Systems and methods for active filters in bidirectional on-board battery chargers

Abstract

Systems and methods for active filters for bidirectional on-board battery chargers. This disclosure provides a system comprising: a transformer including a primary side and a secondary side; a matrix converter connected to the primary side of the transformer and to a line connected to a voltage source or load; and an active filter configured to reduce ripple in the system.

Description

Technical Field

[0001] Various embodiments of this disclosure generally relate to matrix converters with active filters, and more specifically to four-arm matrix converters with active filters for high-voltage and low-voltage converters in bidirectional on-board battery chargers for electric vehicles. Background Technology

[0002] In the field of battery chargers, a two-stage layout is typically used to meet the requirements for use as an on-board charger in automobiles. These on-board chargers offer high power density, are lighter, and require less space. The configuration used in single-phase or three-phase chargers includes an AC-to-DC power factor correction (PFC) converter in stage I and an isolated DC-DC converter in stage II. This two-stage configuration may require several components to reduce ripple current.

[0003] This disclosure aims to overcome one or more of the aforementioned challenges. Summary of the Invention

[0004] In some aspects, the technology described herein relates to a system comprising: a transformer including a primary side and a secondary side; a matrix converter connected to the primary side of the transformer and to a line connected to a voltage source or load; and an active filter configured to reduce ripple in the system.

[0005] In some respects, the techniques described herein relate to a system in which an active filter is connected to the primary side of a transformer.

[0006] In some respects, the techniques described herein relate to a system in which an active filter is connected to the secondary side of a transformer.

[0007] In some respects, the technology described herein relates to a system in which a matrix converter includes: a first phase upper bidirectional switch, a first phase lower bidirectional switch, a second phase upper bidirectional switch, a second phase lower bidirectional switch, a third phase upper bidirectional switch, a third phase lower bidirectional switch, a neutral phase upper bidirectional switch, and a neutral phase lower bidirectional switch.

[0008] In some respects, the technology described herein relates to a system in which an active filter includes: a capacitor, a first switch, a second switch, a third switch, and a fourth switch.

[0009] In some respects, the technology described herein relates to a system that further includes a high-voltage bridge rectifier connected to the secondary side of a transformer.

[0010] In some respects, the technology described herein relates to a system in which a high-voltage bridge rectifier includes pairs of inductors.

[0011] In some respects, the technology described herein relates to a system in which the transformer further includes a three-stage side.

[0012] In some respects, the technology described herein relates to a system that further includes a low-voltage bridge rectifier connected to the third-stage side of a transformer.

[0013] In some respects, the techniques described herein relate to a system in which a low-voltage bridge rectifier includes pairs of inductors.

[0014] In some respects, the technology described herein relates to a system configured to operate in each of the following: three-phase power supply to battery operation, battery to three-phase load operation, single-phase power supply to battery operation, battery to single-phase load operation, battery to battery operation, and simultaneous battery to load and battery to battery operation.

[0015] In some respects, the technology described herein relates to a system that further includes: one or more controllers configured to control the operation of one or more of a matrix converter or an active filter.

[0016] In some aspects, the technology described herein relates to a system that further includes: one or more batteries, wherein the system is provided as a bidirectional battery charger configured to: receive input AC power from the power source of the line, convert the input AC power into output DC power and supply the output DC power to charge the one or more batteries; and receive input DC power from the one or more batteries, convert the input DC power into output AC power and supply the output AC power to the load of the line.

[0017] In some respects, the technology described herein relates to a system that further includes: a battery; and a motor, wherein the system is provided as an electric vehicle.

[0018] In some aspects, the technology described herein relates to an active filter for a power converter including a matrix converter, the active filter comprising: a capacitor connected to a first node and a second node; a first switch connected to the first node and a first external connection; a second switch connected to the second node and the first external connection; a third switch connected to the first node and the second external connection; and a fourth switch connected to the second node and the second external connection.

[0019] In some respects, the techniques described herein relate to an active filter in which a first external connection and a second external connection are connected to the matrix converter of a power converter and the primary side of the transformer of the power converter.

[0020] In some respects, the techniques described herein relate to an active filter in which a first external connection and a second external connection are connected to a high-voltage bridge rectifier of a power converter.

[0021] In some aspects, the technology described herein relates to a bidirectional current-feed dual active bridge converter comprising: a transformer including a primary side, a first stage side, and a second stage side; a matrix converter connected to the primary side of the transformer and to a line connected to a voltage source or load; an active filter including a capacitor and four switches; a first voltage bridge rectifier connected to the first stage side of the transformer; and a second voltage bridge rectifier connected to the second stage side of the transformer.

[0022] In some respects, the technology described herein relates to a bidirectional current-fed dual active bridge converter, further comprising: a first switch selectively connecting a first phase bridge arm and a second phase bridge arm of the matrix converter; and a second switch selectively connecting a third phase bridge arm and a neutral phase bridge arm of the matrix converter.

