On-board charging system for electric vehicle

Abstract

Embodiments include an electric vehicle having: a charging port configured to receive alternating current (AC) power; a direct current (DC) battery; and a bidirectional inverter configured to convert the AC power to the DC power and to convert the DC power to the AC power, the bidirectional inverter selectively connected to the DC battery through the propulsion switch. The electric vehicle further includes: an AC motor connected to the bidirectional inverter and selectively connected to the charging port through a first charging switch; an isolated DC / DC converter motor selectively connected to the DC battery via a second charging switch and a third charging switch; and a processor configured to control operation of the propulsion switch, the first charging switch, the second charging switch, and the third charging switch based on an operation mode of the electric vehicle.

Description

Technical Field

[0001] The subject disclosure relates to electric vehicles. In particular, the present invention relates to an on-board charging system for charging an electric vehicle. Background Art

[0002] An on-board charging module, also known as an on-board charger (OBC), is a component in an electric vehicle that is responsible for converting alternating current (AC) from an external power source (such as a charging station or wall socket) into direct current (DC) in order to charge the vehicle battery pack.

[0003] The on-board charging module is typically located inside the EV and connects to the charging port. When the vehicle is plugged in, the OBC receives AC power and uses internal circuitry to convert it to the appropriate DC voltage and current levels required by the vehicle's battery pack. This conversion process includes converting the AC power to DC using a controlled rectifier, and regulating the voltage and current to ensure safe and efficient charging.

[0004] The onboard charging module typically contains various safety features and monitoring systems to prevent overcharging, overcurrent and other potential problems. It can also communicate with an external charging station or power source to negotiate charging parameters and monitor charging progress. Summary of the invention

[0005] In an exemplary embodiment, an electric vehicle is provided. The electric vehicle includes a charging port configured to receive alternating current (AC) power, a direct current (DC) battery, and a bidirectional inverter configured to convert AC power into DC power and convert DC power into AC power, the bidirectional inverter being selectively connected to the DC battery through a propulsion switch. The electric vehicle also includes an AC motor connected to the bidirectional inverter and selectively connected to the charging port through a first charging switch, an isolated DC / DC converter motor selectively connected to the DC battery via a second charging switch and a third charging switch, and a processor configured to control the operation of the propulsion switch, the first charging switch, the second charging switch, and the third charging switch based on an operating mode of the electric vehicle.

[0006] In addition to one or more features described herein, during a charging state of the electric vehicle, the processor causes the propulsion switch to be in an open position and causes the first charging switch, the second charging switch, and the third charging switch to be in a closed position.

[0007] In addition to one or more features described herein, during an active state of the electric vehicle, the processor causes the propulsion switch to be in a closed position and causes the first, second, and third charging switches to be in open positions.

[0008] In addition to one or more features described herein, an operating mode of the electric vehicle is determined based on detecting connection of a charging power source to the charging port.

[0009] In addition to one or more features described herein, the AC motor includes a neutral point connected to a winding of the AC motor, and wherein the neutral point of the AC motor is selectively connected to the charging port via a first charging switch.

[0010] In addition to one or more features described herein, the AC motor includes three sets of windings, and wherein the AC motor is selectively connected between one of the three sets of windings and the bidirectional inverter via a first charging switch.

[0011] In addition to one or more features described herein, the electric vehicle also includes a second AC motor connected to the bidirectional inverter and selectively connected to the charging port through a fourth charging switch.

[0012] In addition to one or more features described herein, the second AC motor includes a neutral point connected to the windings of the second AC motor, and wherein the neutral point of the second AC motor is selectively connected to the charging port via a fourth charging switch.

[0013] In addition to one or more features described herein, the AC motor includes three sets of windings, and wherein the connection between each of the three sets of windings of the AC motor and the bidirectional inverter is selectively connected to the charging port via a first charging switch, a fourth charging switch, and a fifth charging switch, respectively, and wherein the first charging switch connects the AC motor to the bidirectional inverter.

