Systems and methods for power management and control

Abstract

Systems and methods are directed to improving battery management, motor control, energy storage, and battery charging. The systems and methods enable vehicle electrification and provide a paradigm-changing platform that enables integration of battery management, charging, and motor control with devices that manage regenerative braking, traction, and handling. In an embodiment, the systems and methods are directed to a unified modular battery pack system with a cascade architecture that includes an integrated combination of networked low-voltage converters / controllers with peer-to-peer communication capabilities, embedded ultracapacitors or other secondary energy storage elements, a battery management system, and series-connected groups of individual cells as basic building blocks.

Description

Technical Field

[0001] The present disclosure relates to electrical power management and control of battery systems, and more particularly to systems and methods that facilitate improved battery management, motor control, energy storage, and battery charging for electric vehicles and other stationary applications. Background Art

[0002] The characteristics of today's automotive technology, which has evolved over the past century, are particularly the interaction of motors, mechanical elements and electronic devices. These are key components that affect vehicle performance and driver experience. The motors are of combustion or electric type, and one motor is usually found per vehicle, but the vehicles with specific hybrid drive systems are exceptions, which feature a combination of an internal combustion engine with one or two electric motors, or performance-oriented electric vehicles equipped with two motors. In almost all cases, the rotational energy from the (one or more) motors is transmitted via a set of highly complex mechanical elements, such as clutches, transmissions, differentials, drive shafts, torque tubes, couplers, etc. These components largely control the torque conversion and power distribution to the wheels, and are key elements that define the performance of the car. They also affect road handling. Over the years, various automobile manufacturers have highly optimized these mechanical components to provide better performance, higher fuel efficiency and ultimately differentiation in the market. On the control side, in addition to driver comfort such as entertainment, navigation and human-machine interface elements, there are usually only a few sets of dedicated electronic hardware and embedded software that control / optimize the motor, clutch / transmission operation and road holding / handling.

[0003] Today's electric vehicles or vehicles (EVs) have largely adopted much of the century-old design paradigm of combustion vehicles, with batteries, charging systems, and electric motors clearly replacing the usual gas tank, fuel pump / injectors, and internal combustion engine. While control electronics fit into the differentiation of components, it is important to recognize that most of the mechanical drivetrain components described above are still there (see, for example, Figure 1 A and 1B). That said, the overall design philosophy of current EVs barely moves beyond the norm. As a result, the true potential of electrification has yet to be realized.

[0004] An EV includes various electrical systems associated with the drivetrain, which includes, among other things, batteries, chargers, and motor controls. A short list of the current capabilities and shortcomings of these electrical systems includes:

[0005] Conventional battery design

[0006] Currently, high voltage battery packs are typically organized in a series chain of lower voltage battery modules. Each such module further includes a group of individual cells connected in series and a simple embedded battery management system to regulate basic cell-related characteristics such as charge state and voltage. There are no electronic devices with more complex capabilities or some form of smart interconnection. As a result, any monitoring or control functions are handled by a separate system, which lacks the ability to monitor individual cell health, charge state, temperature, and other performance-affecting metrics if they are present elsewhere in the vehicle. There is also no ability to adjust the power draw of each individual cell in any form. Some of the main consequences are: (1) the weakest cell constrains the overall performance of the entire battery pack; (2) the failure of any cell or module results in the need to replace the entire pack; (3) battery reliability and safety are greatly reduced; (4) battery life is limited; (5) thermal management is difficult; (6) the battery pack is always operated below maximum capacity; (7) the sudden influx of electrical power derived from regenerative braking into the battery pack cannot be easily stored in the battery and will need to be dissipated via dump resistors.

[0007] Current Charger Design

[0008] The charging circuits are typically implemented in a separate onboard system. They stage the power from outside the EV in the form of an AC signal or a DC signal, convert it to DC and feed it to the battery pack(s). The charging system monitors the voltage and current and typically supplies a steady constant feed. Given the design of the battery pack and typical charging circuits, there is little ability to adjust the charge flow to the individual battery modules based on cell health, performance characteristics, temperature, etc. Charging cycles are also typically long because the charging system and battery pack lack circuitry to allow pulse charging or other techniques that would optimize charge transfer or the total charge that can be achieved.

[0009] Current Motor Control Design

[0010] Conventional controls contain a DC to DC conversion stage to adjust the battery pack voltage level to the bus voltage of the EV's electrical system. In turn, the motor is then driven by a simple two-level multiphase converter that provides the required (one or more) AC signals to the electric motor. Traditionally, each motor is controlled by a separate controller that drives the motor in a 3-phase design. A dual-motor EV will require two controllers, while an EV using four in-wheel motors will require 4 separate controllers. Conventional controller designs also lack the ability to drive next-generation motors, such as switched reluctance motors (SRMs), which are characterized by a higher number of pole pieces. Adaptation will require a higher phase design, making the system more complex, and ultimately unable to address electric noise and drive performance issues, such as high torque pulsation and acoustic noise.

[0011] In view of the foregoing limitations, it would be desirable to facilitate improved systems and methods of battery management, motor control, power storage, and battery charging that address the above-mentioned shortcomings and provide a paradigm-changing platform. Summary of the invention

[0012] Embodiments of the present disclosure are directed to systems and methods that facilitate improved battery management, motor control, energy storage, and battery charging. Thus, the systems and methods provided herein enable the true potential of vehicle electrification to be realized and provide a paradigm-changing platform that intelligently integrates battery management, charging, and motor control with devices that manage regenerative braking, traction, and handling.

[0013] Exemplary embodiments of the present disclosure are preferably directed to a unified modular battery pack system having a cascade architecture that includes an integrated combination of a networked low voltage converter / controller with peer-to-peer communication capabilities, an embedded ultracapacitor or other secondary energy storage element, a battery management system, and a group of individual cells connected in series as basic building blocks. The interconnected components of such smart battery modules effectively become a smart electrical "neural network" and replace: (1) the charging system, (2) the battery management module, (3) the DC to DC converter, and (4) (one or more) motor controllers.

[0014] This modular, smart battery pack system can be combined not only with conventional EV motors and drivetrains, but also with new in-wheel EV motors developed for use in future EVs.

[0015] In the exemplary embodiments provided herein, the electronics of each modular smart battery pack is based on a multi-level controller, which in certain exemplary embodiments is preferably a bi-directional multi-level hysteretic controller, combined with a temperature sensor and networking interface logic. This design offers many advantages: (1) Improved battery utilization through individual switching of modules based on module age, thermal condition, and performance characteristics; (2) Reduced heat loss of cells through careful power consumption or power generation balancing; (3) Slowed cell aging through better individual thermal management and filtering of high-order current harmonics; (4) Fine-grained monitoring of battery health and the ability to warn of maintenance needs; (5) Fail-safe and redundant design that maintains drivability even when individual modules fail; (6) Higher efficiency and better economic benefits by leveraging new semiconductor technologies that operate at lower component voltages to reduce power losses and costs; (7) Software-based topology optimization and control methods to adapt to different vehicle characteristics; (8) Almost complete avoidance of energy from regenerative braking, and fast response to acceleration, thanks to embedded ultracapacitors; (9) Integrated on-board optimized charging, including ultra-fast pulse charging driven by intelligent controller circuits, due to load balancing and monitoring of individual cells; (10) Reduced electromagnetic interference and sensitivity of circuit topology; (11) Adaptive neural network-based coordination between modules to enhance overall system performance, response time, thermal management and overall system efficiency; (12) Elimination of mechanical driveline components and associated losses when combined with in-wheel motors; (13) Reduction of overall driveline magnetic and electrical losses; (14) Increased power density when used with in-wheel motors; (15) Reduced torque pulsation and improved passenger comfort due to reduced electrical and mechanical noise from refined motor control and electrical filtering; (16) Ability to adapt to and optimize all current and next generation motor designs; (17) Reduction in space to provide more room (greater range) for passengers / cargo / additional batteries; (18) Weight reduction to provide better performance, higher vehicle efficiency, and longer driving range; (19) Better handling and better traction when combined with in-wheel motors; (20) Universal building blocks that can be adapted for use in vehicles ranging from small passenger cars to large buses and commercial trucks; (21) Vehicle feature differentiation based on software rather than through traditional mechanical component design.

[0016] Other systems, methods, features and advantages of the example embodiments will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The details of the example embodiments, including structure and operation, can be gathered in part by studying the accompanying drawings, in which like reference numerals refer to like parts. The components in the drawings are not necessarily to scale, but emphasis is placed on illustrating the principles of the present disclosure. In addition, all illustrations are intended to convey concepts, in which relative sizes, shapes and other detailed attributes may be illustrated schematically rather than literally or precisely.

[0018] Figure 1 A simplified schematic diagram of the power electronics and electric motor of a conventional battery electric vehicle is shown.

[0019] Figure 2 A schematic diagram of a power electronic circuit and an electric motor for a battery electric vehicle according to an embodiment of the present disclosure is illustrated, the power electronic circuit and the electric motor having a unified modular system with a cascade architecture, the unified modular system including an intelligent modular AC battery pack, the intelligent modular AC battery pack including a series connection of intelligent low-voltage battery modules.