[0023] In some respects, the technology described herein relates to a bidirectional current-fed dual active bridge converter, wherein each phase bridge arm of the matrix converter includes two bidirectional switches.

[0024] Further objects and advantages of the disclosed embodiments will be set forth in part in the description which follows, and will be apparent in part from the description, or may be learned by practice of the disclosed embodiments. The objects and advantages of the disclosed embodiments will be realized and achieved by means of the elements and combinations particularly pointed out in the appended claims.

[0025] It should be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only, and do not limit the claimed disclosed embodiments. Attached Figure Description

[0026] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate various exemplary embodiments and, together with the description, serve to explain the principles of the disclosed embodiments.

[0027] Figure 1 An exemplary system infrastructure for a vehicle including a power converter, according to one or more embodiments, is described.

[0028] Figure 2 An exemplary system infrastructure for a power converter according to one or more embodiments is described.

[0029] Figure 3 An exemplary system infrastructure for a controller is described according to one or more embodiments.

[0030] Figure 4 An exemplary system infrastructure for a power converter having an active filter on the secondary side of a transformer, according to one or more embodiments, is described.

[0031] Figure 5 An exemplary system infrastructure for a power converter having an active filter on the primary side of a transformer, according to one or more embodiments, is described.

[0032] Figure 6 An exemplary power converter, according to one or more embodiments, is depicted in three-phase balanced operation with the active filter off.

[0033] Figure 7 An exemplary power converter is described according to one or more embodiments, which operates in three-phase unbalanced mode with the active filter off.

[0034] Figure 8 An exemplary power converter is described according to one or more embodiments, which operates in three-phase unbalanced mode with the active filter on.

[0035] Figure 9 An exemplary power converter, according to one or more embodiments, is depicted in single-phase operation with the active filter turned on.

[0036] Figure 10 An exemplary power converter in battery-to-battery operation with the active filter off, according to one or more embodiments, is described.

[0037] Figure 11 An exemplary system infrastructure for a current-feed dual active bridge (CFDAB) converter according to one or more embodiments is described.

[0038] Figure 12 An exemplary CFDAB converter in vehicle-to-load operation according to one or more embodiments is depicted.

[0039] Figure 13 An exemplary CFDAB converter, according to one or more embodiments, is depicted in simultaneous vehicle-to-load and battery-to-battery operation. Detailed Implementation

[0040] Both the foregoing general description and the following detailed description are exemplary and interpretive only, and do not limit the claimed features. As used herein, the terms “comprises,” “comprising,” “has,” “having,” “includes,” “including,” or other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed or inherent to such process, method, article, or apparatus. In this disclosure, unless otherwise stated, relative terms (such as, for example, “about,” “substantially,” and “approximately”) are used to indicate possible ±10% variation in the stated values. In this disclosure, unless otherwise stated, any numerical value may include possible ±10% variation in the stated values.

[0041] The terminology used below may be interpreted in its broadest and most reasonable manner, although it is used in conjunction with a detailed description of certain specific examples of this disclosure. Indeed, some terms may even be emphasized below; however, any term intended to be interpreted in any constrained manner will be explicitly and specifically defined in this Detailed Description section. For example, in the context of this disclosure, a switching device may be described as a switch or device, but may refer to any device used to control the flow of power in a circuit. For example, a switch may be, for instance, a metal-oxide-semiconductor field-effect transistor (MOSFET), a bipolar junction transistor (BJT), an insulated-gate bipolar transistor (IGBT), or a relay, or any combination thereof, but is not limited thereto.

[0042] Various embodiments of this disclosure generally relate to matrix converters with active filters, and more specifically to four-arm matrix converters with active filters for high-voltage and low-voltage converters in bidirectional on-board battery chargers for electric vehicles.

[0043] The power converter (such as, for example, a battery charger) according to this disclosure can operate using a variety of types of AC input power supplies, including single-phase, split-phase / two-phase / two-phase and three-phase power supplies. The charger is compatible with a wide range of configurations.

[0044] The power converter according to this disclosure can operate solely as a battery charger, or it can operate bidirectionally for charging or power supply operations. The converter can receive power from an AC power source and supply DC power to the battery, or receive power from the battery and supply power as an AC power source. Vehicle-to-grid (V2G) or vehicle-to-load (V2L, V2X) configurations can be achieved through designed control strategies for single-phase, two-phase, and three-phase systems. The battery charger switches can be any device, such as, for example, a GTO, thyristor, or MOSFET / IGBT with a series diode. These switches can also be mechanical components (such as relays or contactors) if sufficient failure rate and arcing conditions during operation are met. Additionally, if the switch position is semi-permanent, the switch can be implemented as one or more jumper connectors or dual in-line package (DIP) switches.

