Fast charging system using compact power generation

Abstract

A charging system includes a prime mover, a gear box coupled to the prime mover, and at least one generator coupled to the gear box. The generator is configured to generate an AC output having a frequency of at least about 300 Hz. At least one power converter is coupled to the generator, the power converter configured to convert the AC output to an HVDC power output of at least about 50 kW. A generator control unit is coupled to the generator and the power converter. The generator control unit selectively regulates a voltage of the HVDC power output from the power converter in one of a plurality of modes; and selectively regulates a power of the power converter in another of the modes. At least one interface is configured to be coupled to provide the HVDC power output from the power converter to a battery of an electric vehicle.

Description

Background Technology

[0001] Plug-in hybrid electric vehicles (PHEVs) require a power electronics system between the power grid and a high-voltage battery pack located inside the vehicle. This power electronics system is divided into two parts: a charging station, also known as an Electric Vehicle Service Equipment (EVSE) or off-board charger; and an on-board charger located inside the vehicle. Charging stations are part of the grid infrastructure installed along streets, in parking lots, or in home garages. The primary purpose of a charging station is to supply power to the PHEV to charge its battery. The on-board charger handles the final stage of charging the battery pack inside the vehicle. The on-board charger draws AC power from the EVSE and converts the AC power to the desired battery charging profile.

[0002] In a typical AC charging operation, AC power is supplied from the charging station to the onboard charger in the electric vehicle (EV), which converts the AC power into direct current (DC) power to charge the EV battery. This type of AC charging operation takes several hours to charge the EV battery. For example, a residential AC charging station might take up to approximately 17 hours to charge an EV battery. A commercial AC charging station might take up to approximately 8 hours to charge an EV battery.

[0003] In conventional fast charging systems, DC power is supplied directly to the vehicle battery, bypassing the onboard charger in the EV. For example, in DC fast charging, AC power from the grid is converted to DC power at the charging station, which then supplies that DC power directly to the EV battery. Fast charging can reduce charging time to approximately 30 minutes.

[0004] In addition to traditional grid-connected charging stations, mobile charging stations have been developed as another source of charging for electric vehicles. While these mobile charging stations have advantages over traditional grid-connected stations, they also have several disadvantages, including being large, heavy, technologically complex, expensive, and having limited reliability. Summary of the Invention

[0005] A charging system includes a prime mover, a gearbox operatively coupled to the prime mover, and at least one generator operatively coupled to the gearbox. The at least one generator is configured to generate an alternating current (AC) output having a frequency of at least about 300 Hz. At least one power converter is operatively coupled to the at least one generator, and the at least one power converter is configured to convert the AC output into a high-voltage direct current (HVDC) power output of at least about 50 kW. A generator control unit is operatively coupled to the at least one generator and the at least one power converter. The generator control unit is configured to selectively regulate the voltage of the HVDC power output from the at least one power converter in one of a plurality of modes; and to selectively regulate the power of the at least one power converter in another of the plurality of modes. At least one interface is configured to be coupled to provide the HVDC power output from the at least one power converter to a battery of at least one electric vehicle. Attached Figure Description

[0006] The features of the invention will become apparent to those skilled in the art from the following description with reference to the accompanying drawings. It should be understood that the drawings illustrate only typical embodiments and are therefore not intended to limit the scope of the invention. The invention will be described with additional features and details using the drawings, wherein:

[0007] Figure 1 This is a block diagram of a mobile charging system for electric vehicle batteries according to one implementation scheme;

[0008] Figure 2 It is a graph illustrating the operation of a mobile fast charging system based on an example;

[0009] Figure 3 This is a schematic diagram of an electric power generator system for charging the battery of an electric vehicle according to another embodiment.

[0010] Figure 4 An example is illustrated by a fast charging system using a compact power generator according to a specific implementation;

[0011] Figure 5 An example is illustrated by a fast charging system using a compact power generator according to another specific embodiment;

[0012] Figure 6 An example is a 1,000kW generator that can be used in a fast charging system;

[0013] Figure 7 An example is a 250kW generator that can be used in a fast charging system;

[0014] Figure 8 An example is shown of a high-voltage DC generator control unit that can be used in a fast-charging system; and

[0015] Figure 9 An advanced rectifier filter unit that can be used in a fast charging system is illustrated. Detailed Implementation

[0016] In the following detailed description, the embodiments are fully described to enable those skilled in the art to practice the invention. It should be understood that other embodiments may be utilized without departing from the scope of the invention. Therefore, the following detailed description should not be considered limiting.

[0017] This article describes an implementation scheme for a fast charging system using a compact power generation device.