[0014] In addition to one or more features described herein, the processor is configured to control operation of the first charging switch, the fourth charging switch, and the fifth charging switch to ensure that only one of the first charging switch, the fourth charging switch, and the fifth charging switch is in a closed position at a given time, and wherein the determination as to which one of the first charging switch, the fourth charging switch, and the fifth charging switch to close is based at least in part on the temperature of the three sets of windings of the AC motor.

[0015] In an exemplary embodiment, an on-board charging system for an electric vehicle is provided. The on-board charging system includes a charging port configured to receive alternating current (AC) power, a direct current (DC) battery, and a bidirectional inverter configured to convert AC power into DC power and convert DC power into AC power, the bidirectional inverter being selectively connected to the DC battery via a propulsion switch. The electric vehicle also includes an AC motor connected to the bidirectional inverter and selectively connected to the charging port via a first charging switch, an isolated DC / DC converter motor selectively connected to the DC battery via a second charging switch and a third charging switch, and a processor configured to control the operation of the propulsion switch, the first charging switch, the second charging switch, and the third charging switch based on an operating mode of the electric vehicle.

[0016] In addition to one or more features described herein, during a charging state of the electric vehicle, the processor causes the propulsion switch to be in an open position and causes the first charging switch, the second charging switch, and the third charging switch to be in a closed position.

[0017] In addition to one or more features described herein, during an active state of the electric vehicle, the processor causes the propulsion switch to be in a closed position and causes the first, second, and third charging switches to be in open positions.

[0018] In addition to one or more features described herein, an operating mode of the electric vehicle is determined based on detecting connection of a charging power source to the charging port.

[0019] In addition to one or more features described herein, the AC motor includes a neutral point connected to a winding of the AC motor, and wherein the neutral point of the AC motor is selectively connected to the charging port via a first charging switch.

[0020] In addition to one or more features described herein, the AC motor includes three sets of windings, and wherein the AC motor is selectively connected between one of the three sets of windings and the bidirectional inverter via a first charging switch.

[0021] In addition to one or more features described herein, the on-board charging system also includes a second AC motor connected to the bidirectional inverter and selectively connected to the charging port via a fourth charging switch.

[0022] In addition to one or more features described herein, the second AC motor includes a neutral point connected to the windings of the second AC motor, and wherein the neutral point of the second AC motor is selectively connected to the charging port via a fourth charging switch.

[0023] In addition to one or more features described herein, the AC motor includes three sets of windings, and wherein the connection between each of the three sets of windings of the AC motor and the bidirectional inverter is selectively connected to the charging port via a first charging switch, a fourth charging switch, and a fifth charging switch, respectively, and wherein the first charging switch connects the AC motor to the bidirectional inverter.

[0024] In addition to one or more features described herein, the processor is configured to control operation of the first charging switch, the fourth charging switch, and the fifth charging switch to ensure that only one of the first charging switch, the fourth charging switch, and the fifth charging switch is in a closed position at a given time, and wherein the determination as to which one of the first charging switch, the fourth charging switch, and the fifth charging switch to close is based at least in part on the temperature of the three sets of windings of the AC motor.

[0025] The above features and advantages and other features and advantages of the present disclosure will become apparent when the following detailed description is read in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Other features, advantages and details appear by way of example only in the following detailed description, which refers to the accompanying drawings, in which:

[0027] Figure 1 is a schematic diagram of a vehicle used in conjunction with one or more embodiments of the present disclosure;

[0028] Figure 2 is a block diagram of an onboard charging system for an electric vehicle used in conjunction with one or more embodiments of the present disclosure;

[0029] Figure 3A is a circuit diagram of an on-board charging system for an electric vehicle according to one or more embodiments of the present disclosure;

[0030] Figure 3B is a circuit diagram of an on-board charging system for an electric vehicle according to one or more embodiments of the present disclosure;

[0031] Figure 3C is a circuit diagram of an on-board charging system for an electric vehicle according to one or more embodiments of the present disclosure;

[0032] Figure 3D is a circuit diagram of an on-board charging system for an electric vehicle according to one or more embodiments of the present disclosure; and

[0033] Figure 3E is a circuit diagram of an on-board charging system for an electric vehicle according to one or more embodiments of the present disclosure. DETAILED DESCRIPTION

[0034] The following description is merely exemplary in nature and is not intended to limit the present disclosure, its application or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate the same or corresponding parts and features.