[0020] Figures 3A to 3I A schematic diagram is illustrated, which shows a power electronic circuit according to an embodiment of the present disclosure, as Figure 1 An intelligent, modular representation of a conventional high-voltage power electronics circuit for a battery electric vehicle as shown in; Figure 3A A high voltage battery pack comprising a series chain of low voltage battery modules is shown; Figure 3B Each battery module is shown including a series connection of lower voltage battery cells and an integrated battery management or control system; Figure 3C It shows a high voltage DC / AC converter divided into a plurality of low voltage DC / AC converters connected in series; Figure 3D shows each low voltage DC / AC converter integrated within each battery module; Figure 3E shows ultracapacitors or supercapacitors integrated within individual battery modules to intermittently store braking power inrush; Figure 3F A high voltage smart modular AC battery pack is shown, which includes a series connection of lower voltage smart battery modules integrated with a battery management or control system, a low voltage converter, and an ultracapacitor; Figure 3G and 3H shows a DC / DC converter removed from a power electronics circuit; Fig. 3I The AC / DC converter / charger is shown removed from the power electronics circuit.

[0021] Figure 4 Illustrated is a perspective conceptual representation of a smart battery module including a battery, a low voltage converter, and an ultracapacitor integrated with a battery management and control system according to an embodiment of the present disclosure.

[0022] Figure 5A schematic diagram of a smart battery module according to an embodiment of the present disclosure is illustrated, the smart battery module being coupled to a battery module control system (or local electronic control unit (ECU)) and a master control system (or master ECU).

[0023] Figure 6 A schematic diagram of a plurality of smart modular AC battery packs coupled to a three-phase motor and a charging coupler for coupling to a single-phase or three-phase grid or power source is illustrated according to an embodiment of the present disclosure.

[0024] Fig. 7A and 7B The diagram shows a (1) smart battery module ( Fig. 7A ) and a typical waveform of the output voltage of a one (1) phase smart modular AC battery pack having six (6) smart battery modules ( Figure 7B ).

[0025] Fig. 8A , 8B , 8C and 8D illustrate diagrams showing the principle of phase-shifted carrier technology.

[0026] Fig. 9 A schematic diagram illustrating the functional diagram of a voltage level selector of a nine-level four-quadrant hysteretic controller is shown.

[0027] Fig. 10A , 10B and 10C illustrate a diagram showing the operation of a nine-level four-quadrant hysteresis controller; Fig. 10A The current control error I ERROR The figure shows I REAL and I REF The difference between Fig. 10B The reference current I in the motor phase is shown REF and the actual current I REAL ; Fig. 10C The converter output voltage V OUT .

[0028] Fig.11 A functional diagram of a 9-level 4-quadrant hysteretic current controller with state of charge (SOC) balancing and zero-state rotation is illustrated.

[0029] Fig.12 Illustrated is a functional diagram of a smart battery module rotation controller.

[0030] Fig.13 A functional diagram of the di / dt estimator is shown.

[0031] Fig.14A and 14B The diagram shows -0VDC rotation ( Fig.14A ) and +0VDC rotation ( Fig. 14B ) block’s functional diagram.

[0032] Fig.15A and 15B The diagram shows the +1VDC rotation ( Fig.15A ) and -1VDC rotation ( Fig. 15B ) block’s functional diagram.

[0033] Fig.16A , 16B , 16C and 16D illustrate a 0VDC rotary generator ( Fig.16A )、1VDC Rotary Generator( Fig. 16B )、2VDC Rotary Generator( Fig. 16C ) and 3VDC rotary generator ( Fig.16D ) functional diagram.

[0034] Fig.17 A schematic diagram illustrating the centralized connection of all smart modules to the main ECU for state of charge (SOC) balancing.

[0035] Fig.18 A flow chart illustrating structural power flow management in a smart battery module is shown.

[0036] Fig.19 A circuit diagram showing the topology of a smart battery module and the current in node 1 is illustrated.

[0037] FIG. 20 illustrates a graph of current in a smart battery module when the supercapacitor module operates as an active filter.

[0038] Fig.21 The diagram shows a single-phase smart battery pack connected to a single-phase load.

[0039] Fig. 22 Illustration of a three-phase smart battery pack connected to a switched reluctance motor.

[0040] It should be noted that throughout the drawings, elements of similar structure or function are generally denoted by similar reference numerals for illustrative purposes. It should also be noted that the drawings are only intended to facilitate the description of the preferred embodiments. DETAILED DESCRIPTION

[0041] The following embodiments are described in detail to enable those skilled in the art to make and use various embodiments of the present disclosure. It should be understood that other embodiments will be apparent based on the present disclosure, and that systems, processes or changes may be made without departing from the scope of the present embodiments.

[0042] Embodiments of the present disclosure are directed to systems and methods that facilitate improved battery management, motor control, energy storage, and battery charging. Thus, the systems and methods provided herein enable the true potential of vehicle electrification to be realized and provide a paradigm-changing platform that intelligently integrates battery management, charging, and motor control with devices for managing regenerative braking, traction, and handling.

[0043] Exemplary embodiments of the present disclosure are preferably directed to a unified modular battery pack system having a cascade architecture that includes an integrated combination of a networked low voltage converter / controller with peer-to-peer communication capabilities, an embedded ultracapacitor, a battery management system, and a group of individual units connected in series as basic building blocks. The interconnected components of such smart battery modules effectively become a smart electrical "neural network" and replace: (1) the charging system, (2) the battery management module, (3) the DC to DC converter, and (4) the motor controller(s).

[0044] This modular smart battery pack system can be combined not only with conventional EV motors and drivetrains, but also with new in-wheel EV motors being developed for future EVs.

[0045] In exemplary embodiments provided herein, the electronic device is based on a bidirectional multi-level controller combined with a temperature sensor and networking interface logic. In certain exemplary embodiments, the bidirectional controller is a bidirectional multi-level hysteretic controller.

[0046] Turning to the attached drawings in detail, Figure 1 A simplified schematic diagram of a conventional power electronic circuit 10 and an electric motor 70 is shown in FIG. Figure 1 As shown in , the power electronic circuit 10 generally includes: a charger 20, which includes an AC-DC converter; a high-voltage battery pack 30, which is electrically coupled to the charger 20; a DC-DC converter 40, which is electrically coupled to the high-voltage battery pack 30; a DC-AC converter 50, which is electrically coupled to the DC-DC converter 40; and an electric motor 60, which is electrically coupled to the DC-AC converter 50.

[0047] Conventional high voltage battery packs 30 are typically organized in a series chain of low voltage battery modules 32 (see, e.g. Figure 3A and 3B Each such module 32 further includes a group of individual lower voltage cells 34 connected in series and a simple embedded battery management system 36 to regulate characteristics associated with the basic cells, such as state of charge and voltage (see, e.g. Figure 3B). There are no electronics with more complex capabilities or some form of clever interconnect. Therefore, there is no ability to adjust the power draw of each individual cell 34 in any form. Some of the main consequences are: (1) the weakest cell constrains the overall performance of the entire battery pack; (2) failure of any cell / module requires replacement of the entire pack; (3) battery reliability and safety are greatly reduced; (4) battery life is limited; (5) thermal management is difficult; (6) the pack is always operated below maximum capacity; (7) sudden influxes of electrical power derived from regenerative braking cannot be easily stored in the battery.

[0048] Conventional charging circuits or systems, such as those represented by charger 20, are typically implemented in a separate onboard system. Such a charging system stages power (AC or DC signal) from outside the EV and converts it to DC and feeds it to the battery pack(s) 30. The charging system monitors the voltage and current and typically supplies a steady constant feed. Given the design of the batteries and typical charging circuits, there is little ability to adjust the charge flow to the individual battery modules 32 of the battery pack 30 based on cell health, performance characteristics, temperature, etc. Charging cycles are also typically long because the charging system and battery pack 30 and individual modules 32 lack circuitry to allow for pulse charging or other techniques that would optimize charge transfer or the total charge that can be achieved.

[0049] Conventional controls include a DC to DC conversion stage (e.g., see DC-DC converter 40) to adjust the voltage level of the battery pack 30 to the bus voltage of the EV's electrical system. A motor such as motor 60 is then in turn driven by a simple two-level multiphase converter (e.g., see DC-AC converter 50), which provides the required (one or more) AC signals to motor 60. Traditionally, each motor is controlled by a separate controller that drives the motor in a 3-phase design. A dual-motor EV would require two controllers, while an EV using four in-wheel motors would require 4 separate controllers. Conventional controller designs also lack the ability to drive next-generation motors, such as, for example, switched reluctance motors (SRMs), which are characterized by a higher number of pole pieces. Adaptation would require a higher phase design, making the system more complex, and ultimately fail to address electric noise and drive performance issues, such as high torque pulsation and acoustic noise.