[0018] In one embodiment, a compact and lightweight mobile fast charger system is provided that utilizes a turbine generator instead of a large and heavy 50 / 60Hz diesel generator and AC / DC and DC / DC off-vehicle Level 3 chargers, wherein the prime mover is a turbine engine driving a generator with high-voltage direct current (HVDC) power output. In an alternative embodiment, a high-speed compact HVDC generator may be employed, which uses a diesel engine or other type of engine with a speed increaser gearbox to generate the mobile fast charger system.

[0019] Compact fast chargers using high-speed generators can also be combined with energy storage to increase capacity and enable quiet operation. Alternatively, high-speed compact HVDC generators using diesel engines or other types of engines can be employed. In these cases, a speed increaser gearbox may be necessary.

[0020] The mobile fast charger system of the present invention offers several advantages over conventional fast charging systems, including lighter weight, smaller size, lower cost, and greater reliability. The mobile fast charger system of the present invention also provides a significant reduction in charging time, thereby enabling remote charging.

[0021] Further details of various embodiments are described below with reference to the accompanying drawings.

[0022] Figure 1An example of a mobile charging system 100 for an electric vehicle battery according to one embodiment is illustrated. The charging system 100 includes a prime mover 110 and a gearbox 112, which is operatively coupled to the prime mover 110 via a drive shaft. The gearbox 112 is configured to increase or decrease the speed of the drive shaft. A high-voltage generator 114 is operatively coupled to the gearbox 112 and generates an AC output having a frequency of at least about 300 Hz. For example, the generator 114 may be a 1,000 kW generator or a 50 kW generator. The prime mover 110 provides drive torque to the generator 114. For example, the prime mover 110 may be a turbine, a diesel engine, a Wankel engine, or some other type of engine or torque generating device.

[0023] At least one power converter 116 (...116n) is operatively coupled to the generator 114 and configured to convert the AC output into HVDC power of at least about 50 kW. For example, the power converter 116 may be an advanced rectifier filter unit (ARFU).

[0024] A generator control unit (GCU) 118 is operatively coupled to a high-voltage generator 114 and a power converter 116. The generator control unit 118 is configured to selectively regulate the HVDC voltage at the output of the power converter 116 in a voltage control mode. The generator control unit 118 is also configured to selectively regulate the power of the power converter 116 in a power control mode. For example, the generator control unit 118 may be configured to selectively control the AC output of the generator 114 using AC voltage regulation and to selectively control the HVDC output of the power converter 116 using DC voltage regulation. The generator control unit 118 may also be configured to selectively regulate the power of the power converter 116 based on parameters of the electric vehicle's battery. In one example embodiment, the generator control unit 118 may be an HVDC generator control unit. The generator control unit 118 is configured to increase or decrease the excitation current to the generator 114.

[0025] In addition, the battery interface 120 is configured to be connected to provide HVDC power output from the power converter 116 to the battery of the electric vehicle.

[0026] Figure 2 Graph 200 is an example of the operation of a mobile fast-charging system using a compact power generator, representing an example of the method according to the invention. Graph 200 depicts power, voltage, and current over time for regions A, B, and C relative to voltage control mode and power control mode. It should be noted that the time axis is not plotted to scale.

[0027] In region A, the voltage control mode regulates the charging system voltage and determines the charging rate. Simultaneously, it adjusts the charging system voltage to match the vehicle battery voltage while maintaining current and power at minimum levels.

[0028] In Zone B, the power control mode adjusts the charging system's power and current to the maximum values ​​allowed by the battery's state of charge. Typically, the current is maintained at its maximum while the voltage is increased, and the power is gradually reduced.

[0029] In Zone C, the voltage control mode regulates the charging system voltage, slowing down charging to protect the battery. Zone C typically begins after the battery has reached at least approximately 80% charge. Generally, current and power are reduced while maintaining the voltage level.

[0030] Voltage regulation that can be used by the voltage control mode in the system of the present invention is described in more detail in U.S. Patent No. 11,770,084 entitled “Voltage Regulation of High Voltage Direct Current Systems”, the disclosure of which is hereby incorporated herein by reference.

[0031] The regulation of power and current that can be used by the power control mode in the system of the present invention is described in more detail in U.S. Patent Application Publication No. 2024 / 0072566 entitled “ENERGY MANAGEMENT OF HYBRID ELECTRICAL SYSTEMS”, the disclosure of which is incorporated herein by reference.

[0032] Figure 3 This is a schematic diagram of a system 300 for fast charging a battery of an electric vehicle according to another embodiment. System 300 is implemented in a mobile charging unit 302 and includes a generator 310, such as a 1,000 kW generator. Generator 310 can produce six-phase or other numbers of multi-phase AC power outputs. Generator 310 includes a rotor 312 coupled to a drive shaft 314 that rotates an exciter rotor 316 relative to an exciter stator 318. Exciter rotor 316 can generate three-phase AC power supplied to a rectifier assembly 320 including rotating diodes. Rectifier assembly 320 provides DC power to drive a generator rotor 322 rotating relative to a generator stator 324. Generator stator 324 provides AC power as the output of generator 310, which is directed to a set of buses 326 (e.g., 24 flexible buses).