[0035] According to an exemplary embodiment, an electric vehicle with an improved on-board charging system is provided. In an exemplary embodiment, the on-board charging system of the electric vehicle includes an alternating current (AC) motor acting as an inductor and a bidirectional inverter connected to the AC motor acting as a synchronous rectifier. Therefore, when single-phase or three-phase AC power is applied to the AC motor, the bidirectional inverter will generate direct current (DC) power. The DC power is provided to an isolated DC / DC converter, which generates a DC output to charge the battery of the electric vehicle. Therefore, the AC motor and the bidirectional inverter are used to charge the DC battery of the electric vehicle in addition to providing propulsion for the electric vehicle. Advantageously, by utilizing the existing AC motor and bidirectional inverter of the electric vehicle to convert AC power into DC power to charge the electric vehicle, the controllable rectifier in the existing on-board charger of the electric vehicle can be removed, thereby reducing the complexity and cost of the on-board charging system.

[0036] Reference now Figure 1 , a schematic diagram of a vehicle 100 used in conjunction with one or more embodiments of the present disclosure is shown. The vehicle 100 includes a charging port 102, a battery 104, and an electric motor 106. In one embodiment, the vehicle 100 is a hybrid vehicle utilizing an internal combustion engine and an electric motor. In another embodiment, the vehicle 100 is an electric vehicle using only an electric motor. In an exemplary embodiment, the vehicle 100 is configured to be connected to a single-phase or three-phase AC power source via the charging port 102, which is used to charge the battery 104. In the following description, single-phase AC is used as an example, and the concept can also be applied to a three-phase AC power source. The electric motor 106 is configured to receive power from the battery 104 to provide propulsion for the vehicle 100. In an exemplary embodiment, the battery 104 is configured to provide direct current (DC) power to an inverter (not shown), which converts the DC power into three-phase alternating current (AC) power. The three-phase AC power is supplied to the electric motor 106 to propel the vehicle 100.

[0037] Reference now Figure 2 , a schematic diagram of an onboard charging system 200 of an electric vehicle used in combination with one or more embodiments of the present disclosure is shown. As shown in the figure, the onboard charging system 200 includes a charging port 202, a processor 204, an isolated DC / DC converter 206, a DC battery 208, an AC motor 210, a bidirectional inverter 212, a plurality of charging switches 201, and a plurality of propulsion switches 203.

[0038] The charging port 202 is configured to receive single-phase AC power from a charging power source. In one embodiment, the voltage of the single-phase AC power is between 85 and 270 volts. In one embodiment, the charging port 202 includes one or more sensors (not shown) configured to detect whether a charging power source has been connected to the charging port 200. In one embodiment, the sensor communicates with the processor 204.

[0039] The direct current (DC) battery 208 is a high voltage battery and has a capacity greater than about 300 volts. In one embodiment, the battery 208 is a lithium-ion battery. The battery 208 may include one or more NCM (lithium nickel manganese cobalt oxide) battery cells and one or more LFP (lithium iron phosphate) battery cells.

[0040] The bidirectional inverter 212 is configured to convert AC power to DC power and DC power to AC power. The bidirectional inverter is selectively connected to the DC battery through the propulsion switch 203. The term "bidirectional" means that the inverter can operate in both directions, allowing power to flow into and out of the battery 208.

[0041] In AC-DC mode or rectification mode, the bidirectional inverter 212 converts AC power from the motor 210 to DC power. The AC input from the motor 218 is connected to the bidirectional inverter 212, which is connected to the isolated DC / DC converter 206. The isolated DC / DC converter 206 is connected to the battery 208 through the charging switch 201. The rectifier of the bidirectional inverter 212 converts the AC input to DC using power electronic switches (e.g., insulated gate bipolar transistors or IGBTs).