[0045] For example, electric vehicles, energy storage systems, and backup generators convert electricity from one form to another. Additionally, on-board chargers for vehicles, for example, can have dual uses. An on-board charger can be a bidirectional system that converts AC voltage to DC voltage in charging mode (grid to battery) and converts DC voltage to AC voltage in discharging or inverter mode (battery to grid). In charging mode, grid AC voltage can be converted to DC voltage to charge the vehicle's high-voltage (HV) battery, and in discharging or inverter mode, the HV battery DC voltage can be converted to AC voltage, which can be supplied, for example, to loads connected to the grid line, act as a backup generator to power a house during a grid outage, or act as an inverter to supply voltage to the vehicle's AC outlet. On-board chargers can have isolated converters to meet automotive requirements.

[0046] An on-board charger may include a converter for transforming a high voltage (HV) to a low voltage (LV) for use in auxiliary circuitry, such as in an electric vehicle or a plug-in hybrid electric vehicle. The high voltage may be, for example, 400V or 800V. The low voltage may be, for example, 12V or 48V. The on-board charger may operate in various modes, such as pre-charging a large-capacity capacitor. This disclosure relates to high and low voltages, wherein the high voltage is a voltage greater than the low voltage. However, this disclosure is not limited thereto. For example, the high voltage may be a first voltage, and the low voltage may be a second voltage, wherein the first voltage may be less than, greater than, or equal to the second voltage.

[0047] One or more embodiments may include active filters for HV and LV converters to reduce ripple and the number of passive devices. One or more embodiments may provide chargers that operate with any type of AC power supply (single-phase, split-phase (two-phase), and three-phase power supplies) and achieve greater compatibility and a wider range of operation using fewer components. One or more embodiments may provide algorithms designed to ensure that the converter operates with a wide range of input power supplies with varying input voltages to generate a wide range of output voltages.

[0048] One or more embodiments may provide a single-stage matrix converter with four arms for operation in both single-phase and three-phase operation. Active filters are used to suppress low-frequency ripple in single-phase operation. Activation and deactivation of the active filters are performed based on the input power supply and ripple content (peak-to-peak). Depending on the operating voltage range, these operations may be performed by gallium nitride (GaN) devices, silicon carbide (SiC) devices, or bidirectional switching (BDS) devices.

[0049] One or more embodiments may provide a four-arm matrix converter for use in on-board battery chargers with both single-phase and three-phase operation. One or more embodiments may provide phase-stripping operation based on current ratings in single-phase operation. One or more embodiments may provide active filters to reduce low-frequency ripple content. One or more embodiments may provide an improved light-load operating point (i.e., a reduced switching frequency). One or more embodiments may improve the switching state of converter operation by cascading HV and LV. One or more embodiments may provide a power converter that operates efficiently over a wide range of input and output voltages.

[0050] Figure 1An exemplary system infrastructure for a vehicle including a power converter is depicted according to one or more embodiments. The power converter 100 may be a combined inverter and converter. An electric vehicle 185 may include the power converter 100, a motor 190, and a battery 140. The power converter 100 may include components for receiving electrical power from an external source and outputting electrical power to charge the battery 140 of the electric vehicle 185. For example, the power converter 100 may convert DC power from the battery 140 in the electric vehicle 185 into AC power to drive the motor 190 of the electric vehicle 185, but the embodiments are not limited thereto. For example, the power converter 100 may include components for receiving electrical power from an external source and outputting electrical power to charge the battery 140 when the motor 190 is not connected to the power converter 100. The power converter 100 may convert DC power from the battery 140 in the electric vehicle 185 into AC power to drive AC components other than the motor 190 of the electric vehicle 185. For example, the power converter 100 may be bidirectional and may convert DC power to AC power or AC power to DC power, such as during regenerative braking. The power converter 100 may be a three-phase inverter, a single-phase inverter, or a multi-phase inverter.

[0051] Figure 2 An exemplary system infrastructure for a battery charger according to one or more embodiments is depicted. The power converter 100 may include a charging connector 110, or be electrically connected to the charging connector. The charging connector 110 provides an electrical connection from an external power supply to the power converter 100 and may be, for example, a Type 1 or Type 2 connector. The charging connector 110 can transmit single-phase, two-phase, or three-phase power.

[0052] Power converter 100 may include an isolated single-stage converter 120 and a controller 300 that receives signals from input sensor 150. The isolated single-stage converter 120 may be an AC-DC converter. The controller 300 may include one or more controllers. Power converter 100 may include a battery 140, or be electrically connected to that battery. Power converter 100 may be used in an automobile as an on-board charger to transfer power from an external power source to battery 140 via charging connector 110 in grid-to-battery operation, or to transfer power from battery 140 in a vehicle-to-load configuration (battery-to-load operation). Power converter 100 may be included in a system provided as an electric vehicle, the system including a motor that rotates based on power received from battery 140.

[0053] Figure 3 An exemplary system infrastructure for a controller is depicted according to one or more embodiments. Controller 300 may include one or more controllers.

[0054] The controller 300 may include a set of instructions that can be executed to cause the controller 300 to perform any or more of the methods or computer-based functions disclosed herein. The controller 300 may operate as a stand-alone device or may be connected to other computer systems or peripheral devices, for example, via a network.