[0033] A set of power converters 330-1 to 330-4 operate to receive AC power from generator 310 via bus 326 and convert the AC power output to HVDC power. Power converters 330-1 to 330-4 may be advanced rectifier filter units (ARFU).

[0034] A generator control unit (GCU) 340 is operatively coupled to a generator 310 and power converters 330-1 to 330-4. The generator control unit 340 is configured to selectively regulate the HVDC power output from the power converters 330-1 to 330-4. The generator control unit 340 is also configured to selectively regulate the power and current of the power converters 330-1 to 330-4. The generator control unit 340 provides a voltage regulation module 342, a power regulation module 343, a protection and BIT (built-in test) module 344, and a data communication module 346. The generator control unit 340 can be an HVDC-connected generator control unit (GCU).

[0035] In some implementations, generator 310 provides measurements of AC voltage and AC current to generator control unit 340, which can function as an AC voltage regulator. Generator control unit 340 can also provide an excitation field to exciter stator 318 to control the operation of exciter rotor 316.

[0036] System 300 provides HVDC power output from power converters 330-1 to 330-4 to a load 350 via a set of buses 354, 356, in one embodiment of which the load may be a battery.

[0037] Figure 4 An example is illustrated of a fast-charging system 400 using a compact generator according to a specific embodiment. System 400 provides a compact, lightweight, mobile fast charger having a turbine generator 410 with HVDC output. The turbine generator 410 includes a turbine 412 coupled via a reduction gearbox 413 to a set of generators 414, such as a 250kW generator. A set of power converters 416 operates to receive AC power from the generators 414 and convert the AC power to HVDC power. The power converters 416 may be advanced rectifier filter units. A PHEV battery interface 420 is configured to be connected to provide the HVDC power output from the fast-charging system 400 to the battery of an electric vehicle.

[0038] Figure 5An example of a fast-charging system 500 using a compact generator is illustrated according to another specific embodiment. System 500 provides a compact mobile fast charger combined with energy storage for increasing capacity. System 500 includes a turbine generator 510 with HVDC output, which is coupled to a battery storage system 520 for storing electrical power. Turbine generator 510 includes a turbine 512 coupled via a reduction gearbox 513 to a set of generators 514, such as a 250kW generator. A set of power converters 516 operate to receive AC power from generators 514 and convert the AC power to HVDC power. Power converters 516 may be advanced rectifier filter units. A PHEV battery interface 530 is configured to be coupled to provide the HVDC power output from fast-charging system 500 to the battery of an electric vehicle. The available HVDC power for charging may be provided by the output of turbine generator 510 or by battery storage system 520.

[0039] Figure 6 An example is a 1,000 kW generator 600 that can be used in the fast charging system of the present invention. The generator 600 offers high power density and high efficiency in a compact design with a low weight (e.g., less than about 150 kg).

[0040] Figure 7 An example is a 250kW generator 700 that can be used in the fast charging system of the present invention. The generator 700 offers high power density and high efficiency in a compact design, with an even lower weight (e.g., less than about 40kg).

[0041] Figure 8 An example is illustrated of a high-voltage DC generator control unit 800 that can be used in the fast charging system of the present invention. The generator control unit 800 can be used in charging systems with a DC output of up to about 1000VDC. Higher voltages of up to about 1500VDC can also be used.

[0042] Figure 9 An advanced rectifier filter unit 900 is illustrated that can be used in the fast charging system of the present invention. The advanced rectifier filter unit 900 can be used in charging systems with a DC output of up to about 1000VDC.

[0043] In one example, a fast charging system could employ a single 1,000kW generator (such as a generator 600). Figure 6 ), and a single high-voltage DC-connected generator control unit (such as generator control unit 800 ( Figure 8 )) and four advanced rectifier filter units (such as four advanced rectifier filter units 900 ( Figure 9 )).

[0044] In another example, the fast charging system could employ a single 250kW generator (such as generator 700). Figure 7 (), a single high-voltage DC-connected generator control unit (such as generator control unit 800) and a single advanced rectifier filter unit (such as advanced rectifier filter unit 900).

[0045] Example Implementation Plan

[0046] Example 1 includes a charging system comprising: a prime mover; a gearbox operatively coupled to the prime mover; at least one generator operatively coupled to the gearbox, the at least one generator configured to generate an alternating current (AC) output having a frequency of at least about 300 Hz; at least one power converter operatively coupled to the at least one generator, the at least one power converter configured to convert the AC output into a high-voltage direct current (HVDC) power output of at least about 50 kW; a generator control unit operatively coupled to the at least one generator and the at least one power converter, the generator control unit configured to: selectively regulate the voltage of the HVDC power output from the at least one power converter in one of a plurality of modes; and selectively regulate the power of the at least one power converter in another of the plurality of modes; and at least one interface configured to be coupled to provide the HVDC power output from the at least one power converter to a battery of at least one electric vehicle.

