A charging circuit and method for low-voltage electric motorcycles using a high-voltage DC charging station.

Abstract

A charging circuit and method for a low-voltage electric motorcycle using a high-voltage DC charging pile, wherein the low-voltage electric motorcycle includes a low-voltage power battery, a motor driver, and a motor; the charging circuit includes a motor driver, a motor, and a charging half-bridge circuit; the motor driver includes several switching bridge arms, and the motor includes several motor windings. Each motor winding can be considered as an inductor in the charging circuit, and the filter capacitor in the motor driver can be considered as the output filter capacitor of the charging circuit. Therefore, the motor windings and the motor driver capacitor can be used as part of the charging voltage regulation circuit, enabling the high-voltage DC charging pile to charge the low-voltage power battery without an external charger.

Description

Technical Field

[0001] This application belongs to the field of charging circuit technology, and in particular relates to a charging circuit and method for low-voltage electric motorcycles using a high-voltage DC charging pile. Background Technology

[0002] Currently, common electric motorcycles are charged using external chargers or OBCs (on-board chargers). However, due to limitations in charger size, weight, and cost, common external chargers and OBCs suffer from low charging power and slow charging speeds, making it difficult to meet the market demand for fast charging of long-range electric motorcycles with large-capacity batteries. Additionally, a few electric motorcycles use an additional high-power step-down DC / DC converter to connect to car DC charging stations for fast charging of low-voltage electric motorcycles. However, high-power DC / DC converters are bulky, heavy, and expensive, making them difficult to match the actual market demand. Summary of the Invention

[0003] The purpose of this application is to provide a circuit and method for fast charging of low-voltage electric motorcycles using public automotive DC charging stations, without increasing costs, size, or weight, in order to solve the problem of rapid energy replenishment for low-voltage electric motorcycles.

[0004] A first aspect of this application provides a charging circuit, including: a motor driver, a motor, and a charging half-bridge circuit; the motor driver includes a plurality of switching arms, and the motor includes a plurality of motor windings; both ends of each of the motor driver switching arms are used to connect to a low-voltage power battery, and the midpoint of at least one of the switching arms is connected to the midpoint of the charging half-bridge circuit through at least one of the motor windings, and both ends of the switching arms of the charging half-bridge circuit are used to connect to the positive and negative terminals of a high-voltage DC charging pile.

[0005] In one embodiment, the motor windings correspond one-to-one with the switch bridge arms, the first end of each motor winding is connected to the midpoint of the corresponding switch bridge arm, the second ends of each motor winding are connected to each other, and at least one first end or second end of the motor winding is connected to the midpoint of the bridge arm of the charging half-bridge circuit.

[0006] In one embodiment, the motor driver includes a mode switching switch, a first switch arm, a second switch arm, and a third switch arm. The motor includes a first motor winding, a second motor winding, and a third motor winding. Both ends of the first switch arm are connected to the low-voltage power battery, and the midpoint of the first switch arm is connected to the first end of the first motor winding. Both ends of the second switch arm are connected to the low-voltage power battery, and the midpoint of the second switch arm is connected to the first end of the second motor winding via the mode switching switch. Both ends of the third switch arm are connected to the low-voltage power battery, and the midpoint of the third switch arm is connected to the first end of the third motor winding. The second ends of the first motor winding, the second ends of the second motor winding, and the second ends of the third motor winding are interconnected. The first end of the second motor winding is connected to the midpoint of the arm of the charging half-bridge circuit.

[0007] In one embodiment, the charging half-bridge circuit includes a first voltage regulating switch, a second voltage regulating switch, and a charging input capacitor. The first terminal of the first voltage regulating switch is connected to the positive terminal of the high-voltage DC charging pile, the second terminal of the first voltage regulating switch is connected to the first terminal of the second motor winding, the first terminal of the second voltage regulating switch is connected to the first terminal of the second motor winding, the second terminal of the second voltage regulating switch is connected to the negative terminal of the high-voltage DC charging pile, and the two ends of the charging input capacitor are connected to the first terminal of the first voltage regulating switch and the second terminal of the second voltage regulating switch.