[0055] In a networked deployment, controller 300 can operate as a server, or as a client in a server-client user network environment, or as a peer-to-peer (or distributed) computer system in a peer-to-peer (or distributed) network environment. Controller 300 can also be implemented as or incorporated into various devices, such as power converters, personal computers (PCs), tablet PCs, set-top boxes (STBs), personal digital assistants (PDAs), mobile devices, handheld computers, laptop computers, desktop computers, communication equipment, cordless phones, landline phones, control systems, cameras, scanners, fax machines, printers, pagers, personal trusted devices, network devices, network routers, switches or bridges, or any other machine capable of executing a set of instructions (sequentially or otherwise) specifying the actions to be taken by that machine. In a particular implementation, controller 300 may be implemented using electronic devices that provide voice, video, or data communication. Furthermore, while controller 300 is presented as a single system, the term "system" should also be understood to include any collection of systems or subsystems that individually or jointly execute one or more sets of instructions to perform one or more computer functions.

[0056] like Figure 3 As shown, controller 300 may include processor 302, such as a central processing unit (CPU), graphics processing unit (GPU), or both. Processor 302 can be a component in a variety of systems. Processor 302 can be one or more general-purpose processors, digital signal processors, application-specific integrated circuits (ASICs), field-programmable gate arrays (FPGAs), servers, networks, digital circuits, analog circuits, combinations thereof, or other devices now known or later developed for analyzing and processing data. Processor 302 may implement software programs, such as manually generated (i.e., programmed) code.

[0057] Controller 300 may include memory 304 communicatable via bus 308. Memory 304 may be main memory, static memory, or dynamic memory. Memory 304 may include, but is not limited to, computer-readable storage media, such as various types of volatile and non-volatile storage media, including but not limited to random access memory, read-only memory, programmable read-only memory, electrically programmable read-only memory, electrically erasable read-only memory, flash memory, magnetic tape or disk, optical media, etc. In one embodiment, memory 304 includes a cache or random access memory for processor 302. In alternative embodiments, memory 304 is decoupled from processor 302, such as processor cache memory, system memory, or other memory. Memory 304 may be an external storage device or database for storing data. Examples include hard disk drives, optical discs (“CDs”), digital video discs (“DVDs”), memory cards, memory sticks, floppy disks, universal serial bus (“USB”) storage devices, or any other device operable for storing data. Memory 304 is operable to store instructions executable by processor 302. The functions, actions, or tasks shown in the figures or described herein can be performed by processor 302, which executes instructions stored in memory 304. These functions, actions, or tasks are independent of a specific type of instruction set, storage medium, processor, or processing strategy, and can be performed by software, hardware, integrated circuits, firmware, microcode, etc., operating individually or in combination. Similarly, processing strategies may include multiprocessing, multitasking, parallel processing, etc.

[0058] As shown in the figure, the controller 300 may further include a display 310, such as a liquid crystal display (LCD), an organic light-emitting diode (OLED), a flat panel display, a solid-state display, a cathode ray tube (CRT), a projector, a printer, or other display device now known or later developed for outputting defined information. The display 310 may serve as an interface for a user to view the operation of the processor 302, or specifically as an interface with software stored in the memory 304 or the drive unit 306.

[0059] Alternatively or additionally, the controller 300 may include an input device 312 configured to allow a user to interact with any component of the controller 300. The input device 312 may be a numeric keypad, keyboard, or cursor control device (such as a mouse or joystick), touchscreen display, remote control, or any other device operable to interact with the controller 300.

[0060] The controller 300 may also, or alternatively, include a drive unit 306 implemented as a disk or optical disc drive. The drive unit 306 may include a computer-readable medium 322 in which one or more sets of instructions 324 (e.g., software) may be embedded. Further, the instructions 324 may embody one or more of the methods or logic described herein. The instructions 324 may reside wholly or partially within memory 304 and / or processor 302 during execution by the controller 300. Memory 304 and processor 302 may also include the computer-readable medium described above.

[0061] In some systems, computer-readable medium 322 includes instructions 324 or receives and executes instructions 324 in response to a propagated signal, enabling devices connected to network 370 to transmit voice, video, audio, images, or any other data through network 370. Further, instructions 324 may be transmitted or received via communication port or interface 320 through network 370 and / or using bus 308. Communication port or interface 320 may be part of processor 302 or may be a separate component. Communication port or interface 320 may be formed in software or may be a physical connector in hardware. Communication port or interface 320 may be configured to connect to network 370, external media, display 310, or any other component of controller 300, or a combination thereof. Connection to network 370 may be a physical connection (such as a wired Ethernet connection) or may be established wirelessly, as described below. Similarly, additional connections to other components of controller 300 may be physical connections or may be established wirelessly. Network 370 may alternatively be directly connected to bus 308.

[0062] Although computer-readable medium 322 is shown as a single medium, the term "computer-readable medium" can include a single medium or multiple media (such as a centralized or distributed database and / or associated caches and servers) storing one or more sets of instructions. The term "computer-readable medium" can also include any medium capable of storing, encoding, or carrying a set of instructions for execution by a processor or causing a computer system to perform any one or more of the methods or operations disclosed herein. Computer-readable medium 322 can be non-transitory and can be tangible.