[0050] Compared to the complex power electronic circuit 10 of a conventional EV, the exemplary embodiments provided herein are as follows: Figure 2 As shown in FIG. 1 , the charging system 20, battery management module, DC to DC converter 40 and (one or more) motor controllers 50 are replaced with an intelligent or smart modular AC battery pack 130, which includes interconnected components of intelligent or smart battery modules 132 that effectively provide a smart electrical "neural network."

[0051] Go to Figures 3A to 3I , a series of schematic diagrams illustrating the Figure 1 The complex high voltage power electronic circuit 10 of a conventional EV shown in FIG. 1 is simplified to Figure 2 , which includes interconnected components of smart battery modules 132 according to an exemplary embodiment of the present disclosure. Figure 3A As shown in FIG. 1 , the high voltage battery pack 30 includes a series chain of lower voltage battery modules 32, each of which includes a series connection of lower voltage battery cells 34 and a series connection of lower voltage battery cells 34. Figure 3B The integrated battery management and control system 36 shown in FIG. The high voltage DC / AC converter 50 can be divided into Figure 3C . Each of the low voltage DC / AC converters 52 can be integrated into each battery module to form a plurality of low voltage DC / AC converters 52 connected in series. Figure 3D In order to intermittently store the influx of braking power, Figure 3E The ultracapacitor 38 is shown integrated into each smart battery module 132 (see also, for example, Figure 4 ).like Figure 3F As shown in FIG. 1 , the high voltage smart battery pack 130 includes an interconnected assembly of smart battery modules 132. Figure 3G and 3H As shown in , the high voltage smart battery pack 130 effectively eliminates the need for the DC / DC converter 40. Figure 3H and 3I As shown in , the high voltage smart battery pack 130 is actually a smart modular AC battery pack 130 , effectively eliminating the need for the AC / DC converter / charger 20 .

[0052] Smart battery module architecture

[0053] Figure 4 and 5 A perspective view and a diagram are shown, respectively, of a smart battery module 132 having regenerative braking / acceleration capability using supercapacitors (or ultracapacitors). It has three main components: a battery 32 with a BMS 36, an ultracapacitor module 38 with a bidirectional DC-DC converter based on MOSFET transistors (MOSFETs) S1 and S2 (which has an ultracapacitor group CSC and a coupled inductor LC), and an output converter 52 based on a four-quadrant H-bridge topology with four MOSFETs S3-S6. Figure 5 As shown in , the smart battery module 132 is coupled to a battery module control system 200 (or a local electronic control unit (ECU)) and a master control system 210 (or a master ECU).

[0054] How the ACi Battery Pack Works

[0055] Figure 6 A topology of a 3-phase ACi battery pack (130A, 130B, 130C) connected to an electric machine 60 and comprising N smart battery modules connected in series in each phase is depicted. Figure 5 and 6 Each smart battery module in the embodiment can generate three different voltage outputs +V by connecting the DC voltage VDC (of the battery) to the AC output through different combinations of four switches (S3, S4, S5 and S6). dc , 0, and -V dc In order to obtain +V dc , switches S3 and S6 are turned on, and -V dc It can be obtained by turning on switches S4 and S5. By turning on S3 and S5 or S4 and S6, the output voltage is 0. The AC output of each of the different output converter levels is connected in series so that the composite voltage waveform is the sum of the inverter outputs. The number of output phase voltage levels m in the ACi battery pack is defined by m=2s+1, where s is the number of smart battery modules. Figure 7B Example phase voltage waveforms for a pulse width modulation (PWM) modulated 13-level ACi battery pack with six series-connected smart battery modules in each phase are presented in FIG; and Fig. 7A The output voltage of one of the smart battery modules 132 is shown in FIG.

[0056] like Figure 6 As shown in , the ACi battery pack can also be used as a rectifier / charger for the smart battery module 132 batteries when the vehicle is connected to AC power.

[0057] The switch signal S3÷S6 (see FIG. 1 ) of the switch S3÷S6 of the output converter 152 in each smart battery module 132 Figure 5 and Figure 6 ) can be generated in different ways depending on the flexibility and requirements of the control hardware employed. One approach is to use space vector modulation or sinusoidal PWM to generate a reference voltage for each phase of the smart battery module 132. The switching signals for the output converter of each smart battery module can then be generated using a phase shift carrier technique. This technique ensures that the units rotate continuously and that power is distributed almost equally among them.

[0058] Modulation of output voltage in ACi battery pack - Multi-level PWM modulation

[0059] The principle of phase shifting technique is to generate a multi-level output PWM waveform using an incrementally shifted two-level waveform. Therefore, an N-level PWM waveform is created by summing N-1 two-level PWM waveforms. These two-level waveforms are generated by comparing a reference waveform with a triangular carrier wave that is incrementally shifted by 360° / (N-1). The 9-level example is shown in Fig. 8A The carrier wave is shifted incrementally by 360° / (9-1)=45° and compared with the reference waveform. The resulting two-level PWM waveform is shown in Figure 8C These two-level waveforms can be used as gate signals for the output converter (H-bridge) MOSFETs in each smart battery module. For our 9-level example, which includes four H-bridges, the first module uses a 0° signal for S3 and a 180° signal for S6; the second module uses a 45° signal for S3 and a 225° signal for S6, and so on. Note that in all H-bridges, the signal for S4 is the complement of S3 and the signal for S5 is the complement of S6, along with some dead time to avoid shoot-through in each branch.

[0060] Depending on the resources and limitations of the hardware used to implement the modulation, an alternative is to generate a negative reference signal along with the first (N-1) / 2 carriers. Figure 8B In this case, by setting V ref The 0° to 135° PWM signal is generated by comparing it with the corresponding carrier and by ref The comparison with the carrier wave from 0° to 135° is used to generate the PWM signal from 180° to 315°. However, the comparison logic in the latter case must be reversed.

[0061] Other techniques, such as a state machine decoder, can also be used to generate the gate signals for the H-bridge.

[0062] Modulation of output voltage in ACi battery pack - multi-level hysteresis control

[0063] The switching signals S3 ÷ S6 are created for the switches of the output converters in each smart battery module (see Figure 5 and 6 Another method of ) is the multi-level hysteresis control technique. This control method can be used for any type of motor and is very effective, especially for switched reluctance motor (SRM) drives.

[0064] The multi-level hysteresis control is described here for only one of the three phases of the three-phase ACi battery pack. In the case of a PMSM motor, three controllers must be used with an additional circulating current reduction module (not described here). For an SRM motor, the number of controllers can be more than three and no circulating current reduction module is required.

[0065] For 9-level ACi battery packs (see Figure 6 ), which includes four smart battery modules 132 connected in series in each phase, Table 1 presents all possible switching states of the switches of the output converter with corresponding output voltage levels. Only odd-numbered switching elements (MOSFET S3 N and S5 N , where N = 1, 2, 3, 4 is the number of smart battery modules). In fact, in order to avoid the filter capacitor C F N Due to the short circuit, only one switch of the half-bridge of the output H-bridge converter can be turned on (in conducting mode) at any time. Therefore, the even-numbered switching elements (MOSFET S4) can be easily obtained by inverting the state of the odd-numbered switching elements of the same half-bridge. N and S6 N , where N = 1, 2, 3, 4 is the number of smart battery modules). For example, if S3 N =1 and S5 N =0, then S4 N =0 and S6 N =1.

[0066]

[0067]

[0068] Table 1: Switching states of a 9-level 4-quadrant multilevel cascade converter

[0069] If all cells are operated at zero state simultaneously, zero output voltage 0VDC can be ensured. This can be achieved by switching on either the two upper switches or the two lower switches while bypassing the battery. For example, for smart battery module 1: S3 1 =1,S5 1 =1,S4 1 =0,S6 1 =0 or S3 1 =0,S5 1 =0,S4 1 =1,S6 1 =1.

[0070] Voltage levels (both -3VDC and +3VDC) can be obtained using four different combinations (±3VDC1, ±3VDC2, ±3VDC3, ±3VDC4), where the last index corresponds to the number of smart battery modules operating in the zero state, providing an output zero voltage. In turn, each zero state can be encoded using the above two switch combinations. Therefore, there are eight possible combinations for setting the ±3VDC output voltage level.

[0071] Similarly, the voltage level (both -2 VDC and +2 VDC) can be set by five different combinations (±2 VDC12, ±2 VDC13, ±2 VDC14, ±2 VDC23, ±2 VDC24) depending on which two smart battery modules are operating at the zero state voltage. Considering the dual possibility of providing the zero state, the total number of possible combinations of ±2 VDC equals ten.

[0072] The voltage levels (both -1 VDC and +1 VDC) can be obtained using four different combinations (±1 VDC1, ±1 VDC2, ±1 VDC3, ±1 VDC40). The last index corresponds to the number of smart battery modules operating at the ±1 VDC level. Likewise, each zero state is obtained doubly. Therefore, like the ±3 VDC level, there are eight possible combinations that provide ±1 VDC output voltage levels.

[0073] Finally, when all in-phase smart battery modules are operating simultaneously, maximum voltage levels of -4 VDC and +4 VDC can be provided at the phase outputs of the converter. Therefore, for each of these cases, there is only one available combination of switch states.

