at least two of the phases, and to selectively operate the switches based on the phase periods and the periods for the strings of battery cells.

[0023] In further features, a first part of one of the periods for one of the strands lies in a first part of a first of the phases and a second part of one of the periods for one of the strands lies in a second part of a second of the phases.

[0024] In further features, a first part of a second of the periods for a second of the strands lies in a third part of the second of the phases and a second part of the second of the periods for the second of the strands lies in a fourth part of a third of the phases.

[0025] In further features, setting the one of the periods comprises setting the one of the periods for the one of the strings to be included in at least two of the phases based on a first SOC of the one of the strings and a second SOC of a second of the strings.

[0026] In further features, setting the one of the periods comprises setting the one of the periods for one of the strings to be included in the at least two of the phases during discharging of the strings.

[0027] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims, and drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present disclosure will be more fully understood from the detailed description and the accompanying drawings, in which: Fig. 1 shows a functional block diagram of an exemplary engine control system, Fig. 2 shows a functional block diagram of an exemplary battery system of a vehicle, Fig. 3A-3B shows schematic diagrams, including the exemplary implementation of a battery system, Fig. 4 shows a functional block diagram of an exemplary implementation of a battery module in an open arrangement (X), Fig. 5 includes an exemplary representation of the battery module in a series arrangement (S), Fig. 6 includes an exemplary representation of the battery module in a parallel arrangement (P), Fig. 7 shows a functional block diagram of an exemplary shift control module, Fig.8 includes an exemplary time series for operation in a power mode during the charging process, Fig. 9 shows a flowchart illustrating an exemplary method for balancing the SOCs of the battery strings and modules of a battery, Fig. 10 includes an example diagram of the SOCs of battery strings over time during discharge using string and module balancing, Fig. 11 comprises an exemplary time series for operation in a power mode during phase split charging, and Fig. 12 includes an example graph of battery string SOCs over time during discharge using string and module balancing and phase splitting.

[0029] Reference numerals may be reused in the drawings to identify similar and / or identical elements. DETAILED DESCRIPTION

[0030] A vehicle includes a battery having a first terminal on a battery housing for outputting a first operating voltage (e.g., 48 V) and a second output terminal on the housing for outputting a second operating voltage (e.g., 12 V). The battery includes a plurality of battery modules and a plurality of switches. Each battery module includes a plurality of battery strings, and each battery string includes a plurality of battery cells. The switches are configured to connect strings together in series or individually to a terminal. The strings can also be disconnected from the first and second output terminals.

[0031] According to the present application, a model predictive control (MPC) module uses estimates of the battery strings' SOCs and controls the switches to minimize SOC errors across all battery strings and modules. The MPC module also enables phase splitting, where the periods of one or more battery strings overlap with two or more different phases. This ensures that each battery string is charged and discharged as evenly as possible, thereby extending battery life.

[0032] Based on Fig. 1 shows a functional block diagram of an exemplary propulsion system 100. The propulsion system 100 of a vehicle includes an engine 102 that combusts an air-fuel mixture to generate torque. The vehicle may be a non-autonomous or autonomous vehicle.

[0033] Air is drawn into the engine 102 through an intake system 108. The intake system 108 may include an intake manifold 110 and a throttle body 112. For example only, the throttle body 112 may include a throttle valve with a rotatable vane. An engine control module (ECM) 114 controls a throttle actuator module 116, and the throttle actuator module 116 regulates the opening of the throttle body 112 to control airflow into the intake manifold 110.

[0034] Air from intake manifold 110 is drawn into the cylinders of engine 102. Although engine 102 includes multiple cylinders, a single representative cylinder 118 is shown for illustrative purposes. For example only, engine 102 may include 2, 3, 4, 5, 6, 8, 10, and / or 12 cylinders. The ECM 114 may instruct a cylinder actuation module 120 to selectively deactivate some of the cylinders under certain circumstances, which may improve fuel economy.

[0035] The engine 102 may operate on a four-stroke or other suitable engine cycle. The four strokes of a four-stroke cycle described below are referred to as the intake stroke, compression stroke, power stroke, and exhaust stroke. For each revolution of a crankshaft (not shown), two of the four strokes occur within the cylinder 118. Therefore, two crankshaft revolutions are required for the cylinder 118 to complete all four strokes. In four-stroke engines, one engine cycle may correspond to two crankshaft revolutions.

[0036] When cylinder 118 is activated, air is drawn from intake manifold 110 through an intake valve 122 into cylinder 118 during the intake stroke. The ECM 114 controls a fuel control module 124, which regulates fuel injection to achieve a desired air-fuel ratio. Fuel may be injected at a central location or at multiple locations within intake manifold 110, such as near the intake valve 122 of each cylinder. In various implementations (not shown), fuel may be injected directly into the cylinders or into the mixing chambers / ports associated with the cylinders. The fuel control module 124 may interrupt the injection of fuel into deactivated cylinders.

[0037] The injected fuel mixes with air, creating an air-fuel mixture in cylinder 118. During the compression stroke, a piston (not shown) within cylinder 118 compresses the air-fuel mixture. The engine 102 may be a compression-ignition engine, where compression causes the air-fuel mixture to ignite. Alternatively, the engine 102 may be a gasoline engine, where a spark control module 126, based on a signal from the ECM 114, activates a spark plug 128 in cylinder 118, igniting the air-fuel mixture. Some engine types, such as homogeneous charge compression ignition (HCCI) engines, may have both compression ignition and spark ignition. Ignition timing can be specified relative to the time at which the piston is at its top position, known as top dead center (TDC).

[0038] The spark control module 126 can be controlled by a timing signal that indicates how far before or after TDC the spark should be generated. Since piston position is directly related to crankshaft rotation, the operation of the spark control module 126 can be synchronized with the crankshaft position. The spark control module 126 can interrupt or provide spark to deactivated cylinders.

[0039] During the power stroke, the combustion of the air-fuel mixture drives the piston downward, thus rotating the crankshaft. The power stroke can be defined as the time between the time the piston reaches top dead center (TDC) and the time the piston returns to its lowest position, known as bottom dead center (BDC).