[0063] Computer-readable medium 322 may include solid-state memory, such as a memory card, or other package housing one or more non-volatile read-only memories. Computer-readable medium 322 may be random access memory or other volatile rewritable memory. Alternatively or additionally, computer-readable medium 322 may include magneto-optical or optical media, such as magnetic disks or magnetic tapes, or other storage devices for capturing carrier signals (such as signals transmitted via a transmission medium). Digital file attachments to emails or other self-contained information archives or archive sets can be considered as distribution media as tangible storage media. Therefore, this disclosure is to be construed as including any one or more computer-readable media or distribution media in which data or instructions can be stored, as well as other equivalents and successor media.

[0064] In alternative embodiments, specialized hardware implementations (such as application-specific integrated circuits, programmable logic arrays, and other hardware devices) may be configured to implement one or more of the methods described herein. Applications that may include various implementations of the apparatus and systems can broadly encompass a wide range of electronic and computer systems. One or more implementations described herein may use two or more specific interconnected hardware modules or devices having associated control and data signals that can be transferred between or through modules, or as part of an application-specific integrated circuit, to implement functionality. Therefore, this system encompasses software, firmware, and hardware implementations.

[0065] Controller 300 can be connected to network 370. Network 370 may define one or more networks, including wired or wireless networks. Wireless networks may be cellular telephone networks, 802.11, 802.16, 802.20, or WiMAX networks. Further, such networks may include public networks (such as the Internet), private networks (such as intranets), or combinations thereof, and may utilize a variety of networking protocols now available or later developed, including but not limited to TCP / IP-based networking protocols. Network 370 may include wide area networks (WANs) (such as the Internet), local area networks (LANs), campus area networks, metropolitan area networks, direct connections (such as via a universal serial bus (USB) port), or any other network that allows data communication. Network 370 may be configured to couple one computing device to another to enable data communication between the devices. Typically, network 370 may be able to use any form of machine-readable medium to transfer information from one device to another. Network 370 may include communication methods through which its information can travel between computing devices. Network 370 may be divided into subnets. A subnet may allow access to all other components in other components connected to it, or a subnet may restrict access between components. Network 370 may be considered a public or private network connection and may include, for example, a virtual private network or encryption or other security mechanisms employed on the public Internet.

[0066] According to various embodiments of this disclosure, the methods described herein can be implemented by software programs executable by a computer system. Further, in exemplary non-limiting embodiments, the implementation may include distributed processing, component or object distributed processing, and parallel processing. Alternatively, virtual computer system processing may be configured to implement one or more of the methods or functionalities described herein.

[0067] Although this specification describes components and functions implemented in specific implementations of particular standards and protocols, this disclosure is not limited to such standards and protocols. For example, standards for transmission over the Internet and other packet-switched networks (e.g., TCP / IP, UDP / IP, HTML, HTTP) represent examples of prior art. Such standards are periodically superseded by faster or more efficient equivalents with substantially the same functionality. Therefore, alternative standards and protocols with the same or similar functionality as those disclosed herein are considered their equivalents.

[0068] It will be understood that, in one embodiment, the operation of the method in question is performed by a suitable processor (or processors) of a processing (i.e., computer) system that executes instructions (computer-readable code) stored in a storage device. It will also be understood that this disclosure is not limited to any particular specific implementation or programming technique, and that any suitable technique used to implement the functionality described herein may be used to implement this disclosure. This disclosure is not limited to any particular programming language or operating system.

[0069] Figure 4 An exemplary system infrastructure for a power converter having an active filter on the secondary side of a transformer, according to one or more embodiments, is described. Figure 4 As depicted, system 400 may include line 405, line filter 410, line switch 415, matrix converter 420, transformer 425, HV bridge rectifier 430, LV bridge rectifier 435, HV battery 440, LV battery 445, and active filter 450.

[0070] Line 405 may include, for example Figure 4 The three-phase voltage source or load, two-phase voltage source or load shown, or for example, Figure 9The depicted single-phase voltage source or load. For example, line filter 410 can suppress electromagnetic noise transmitted through conduction. Line switch 415 may include a first switch Sx that selectively connects the first phase bridge arm and the second phase bridge arm, and a second switch Sy that selectively connects the third phase bridge arm and the neutral phase bridge arm. For example, in three-phase operation, the first switch Sx and the second switch Sy may be open, and in single-phase or split-phase operation, the first switch Sx may be closed to connect the first phase bridge arm and the second phase bridge arm, and the second switch Sy may be closed to connect the third phase bridge arm and the neutral phase bridge arm. Figure 4 As depicted, each of the first switch Sx and the second switch Sy can be a bidirectional switch, but this disclosure is not limited thereto.