[0074] Voltage level selection in hysteresis control

[0075] It has been explained previously how to obtain each voltage level of the nine-level ACi battery pack by different switching combinations of the output converters of the four smart battery modules 142. However, the most important task for the multi-level hysteresis controller is to obtain the voltage level of the nine-level ACi battery pack based on the current feedback (motor phase) signal I REAL , identifying the appropriate output voltage level at any time when the converter is operating.

[0076] The block diagram of the voltage level selector 300 is shown in Fig. 9 The voltage level selector includes two summation blocks (sum 1 301 and sum 2 307), five hysteresis blocks (302, 303, 304, 305 and 306), and a lookup table for voltage level determination. REF and the current error signal I ERROR Subtract the actual feedback current signal I REAL , because their difference reaches the input of all five hysteresis blocks. As presented in Table 2, each of these blocks has different settings for the high (HB) and low (LB) boundary thresholds, where ΔI is the preset value of the maximum allowed current error. ERROR When the corresponding high boundary (HB) of the hysteresis block is reached, its output value is set to "1" and remains at this level until I ERROR This sets a “0” at the output of the hysteresis block and the output remains at that level until IERROR HB is reached again. Therefore, if the low and high boundaries of the five hysteresis blocks are distributed within the range between -△I and +△I (as shown in Table 2), the output of summation 2 will vary between 1 and 6, depending on I ERROR value. Fig. 9 The lookup table 308 presented in is used to determine the desired output voltage level based on the total state value of the hysteresis block (the output of summation 2) and taking into account the sign of the actual (or reference) current derivative di / dt. As described below, the sign of di / dt can be determined to be positive at the moment when summation 2 reaches the value 6, and will change to negative when summation 2 becomes equal to 1.

[0077] Hysteresis Boundary Current threshold HB1 ΔI / 5 LB1 -ΔI / 5 HB2 2ΔI / 5 LB2 -2ΔI / 5 HB3 3ΔI / 5 LB3 -3ΔI / 5 HB4 4ΔI / 5 LB4 -4ΔI / 5 HB5 ΔI LB5 -ΔI

[0078] Table 2: Current threshold levels for hysteresis blocks

[0079] Switching between voltage levels in nine-level four-quadrant hysteresis control

[0080] A detailed description of the main principles of switching between voltage levels in a nine-level four-quadrant hysteretic control technique for one phase of a nine-level ACi battery pack operation is presented below.

[0081] exist Fig. 10B In the process, the reference current I in the motor phase is REF (red trace) and the actual current I REAL (blue trace) versus five positive (HB1÷HB5) and five negative (LB1÷LB5) hysteresis boundaries (see Table 2 and also Fig. 10A ) are presented together, which are evenly distributed in I REF -ΔI and I REF +ΔI and are separated from each other by ΔI / 5 (green trace). ERROR , as I REAL and I REF The difference between the converter output voltage V OUT These are presented in Figures 10(a) and 10(c), respectively.

[0082] V in the considered time window (from 23.06ms) OUT The initial state of the control system is preset to +4VDC (where VDC = 80V). At this voltage level, the current I REAL Rising, and when I ERROR When the first hysteresis boundary LB1 at point A (level -ΔI / 5 in FIG. 10( a)) is reached, the output state of the first hysteresis block changes from "1" to "0", so the sum at the output of the summation 2 block decreases from "6" to "5" ( Fig. 9 ). And according to Fig. 9In the table, for di / dt>0, the voltage V OUT becomes +3VDC.

[0083] From the beginning of the considered time window and until time t1 ( Fig. 10C ), current I REF has a positive di / dt value, and the hysteresis controller should be Fig. 10C The voltage levels presented in the second column of the lookup table in (di / dt>0) work. Starting from t1, the current I REF The di / dt sign is negative, but when I ERROR When the fifth hysteresis boundary LB5 is reached and Sum2=1, the hysteretic controller remains in operation for positive di / dt until time t2. This event will switch the operation of the hysteretic controller to the first column of the table for di / dt<0. In other words, at time (t2), the sign of di / dt can be determined to be negative when Sum2 reaches a value of "1" (and will change to positive when Sum2 becomes equal to "6"). This logic is implemented in the di / dt estimator block, which will be presented as described in the next section of this document.

[0084] When V OUT At its maximum negative level of -4 VDC, the current I REAL 10(b)), and when it reaches point F (which corresponds to the first hysteresis boundary HB1 in FIG. 10(a)), the output state of the first hysteresis block changes from “0” to “1”, so the sum at the output of summation 2 increases by one from “1” to “2” ( Fig. 9 ). And according to Fig. 9 The lookup table for di / dt<0 in the voltage V OUT becomes -3VDC. At point G, when I REAL and I ERROR When HB2 is reached, Sum 2 increases again and V OUT becomes -2VDC.

[0085] In the hysteresis control method provided in this article, the maximum current error △I is only REF In addition to these key points, the method works in such a way that the current error I at △I / 5 is reduced as quickly as possible under the given load parameters. ERROR minimize.

[0086] Overall method description

[0087] A general functional diagram of a 9-level 4-quadrant hysteretic current controller 500 with charge balance states and zero state rotation is shown in Fig.11 It comprises a switch level selector 300, the function of which is as described above. Fig. 9 The output signal of summation 2 is Fig.11 The signal represents the numerical value of the general level (from 1 to 6) of the nine-level hysteresis controller, which is further used in the method to select the appropriate output voltage level of the smart battery module output converter.

[0088] according to Fig. 9 The lookup table in the , needs to know the di / dt sign to select the appropriate output voltage level. As mentioned earlier, when "level" reaches the value "1", the sign of di / dt can be determined to be negative; and when "level" becomes equal to "6", the sign of di / dt will change to positive. This logic is implemented in the di / dt estimator block, in Fig.13 . The estimator block includes two digital comparators (Comp 1 and Comp 2) and an RS flip-flop element. When the "level" signal is equal to "6" (Comp 1) and "1" (Comp 2), the two comparators provide a transition pulse from "false" to "true" at that moment. These rising edges are detected by the RS flip-flop, which changes its output state accordingly, thereby providing a "true" signal at its non-inverting output Q when di / dt>0 and a "false" signal when di / dt<0.

[0089] As previously described and presented in Table 1, there are many available switching states for each voltage level of the nine-level ACi battery pack, except for ±4VDC, when all smart battery modules participate in providing the maximum positive or negative output voltage. Therefore, considering that the hysteresis "level" and the sign of di / dt are known parameters, there are the following main tasks that must be solved to control the motor current:

[0090] 1) Based on the state of charge (SOC) of each smart battery module, identification of the smart battery modules must be repeatedly switched for a period of time to provide the desired output voltage level and output current regulation. This identification method must ensure the balance of the state of charge during the operation of the ACi battery pack. When this function is provided, the energy stored in the battery or transferred from or to the motor is equally distributed among all smart battery modules. This is a necessary condition for the correct operation of the ACi battery pack, where each unit must be designed for a specific temperature profile of the semiconductor switches based on the operating mode of the semiconductor switches. This task is performed by the SOC balancing block in the method provided in this article (see Fig.11 ) is executed, and Fig.12 A functional diagram of the intelligent battery module rotation controller 600 as the main component of this block is presented in FIG.

[0091] 2) For smart battery modules, a rotation of the zero switching state is identified by the SOC balancing block. This rotation provides energy distribution between switches within a particular module in operation. There are two possible switch combinations to provide zero voltage at the output of the smart battery module, as shown in Table 1. The rotation method alternates between switches that provide zero voltage at every other positive or negative operating level of the cell. In fact, as will be shown in the next section of this document, this rotation reduces the switching frequency to half compared to the output voltage frequency of the smart battery module and the entire ACi battery pack. In the method provided herein, there are four rotating generator blocks 1001, 1002, 1003 and 1004 for different levels of output voltage from 0VDC to 3VDC, such as Fig.16A , 16B , 16C and 16D.

[0092] Fig.16A , 16B Each of the four rotation generators in 16C and 16D includes: four digital comparators, an inverting element, four logic elements "AND", two SR flip-flops latch 1 and latch 2 and two 2 dividers. The structure and operating principle of all rotation generator blocks are the same; only the preset values ​​of the digital comparators are different. In the 0VDC rotation generator, when the "di / dt" signal from the di / dt estimator output is "true", when the "level" signal is equal to "3", the comparator Comp1 sets the SR flip-flop latch 1 output to "true", which corresponds to the output voltage level of +1VDC. When the "level" signal is equal to "2", another comparator Comp2, at a positive di / dt, will reset latch 2, which corresponds to an output voltage level of +0VDC. In other words, the high-level pulse train at the output of latch 1 will correspond to the +1VDC voltage at the output of the nine-level converter, and its zero level will indicate the +0VDC voltage level (+0 indicates that the 0VDC level is after and / or before the +VDC level). Finally, the circuit, which includes the divider block and the logic element "AND", is intended to set the output signal Rot+OVDC to "true" where the high level of the latch 1 output occurs at the +1VDC output voltage level and maintain this "true" signal until a second transition from +OVDC to +1VDC occurs. In the operation of providing the +1VDC voltage level, this output signal Rot+OVDC is used to alternate between the two possible zero-state switch combinations for the smart battery module. The same operation logic is followed by the Rot-0VDC signal, which is generated by the same 0VDC rotation generator to alternate between the two zero-state switch combinations for the smart battery module in the operation of providing the -1VDC voltage level.