[0042] In DC-AC mode or inverter mode, the bidirectional inverter 212 converts DC power from the battery 208 into AC power. The DC output from the battery 208 is connected to the bidirectional inverter 212 through the propulsion switch 203. The inverter in the bidirectional inverter 212 uses power electronic switches (e.g., insulated gate bipolar transistors IGBTs, wide bandgap switches, etc.) to convert the DC input into AC. For example, the bidirectional inverter 212 can use pulse width modulation (PWM) technology to convert DC power into a high-frequency AC waveform. In an exemplary embodiment, the bidirectional inverter 212 includes a control circuit that adjusts the AC output voltage and frequency to match the requirements of the motor 210.

[0043] The on-board charging system 200 charges the battery 208 using one or more AC motors 210 of the electric vehicle, which are also used to provide propulsion for the electric vehicle. In one embodiment, the AC motor 210 is selectively connected to the charging port 202 through the first charging switch 201. During the charging mode of the electric vehicle, the processor 204 closes the first charging switch 201, allowing AC power to flow from the charging port 202 to the electric motor. In one embodiment, the AC power can be provided to one of the windings of the AC motor 210 or the neutral point of the windings of the AC motor 210. The motor winding acts as an inductor for the provided AC power.

[0044] The on-board charging system 200 includes an isolated DC / DC converter 206, which is selectively connected to a DC battery via a second charging switch 201 and a third charging switch 201. During the charging mode of the electric vehicle, the processor 204 closes the second and third charging switches 201 and opens the switch 203, thereby allowing DC power to flow from the isolated DC / DC converter 206 to the battery 208. The isolated DC / DC converter 206 is configured to convert the DC power output of the bidirectional inverter 212 into a DC output voltage suitable for charging the battery 208. In addition, the isolated DC / DC converter 206 provides electrical isolation between an AC power source (not shown) and the battery 208.

[0045] The processor 204 controls the operation of the propulsion switch 203 and the charging switch 201 of the on-board charging system 200. During the propulsion mode of the electric vehicle, the processor 204 closes the propulsion switch 203, allowing DC power to flow from the battery 208 through the bidirectional inverter 212, which provides AC power to the motor 210. During the propulsion mode of the electric vehicle, the processor 204 opens all the charging switches 201. During the charging mode of the electric vehicle, the processor 204 closes the charging switch 201, allowing AC power to flow from the charging port 202 through the motor 210 to the bidirectional inverter 212, which provides DC power to the isolated DC / DC converter 206. The DC / DC converter 206 then provides DC power to the battery 208. During the charging mode of the electric vehicle, the processor 204 opens all the propulsion switches 203.

[0046] Figure 3A , 3B , 3C, 3D, and 3E each show a circuit diagram of an example configuration of an on-vehicle charging system 300 according to one or more embodiments of the present disclosure. The on-vehicle charging system 300 includes a charging port 302, a DC battery 304, an AC motor 306, an isolated DC / DC converter 307, a bidirectional inverter 308, a propulsion switch 310, a pre-charge resistor 311, a charging switch 312, a fuse 313, and a capacitor 314.

[0047] In one embodiment, if Figure 3A As shown, the positive terminal of the charging port 302 of the on-board charging system 300 is selectively connected to the neutral point of the winding of the AC motor 306 via the charging switch 312. The negative terminal of the charging port 302 of the on-board charging system 300 is selectively connected to the IGBT, which is connected in parallel to the bidirectional inverter 308 and the isolated DC / DC converter 307. In this configuration, the winding of the AC motor 306 acts as an inductor, and the bidirectional inverter 308 acts as a synchronous rectifier.

[0048] In one embodiment, if Figure 3BAs shown, the positive terminal of the charging port 302 of the on-board charging system 300 is selectively connected to the neutral point of the winding of the AC motor 306 via the charging switch 312. In this configuration, the capacitor of the bidirectional inverter 308 is divided into two capacitors 314, and the negative terminal of the charging port 302 of the on-board charging system 300 is selectively connected between the two capacitors 314 of the bidirectional inverter 308. In this configuration, the winding of the AC motor 306 acts as an inductor, and the bidirectional inverter 308 acts as a synchronous rectifier.