[0071] The matrix converter 420 may include bidirectional switches SaP1 and SaP2 on the first phase, bidirectional switches SaN1 and SaN2 on the first phase, bidirectional switches SbP1 and SbP2 on the second phase, bidirectional switches SbN1 and SbN2 on the second phase, bidirectional switches ScP1 and ScP2 on the third phase, bidirectional switches ScN1 and ScN2 on the third phase, bidirectional switches SnP1 and SnP2 on the neutral phase, and bidirectional switches SnN1 and SnN2 on the neutral phase. Figure 4 As depicted, each switch of the matrix converter 420 may be a bidirectional switch, but this disclosure is not limited thereto.

[0072] Transformer 425 can be one or more high-frequency transformers, and can be a single transformer with multiple coils or windings, multiple transformers with a single coil or winding, or any combination thereof. HV bridge rectifier 430 may include a first switch Hs1, a second switch Hs2, a third switch Hs3, and a fourth switch Hs4. LV bridge rectifier 435 may include a first switch Gs1, a second switch Gs2, a third switch Gs3, and a fourth switch Gs4. The switches of HV bridge rectifier 430 and LV bridge rectifier 435 can convert square wave signals into DC power and vice versa.

[0073] Matrix converter 420 can be connected to the primary side of transformer 425. HV bridge rectifier 430 can be connected to the secondary side of transformer 425 and HV battery 440. LV bridge rectifier 435 can be connected to the tertiary side (or another secondary side) of transformer 425 and LV battery 445. Active filter 450 may include capacitor Cf1, first switch Tp1, second switch Tp2, third switch Tp3, and fourth switch Tp4. Capacitor Cf1 can be connected to a first node and a second node of active filter 450. First switch Tp1 can be connected to the first node and a first external connection. Second switch Tp2 can be connected to the second node and a first external connection. Third switch Tp3 can be connected to the first node and a second external connection. Fourth switch Tp4 can be connected to the second node and a second external connection. Active filter 450 can be connected to the secondary side of transformer 425 near HV battery 440 via the first and second external connections to suppress low-frequency ripple. The active filter 450 can be configured as a boost converter with the third switch Tp3 open and the fourth switch Tp4 closed.

[0074] Figure 5 An exemplary system infrastructure for a power converter with an active filter on the primary side of a transformer, according to one or more embodiments, is depicted. System 500 may be similar to system 400, except for the connection of the active filter 450. Low-frequency ripple may be observed on the primary or secondary side of transformer 425. During, for example, charging mode, additional filter capacitors may be required on the primary side, but the primary-side layout of the active filter 450 can serve as a V2G mode with a separate connection. On the secondary side of transformer 425, the layout of the active filter 450 facilitates filtering of low-frequency ripple to the HV battery 440. Figure 5 As depicted, the active filter 450 can be connected to the primary side of the transformer 425. Figure 5 A system 500 operating in charging mode is depicted, wherein power flows from a three-phase power source at line 405 to HV battery 440 and LV battery 445. However, system 500 can also operate in battery-to-battery mode (e.g., Figure 10 Vehicle-to-load (battery-to-load) operations (e.g., similar to...) Figure 12 Or simultaneously vehicle-to-load and battery-to-battery operations (e.g., similar to...) Figure 13 (The operation is performed in the middle.)

[0075] Controller 300 can control the switching operation of each of the line switch 415, matrix converter 420, HV bridge rectifier 430, LV bridge rectifier 435, and active filter 450 to control the direction and amount of current through system 500. For example, controller 300 can operate matrix converter 420 to convert the input AC voltage from line 405 to a high-frequency voltage to transformer 425, or vice versa. Controller 300 can operate HV bridge rectifier 430 to convert the high-frequency voltage from transformer 425 to high-voltage DC power to HV battery 440, or vice versa. Controller 300 can operate LV bridge rectifier 435 to convert the high-frequency voltage from transformer 425 to low-voltage DC power to LV battery 445, or vice versa.

[0076] Figure 6 An exemplary power converter, according to one or more embodiments, is depicted in three-phase balanced operation with the active filter off. For example... Figure 6 As depicted, the three-phase power supply or load at line 405 can be balanced, eliminating the need for a neutral phase and filtering. Three-phase voltage and current can be monitored by sensors. Controller 300 ensures that Ia+Ib+Ic ≈0 or va+vb+vc ≈0, and that the neutral current sensor also detects zero or near-zero (e.g., an acceptable small value for a balanced power supply), thus the supply is balanced. Controller 300 can initially determine these conditions and enable the system accordingly. Therefore, controller 300 can operate the bidirectional switches SnP1 and SnP2 on the neutral phase and the bidirectional switches SnN1 and SnN2 on the neutral phase of matrix converter 420 to be closed. Controller 300 can operate the active filter 450 to be closed, and more specifically, can operate the first switch Tp1, the second switch Tp2, the third switch Tp3, and the fourth switch Tp4 to be closed, preventing current from flowing through the active filter 450.