[0093] Further explain the intelligent battery module rotation controller 600 and the SOC balancing block for the multilevel hysteresis controller provided in this article. The detailed functional diagram of the intelligent battery module rotation controller is presented in Fig.12 . The inputs to this module are the measured state-of-charge SOC1, SOC2, SOC3, and SOC4 from the battery management systems (BMS) of all four intelligent battery modules in one phase. The output signals are the number of intelligent battery modules (from 1 to 4), their maximum state-of-charge SOCmax, minimum state-of-charge SOCmin, and then SOCrot3 and SOCrot4, which are distributed as follows: SOCmin < SOCrot4 < SOCrot3 < SOCmax. At the start, SOC1 and SOC2 are compared with each other, and if their difference △SOC 12 is above or below the positive or negative threshold of the hysteresis block Hyst 1, the output of this block is set to "1" or "0" respectively, otherwise, it maintains its previously set value at the output. This threshold helps to ignore a certain level of noise in the feedback signal and regulate how often the intelligent battery modules should rotate. Based on the Hyst 1 output signal, switch 1 selects the number of the intelligent battery module with the higher SOC (1 or 2), while switch 5 passes its corresponding SOC value to summing 3, which compares it with the lowest state-of-charge of SOC3 and SOC4, and they go through the same comparison technique. Thus, at the output of the intelligent battery module rotation controller, the intelligent battery module numbers are distributed as SOCmin < SOCrot4 < SOCrot3 < SOCmax according to their SOC. Before going to rotation, considering the sign of the reference current I REF , the block signals SOCmax and SOCmin are reassigned to SOCrot1 and SOCrot2 in the SOC balancing block (see Fig.11 ). If the current I REF is positive (corresponding to energy transfer from the intelligent battery module to the motor), the intelligent battery module with the maximum SOC will participate in the rotation of all positive output voltage levels (but not simultaneously). This will cause the intelligent battery module with the maximum SOC to discharge faster because, under positive output voltage and positive load current, there is only one way of energy transfer: from the intelligent battery module to the motor. At the same time, at positive output current (or I REF ), the intelligent battery module with the minimum SOC must participate in providing only negative output voltage levels to charge the voltage of its battery as soon as possible. This is because, in the case of positive load current but negative output voltage of the output converter, there is only one direction of energy transfer: from the motor to the battery.

[0094] The 0VDC rotation and 1VDC rotation blocks are presented in Fig.14A , 14B, 15A and 15B. Let us first describe the +0VDC rotation. This block receives a control signal from the smart battery module balancing module SOCrotl and a signal Rot+0VDC from the OVDC rotation generator, and provides control signals for the switching elements of the nine-level ACi battery pack for the +OVDC output voltage, where +0 means that the 0VDC level is after and / or before the +VDC level. The multiplexer switch 1 selects one of four different combinations of switch signals based on the input signal SOCrot1, which indicates which smart battery module is operating while providing the +VDC output level. This means that a rotation of zero switching states must be performed for this particular smart battery module (with SOCrotl number). The input signal Rot+0VDC controls the order in which the same smart battery module switches between two possible zero states [1 1] and [0 0].

[0095] The block +1VDC rotation has a more complex structure. In addition to the control signal Rot+1VDC from the 1VDC rotation generator block, it also receives two control signals SOCrot1 and SOCrot3 from the SOC balancing block. The multiplexer switch 1 uses the first signal SOC1rot to set a positive voltage at the output of the smart battery module, the amount of which is specified by this signal. This can be done by providing the switch combination [1 0] for this smart battery module. All other three smart battery modules must provide a zero switch state. If at the output of the converter, the voltage changes between +0VDC and +1VDC, the signal Rot+lVDC is always "true" and the zero switch state does not rotate for the other three units. If the output voltage changes between +1VDC and +2VDC, the zero state rotation must be performed only for one specific smart battery module that participates in the generation of the +2VDC level. The input signal Rot+1VDC controls the order in which this smart battery module switches between the two possible zero states [1 1] and [0 0].

[0096] The same operating principle is valid for -0 VDC rotation and -1 VDC rotation, where only the input signal SOCrot2 is different instead of SOCrot1 and Rot-1 VDC instead of Rot+1 VDC. The SOCrot3 signal, indicating the number of cells operating at +2 DC and -2 VDC levels, remains the same as for the positive rotation block.

[0097] The blocks +2VDC Rotation and +3VDC Rotation have a complex structure of four input signals, three of which SOCrot1, SOCrot2 and SOCrot3 come from the SOC Balancing block, and one signal from the 2VDC Rotation Generator or the 3VDC Rotation Generator, designed to control the order in which a specific smart battery module changes between zero switching states.

[0098] A detailed discussion of multi-level hysteresis control is provided in U.S. Provisional Application No. 62 / 518,331, filed on June 12, 2017, and U.S. Provisional Application No. 62 / 521,227, filed on June 16, 2017, which are incorporated by reference as if fully set forth.

[0099] Local and Master ECU Functionality

[0100] power electronic converters and manage intelligent battery module operations 132 (see Figure 5 The local ECU 200 of the smart battery module works by measuring the initial SOC of the battery using a state of charge (SOC) estimator. The main control system (ECU) 210 receives the initial SOC data of all smart battery modules (such as Fig.17 Described in (see also Figure 5 )), and classify them.

[0101] The SOC balancing technique for a multi-level hysteretic controller is described above. For multi-level PWM, this balancing method is as follows: Assuming that all cells are balanced before discharge, when the ACi battery pack is fully charged, the strongest cell is the cell with the highest initial SOC, and the weakest cell is the cell with the lowest initial SOC.

[0102] Depending on this data, the master ECU 210 calculates the corresponding switch signal array necessary for the proper operation of each individual smart battery module based on its battery capacity. In other words, in order to balance the state of charge of the modules, the SOC of each module should be compared to the total SOC, which can be calculated as:

[0103]

[0104] Among them, SOC i and Q i - The individual SOC and capacity of the batteries of the i-th smart battery module and the difference together with the PI controller can be used to control the modulation index (M) of each module. Note that when the modules are charged, the direction of the effect of the SOC difference must be reversed, because in this case, the module with a higher SOC is expected to receive less energy than the other modules.

[0105] The local control system of the smart battery module 132 obtains this information, and therefore, for each smart battery module, there is a different switch signal array S 1……N , which determines the individual DC currents of the system (I DC1 ,I DC2 ……I DCN ) and the DC bus voltage (battery voltage V B1 、V B2……V BN ). In this way, the power management operation and the built-in power electronics unit autonomously manage the output power of each smart battery module. The strongest battery carries the highest current, while the weakest battery carries the least current, so that the SOC of all batteries converges at a specific time.

[0106] Supercapacitor Module

[0107] Intelligent battery module 132 ( Figure 5 ) is connected in parallel to the main battery 32 and the output converter 52. During acceleration, the capacitor voltage is allowed to discharge from a full charge (50Vdc) to about one-third of its nominal voltage (17Vdc), allowing it to deliver 11kW of useful energy. This amount of energy allows 2.2kW of power to be drawn from one smart battery module during 5 seconds, and if 30 smart battery modules are placed in the ACi battery pack, a total of 66kW can be drawn, which is enough power and time for good acceleration without compromising battery life. During deceleration (regenerative braking), energy is recovered in a similar manner, charging back into the supercapacitors.

[0108] When the vehicle accelerates, the battery delivers the amount of current required by the motor. If this current exceeds the battery's current limit, the supercapacitor provides the difference. Regenerative braking operates similarly. In this case, the motor works as a generator, which delivers the recovered energy into the battery, but if the injected current exceeds the limit, the DC-DC converter injects the excess into the supercapacitor.

[0109] The DC-DC converter operates in two modes: boost operation for acceleration, which discharges the supercapacitor, and buck operation for deceleration (regenerative braking), which charges the supercapacitor. During boost operation (acceleration), MOSFET S2 is turned on and off at a controlled duty cycle D to transfer the required amount of energy from the capacitor to the battery pack. When S2 is on, energy is taken from the supercapacitor and stored in the inductor L C When S2 is turned off, the current stored in L C The energy in is transferred to C through S1 F , and then transferred to the motor and / or battery. During buck operation, the converter directs energy from the battery into the supercapacitor. This operation is accomplished by controlled operation on S1. When S1 is turned on, energy goes from the battery to the supercapacitor, and L C When S1 is turned off, the energy stored in L C The remaining energy in the supercapacitor is transferred through the diode of S2.