[0040] During the exhaust stroke, the piston begins to move upward from BDC and expels the combustion byproducts through an exhaust valve 130. The combustion byproducts are removed from the vehicle via an exhaust system 134.

[0041] Intake valve 122 may be controlled by an intake camshaft 140, while exhaust valve 130 may be controlled by an exhaust camshaft 142. In various implementations, multiple intake camshafts (including intake camshaft 140) may control multiple intake valves (including intake valve 122) for cylinder 118 and / or control the intake valves (including intake valve 122) of multiple banks of cylinders (including cylinder 118). Similarly, multiple exhaust camshafts (including exhaust camshaft 142) may control multiple exhaust valves for cylinder 118 and / or control exhaust valves (including exhaust valve 130) for multiple banks of cylinders (including cylinder 118). Valve actuation is shown and explained using a single camshaft, but camless valve actuation may also be used.Although separate intake and exhaust camshafts are shown, a single camshaft with cams for the intake and exhaust valves can also be used.

[0042] The cylinder actuation module 120 may deactivate the cylinder 118 by blocking the opening of the intake valve 122 and / or the exhaust valve 130. The timing at which the intake valve 122 opens relative to piston TDC may be varied by an intake camshaft phaser 148. The timing at which the exhaust valve 130 opens relative to piston TDC may be varied by an exhaust camshaft phaser 150. A phaser actuation module 158 may control the intake camshaft phaser 148 and the exhaust camshaft phaser 150 based on signals from the ECM 114. In various implementations, camshaft timing may be omitted. Variable valve lift, not shown, may also be controlled by the phaser actuation module 158. In various other embodiments, the intake valve 122 and / or the exhaust valve 130 may be controlled by actuators other than a camshaft, e.g.by electromechanical actuators, electrohydraulic actuators, electromagnetic actuators, etc.

[0043] The engine 102 may include none, one, or more than one boost device that supplies compressed air to the intake manifold 110. Fig. For example, Figure 1 shows a turbocharger with a turbocharger turbine 160-1 driven by the exhaust gases flowing through the exhaust system 134. Superchargers represent another type of boost pressure device.

[0044] The turbocharger also includes a turbocharger compressor 160-2, which is driven by the turbocharger turbine 160-1 and compresses the air flowing into the throttle body 112. A wastegate (WV) 162 controls the flow of exhaust gas through and past the turbocharger turbine 160-1. Boost valves may also be referred to as (turbocharger) turbine bypass valves. The wastegate 162 allows exhaust gas to bypass the turbocharger turbine 160-1 to reduce the intake air compression generated by the turbocharger. The ECM 114 may control the turbocharger via a boost control module 164. The boost control module 164 may modulate the turbocharger boost pressure by controlling the opening of the wastegate 162.

[0045] A cooler (e.g., a charge air cooler or intercooler) may remove some of the heat contained in the compressed air charge that may be generated during air compression. Although shown separately for illustrative purposes, the turbocharger turbine 160-1 and the turbocharger compressor 160-2 may be mechanically linked so that the intake air is in close proximity to the hot exhaust gases. The compressed air charge may absorb heat from the components of the exhaust system 134.

[0046] The engine 102 may include an exhaust gas recirculation (EGR) valve 170 that selectively redirects exhaust gases to the intake manifold 110. The EGR valve 170 may receive exhaust gases upstream of the turbocharger turbine 160-1 in the exhaust system 134. The EGR valve 170 may be controlled by an EGR actuator module 172.

[0047] Crankshaft position may be measured with a crankshaft position sensor 180. Engine speed may be determined from the crankshaft position measured with the crankshaft position sensor 180. Engine coolant temperature may be measured with an engine coolant temperature (ECT) sensor 182. The ECT sensor 182 may be located within the engine 102 or at other locations where coolant circulates, such as on a radiator (not shown).

[0048] The pressure in the intake manifold 110 may be measured with a manifold absolute pressure (MAP) sensor 184. In various implementations, the boost pressure, i.e., the difference between the ambient air pressure and the pressure within the intake manifold 110, may be measured. The mass flow of air flowing into the intake manifold 110 may be measured with a mass air flow (MAF) sensor 186. In various implementations, the MAF sensor 186 may be housed in a housing that also includes the throttle body 112.

[0049] The position of the throttle valve 112 may be measured using one or more throttle position (TPS) sensors 190. The temperature of the air drawn into the engine 102 may be measured using an intake air temperature (IAT) sensor 192. One or more other sensors 193 may also be employed. The other sensors 193 include an accelerator pedal position (APP) sensor, a brake pedal position (BPP) sensor, a clutch pedal position (CPP) sensor (e.g., in a manual transmission), and one or more other sensor types. An APP sensor measures the position of an accelerator pedal in the passenger compartment of the vehicle. A BPP sensor measures the position of a brake pedal in the passenger compartment of the vehicle. A CPP sensor measures the position of a clutch pedal in the passenger compartment of the vehicle. The other sensors 193 may also include one or more acceleration sensors that measure the longitudinal acceleration (e.g.Measure the vehicle's forward / reverse acceleration and lateral acceleration. An accelerometer is just one example of an acceleration sensor. However, other types of acceleration sensors may also be used. The ECM 114 may use signals from the sensors to make control decisions for the engine 102.

[0050] For example, the ECM 114 may communicate with a transmission control module 194 to coordinate engine operation with gear shifting in a transmission 195. For example, the ECM 114 may communicate with a hybrid control module 196 to coordinate operation of the engine 102 and an electric motor 198. Although the example of one electric motor is given, multiple electric motors may be used. The electric motor 198 may be a permanent magnet electric motor or other suitable electric motor that outputs a voltage when freely rotated due to back-to-back electromagnetic fields (EMF), such as a direct current (DC) or synchronous electric motor. In various implementations, various functions of the ECM 114, the transmission control module 194, and the hybrid control module 196 may be integrated into one or more modules.

[0051] Any system that changes an engine parameter may be referred to as an engine actuator. Each engine actuator is associated with an actuator value. For example, the throttle actuator module 116 may be referred to as the engine actuator, and the throttle opening range may be referred to as the actuator value. In the example of Fig. 1, the throttle valve actuating module 116 achieves the throttle valve opening range by adjusting an angle of the blade of the throttle valve 112.