[0047] Example 2 includes the charging system according to Example 1, wherein the prime mover includes a turbine, a diesel engine, or a Wankel engine.

[0048] Example 3 includes a charging system according to any one of Examples 1 to 2, wherein the at least one generator includes a high-speed generator.

[0049] Example 4 includes a charging system according to any one of Examples 1 to 3, wherein the at least one power converter includes at least one rectifier.

[0050] Example 5 includes a charging system according to any one of Examples 1 to 4, wherein the generator control unit is configured to selectively regulate the voltage of the HVDC power output.

[0051] Example 6 includes a charging system according to any one of Examples 1 to 5, wherein the generator control unit is configured to selectively control the HVDC output of the at least one generator using AC voltage regulation and DC voltage regulation.

[0052] Example 7 includes a charging system according to any one of Examples 1 to 6, wherein the generator control unit is configured to selectively adjust the power of the at least one power converter based on parameters of the battery of the electric vehicle.

[0053] Example 8 includes a charging system according to any one of Examples 1 to 7, wherein the generator control unit is configured to increase or decrease the excitation current to the at least one generator.

[0054] Example 9 includes a charging system according to any one of Examples 1 to 8, wherein the charging system is implemented in a mobile charging unit.

[0055] Example 10 includes a charging system according to any one of Examples 1 to 9, wherein the at least one generator is a 50kW generator.

[0056] Example 11 includes a charging system according to any one of Examples 1 to 9, wherein the at least one generator is a 1,000 kW generator.

[0057] Example 12 includes a charging system according to any one of Examples 1 to 11, the charging system further including a battery storage system for storing electrical power and configured to receive the HVDC power output.

[0058] Example 13 includes the charging system according to Example 12, wherein at least one interface is configured to be coupled to the battery storage system to provide HVDC power to the battery of at least one electric vehicle.

[0059] Example 14 includes a system for charging a battery of an electric vehicle, the system comprising: a generator configured to generate a multiphase alternating current (AC) power output; a set of power converters operatively coupled to the generator, the power converters being configured to convert the AC power output into a high-voltage direct current (HVDC) power output; and a generator control unit operatively coupled to the generator and the power converters, the generator control unit being configured to: selectively regulate the HVDC power output from the power converters in a voltage control mode; and selectively regulate the power and current of the power converters in a power control mode; wherein the HVDC power output from the power converters is directed to a load via a set of buses.

[0060] Example 15 includes the charging system according to Example 14, wherein the generator includes a high-speed generator.

[0061] Example 16 includes a charging system according to any one of Examples 14 to 15, wherein the generator is a 1,000 kW generator.

[0062] Example 17 includes a charging system according to any one of Examples 14 to 16, wherein the power converter is a rectifier filter unit.

[0063] Example 18 includes a charging system according to any one of Examples 14 to 17, wherein the charging system is implemented in a mobile charging unit.

[0064] This invention may be embodied in other specific forms without departing from its essential characteristics. The described embodiments are to be regarded in all respects as illustrative rather than restrictive. Therefore, the scope of the invention is indicated by the appended claims rather than the foregoing description. All variations within the meaning and scope of the equivalence of the claims are to be covered within its scope.

Claims

1. A charging system, the charging system comprising: prime mover; A gearbox, which is operatively connected to the prime mover; At least one generator, operatively coupled to the gearbox, the at least one generator being configured to produce an alternating current (AC) output having a frequency of at least about 300 Hz; At least one power converter, operatively coupled to the at least one generator, the at least one power converter being configured to convert the AC output into a high-voltage direct current (HVDC) power output of at least about 50 kW; A generator control unit, operatively coupled to the at least one generator and the at least one power converter, is configured to: In one of a plurality of modes, the voltage of the HVDC power output from the at least one power converter is selectively adjusted; as well as In another of the plurality of modes, the power of the at least one power converter is selectively adjusted; and At least one interface, the at least one interface being configured to be connected to provide the HVDC power output from the at least one power converter to the battery of at least one electric vehicle.

2. The charging system according to claim 1, wherein: The at least one generator includes a high-speed generator; and The at least one power converter includes at least one rectifier.

3. The charging system according to claim 1, wherein the generator control unit is configured to: Selectively adjust the voltage of the HVDC power output; The HVDC output of the at least one generator is selectively controlled using both AC voltage regulation and DC voltage regulation; and The power of the at least one power converter is selectively adjusted based on the parameters of the battery of the electric vehicle.

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