[0110] The battery as the primary energy source is the one with the highest energy content and should therefore supply the average power required by the motor. The supercapacitor is the secondary energy source and assists the battery by providing / absorbing instantaneous load power peaks.

[0111] Fig.18 A redundant structure for power flow management between two power supplies and the motor is presented in FIG. It has advantages over other power control methods because it allows complete decoupling between the electrical characteristics (terminal voltage and current) of each power supply and the electrical characteristics of the load. The power flow controller 1 receives a reference battery power flow P from the local ECU of the smart battery module. BATT，REF This signal is generated by the main power management controller located in the main ECU based on the motor power P iBATTERY The power flow controller 1 estimates the maximum allowable battery charge / discharge current and calculates the actual allowed battery power flow P BATT . Combine this signal with P iBATTERY Compare them and use their difference as signal P SC，REF Applied to the power flow controller 2. The controller is based on the supercapacitor voltage V SC Computation I SCM The current is determined by the switching signals S1 and S2 of the buck / boost converter of the supercapacitor module, and its basic working principle is described above. iBATTERY The stream is provided by the output converter, P BATT is estimated based on the maximum battery current and actual SOC and is guaranteed to be P iBATTERY and P SC The difference between the two, the last of which is managed by the converter of the supercapacitor module.

[0112] Another important function performed by the supercapacitor module is to control the DC current I DC Active filtering of the second-order current harmonics that appear in the current is caused by the inherent pulsating power nature of the single-phase system. OUT and I(t) OUT Considered as the output voltage and current of the smart battery module:

[0113]

[0114] The instantaneous input-output power balance of the smart battery module is given by:

[0115]

[0116] The first constant term refers to the average power used to charge / discharge the battery. However, the second oscillatory term does not contribute to the average battery SOC. This component has a considerable peak-to-peak value, which can reach twice the grid current amplitude when the modulation index is consistent. The second-order current component exhibits some disadvantages, such as an increase in internal battery resistance losses related to the generated current RMS value and periodic changes in battery behavior.

[0117] The main waveforms of active filtering are Fig. 20A and 20B The supercapacitor is used as an active filter to eliminate the battery current I B Before compensation starts (before time t1), the battery I B The current includes a DC component (I B =130A) and has an amplitude of I 2AC =60A second-order component. Starting from time t1, the supercapacitor module starts to generate supercapacitor current I SC , so that the current I B The second harmonics are redirected to the supercapacitor (see Fig. 20B ). The current I SC The amplitude of the main harmonic is equal to I DC The amplitude of the second harmonic of the current (see Fig.19 ), but with an almost opposite phase angle, in such a way that the battery I B The current generated in the circuit includes only a DC component, or a mostly DC component, with some significantly reduced AC ripple, such as Fig. 20A as shown in .

[0118] At high RPM, the filter capacitor C F The second-order current harmonics are significantly suppressed and the operation of the supercapacitor module is not required.

[0119] Fig.21 A single-phase nine-level four-quadrant smart battery pack connected to a single-phase load (presented as an RL load) is shown. The system can be used for energy storage and interruptible power supply systems for residential or commercial buildings.

[0120] Fig. 22 A three-phase smart battery pack is shown, which includes three nine-level two-quadrant single-phase smart battery packs connected to a three-phase switched reluctance motor (SRM). The use of a multi-level hysteresis current controller and smart battery packs allows for improved efficiency and overall performance of the SRM, as well as significant reductions in torque ripple and acoustic noise.

[0121] In the foregoing description, many specific details are given to provide a thorough understanding of the present embodiment. However, it will be apparent that the present embodiment can be practiced without these specific details. In order to increase clarity, some well-known circuits, system configurations, and processing steps may not be described in detail. In other examples, structures and devices are shown in block diagram form to avoid making the present invention difficult to understand.

[0122] The drawings showing embodiments of the present disclosure are semi-schematic and not to scale and, particularly, some of the dimensions are for clarity of presentation and are shown exaggerated in the drawings.

[0123] References to "one embodiment" or "an embodiment" or "some embodiments" in the foregoing description mean that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention. The phrase "in one embodiment" appearing in various places in the specification does not necessarily refer to the same embodiment.

[0124] Certain portions of the detailed description are presented in terms of algorithms and symbolic representations of operations on data bits within a computer memory. These algorithmic descriptions and representations are methods used by those skilled in the art of data processing to most effectively communicate the essence of their work to other persons skilled in the art. Here, an algorithm is generally considered to be a self-consistent sequence of steps leading to a desired result. These steps are steps that require physical manipulation of physical quantities. Typically, although not necessarily, these quantities take the form of electrical or magnetic signals that can be stored, transferred, combined, compared, or otherwise manipulated. Mainly for general reasons, it has sometimes proven convenient to refer to these signals as bits, values, elements, symbols, characters, terms, numbers, etc.

[0125] It should be remembered, however, that all of these and similar terms are to be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities. Unless otherwise expressly noted, as will be apparent from the following disclosure, it should be understood that throughout the disclosure, terms such as "processing," "computing," "calculating," "determining," "displaying," and the like refer to the actions and processes of a computer system or similar electronic computing device that manipulates and transforms data represented as physical (electronic) quantities within the computer system's registers and memories into other data similarly represented as physical quantities within the computer system's memories or registers or other such information storage, transmission, or display devices.

[0126] The present embodiment also relates to a device for performing the operations herein. The device may be specially constructed for the desired purpose, or it may be a general-purpose computer selectively activated or reconfigured by a computer program stored in the computer. The present embodiment may take the form of a complete hardware embodiment, a complete software embodiment, or an embodiment including both hardware and software elements. In one embodiment, the present embodiment is implemented with software including instructions or data stored on a computer-readable storage medium, which includes but is not limited to firmware, resident software, microcode, or another method for storing instructions for execution by a processor.

[0127] In addition, the present embodiment can take the form of a computer program product accessible from a computer-usable or computer-readable storage medium that provides program code for use by or in conjunction with a computer or any instruction execution system. For the purpose of this description, a computer-usable or computer-readable storage medium is any device that can contain, store or transmit a program for use by or in conjunction with an instruction execution system, device or equipment. The computer-readable storage medium can be an electronic, magnetic, optical, electromagnetic, infrared or semiconductor system (or device or equipment) or a propagation medium. Examples of tangible computer-readable storage media include, but are not limited to, semiconductor or solid-state memory, magnetic tape, removable computer disk, random access memory (RAM), read-only memory (ROM), hard disk, optical disk, EPROM, EEPROM, magnetic card or optical card, or any type of computer-readable storage medium suitable for storing electronic instructions, and each is coupled to a computer system bus. Examples of optical disks include compact disk-read only memory (CD-ROM), compact disk-read / write (CD-R / W) and digital video disk (DVD).

[0128] To the extent that the embodiments disclosed herein include memory, storage, and / or computer-readable media or operate in association with memory, storage, and / or computer-readable media, then the memory, storage, and / or computer-readable media is non-transitory. Therefore, to the extent that memory, storage, and / or computer-readable media are covered by one or more claims, then the memory, storage, and / or computer-readable media is only non-transitory. The terms "non-transitory" and "tangible" as used herein are intended to describe memory, storage, and / or computer-readable media, but do not include propagating electromagnetic signals, but are not intended to limit the types of memory, storage, and / or computer-readable media in terms of persistence of storage or other aspects. For example, "non-transitory" and / or "tangible" memory, storage, and / or computer-readable media cover volatile and non-volatile media, such as random access media (e.g., RAM, SRAM, DRAM, FRAM, etc.), read-only media (e.g., ROM, PROM, EPROM, EEPROM, flash memory, etc.) and combinations thereof (e.g., hybrid RAM and ROM, NVRAM, etc.) and variants subsequently developed therefrom.

[0129] A data processing system suitable for storing and / or executing program codes comprises at least one processor directly or indirectly coupled to a memory element via a system bus. The memory element may comprise a local memory, a bulk storage, and a cache memory providing temporary storage of at least some program codes to reduce the number of times the code must be retrieved from the bulk storage during execution. In some embodiments, an input / output (I / O) device (e.g., a keyboard, display, pointing device, or other device configured to receive data or present data) is coupled to the system directly or via an intermediate I / O controller.

[0130] Network adapters may also be coupled to the data processing system to enable coupling to other data processing systems or remote printers or storage devices through intervening private or public networks. Modems, cable modem and Ethernet cards are just examples of currently available types of network adapters.

[0131] Finally, the methods and displays presented herein are not inherently related to any particular computer or other device. Various general purpose systems may be used in conjunction with the programs according to the teachings herein, or it may prove convenient to construct more specialized devices to perform the required method steps. The structures required for a variety of these systems will be apparent from the following description. It should be understood that a variety of programming languages ​​may be used to implement the teachings of the present invention as described herein.

[0132] The drawings and detailed description describe certain embodiments by way of illustration only. Those skilled in the art will readily recognize from the foregoing description that alternative embodiments of the structures and methods illustrated herein may be employed without departing from the principles described herein. Reference will now be made in detail to several embodiments, examples of which are illustrated in the accompanying drawings. It is noted that similar or identical reference numerals may be used in the drawings to indicate similar or identical functionality, where practicable.