[0052] The spark control module 126 may also be referred to as the engine actuator, while the corresponding actuator value may be the amount of spark advance relative to cylinder TDC. Other engine actuators may include the cylinder actuator module 120, the fuel control module 124, the phaser actuator module 158, the boost control module 164, and the EGR control module 172. For these engine actuators, the actuator values ​​may correspond to a cylinder activation / deactivation sequence, fuel delivery, intake and exhaust camshaft angles, a desired wastegate opening, and the EGR valve opening, respectively.

[0053] The ECM 114 may control the actuator values ​​to cause the engine 102 to output torque based on a torque request. For example, the ECM 114 may determine the torque request based on one or more driver inputs such as an APP, a BPP, a CPP, and / or one or more other suitable driver inputs. For example, the ECM 114 may determine the torque request using one or more functions or lookup tables that relate the driver input(s) to torque requests.

[0054] Under certain circumstances, the hybrid control module 196 controls the electric motor 198 to output torque, for example, to supplement the torque output of the engine. The hybrid control module 196 may also control the electric motor 198 to output torque for vehicle propulsion when the engine 102 is off.

[0055] The hybrid control module 196 supplies the electric motor 198 with electrical energy from a battery 208 to cause the electric motor 198 to output positive torque. The battery is discussed further below. The electric motor 198 may output torque, for example, to an input shaft of the transmission 195, to an output shaft of the transmission 195, or to another component. A clutch 200 may be used to couple the electric motor 198 to the transmission 195 and to decouple the electric motor 198 from the transmission 195. One or more gearing devices may be installed between an output of the electric motor 198 and an 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 implementations, the electric motor 198 may be omitted.

[0056] The ECM 114 starts the engine 102 via a starter motor 202. The ECM 114 or another suitable module of the vehicle connects the starter motor 202 to the engine 102 for an engine starting operation. For example only, the ECM 114 may connect the starter motor 202 to the engine 102 when a key-on command is received. A driver may input a key-on command, such as by actuating one or more of the vehicle's ignition keys, buttons, and / or switches, or a vehicle key fob. The starter motor 202 may energize a flywheel coupled to the crankshaft or one or more other suitable components that rotate the crankshaft.

[0057] The ECM 114 may also start the engine following an auto-start command during an auto-stop / start event or following an engine start command for a coasting event. Auto-stop / start events include shutting down the engine 102 while the vehicle is stationary, if the driver has applied the brake pedal and has not provided a key-off command. An auto-start command may be generated when the engine 102 is shut down for an auto-stop / start event, such as when the driver releases the brake pedal and / or applies the accelerator pedal.

[0058] Coasting events may include the ECM 114 shutting down the engine 102 when the vehicle is moving (e.g., when the vehicle speed is above a predetermined speed, such as approximately 50 mph), the driver is not pressing the accelerator pedal, and the driver has not input a key-off command. An engine start command may be generated when the engine 102 is shut down for a coasting event, e.g., when the driver presses the accelerator pedal. The driver may input a key-off command, such as by pressing the one or more ignition keys, buttons, and / or switches as described above.

[0059] A starter actuator, such as a solenoid, may engage the starter 202 with the engine 102. For example only, the starter actuator may engage a starter pinion gear with a flywheel coupled to the crankshaft. In various implementations, the starter pinion gear may be connected to the starter 202 via a driveshaft and a one-way clutch. A starter actuator module 204 controls the starter actuator and the starter 202 based on signals from a starter control module, as described further below. In various implementations, the starter 202 may be maintained engaged with the engine 102.

[0060] Upon a command to start the engine 102 (e.g., an autostart command, an engine start command to end a coasting event, or when a key-on command is received), the starter actuator module 204 supplies power to the starter 202 to start the engine 102. The starter actuator module 204 may also trigger the starter actuator to connect the starter 202 to the engine 102. The starter actuator module 204 may supply power to the starter 202 after the starter 202 is connected to the engine 102, for example, to enable gear engagement.

[0061] By supplying power to starter 202, starter 202 rotates, and starter 202 rotates the crankshaft (e.g., via the flywheel). The period during which starter 202 drives the crankshaft to start engine 102 may be referred to as engine cranking.

[0062] The starter motor 202 draws power from the battery 208 to start the engine 102. Once the engine 102 is running following the engine cranking process, the starter motor 202 disengages or decouples from the engine 102, and power flow to the starter motor 202 may be interrupted. For example, the engine 102 may be considered running when the engine speed exceeds a predetermined speed, such as a predetermined idle speed. For example only, the predetermined idle speed may be approximately 700 revolutions per minute (RPM) or another suitable speed. Engine cranking may be considered complete when the engine 102 is running.

[0063] A generator 206 converts the mechanical energy of the engine 102 into alternating current (AC) power. For example, the generator 206 may be coupled to the crankshaft (e.g., via a gear or belt) and convert the mechanical energy of the engine 102 into AC power by applying a load to the crankshaft. The generator 206 converts the AC power to DC power and stores the DC power in the battery 208. Alternatively, a rectifier may be implemented external to the generator 206 to convert the AC power to DC power. The generator 206 may, for example, be an AC generator. In various implementations, such as a belt-driven starter-generator (RSG), the starter 202 and the generator 206 may be implemented together.

[0064] Fig.2 is a functional block diagram of an exemplary battery system of a vehicle. Battery 208 has at least two output terminals and one negative terminal to provide at least two DC operating voltages. For example only, battery 208 may have a first positive terminal 210 (e.g., nominally rated at 48 volts (V)), a negative terminal 212, and a second positive terminal 214 (e.g., nominally rated at 12 V). Although battery 208 has a nominal operating voltage of 48 V and a nominal operating voltage of 12 V in this example, battery 208 may also have one or more other operating voltages.

[0065] The battery 208 includes a plurality of battery modules, such as a first battery module 224-1, ... and an Nth battery module 224-N ("battery modules 224"), where N is an integer greater than or equal to 2. In various implementations, N may be equal to 2, 3, 4, 5, 6, 8, 10, or 12.