[0008] In one embodiment, the motor driver includes a first switch bridge arm, a second switch bridge arm, and a third switch bridge arm; the motor includes a first motor winding, a second motor winding, and a third motor winding; both ends of the first switch bridge arm are connected to the low-voltage power battery, and the midpoint of the first switch bridge arm is connected to the first end of the first motor winding; both ends of the second switch bridge arm are connected to the low-voltage power battery, and the midpoint of the second switch bridge arm is connected to the first end of the second motor winding; both ends of the third switch bridge arm are connected to the low-voltage power battery, and the midpoint of the third switch bridge arm is connected to the first end of the third motor winding; the second ends of the first motor winding, the second ends of the second motor winding, and the second ends of the third motor winding are interconnected (motor center point) and connected to the midpoint of the bridge arm of the charging half-bridge circuit.

[0009] In one embodiment, the charging half-bridge circuit includes a first voltage regulating switch, a second voltage regulating switch, and a charging input capacitor. The first terminal of the first voltage regulating switch is connected to the positive terminal of the high-voltage DC charging pile, the second terminal of the first voltage regulating switch is connected to the center point of the motor, the first terminal of the second voltage regulating switch is connected to the center point of the motor, the second terminal of the second voltage regulating switch is connected to the negative terminal of the high-voltage DC charging pile, and the two ends of the charging input capacitor are connected to the first terminal of the first voltage regulating switch and the second terminal of the second voltage regulating switch.

[0010] In one embodiment, the motor driver includes a filter capacitor, the two ends of which are respectively connected to the positive and negative terminals of the low-voltage power battery.

[0011] In one embodiment, the charging circuit is configured such that: in discharge mode, the mode switching switch is turned on, and the motor driver drives the motor to work based on the electrical energy provided by the low-voltage power battery; in charging mode, the mode switching switch is turned off, the upper arm of the first switch bridge arm and the upper arm of the third switch bridge arm are turned on, and the other switches of the motor driver switch bridge arm are all in the off state; the first voltage regulating switch and the second voltage regulating switch are turned on and off according to a set switching frequency and a set conduction duration.

[0012] In one embodiment, the charging circuit is configured such that: in discharge mode, the first voltage regulating switch and the second voltage regulating switch are turned off, and the motor driver drives the motor to work based on the electrical energy provided by the low-voltage power battery; in charging mode, the upper arm of the first switch bridge arm, the upper arm of the second switch bridge arm, and the upper arm of the third switch bridge arm are turned on, and the other switches of the motor driver switch bridge arm are all in the off state, and the first voltage regulating switch and the second voltage regulating switch are turned on and off with a set switching frequency and a set conduction duration.

[0013] A second aspect of this application provides a method for charging a low-voltage electric motorcycle using a high-voltage DC charging pile, comprising: a high-voltage DC charging pile, a low-voltage power battery, and a charging circuit as described above, wherein the output terminal of the charging circuit is connected to the low-voltage power battery, and the input terminal of the charging circuit is connected to the high-voltage DC charging pile.

[0014] The beneficial effects of this application embodiment compared with the prior art are as follows: by connecting the motor windings of the motor in series between the motor driver and the charging half-bridge circuit, each motor winding can be regarded as an inductor in the circuit, and the input capacitor in the motor driver can be regarded as the output filter capacitor of the charging circuit. Thus, the motor windings and the motor driver capacitor can be used as part of the charging voltage regulation circuit, and together with the charging half-bridge circuit, they form a BUCK circuit to realize the regulation of the charging voltage. The charging of the low-voltage power battery by the high-voltage DC charging pile can be realized without the need for an additional charger.