[0077] Figure 7 An exemplary power converter, according to one or more embodiments, is depicted in three-phase unbalanced operation with the active filter off. For example... Figure 7 As depicted, the three-phase power supply or load at line 405 may be unbalanced, requiring a neutral phase but potentially eliminating the need for filtering. Therefore, controller 300 can operate the bidirectional switches SnP1 and SnP2 on the neutral phase and the bidirectional switches SnN1 and SnN2 on the neutral phase of matrix converter 420 in neutral phase switching operation. Controller 300 can also operate the active filter 450 off, and more specifically, can operate the first switch Tp1, the second switch Tp2, the third switch Tp3, and the fourth switch Tp4 off, preventing current flow through the active filter 450.

[0078] Figure 8An exemplary power converter, according to one or more embodiments, is depicted in three-phase unbalanced operation with the active filter on. For example... Figure 8 As depicted, the three-phase power supply or load at line 405 may be unbalanced, necessitating a neutral phase and potentially requiring filtering. Therefore, controller 300 can operate the bidirectional switches SnP1 and SnP2 on the neutral phase and the bidirectional switches SnN1 and SnN2 on the neutral phase of matrix converter 420 in neutral phase switching operation. Controller 300 can also operate active filter 450 on, and more specifically, can utilize Cf1 to operate the first switch Tp1, the second switch Tp2, the third switch Tp3, and the fourth switch Tp4 in active filtering operation.

[0079] Figure 9 An exemplary power converter, according to one or more embodiments, is depicted in single-phase operation with the active filter on. For example... Figure 9 As depicted, a single-phase power supply or load at line 405 may be connected in a manner that requires a neutral phase and may require filtering. Therefore, controller 300 can operate the bidirectional switches SnP1 and SnP2 on the neutral phase and the bidirectional switches SnN1 and SnN2 on the neutral phase of matrix converter 420 in neutral phase switching operation. Controller 300 can operate active filter 450 to be on, and more specifically, can use Cf1 to operate the first switch Tp1, the second switch Tp2, the third switch Tp3, and the fourth switch Tp4 in active filtering operation. When a single-phase power supply or load is detected at line 405, controller 300 can close line switch 415, and more specifically, can close the first switch Sx to connect the first phase bridge arm and the second phase bridge arm, and close the second switch Sy to connect the third phase bridge arm and the neutral phase bridge arm.

[0080] Figure 10 An exemplary power converter, according to one or more embodiments, is depicted in battery-to-battery operation with the active filter off. For example... Figure 10 As described, in battery-to-battery operations (such as HV battery 440 charging LV battery 445 or LV battery 445 pre-charging a connection to HV battery 440), the primary side of transformer 425 can be isolated and a neutral phase and filtering may not be required. Therefore, controller 300 can operate all switches of matrix converter 420 to be off. Controller 300 can operate active filter 450 to be off, and more specifically, can operate first switch Tp1, second switch Tp2, third switch Tp3, and fourth switch Tp4 to be off, preventing current from flowing through active filter 450.

[0081] Figure 11An exemplary system infrastructure for a current-feed dual active bridge (CFDAB) converter according to one or more embodiments is depicted. System 1100 may be similar to system 500, except for HV bridge rectifier 1130 and LV bridge rectifier 1135. Each of HV bridge rectifier 1130 and LV bridge rectifier 1135 may include an inductor pair. Figure 11 A system 1100 operating in charging mode is depicted, wherein power flows from line 405 to HV battery 440 and LV battery 445.

[0082] like Figure 11 As described, the three-phase power supply at line 405 may be unbalanced, necessitating a neutral phase and potentially requiring filtering. Therefore, controller 300 can operate the bidirectional switches SnP1 and SnP2 on the neutral phase and the bidirectional switches SnN1 and SnN2 on the neutral phase of matrix converter 420 in neutral phase switching operation. Controller 300 can also operate active filter 450 on, and more specifically, can use Cf1 to operate the first switch Tp1, the second switch Tp2, the third switch Tp3, and the fourth switch Tp4 in active filtering operation.

[0083] Figure 12 An exemplary CFDAB converter in vehicle-to-load operation according to one or more embodiments is depicted. Figure 12 A system 1100 in vehicle-to-load operation is depicted, wherein power flows from HV battery 440 and LV battery 445 to a three-phase load at line 405.

[0084] like Figure 12 As described, the three-phase load at line 405 may be unbalanced, necessitating a neutral phase and potentially requiring filtering. Therefore, controller 300 can operate the bidirectional switches SnP1 and SnP2 on the neutral phase and the bidirectional switches SnN1 and SnN2 on the neutral phase of matrix converter 420 in neutral phase switching operation. Controller 300 can also operate active filter 450 on, and more specifically, can utilize Cf1 to operate the first switch Tp1, the second switch Tp2, the third switch Tp3, and the fourth switch Tp4 in active filtering operation.

[0085] Figure 13 An exemplary CFDAB converter, according to one or more embodiments, is depicted in simultaneous vehicle-to-load and battery-to-battery operation. Figure 12 A system 1100 is described that operates simultaneously from vehicle to load and from battery to battery, wherein power flows from HV battery 440 to a three-phase load at line 405 and simultaneously from HV battery 440 to LV battery 445.