[0066] As shown below Fig. As explained in Figure 4, each of the battery modules 224 includes multiple battery strings. Each battery string may be individually replaceable. Because the battery strings can be individually replaced, the battery 208 may have a shorter warranty period and lower warranty costs. The battery strings may also be individually disconnected, for example, in the event of a failure in one battery string. In various implementations, the battery 208 may have the form factor of a standard 12V automotive battery.

[0067] Battery 208 includes a plurality of switches, such as first switches 232-1, ..., Nth switches 232-N (collectively, "switch 232"). Switches 232 can connect battery strings 224 in series, parallel, or a combination of series and parallel to provide desired output voltages and capacitances at the output terminals.

[0068] A switching control module 240 controls the switches 232 to provide the desired output voltages and capacitances at the output terminals. The switching control module 240 controls the switches 232 using model predictive control (MPC) to balance the states of charge (SOCs) of the battery strings as closely as possible.

[0069] Fig.3A-3B are schematic representations of an example battery system including battery 208. Sets of battery strings may be connected in series (via one of switches 232) to first positive terminal 210 and negative terminal 212 to provide a first nominal output voltage (e.g., 48 V) across first positive terminal 210. Individual ones of the battery strings may be connected (via individual ones of switches 232) to second positive terminal 214 and negative terminal 212 to provide a second nominal output voltage (e.g., 12 V) across second positive terminal 214. How many of the battery strings are connected to first positive terminal 210 and second positive terminal 214 determines the amounts of total capacity of battery 208 available at each of the positive terminals.

[0070] As in Fig.3B, a first set of vehicle electrical components operates at one of the two or more operating voltages of battery 208. For example, the first set of vehicle electrical components may be connected to second positive terminal 214. The first set of vehicle electrical components may include, for example, but not limited to, the ECM 114 and other control modules of the vehicle, the starter 202, and / or other electrical loads, such as first 12V loads 304, second 12V loads 308, other control modules 312, third 12V loads 316, and fourth 12V loads 320. In various implementations, a switching device 324 may be implemented.

[0071] As in Fig.3A, a second set of vehicle electrical components operates at a different one of the two or more operating voltages of battery 208. For example, the second set of vehicle electrical components may be connected to the first positive terminal 210. The second set of vehicle electrical components may include, for example, but not limited to, the generator 206 and various electrical loads, such as 48V loads 328. The generator 206 may be controlled to charge the battery 208.

[0072] Each of the switches 232 may be an insulated gate bipolar transistor (IGBT), a field effect transistor (FET), such as a metal oxide semiconductor FET (MOSFET), or another suitable type of switch.

[0073] Fig.4 is a functional block diagram of an exemplary embodiment of one of the battery modules 224, a numbered battery module 404, and a set of switches 232. Each of the battery modules 224 may be identical, and each set of switches 232 may be identical.

[0074] Battery module 404 includes three battery strings, 408, 412, and 416. Battery strings 408-416 are identical and each include four battery cells 420, 424, 428, and 432. Battery cells 420-432 are connected in series to provide the second operating voltage (e.g., 12 V). Each of battery cells 420-432 may, for example, be a 3 V battery or have another suitable voltage to provide the second operating voltage. Battery cells 420-432 may, for example, be lithium ferrophosphate (LFP) battery cells or cells with another suitable chemistry.

[0075] The negative terminals of battery strings 408-416 are connected to negative terminal 212. The negative terminals of battery strings 408 and 412 are connected to negative terminal 212 via switches 436 and 440, respectively, when switches 436 and 440 are closed. 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 connected directly to negative terminal 212.

[0076] The positive terminal of battery string 416 is connected to the negative terminal of battery string 412, so 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, so 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.

[0077] Switches 452, 456, and 460 connect and disconnect the positive terminals of battery strings 408, 412, and 416 to and from a first bus (e.g., a 12V bus) connected to the second positive terminal 214. Switch 464 connects and disconnects the positive terminal of battery string 408 to and from a second bus (e.g., a 48V bus) connected to the first positive terminal 210.

[0078] The switching control module 240 controls the switching of the switches of the individual battery modules 224. The switching control module 240 can actuate the switches associated with a battery module at any time so that the battery module is in an open configuration (X), a series configuration (S), or a parallel configuration (P). Fig.Figure 4 contains an exemplary illustration of the battery module 404 in the open configuration (X). When a battery module is in the open configuration (X), all battery strings of the battery module are disconnected from both the first positive terminal 210 and the second positive terminal 214.

[0079] Fig. Figure 5 contains an exemplary illustration of the battery module 404 in the series configuration (S). When a battery module is connected in series (S), all battery strings of the battery module are connected in series and connected to the first positive terminal 210. To do this, switches 444, 448, and 464 are closed and all other switches 436, 440, 452, 456, and 460 are opened. None of the battery strings are connected to the second positive terminal 214 when the battery module is in the series configuration (S).

[0080] Fig.6 contains an exemplary illustration of the battery module 404 in the parallel (P) configuration. When a battery module is connected in parallel (P), all battery strings of the battery module are connected in parallel to the second positive terminal 214. To do this, switches 452, 456, 460, 436, and 440 are closed and all other switches 444, 448, and 464 are opened. None of the battery strings are connected to the first positive terminal 210 when the battery module is in the parallel (P) configuration.

[0081] Fig. 7 shows a functional block diagram of an exemplary implementation of the switching control module 240. A switching module 704 applies signals to the switches 232 (e.g., to their gate terminals) to control the operation of the switches 232 and to control whether each of the battery modules 224 is in the open state (X), the series state (S), or the parallel state (P).

[0082] The switching module 704 applies the signals based on inputs from an MPC module 708. The MPC module 708 determines a current power mode based on one or more operating parameters and generates the output to the switching module 704 based on the current power mode. The MPC module 708 also generates the output based on constraints 712 set by a constraint module 716. Examples of constraints 712 include that a battery string cannot be connected to either the first or second positive terminals 210 or 214 if its battery module is in the X-connection. A battery string cannot be connected to the first and second positive terminals 210 or 214 at the same time. The duration of each string's connection may be limited (constrained) to the end of the phase. The number of channels (battery strings) per battery module may be limited to meet the demand on the second positive terminal 210.The constraints 712 do not include that the phase duration may be limited to meet the demand at the first positive terminal 210. As such, a string of a battery module may be switched beyond the end of a phase when that battery module is to be connected in parallel mode (P), to another phase if another battery module (and / or the same battery module) is to be connected in parallel mode (P).