[0133] Embodiments of the present disclosure are directed to a converter-battery module architecture for an intelligent battery (iBattery) module, which is used as a building unit of an intelligent battery pack or a system of intelligent battery packs. In an embodiment, an iBattery module includes a battery cell, a supercapacitor or supercapacitor module unit, and an output converter unit. In an embodiment, the local control unit of the iBattery module is configured to receive, process and transmit signals, including but not limited to, temperature, voltage and current sensors, etc. from the iBattery module; trigger and fault signals to and from semiconductor switches; voltages of element units of battery cells and supercapacitor modules. In an embodiment, the local control system performs communication with a master control unit of an intelligent AC battery pack (ACi-battery pack) including multiple iBattery modules and transmission of corresponding control signals therefrom.

[0134] Embodiments of the present disclosure are directed to an intelligent AC battery pack (ACi-battery pack) comprising two or more iBattery modules interconnected together in each phase. In embodiments, an output voltage of any shape and frequency can be generated at the output of the ACi battery pack as a superposition of the output voltages of the individual iBattery modules.

[0135] Embodiments of the present disclosure are directed to a method for controlling an ACi battery pack to provide a multi-level current hysteresis control for balancing the SOC and iBatteries in the ACi battery pack. In an embodiment, the method enables power sharing between all iBattery modules in the ACi battery pack. In an embodiment, power sharing between all iBattery modules can be used to always maintain the SOC balance of the battery modules of the iBatteriy during operation, which ensures that the full capacity of each module is utilized regardless of the possible difference in capacity.

[0136] Embodiments of the present disclosure are directed to processes, methods, and systems described herein that relate to electric vehicles and stationary energy storage systems.

[0137] Embodiments of the present disclosure are directed to an electric vehicle having a chassis, three or more wheels operably coupled to the chassis, one or more electric motors operably coupled to the three or more wheels, one or more intelligent modular battery packs operably coupled to the one or more motors, and a control system operably coupled to the one or more battery packs and the one or more motors.

[0138] In an embodiment, the chassis is driveline-less.In an embodiment, one or more motors are in-wheel motors.

[0139] In an embodiment, one or more intelligent modular battery packs have a cascaded interconnected architecture.

[0140] In an embodiment, a battery pack includes a plurality of interconnected smart battery modules.

[0141] In an embodiment, a battery module includes an integrated combination of a networked low voltage converter / controller with peer-to-peer communication capabilities, an embedded ultracapacitor or supercapacitor, a battery management system, and a group of individual cells connected in series.

[0142] In an embodiment, a battery pack includes a neural network comprising a plurality of interconnected intelligent battery modules.

[0143] In an embodiment, a battery module includes an integrated combination of a battery with a BMS, a supercapacitor module, and an output converter.

[0144] In an embodiment, the supercapacitor module includes a bidirectional DC-DC converter and a supercapacitor group.

[0145] In an embodiment, the output converter comprises a four-quadrant H-bridge.

[0146] In an embodiment, the control system comprises a bidirectional multi-level controller.

[0147] In an embodiment, the bidirectional multilevel controller is a bidirectional multilevel hysteresis controller.

[0148] In an embodiment, a bidirectional multi-level controller is combined with a temperature sensor and networking interface logic.

[0149] In an embodiment, the control system is configured to balance battery utilization through individual switching of modules based on module age, thermal conditions, and performance characteristics.

[0150] In an embodiment, the battery pack may be switched to rectifier / charger operation.

[0151] Embodiments of the present disclosure are directed to an intelligent modular battery pack including a cascade architecture including a plurality of interconnected intelligent battery modules.

[0152] In an embodiment, a battery module includes an integrated combination of a networked low voltage converter / controller with peer-to-peer communication capabilities, an embedded ultracapacitor, a battery management system, and groups of individual cells connected in series.

[0153] In an embodiment, the interconnected intelligent battery modules include a neural network.

[0154] In an embodiment, a battery module includes an integrated combination of a battery with a BMS, a supercapacitor module, and an output converter.

[0155] In an embodiment, the supercapacitor module includes a bidirectional DC-DC converter and a supercapacitor group.

[0156] In an embodiment, the output converter comprises a four-quadrant H-bridge.

[0157] Embodiments of the present disclosure are directed to a smart battery module that includes an integrated low voltage converter / controller with peer-to-peer communication capabilities, an embedded ultracapacitor, a battery management system, and a plurality of series-connected groups of individual cells.

[0158] Embodiments of the present disclosure are directed to a smart battery module including a battery with an integrated BMS, a supercapacitor module operably coupled to the battery, and an output converter operably coupled to the battery and the supercapacitor module.

[0159] In an embodiment, the supercapacitor module includes a bidirectional DC-DC converter and a supercapacitor group.

[0160] In an embodiment, the output converter comprises a four-quadrant H-bridge.

[0161] All features, elements, components, functions and steps described with respect to any embodiment provided herein are intended to be freely combined and replaced with those from any other embodiment. If a feature, element, component, function or step is described only with respect to one embodiment, it should be understood that unless explicitly stated otherwise, the feature, element, component, function or step can be used with each other embodiment described herein. Therefore, this paragraph is used as a prerequisite basis and written support for the introduction of claims at any time, and the claims combine features, elements, components, functions and steps from different embodiments, or replace features, elements, components, functions and steps from another embodiment with features, elements, components, functions and steps of one embodiment, even if the following description does not explicitly indicate in special cases, such combination or replacement is possible. The explicit description of each possible combination and replacement is very cumbersome, especially considering that a person of ordinary skill in the art will easily recognize the permissibility of each such combination and replacement after reading this specification.

[0162] In many cases, entities are described herein as being coupled to other entities. It should be understood that the terms "coupled" and "connected" or any form thereof are used interchangeably herein, and in both cases, generally, without any non-negligible, such as direct coupling of two entities with a parasitic intermediate entity and indirect coupling of two entities with one or more non-negligible intermediate entities. When entities are shown as being directly coupled together, or described as being coupled together without any description of intermediate entities, it should be understood that those entities may also be indirectly coupled together unless the context clearly indicates otherwise.

[0163] Although the embodiments are susceptible to various modifications and alternative forms, specific examples thereof have been shown in the drawings and described in detail herein. However, it should be understood that the embodiments are not limited to the particular forms disclosed, but on the contrary, the embodiments are intended to cover all modifications, equivalent forms and substitutions that fall within the spirit of the present disclosure. In addition, any features, functions, steps or elements of the embodiments may be stated in or added to the claims, and negative limitations on the scope of the invention of the claims may be limited by features, functions, steps or elements that are not within the scope.

Claims

1. A modular battery pack system that is controllable to supply power to a motor load of an electric vehicle (EV), the modular battery pack system comprising: A plurality of converter modules arranged in at least three cascades, each cascade comprising at least two converter modules coupled together to output a single-phase AC voltage signal comprising a superposition of pulse width modulated (PWM) output voltages from each of the at least two converter modules, wherein the at least three cascades together output at least three AC voltage signals of different phases, and wherein each of the plurality of converter modules comprises: a primary energy source coupled between the first node and the common node, wherein the primary energy source is a battery; a switching circuit that is controllable to selectively output three voltages from the module; and a local control device configured to output the switching signal and configured to output a sensed operating parameter regarding the converter module; and A master control device is configured to generate control information using the sensed operating parameters received from each of the local control devices and output the control information to each of the local control devices to balance utilization of each battery across the plurality of converter modules.

2. The modular battery pack system according to claim 1, further comprising: an auxiliary energy source coupled between the inductor and the common node; wherein the switch circuit includes a first plurality of switches controllable to selectively couple an auxiliary energy source to a first node or a common node through an inductor, and a second plurality of switches controllable to selectively output three voltages from the module, and wherein the circuit is controllable to supply power from the auxiliary energy source to supplement power provided by a battery during acceleration of the EV, and to charge the battery and the auxiliary energy source during regenerative braking of the EV; a capacitor coupled between the first node and the common node and adapted to receive and store energy from the inductor; as well as Wherein the local control device is configured to output switching signals to the first plurality of switches and the second plurality of switches.

3. The modular battery pack system according to claim 1, wherein the sensed operating parameter is a battery state of charge (SOC), a battery voltage, a battery current or a temperature.

4. The modular battery pack system of claim 1, wherein each battery comprises a series connection of battery cells.

5. A modular battery pack system according to claim 2, wherein each auxiliary energy source is a supercapacitor or an ultracapacitor.

6. The modular battery pack system of claim 2, wherein each switch of the first plurality of switches is a transistor having a parallel diode.

7. The modular battery pack system of claim 2, wherein for each converter module of the plurality of converter modules, when the charging current generated during regenerative braking of the EV exceeds the battery limit, the switch circuit is controllable to inject excess current to charge the auxiliary energy source.