[0015] Since the motor windings of the motor can withstand a large current, the charging circuit can quickly charge the low-voltage power battery with a large charging power. At the same time, since only an additional charging half-bridge circuit is needed to charge the low-voltage power battery with a high-voltage DC charging pile, the charging circuit of this application can be integrated into the motor controller. Thus, without increasing the cost, size, and weight too much, a car DC charging pile can be used to quickly charge the low-voltage electric motorcycle, solving the problem of rapid energy replenishment for low-voltage electric motorcycles. Attached Figure Description

[0016] Figure 1 A schematic diagram of a charging circuit provided in one embodiment of this application;

[0017] Figure 2 A circuit diagram of a charging circuit provided in an embodiment of this application;

[0018] Figure 3 A waveform diagram of the connection point voltage between the motor and the charging half-bridge circuit provided in an embodiment of this application;

[0019] Figure 4 A waveform diagram of the current flowing through the motor windings provided in one embodiment of this application;

[0020] Figure 5 Another circuit diagram of a charging circuit provided in one embodiment of this application;

[0021] Figure 6 A waveform diagram of the charging voltage provided in one embodiment of the application. Detailed Implementation

[0022] To make the technical problems, technical solutions, and beneficial effects to be solved by this application clearer, the following detailed description is provided in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and are not intended to limit the scope of this application.

[0023] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.

[0024] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0025] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0026] Figure 1 This paper illustrates a schematic diagram of the charging circuit for a low-voltage electric motorcycle provided by a high-voltage DC charging pile according to an embodiment of this application. For ease of explanation, only the parts relevant to this embodiment are shown, and the details are as follows:

[0027] The low-voltage electric motorcycle includes a low-voltage power battery 20, a motor driver 100, and a motor 200.

[0028] The charging circuit 10 includes: the switching bridge arm of the motor driver 100 and the motor winding of the motor 200, and also includes a charging half-bridge circuit 300.

[0029] Both ends of each switch bridge arm are used to connect to the low-voltage power battery 20. The midpoint of at least one switch bridge arm is connected to the midpoint of the charging half-bridge circuit 300 via at least one motor winding. Both ends of the charging half-bridge circuit 300 are used to connect to the positive and negative terminals of the high-voltage DC charging pile 30.

[0030] During charging, inductors are crucial for voltage regulation. In this embodiment, by connecting the motor windings of the motor 200 in series between the motor driver 100 and the charging half-bridge circuit 300, each motor winding can be considered an inductor in the circuit, and the filter capacitor in the motor driver 100 can be considered the output filter capacitor of the charging circuit 10. Thus, the inductance of the motor windings and the filter capacitor in the motor driver 100 can be used as part of the charging circuit 10, forming a BUCK circuit with the charging half-bridge circuit 300 to regulate the charging voltage. This allows for high-power charging of the low-voltage power battery 20 by the high-voltage DC charging pile 30 without the need for an additional high-power DC / DC converter.

[0031] In one embodiment, the motor windings correspond one-to-one with the switching bridge arms of the motor driver, the first end of each motor winding is connected to the midpoint of the corresponding switching bridge arm, the second ends of each motor winding are connected to each other, and the first end or the second end of at least one motor winding is connected to the midpoint of the bridge arm of the charging half-bridge circuit 300.

[0032] When the low-voltage power battery 20 is discharging, the motor driver 100 can provide electrical energy to each motor winding based on the voltage output by the low-voltage power battery 20, driving the motor 200 to work. When charging the low-voltage power battery 20, by controlling the on and off of the corresponding switching devices in the motor driver 100, at least one motor winding can be connected in series between the charging half-bridge circuit 300 and the low-voltage power battery 20, acting as an inductor to participate in voltage regulation.

[0033] In one embodiment, such as Figure 2 As shown, the motor driver 100 includes a mode switching switch S1, a first switch arm, a second switch arm, and a third switch arm. The motor 200 includes a first motor winding L1, a second motor winding L2, and a third motor winding L3. Both ends of the first switch arm are connected to the low-voltage power battery 20, and the midpoint of the first switch arm is connected to the first end of the first motor winding L1. Both ends of the second switch arm are connected to the low-voltage power battery 20, and the midpoint of the second switch arm is connected to the first end of the second motor winding L2 via the mode switching switch S1. Both ends of the third switch arm are connected to the low-voltage power battery 20, and the midpoint of the third switch arm is connected to the first end of the third motor winding L3. The second ends of the first motor winding L1, the second ends of the second motor winding L2, and the second ends of the third motor winding L3 are interconnected. The first end of the second motor winding L2, the second end of the mode switching switch S1, and the midpoint of the charging half-bridge circuit 300 arm are interconnected.