[0083] One, several, or all of the constraints 712 may be specified. In various implementations, one or more of the constraints 712 may be variable. The constraint module 716 may specify variable constraints based on one or more operating parameters 714. The operating parameters 714 include, for example, the current power mode, the expected duration of the current power mode, and other example operating parameters.

[0084] A state of charge (SOC) module 718 determines the current state of charge (SOC) 720 of each battery string. In other words, the SOC module 718 determines the current SOCs 720 of the respective battery strings. The SOC module 718 may determine the current SOC of a battery string based, for example, on a voltage across the battery string and / or a current to and from that battery string. The SOC module 718 may determine the current SOC of a battery string using at least one equation or a lookup table that relates the voltage and / or current to the SOC. In various implementations, the SOC module 718 may determine the SOC of a battery based on the impedance of the battery, for example, to more accurately relate voltage and current to the SOC. The SOC module 718 does this for each battery string. The voltages and currents of the battery strings 724 may be measured using voltage and current sensors, respectively.

[0085] The MPC module 708 controls the switching of the switches (via the switching module 704) to minimize an error (e.g., a sum of squared errors) between the SOCs of the respective battery strings in the current power mode. The MPC module 708 may further control the switching of the switches based on current power demands via the first and second positive terminals 210 and 214, respectively, and predicted power demands from the first and second positive terminals 210 and 214, respectively. The current and predicted power demands are represented by 728.

[0086] To balance the SOCs of the strings 720, the MPC module 708 uses model predictive control to set the phase duration for each of the three phases (Phase 1, Phase 2, and Phase 3), the number of battery strings connected in P-mode, and the duration for which each of the battery strings is connected in P-mode. Each power mode is associated with a set of configurations (X-mode, P-mode, or S-mode) of the battery modules 224 for that power mode. The table below shows the power modes and the battery module modes for each phase. The MPC module 708 cycles through the phases (Phase 1, Phase 2, Phase 3, then back to Phase 1, etc.) repeatedly until the power mode is changed. Performance mode Phase 1 Phase 2 Phase 3 situation 1 (XXX mode) XXX XXX XXX OUT OF 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 dual-voltage mode with diagnostics 6 (XSS mode) XSS SXS SSX 48 V medium power with diagnostics 7 (PPP mode) PPP PPP PPP 12V high-performance starting mode 8 (PPS mode) PPS SPP PSP Normal 2 voltage mode 9 (PSS mode) PSS PLC SSP Normal 2 voltage mode 10 (SSS mode) SSS SSS SSS 48V high-performance mode

[0087] The example table above shows the battery module mode of the respective battery modules for each phase. For example, in Power Mode 5 (SXP mode), during the first phase (Phase 1), the first battery module operates in series mode (S), the second battery module operates in open mode (X), and the third battery module operates in parallel mode (P). During the second phase (Phase 2) of Power Mode 5, the first battery module operates in parallel mode (P), the second battery module operates in series mode (S), and the third battery module operates in open mode (X). During the third phase (Phase 3) of Power Mode 5, the first battery module operates in open mode (X), the second battery module operates in parallel mode (P), and the third battery module operates in series mode (S).

[0088] The MPC module 708 sets the duration (length) of the first, second, and third phases to optimize the balancing of the SOCs of each battery string. For example, if the battery strings (e.g., on average) of one battery module have lower SOCs than the other two battery modules, the MPC module 708 can set the phase(s) in which one battery module operates in parallel mode (P) to be longer than the phase(s) in which the other two battery modules operate. This increases the SOCs of the other two battery modules by less than the SOC of one of the battery modules, so that the SOCs of the battery modules are more balanced. During discharging, the battery strings (e.g.,If one battery module (on average) has lower SOCs than the other two battery modules, the MPC module 708 can then set the phase(s) in which one battery module operates in parallel mode (P) to be shorter than the phase(s) in which the other two battery modules operate. This reduces the SOCs of the other two battery modules more than the SOC of one of the battery modules, so that the SOCs of the battery modules are more balanced.

[0089] The MPC module 708 also determines the duration (length / period) of each phase in which each battery string is connected to the second positive terminal 214 to equalize the individual SOCs of the battery strings of each module. For example, if during charging, one battery string of a battery module has a lower SOC than the other battery strings of that battery module, the MPC module 708 may set the duration in which one of the battery strings is connected to the second positive terminal 214 to be longer than the duration of the other battery strings of the battery module. This increases the SOC of one battery string of the battery module more than the SOCs of the other battery strings of the battery module, so that the SOCs within the battery module are more balanced. The MPC module 708 does this for each battery module.If, during the discharge process, one battery string of a battery module has a lower SOC than the other battery strings of that battery module, the MPC module 708 can set the duration during which one of the battery strings is connected to the second positive terminal 214 to be shorter than the duration of the other battery strings of the battery module. This increases the SOC of one battery string of the battery module more than the SOCs of the other battery strings of the battery module, so that the SOCs within the battery module are more balanced. The MPC module 708 does this for each battery module.

[0090] Under certain circumstances, the MPC module 708 may switch a battery string of a first battery module beyond the end of a phase in which the first battery module is to be connected in parallel mode (P) into the period of another phase in which a second battery module (and / or the first battery module) is to be connected in parallel mode (P). This may be referred to as phase splitting. The MPC module 708 may perform this (i.e., phase splitting), for example, during the charging process if the SOC of the battery string is lower (e.g., by more than a predetermined amount) than the SOC of a battery string of the second battery module. Additionally or alternatively, the MPC module 708 may do this, for example, during discharging if the SOC of the battery string is higher (e.g., by more than a predetermined amount) than the SOC of a battery string of the second battery module.This allows the SOCs of the battery strings and the SOCs of the battery modules to be balanced more quickly.