8. The modular battery pack system of claim 2, wherein for each converter module of the plurality of converter modules, the switch circuit is controllable to decouple the battery and the auxiliary energy source from the motor load of the EV.

9. The modular battery pack system of claim 2, wherein for each converter module of the plurality of converter modules, the switching circuit is controllable to use current from the auxiliary energy source to actively filter second order harmonics in the current from the battery. 10 . The modular battery pack system of claim 1 , wherein the master control device is configured to generate control information including a switch signal and output the control information to each of the local control devices.

11. The modular battery pack system of claim 2, wherein for each converter module of the plurality of converter modules, the local control device is configured to generate and output switching signals for the first plurality of switches.

12. The modular battery pack system of claim 1, wherein each converter module of the plurality of converter modules comprises temperature, voltage, and current sensors, and the local control device is configured to process signals from the temperature, voltage, and current sensors of the converter modules.

13. The modular battery pack system according to claim 2, wherein each cascade comprises S converter modules, wherein S is two or more, and the system is configured as follows: generating at least one reference signal and at least S carrier signals for each cascade, wherein each of the at least S carrier signals has a different phase; generating at least 2S pulse width modulated (PWM) switching signals for each cascade by using at least one reference signal and at least S carrier signals; as well as The second plurality of switches of each cascaded S converter modules are controlled by a PWM switching signal so that each cascade outputs a single-phase AC voltage signal including a superposition of output voltages from each of the cascaded S converter modules.

14. An intelligent modular battery pack system, comprising a cascade architecture, the cascade architecture comprising a plurality of interconnected intelligent battery converter modules, the intelligent modular battery pack system being controllable to supply power to a load, and comprising: A plurality of converter modules arranged in at least three cascades, each cascade comprising at least two converter modules coupled together to output a single-phase AC voltage signal comprising a superposition of pulse width modulated (PWM) output voltages from each of the at least two converter modules, wherein the at least three cascades together output at least three AC voltage signals of different phases, and wherein each of the plurality of converter modules comprises: A primary energy source coupled between a first node and a common node, wherein the primary energy source is a battery, and wherein the voltage between the first node and the common node is V DC ; A switch circuit that can be controlled to selectively output one of three voltages from the module, wherein the three voltages are +V DC , 0 and V DC ;as well as a local control device configured to output a switch signal to the switch circuit and configured to output information about a state of charge (SOC) of the battery; and A master control device is configured to generate control information using the SOC information received from each of the local control devices and output the control information to each of the local control devices to balance utilization of each battery across the plurality of converter modules.

15. The intelligent modular battery pack system according to claim 14, further comprising: an auxiliary energy source coupled between the inductor and the common node, and wherein the switch circuit includes a first plurality of switches controllable to selectively couple the auxiliary energy source to the first node or the common node through the inductor, and a first plurality of switches controllable to selectively output +V from the module DC , 0 and V DC a second plurality of switches for one of the three voltages; as well as A capacitor is coupled between the first node and the common node and is adapted to receive and store energy from the inductor.

16. The intelligent modular battery pack system of claim 15, wherein each battery comprises a series connection of battery cells.

17. The intelligent modular battery pack system of claim 15, wherein each auxiliary energy source is a supercapacitor or an ultracapacitor.

18. The intelligent modular battery pack system of claim 15, wherein each switch of the first plurality of switches is a transistor with a parallel diode.

19. The intelligent modular battery pack system of claim 15, wherein for each converter module of the plurality of converter modules, a switch circuit is controllable to supply power from the auxiliary energy source to supplement power provided by the battery during acceleration of the EV.

20. The intelligent modular battery pack system of claim 14, wherein for each converter module of the plurality of converter modules, the switch circuit is controllable to charge the battery during regenerative braking of the EV.

21. The intelligent modular battery pack system of claim 15, wherein for each converter module of the plurality of converter modules, when the charging current generated during regenerative braking of the EV exceeds the battery limit, the switch circuit is controllable to inject excess current to charge the auxiliary energy source.

22. The intelligent modular battery pack system of claim 15, wherein for each converter module of the plurality of converter modules, a switch circuit is controllable to decouple the battery and the auxiliary energy source from a motor load of the EV.

23. The intelligent modular battery pack system of claim 15, wherein for each converter module of the plurality of converter modules, a switch circuit is controllable to use current from the auxiliary energy source to actively filter second order harmonics in current from the battery.

24. The intelligent modular battery pack system of claim 14, wherein the master control device is configured to generate control information including a switch signal and output the control information to each of the local control devices.

25. The intelligent modular battery pack system of claim 14, wherein for each converter module in a plurality of converter modules, the local control device is configured to generate and output switching signals for the first plurality of switches.

26. The intelligent modular battery pack system of claim 14, wherein each converter module of the plurality of converter modules comprises temperature, voltage and current sensors, and the local control device is configured to process signals from the temperature, voltage and current sensors of the converter modules.

27. The intelligent modular battery pack system according to claim 14, wherein each cascade comprises S converter modules, wherein S is two or more, and the system is configured as follows: generating at least one reference signal and at least S carrier signals for each cascade, wherein each of the at least S carrier signals has a different phase; generating at least 2S pulse width modulated (PWM) switching signals for each cascade by using at least one reference signal and at least S carrier signals; as well as The second plurality of switches of each cascaded S converter modules are controlled by a PWM switching signal so that each cascade outputs a single-phase AC voltage signal including a superposition of output voltages from each of the cascaded S converter modules.

28. A method for generating power for a load using a modular battery pack system, the modular battery pack system comprising a plurality of converter modules arranged in at least three cascades, each cascade comprising S converter modules coupled in series, wherein S is two or more, wherein the at least three cascades together output at least three AC voltage signals of different phases, and wherein each converter module comprises a battery and a plurality of switches controllable to selectively output a voltage from the module, the method comprising: sensing an operating parameter of a battery relative to the plurality of converter modules; generating at least one reference signal for each cascade; generating at least S carrier signals for each cascade, wherein each of the at least S carrier signals has a different phase; generating at least 2S pulse width modulated (PWM) switching signals for each cascade using at least one reference signal and at least S carrier signals; as well as Controlling a plurality of switches of each cascade of S converter modules using PWM switch signals so that each cascade outputs a single-phase AC voltage signal, the single-phase AC voltage signal including a superposition of output voltages from each of the S converter modules in the cascade, The generated PWM switch signal is used to control multiple switches of each cascaded S converter modules to achieve balanced utilization of each battery across multiple converter modules.

29. The method of claim 28, wherein controlling the plurality of switches of each of the cascaded S converter modules using a PWM switching signal comprises: A plurality of switches of the first converter module of the first cascade are controlled to selectively output one of three output voltages, wherein the three output voltages are +V, 0, and -V.

30. The method of claim 28, wherein the at least S carrier signals each have a different phase spaced 360° / 2S apart.

31. The method of claim 28, wherein a first reference signal Vref and a second reference signal -Vref are generated for each cascade, and wherein the at least S carrier signals are triangular carrier signals.

32. The method of claim 28, wherein the operating parameter comprises a state of charge (SOC) of a battery, and wherein a plurality of switches of each cascaded S converter modules are controlled using a generated PWM switching signal for achieving SOC balancing of each battery across the plurality of converter modules.

33. The method of claim 32, further comprising comparing the state of charge (SOC) of the battery to the total state of charge (SOC) to achieve SOC balance.

34. The method of claim 28, wherein the operating parameters include a state of charge (SOC) and a temperature of the battery, and wherein a generated PWM switching signal is used to control a plurality of switches of each cascaded S converter modules for achieving SOC balancing and thermal management of each battery across the plurality of converter modules.

35. The method of claim 28, wherein the generation of PWM switching signals and the control of the plurality of switches of each cascaded S converter modules using the generated PWM switching signals balances the state of charge (SOC) and temperature of each battery across the plurality of converter modules.

36. The method of claim 28, further comprising controlling a modulation index of each of the S converter modules in each cascade.

37. The method of claim 36, wherein controlling the modulation index of the converter module is based on a state of charge (SOC) and a capacity of a battery of the converter module.

38. The method of claim 28, wherein the battery of each of the plurality of converter modules is a primary energy source, and wherein each of the plurality of converter modules includes an auxiliary energy source.

39. The method of claim 38 further comprising actively filtering second order harmonics in the battery output of each converter module using an auxiliary energy source.

40. The method of claim 28, wherein the load is an electric machine of a vehicle, a battery of each of the plurality of converter modules is a primary energy source, and each of the plurality of converter modules includes an auxiliary energy source.

41. The method of claim 40 further comprising supplying power from each of the auxiliary energy sources to supplement power supplied by each battery during vehicle acceleration.

42. The method of claim 40, further comprising charging each of the battery and the auxiliary energy source using regenerative braking current.

43. The method of claim 40 further comprising injecting at least excess charging current into the auxiliary energy source when charging current generated during regenerative braking exceeds a battery limit.

44. The method of claim 40, wherein each auxiliary energy source is a supercapacitor or an ultracapacitor.

45. The method of claim 28, wherein the load is an in-wheel motor of a vehicle.

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