[0049] In one embodiment, if Figure 3C As shown, the positive terminal of the charging port 302 of the on-board charging system 300 is selectively connected between one of the windings of the AC motor 306 and the bidirectional inverter 308 via a charging switch 312. In this configuration, the capacitor of the bidirectional inverter 308 is divided into two capacitors 314, and the negative terminal of the charging port 302 of the on-board charging system 300 is selectively connected between the two capacitors 314 of the bidirectional inverter 308. In this configuration, the winding of the AC motor 306 acts as an inductor, and the bidirectional inverter 308 acts as a synchronous rectifier.

[0050] In some cases, Figure 3C The configuration shown may cause the windings of the AC motor 306 connected to the positive terminal of the charging port 302 to heat up, which may negatively affect the charging performance and / or the performance of the AC motor 306. Therefore, in another embodiment, as shown in FIG. Figure 3D As shown, the positive terminal of the charging port 302 of the on-board charging system 300 is selectively connected between the winding of the AC motor 306 and the bidirectional inverter 308 via three charging switches 312-1. In this configuration, the three charging switches 312-1 are actively controlled by a processor (not shown) so that only one of the three charging switches 312-1 is closed at any time. The processor is configured to monitor the temperature of the winding of the AC motor 306 and selectively control the three charging switches 312-1 to prevent any winding of the AC motor 306 from exceeding a threshold temperature. In this configuration, the capacitor of the bidirectional inverter 308 is divided into two capacitors 314, and the negative terminal of the charging port 302 of the on-board charging system 300 is selectively connected between the two capacitors 314 of the bidirectional inverter 308. In this configuration, the winding of the AC motor 306 acts as an inductor and the bidirectional inverter 308 acts as a synchronous rectifier.

[0051] In one embodiment, if Figure 3EAs shown, the positive terminal of the charging port 302 of the on-board charging system 300 is selectively connected to the neutral point of the winding of the first AC motor 306-1 via the charging switch 312. The negative terminal of the charging port 302 of the on-board charging system 300 is selectively connected to the neutral point of the winding of the second AC motor 306-2 via the charging switch 312. In this configuration, the windings of the AC motors 306-1 and 306-2 both act as inductors, and the bidirectional inverter 308 acts as a synchronous rectifier.

[0052] In an exemplary embodiment, the fuse 313 is disposed adjacent to the terminals of the DC battery 304 and is configured to prevent damage to the DC battery by preventing current exceeding a threshold level from flowing into or out of the DC battery 304. In an embodiment, a pre-charge resistor 311 is disposed between one of the propulsion switches 310 and the bidirectional inverter 308. The pre-charge resistor 311 is configured to slowly charge the capacitor 314 of the bidirectional inverter 308 before the bidirectional inverter 308 is powered on and prevent a large inrush current from entering the bidirectional inverter 308.

[0053] In an exemplary embodiment, when charging port 302 is connected between one of a set of windings of the AC motor and the bidirectional inverter, the phase current and current angle flowing through AC motor 306 are controlled by bidirectional inverter 308 to prevent relative movement between the rotor and stator of AC motor 306 .

[0054] Figure 3A , 3B The various configurations of the on-board charging system 300 shown in 3C, 3D and 3E are provided as examples of the on-board charging system and are not intended to be limiting. A person skilled in the art will appreciate that other configurations of the on-board charging system 300 according to the present disclosure are possible.

[0055] In an exemplary embodiment, when the onboard charging system 300 is in a charging mode (e.g., when the charging switch is turned on and the propulsion switch is turned off), the onboard charging system 300 can be configured to receive power from the charging port 302 and charge the DC battery 304, or to provide AC power from the DC battery 304 to the charging port 302. Therefore, the DC battery 304 of the electric vehicle can be used to power devices outside the electric vehicle.