[0091] Fig.Figure 8 contains an example time series for operation in power mode 5 (SXP) during charging without phase splitting. 804 is the first phase (phase 1), 808 is the second phase (phase 2), and 812 is the third phase (phase 3). As used herein, the term MNO mode may mean that the first battery module operates in M ​​mode, the second battery module operates in N mode, and the third battery module operates in O mode, where M, N, and O represent parallel mode (P), series mode (S), or open mode (X), respectively. For example, the first phase includes SXP mode, where the first battery module operates in series mode (S), the second battery module operates in open mode (X), and the third battery module operates in parallel mode (P). The second phase includes operation in PSX mode, where the first battery module operates in parallel mode (P), the second battery module operates in series mode (S), and the third battery module operates in open mode (X).The third phase involves operation in XPS mode, where the first battery module operates in open mode (X), the second battery module operates in parallel mode (P), and the third battery module operates in series mode (S).

[0092] In the example according to Fig.8, the MPC module 708 sets the duration of the second phase longer than the duration of the third phase and the duration of the third phase longer than the duration of the first phase when the battery 208 is being charged via the second positive terminal 214 while being charged or discharged via the first positive terminal 210 with, for example, a low current. This allows the battery strings of the first battery module (operating in parallel mode (P) during the second phase) to be charged more than the other battery modules, and allows the battery strings of the second battery module (operating in parallel mode (P) during the third phase) to be charged more than the battery strings of the third battery module. The third battery module is operating in parallel mode (P) during the first phase.

[0093] During the first phase 804, the MPC module 708 has the third battery string 824 of the third battery module connected to the second positive terminal 214 for a shorter total duration than the first and second battery strings 816 and 820 of the third battery module. This allows the first and second battery strings 816 and 820 of the third battery module to be charged more than the third battery string 824 of the third battery module to equalize the SOCs of the first, second, and third battery strings 816, 820, and 824 of the third battery module.

[0094] During the second phase 808, the MPC module 708 has the third battery string 824 of the first battery module connected to the second positive terminal 214 for a shorter total duration than the first and second battery strings 816 and 820 of the first battery module. This allows the first and second battery strings 816 and 820 of the first battery module to be charged more than the third battery string 824 of the first battery module to equalize the SOCs of the first, second, and third battery strings 816, 820, and 824 of the first battery module.

[0095] During the third phase 812, the MPC module 708 has the third battery string 824 of the second battery module connected to the second positive terminal 214 for a shorter total duration than the first and second battery strings 816 and 820 of the second battery module. This allows the first and second battery strings 816 and 820 of the second battery module to be charged more than the third battery string 824 of the second battery module to equalize the SOCs of the first, second, and third battery strings 816, 820, and 824 of the second battery module.

[0096] The controller then returns to the first phase, assuming the power mode hasn't changed. In other words, the controller goes from phase 1 to phase 2 to phase 3, and then repeats phases 1-3 in the same order.

[0097] Although Fig.8 is intended to illustrate the charging process, a similar situation also applies to discharging. For example, if the SOC of the third strings of the first, second, and third battery modules is lower than the SOC of the first or second string of the first-third battery module, the MPC module 708 can connect the third strings of the first-third battery modules to the second positive terminal 214 for a shorter total duration than the first and second strings of the first-third battery modules during the respective phases. As a result, the third strings are discharged less than the first and second strings, and the SOCs of the battery strings are equalized.

[0098] Fig.9 is a flowchart illustrating an example method for balancing the SOCs of the battery strings of the battery modules of battery 208. Control begins at 904, where the SOC module 718 determines the SOCs of the battery strings (first, second, and third) of each of the battery modules 324 (first, second, and third) of battery 208. At 908, the SOC module 718 may determine the SOCs of the battery modules (first, second, and third) based on the battery strings of the respective battery modules. For example, the SOC module 718 may determine a SOC of the first battery module based on an average of the SOCs of the battery strings (first, second, and third) of the first battery module. The SOC module 718 may determine a SOC of the second battery module based on an average of the SOCs of the battery strings (first, second, and third) of the second battery module.The SOC module 718 may determine a SOC of the third battery module based on an average of the SOCs of the battery strings (first, second, and third) of the third battery module.

[0099] At 912, the MPC module 708 determines the power mode. The MPC module 708 may select one of the above-mentioned power modes, such as the SXP mode, the XPP mode, the XXP mode, or another of the above-mentioned modes.

[0100] At 916, the MPC module 708 determines the phase duration based on the power mode and the SOCs of the battery modules. For example, the MPC module 708 may set the duration of a phase in which a battery module is to be connected in parallel mode (P) to be shorter than the duration of the other phases if the SOC of that battery module is lower than the SOC of the other battery modules. The MPC module 708 determines the phase duration during the MPC.

[0101] At 920, the MPC module 708 determines the duration for connecting each string of each battery module within phases and across phases for phase splitting. For example, during charging, the MPC module 708 may charge a battery string longer than other battery strings if it has a lower SOC than the other battery strings. During discharging, the MPC module 708 may discharge a battery longer than the other battery strings if the battery string has a higher SOC than the other battery strings. The MPC module 708 determines the duration of the battery strings using MPC. The MPC module 708 may adjust the duration of a battery string of a battery module to share two phases, for example, if the SOC of that battery string is lower than the SOC of another battery string of a different battery module during charging.The MPC module 708 may adjust the duration of a battery string of a battery module to share two phases, e.g., if the SOC of that battery string is higher than the SOC of another battery string of another battery module during discharge.

[0102] In various implementations, 912 and 916 may be executed concurrently by the MPC module 708. The optimization cost criterion may be zero if all string SOCs are the same and may increase as the differences between the SOCs increase. One possible formulation of such a cost criterion is a weighted sum of the squared differences between the SOCs of neighboring pairs in a cyclic chain encompassing all strings, with this sum being formed over a scheduling horizon consisting of one or more complete cycles across the phases. Additional penalties may be added, such as costs for the total connection times of the strings to avoid overheating of the strings. The variables in the optimization are the duration of the phases and the duration for which each string is connected in the P configuration. The minimization of the cost criterion is subject to the constraints 712.Based on the performance requirements and predictions 728, the MPC module 708 can evaluate the cost criterion for arbitrary connection time spans. The solution to the minimization problem is the set of phase time spans and string connection time spans that best balances the string SOCs over the planning horizon, taking into account the constraints 712 and any additional penalty conditions.