[0086] like Figure 13As described, the three-phase load at line 405 may be unbalanced, necessitating a neutral phase and potentially requiring filtering. Therefore, controller 300 can operate the bidirectional switches SnP1 and SnP2 on the neutral phase and the bidirectional switches SnN1 and SnN2 on the neutral phase of matrix converter 420 in neutral phase switching operation. Controller 300 can also operate active filter 450 on, and more specifically, can utilize Cf1 to operate the first switch Tp1, the second switch Tp2, the third switch Tp3, and the fourth switch Tp4 in active filtering operation.

[0087] One or more embodiments may provide a four-arm matrix converter for use in on-board battery chargers with single-phase and three-phase operation. One or more embodiments may provide phase-stripping operation based on current ratings in single-phase operation. One or more embodiments may provide active filters to reduce low-frequency (LF) ripple content. One or more embodiments may provide an improved light-load operating point (i.e., a reduced switching frequency). One or more embodiments may improve the switching state of converter operation by cascading HV and LV. One or more embodiments may provide a power converter that operates efficiently over a wide range of input and output voltages.

[0088] Other embodiments of this disclosure will be apparent to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. The specification and examples are intended to be illustrative only, and the true scope and spirit of the invention are indicated by the appended claims.

Claims

1. A system comprising: A transformer, comprising a primary side and a secondary side; A matrix converter, the matrix converter being connected to the primary side of the transformer and to a line connected to a voltage source or load; as well as An active filter configured to reduce ripple in the system.

2. The system of claim 1, wherein the active filter is connected to the primary side of the transformer.

3. The system of claim 1, wherein the active filter is connected to the secondary side of the transformer.

4. The system according to claim 1, wherein the matrix transformer comprises: The first phase has a bidirectional switch. First phase bidirectional switch The second phase has a bidirectional switch. Second phase bidirectional switch, The third phase is equipped with a bidirectional switch. Third phase bidirectional switch, Bidirectional switch on neutral phase, and Bidirectional switch under neutral phase.

5. The system according to claim 1, wherein the active filter comprises: capacitor, First switch, Second switch, The third switch, and The fourth switch.

6. The system according to claim 1, further comprising: A high-voltage bridge rectifier is connected to the secondary side of the transformer.

7. The system of claim 6, wherein the high-voltage bridge rectifier includes an inductor pair.

8. The system of claim 1, wherein the transformer further comprises a three-stage side.

9. The system according to claim 8, further comprising: A low-voltage bridge rectifier is connected to the third-stage side of the transformer.

10. The system of claim 9, wherein the low-voltage bridge rectifier includes an inductor pair.

11. The system of claim 1, wherein the system is configured to operate in each of the following: three-phase power supply to battery operation, battery to three-phase load operation, single-phase power supply to battery operation, battery to single-phase load operation, battery to battery operation, and simultaneous battery to load and battery to battery operation.

12. The system according to claim 1, further comprising: One or more controllers are configured to control the operation of one or more of the matrix converter or the active filter.

13. The system according to claim 1, further comprising: One or more batteries, The system is provided as a bidirectional battery charger, which is configured to: Receives input AC power from the power source of the line, converts the input AC power into output DC power, and supplies the output DC power to charge the one or more batteries. Receives input DC power from one or more batteries, converts the input DC power into output AC power, and supplies the output AC power to the load of the line.

14. The system of claim 1, further comprising: Battery; as well as motor, The system is provided as an electric vehicle.

15. An active filter for a power converter including a matrix converter, the active filter comprising: A capacitor, the capacitor being connected to a first node and a second node; A first switch, the first switch being connected to the first node and a first external connection; A second switch is connected to the second node and the first external connection; A third switch is connected to the first node and the second external connection; as well as A fourth switch, which is connected to the second node and the second external connection.

16. The active filter of claim 15, wherein the first external connection and the second external connection are connected to the matrix converter of the power converter and the primary side of the transformer of the power converter.

17. The active filter of claim 15, wherein the first external connection and the second external connection are connected to the high-voltage bridge rectifier of the power converter.

18. A bidirectional current-fed dual active bridge converter, comprising: A transformer, comprising a primary side, a first-stage side, and a second-stage side; A matrix converter, the matrix converter being connected to the primary side of the transformer and to a line connected to a voltage source or load; An active filter, the active filter comprising a capacitor and four switches; A first voltage bridge rectifier is connected to the primary stage side of the transformer; as well as A second voltage bridge rectifier is connected to the second stage side of the transformer.

19. The bidirectional current-fed dual active bridge converter according to claim 18, further comprising: A first switch selectively connects the first phase arm and the second phase arm of the matrix converter, and The second switch selectively connects the third phase bridge arm of the matrix converter and the neutral phase bridge arm of the matrix converter.

20. The bidirectional current-fed dual active bridge converter according to claim 18, wherein each phase bridge arm of the matrix converter includes two bidirectional switches.

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