[0056] The terms "one" and "an" do not indicate a limitation of quantity, but rather indicate the presence of at least one of the referenced items. The term "or" means "and / or", unless the context clearly indicates otherwise. References to "an aspect" throughout the specification mean that a particular element (e.g., feature, structure, step, or characteristic) described in conjunction with that aspect is included in at least one aspect described herein, and may or may not be present in other aspects. In addition, it should be understood that the described elements may be combined in any suitable manner in various aspects.

[0057] When an element such as a layer, film, region, or substrate is referred to as being “on” another element, it can be directly on the other element or intervening elements may also be present. In contrast, when an element is referred to as being “directly on” another element, there are no intervening elements present.

[0058] Unless otherwise indicated herein, all test standards are the most recent standards in effect as of the filing date of the present application or, if priority is claimed, the filing date of the earliest priority application in which the test standards appear.

[0059] Unless defined otherwise, technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs.

[0060] Although the above disclosure has been described with reference to exemplary embodiments, it will be appreciated by those skilled in the art that various changes may be made and equivalents may be substituted for its elements without departing from the scope thereof. In addition, many modifications may be made to adapt specific situations or materials to the teachings of the disclosure without departing from the essential scope of the disclosure. Therefore, it is intended that the disclosure is not limited to the specific embodiments disclosed, but will include all embodiments falling within its scope.

Claims

1. An electric vehicle, comprising: a charging port configured to receive alternating current (AC) power; Direct current (DC) batteries; a bidirectional inverter configured to convert AC power to DC power and convert DC power to AC power, the bidirectional inverter selectively connected to the DC battery through the propulsion switch; an AC motor connected to the bidirectional inverter and selectively connected to the charging port through a first charging switch; an isolated DC / DC converter motor selectively connected to a DC battery via a second charging switch and a third charging switch; as well as A processor is configured to control operation of the propulsion switch, the first charging switch, the second charging switch, and the third charging switch based on an operating mode of the electric vehicle.

2. The electric vehicle according to claim 1, wherein: During a charging state of the electric vehicle, the processor causes the propulsion switch to be in an open position and causes the first, second, and third charging switches to be in closed positions.

3. The electric vehicle according to claim 1, wherein: During an active state of the electric vehicle, the processor causes the propulsion switch to be in a closed position and causes the first, second, and third charging switches to be in an open position.

4. The electric vehicle according to claim 1, wherein: The operating mode of the electric vehicle is determined based on detecting connection of a charging power source to the charging port.

5. The electric vehicle according to claim 1, wherein: The AC motor includes a neutral point connected to a winding of the AC motor, and wherein the neutral point of the AC motor is selectively connected to the charging port through the first charging switch.

6. The electric vehicle according to claim 1, wherein: The AC motor includes three sets of windings, and wherein the charging port is selectively connected between one of the three sets of windings and the bidirectional inverter through the first charging switch. 7 . The electric vehicle of claim 1 , further comprising a second AC motor connected to the bidirectional inverter and selectively connected to the charging port through a fourth charging switch.

8. The electric vehicle according to claim 7, wherein: The second AC motor includes a neutral point connected to a winding of the second AC motor, and the neutral point of the second AC motor is selectively connected to the charging port through the fourth charging switch.

9. The electric vehicle according to claim 1, wherein: The AC motor includes three sets of windings, and wherein the connection between each of the three sets of windings of the AC motor and the bidirectional inverter is selectively connected to the charging port through the first charging switch, the fourth charging switch and the fifth charging switch, respectively, and wherein the first charging switch connects the AC motor to the bidirectional inverter.

10. An on-board charging system for an electric vehicle, the on-board charging system comprising: Direct current (DC) batteries; a bidirectional inverter configured to convert AC power to DC power and convert DC power to AC power, the bidirectional inverter selectively connected to the DC battery through the propulsion switch; an AC motor connected to the bidirectional inverter and selectively connected to a charging port through a first charging switch, wherein the charging port receives AC power during a charging mode; an isolated DC / DC converter motor selectively connected to a DC battery via a second charging switch and a third charging switch; as well as A processor is configured to control operation of the propulsion switch, the first charging switch, the second charging switch, and the third charging switch based on an operating mode of the electric vehicle.

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