[0103] At 924, the switching module 704 actuates the switches 232 according to the power mode, phase duration, and battery string duration. Control returns to 904 to initiate another loop.

[0104] Fig.Figure 10 includes an example plot of the SOCs 1004 of battery strings over time 1008 during discharge according to the string and module balancing described above without phase splitting. As shown, despite the initial differences in SOCs, the SOCs equalize relatively quickly using the SOC balancing described above.

[0105] Fig. Figure 11 contains an example time series for operation in Power Mode 5 (SXP) with phase split, when the battery 208 is being charged via the second positive terminal 214 while being charged or discharged via the first positive terminal 210 with, for example, a low current. 1104 is the first phase (Phase 1), 1108 is the second phase (Phase 2), and 1112 is the third phase (Phase 3).

[0106] In the example according to Fig.11, the MPC module 708 sets the duration of the second phase longer than the duration of the third phase and the duration of the third phase longer than the duration of the first phase, similar to the example according to Fig. 8.

[0107] In the first phase 1104, the second and third battery modules are connected in parallel (P), and the first battery module is operated in series mode (S). In the second phase 1108, the first and third battery modules are connected in parallel (P), and the second battery module is operated in series mode (S). In the third phase 1112, the first and second battery modules are operated in parallel mode (P), and the third battery module is operated in series mode (S).

[0108] The second and third battery strings of the third battery module are connected to the second positive terminal 214 in the first phase 1104, as represented by 1116 and 1120, respectively. The duration of the first, second, and third battery strings of the third battery module is less than or equal to the total duration of the first phase 1104 and the second phase 1108. However, the total duration of the first, second, and third battery strings of the third battery module is greater than or equal to the total duration of the first phase 1104 and the second phase 1108 and less than or equal to the total duration of the double first phase 1104 and second phase 1108. The duration of the first battery string is longer than the duration of the first phase, so that the connection of the first battery string to the second positive terminal 214 extends into the second phase, as represented by 1124.

[0109] During the second phase 1108, the first and third battery modules operate in parallel mode (P), and the second battery module is connected in series (S). As shown, the first string connection of the third battery module extends beyond the end of the first phase 1104 into the second phase 1108. The second string of the third battery module is also connected to the second positive terminal 214 during the first phase 1104 and the second phase 1108, as shown by 1132. The first string of the third battery module and the second string of the third battery module therefore share the first phase 1104 and the second phase 1108.

[0110] In the third phase 1112, the first and second battery modules operate in parallel mode (P), and the third battery module is connected in series (S). As shown, the second string of the second battery module is connected in the first phase 1104 and in the third phase 1112. The first and third strings of the second battery module are also connected to the second positive terminal 214 in the third phase 1112, as shown by 1156 and 1136.

[0111] An exemplary situation in which the first string of the third battery module and the second string of the third battery module share the second phase 1108 as described above occurs during the charging process when the SOC of the first string of the third battery module is lower (e.g., by more than a predetermined amount) than the SOC of the second and third strings of the third battery module. The illustration in Fig.11 allows a stronger charge of the first string of the third battery module than the second and third strings of the third battery module. Another exemplary situation in which the first string of the third battery module and the second and third strings of the third battery module share the second phase 1108 as described above occurs during the discharge process when the SOC of the first string of the third battery module is greater (e.g., by more than a predetermined amount) than the SOC of the second and third strings of the third battery module. The illustration in Fig. 11 allows the first string of the third battery module to discharge more than the second and third strings of the third battery module. This balances the SOCs of the first, second, and third strings of the third battery module.

[0112] An exemplary situation in which the second string of the second battery module shares the first phase 104 as described above occurs during the charging process when the SOC of the second string of the third battery module is lower (e.g., by more than a predetermined amount) than the SOC of the first and third strings of the second battery module. The illustration in Fig. 11 allows a stronger charge of the second string of the third battery module than the first and third strings of the third battery module. Another exemplary situation in which the second string of the second battery module shares the first phase 1104 as described above occurs during the discharge process when the SOC of the second string of the third battery module is greater (e.g., by more than a predetermined amount) than the SOC of the first and third strings of the second battery module. The illustration in Fig.11 allows the second string of the third battery module to discharge more than the first and third strings of the third battery module. This balances the SOCs of the first, second, and third strings of the second battery module.

[0113] Fig. Figure 12 contains an example graph of the SOCs 1204 of battery strings over time 1208 during discharge according to the string and module balancing described above without phase splitting. As shown, despite the initial differences, the SOCs of the strings equalize relatively quickly using the SOC balancing and phase splitting described above. As can be seen from a comparison of Fig. 10 and Fig. As can be seen from Figure 12, the equalization of the SOCs of the strings occurs more quickly with the phase division described above.

[0114] It should be understood that the disclosure may be implemented for a battery system in which the number of modules, the number of strings within a module, and the number of output terminals differ from the examples in the above description. With a larger number of modules, the number of phases in a complete cycle increases. With a larger number of output terminals, the number and type of terminal configurations increase. In all these variations, the teachings of the disclosure continue to apply to achieve the goal of minimizing unbalanced SOCs under the constraints of serving the expected power requirements at all output terminals.

[0115] The foregoing description is merely illustrative and is not intended to limit the disclosure, its application, or uses in any way. The broad teachings of the disclosure may be implemented in a variety of forms. While this disclosure includes specific examples, its true scope should not be limited thereto, since other modifications will become apparent upon review of the drawings, the specification, and the following claims. It is understood that one or more steps within a method may be performed in different orders (or simultaneously) without altering the principles of the present disclosure.Furthermore, although the embodiments are each described above as having specific features, any one or more of these features described with respect to one embodiment of the disclosure may be implemented and / or combined with features of any of the other embodiments, even if this combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and an exchange of one or more embodiments for one another remains within the scope of this disclosure.

[0116] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including "connected," "engaging," "coupled," "adjacent," "beside," "on top of," "over," "below," and "disposed." If a relationship between first and second elements is not explicitly described as "direct" in the above disclosure, that relationship may be a direct relationship, with no other intervening elements between the first and second elements, or an indirect relationship, with one or more intervening elements (either spatial or functional) between the first and second elements.The phrase "at least A, B or C" used here should be interpreted as logical (A OR B OR C) using a non-exclusive logical OR operator and not as "at least one of A, at least one of B and at least one of C".

[0117] In the figures, the direction of an arrow, as indicated by the arrowhead, generally illustrates the flow of information (e.g., data or instructions) of interest for the illustration. For example, if element A and element B exchange a variety of information, but the information transmitted from element A to element B is relevant for the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Furthermore, for information being sent from element A to element B, element B may send requests for or acknowledgments of receipt of the information to element A.

[0118] In this application and the definitions below, the term "module" or the term "controller" may be replaced by the term "circuit". The term "module" may refer to, be part of, or include: an application-specific integrated circuit (ASIC), a digital, analog, or mixed analog / digital discrete circuit, a digital, analog, or mixed analog / digital integrated circuit, a combinational logic circuit, a field-programmable gate array (FPGA), processor circuitry (common, dedicated, or group) that executes code, memory circuitry (common, dedicated, or group) that stores code executed by the processor circuitry, other suitable hardware components that provide the described functionality, or a combination of some or all of the above components, e.g., in a system-on-chip.

[0119] The 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 combinations thereof. The functionality of any given module of the present disclosure may be distributed among multiple modules connected via interface circuits. For example, multiple modules may enable load balancing. In another example, a server module (also referred to as a remote or cloud module) may perform some functions on behalf of a client module.

[0120] The term "code" as used above may include software, firmware, and / or microcode and may refer to programs, routines, functions, classes, data structures, and / or objects. The term "common processor circuitry" includes a single processor circuitry that executes code from multiple modules, in part or in whole. The term "group processor circuitry" includes a processor circuitry that, in combination with additional processor circuitry, executes code from one or more modules, in part or in whole. References to multiple processor circuitry include multiple processor circuitry on discrete chips, multiple processor circuitry on a single chip, multiple cores of a single processor circuitry, multiple threads of a single processor circuitry, or a combination thereof. The term "shared memory circuitry" includes a single memory circuitry that stores code from multiple modules, in part or in whole.The term “group memory circuit” includes a memory circuit that, in combination with additional memories, stores some or all of the code from one or more modules.

[0121] The term "memory circuit" is a subset of the term computer-readable medium. As used herein, the term "computer-readable medium" does not include transitory 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-transitory. Non-limiting examples of a non-transitory, tangible, computer-readable medium include non-volatile memory circuits (e.g., a flash memory circuit, an erasable programmable read-only memory circuit, or a mask read-only memory circuit), volatile memory circuits (e.g., a static random access memory circuit or a dynamic random access memory circuit), magnetic storage media (e.g., an analog or digital magnetic tape or a hard disk drive), and optical storage media (e.g., a CD, a DVD, or a Blu-ray Disc).

[0122] The devices and methods described in this application may be implemented partially or entirely by a special-purpose computer created by configuring a general-purpose computer to perform one or more specific functions contained in computer programs. The functional blocks, flowchart components, and other elements described above serve as software specifications that can be translated into computer programs through the routine work of a skilled technician or programmer.

[0123] The computer programs comprise processor-executable instructions stored on at least one non-transitory, tangible, computer-readable medium. The computer programs may also include or be based on stored data. The computer programs may include a basic input / output system (BIOS) that interacts with the hardware of the special-purpose computer, device drivers that interact with specific devices of the special-purpose computer, one or more operating systems, user applications, background services, background applications, etc.

[0124] The computer programs may comprise: (i) descriptive text to be parsed, e.g. B. HTML (Hypertext Markup Language), XML (Extensible Markup Language) or JSON (JavaScript Object Notation), (ii) assembly code, (iii) object code generated from source code by a compiler, (iv) source code for execution by an interpreter, (v) source code for compilation and execution by a just-in-time compiler, etc. By way of example only, source code may be written using the syntax of 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] Battery system comprising: a first positive pole, a second positive pole, a negative pole, Switch, two battery modules, each of the two battery modules comprising three strings of battery cells which are designed to: in series and to be connected to the first positive pole via the first switch, parallel and to be connected to the second positive pole via the second switch, and to be separated from both the first and second positive poles, and a switching control module designed to to determine the states of charge (SOCs) of the battery cell strings, to determine phase periods or balance the SOCs of the battery modules using a model predictive control, to determine periods for the strands using a model predictive control, including setting one of the periods for one of the strands, which must be included in at least two of the phases, and to selectively operate the switches based on the phase periods and the periods for the strings of battery cells. [2] The battery system of claim 1, wherein a first portion of said one of said periods for said one of said strings is in a first portion of a first of said phases and a second portion of said one of said periods for said one of said strings is in a second portion of a second of said phases. [3] The battery system of claim 2, wherein a first portion of a second of the periods for a second of the strings is in a third portion of the second of the phases and a second portion of the second of the periods for the second of the strings is in a fourth portion of a third of the phases. [4] The battery system of claim 1, wherein the switching control module is configured to set the one of the periods for the one of the strings to be included in at least two of the phases based on a first SOC of the one of the strings and a second SOC of a second of the strings. [5] The battery system of claim 1, wherein the switching control module is configured to set the one of the periods for one of the strings to be included in the at least two of the phases during charging of the strings. [6] The battery system of claim 1, wherein the switching control module is configured to adjust the one of the periods for one of the strings to be included in the at least two of the phases during discharging of the strings. [7] The battery system of claim 1, wherein the switching control module is configured to set the one of the periods longer than the longest of the phase periods. [8] The battery system of claim 1, wherein the switching control module is configured to set a first period for a first of the strings of one of the battery modules longer than a second period for a second of the strings of the one of the battery modules during the charging process when a first SOC of the first of the strings is less than a second SOC of the second of the strings. [9] The battery system of claim 1, wherein the switching control module is configured to set a first period for a first of the strings of one of the battery modules longer than a second period for a second of the strings of the one of the battery modules during the discharging process when a first SOC of the first of the strings is greater than a second SOC of the second of the strings. [10] The battery system of claim 1, wherein the switching control module is configured to selectively set a first period for a first of the phases to be longer than a second period for a second of the phases during the charging process based on the SOCs of the strings.

Images