[0034] It is understandable that when the mode switching switch S1 is turned on, the low-voltage power battery 20 can provide power to drive the motor 200 by controlling the first switch arm, the second switch arm and the third switch arm to turn on and off periodically.

[0035] In some embodiments, the first switch bridge arm includes a first power supply switch Q1 and a second power supply switch Q2. The first end of the first power supply switch Q1 is connected to the positive terminal of the low-voltage power battery 20, the second end of the first power supply switch Q1 is connected to the first end of the first motor winding L1, the first end of the second power supply switch Q2 is connected to the second end of the first power supply switch Q1, and the second end of the second power supply switch Q2 is connected to the negative terminal of the low-voltage power battery 20.

[0036] The second switch arm includes a third power supply switch Q3 and a fourth power supply switch Q4. The first end of the third power supply switch Q3 is connected to the positive terminal of the low-voltage power battery 20. The second end of the third power supply switch Q3 is connected to the first end of the second motor winding L2 through the mode switching switch S1. The first end of the fourth power supply switch Q4 is connected to the second end of the third power supply switch Q3. The second end of the fourth power supply switch Q4 is connected to the negative terminal of the low-voltage power battery 20.

[0037] The third switch bridge arm includes a fifth power supply switch Q5 and a sixth power supply switch Q6. The first end of the fifth power supply switch Q5 is connected to the positive terminal of the low-voltage power battery 20, the second end of the fifth power supply switch Q5 is connected to the first end of the third motor winding L3, the first end of the sixth power supply switch Q6 is connected to the second end of the fifth power supply switch Q5, and the second end of the sixth power supply switch Q6 is connected to the negative terminal of the low-voltage power battery 20.

[0038] Among them, the first power supply switch Q1, the second power supply switch Q2, the third power supply switch Q3, the fourth power supply switch Q4, the fifth power supply switch Q5 and the sixth power supply switch Q6 can all be N-type MOSFETs.

[0039] In one embodiment, the charging half-bridge circuit 300 includes a first voltage regulating switch S2, a second voltage regulating switch S3, and a charging input capacitor C2. The first terminal of the first voltage regulating switch S2 is connected to the positive terminal of the high-voltage DC charging pile 30, the second terminal of the first voltage regulating switch S2 is connected to the first terminal of the second motor winding L2, the first terminal of the second voltage regulating switch S3 is connected to the first terminal of the second motor winding L2, and the second terminal of the second voltage regulating switch S3 is connected to the negative terminal of the high-voltage DC charging pile 30. The two terminals of the charging input capacitor C2 are respectively connected to the first terminal of the first voltage regulating switch S2 and the second terminal of the second voltage regulating switch S3.

[0040] Specifically, the charging circuit 10 is configured such that: in discharge mode, the mode switching switch S1 is turned on, and the motor driver 100 drives the motor 200 to operate based on the electrical energy provided by the low-voltage power battery 20. In charging mode, the mode switching switch S1 is turned off, the upper arm of the first switch bridge arm and the upper arm of the third switch bridge arm are turned on, and the other bridge arm switches of the motor driver 100 are all in the off state (i.e., the lower arm of the first switch bridge arm, the upper arm of the second switch bridge arm, the lower arm of the second switch bridge arm, and the lower arm of the third switch bridge arm are turned off), and the first voltage regulating switch S2 and the second voltage regulating switch S3 are periodically turned on and off according to the set switching frequency and the set conduction duration.

[0041] In this circuit, the set frequency of the first voltage regulating switch S2 is equal to the set frequency of the second voltage regulating switch S3. The sum of the set conduction duration of the first voltage regulating switch S2 and the set conduction duration of the second voltage regulating switch S3 is equal to the duration of one cycle corresponding to the set frequency. That is, the control signal corresponding to the first voltage regulating switch S2 is complementary to the control signal corresponding to the second voltage regulating switch S3. In charging mode, for example, the voltage waveform at the connection point between the motor 200 and the charging half-bridge circuit 300 and the current waveform flowing through the motor windings are as follows: Figure 3 , Figure 4 As shown, the switching frequency and conduction time of the first voltage regulating switch S2 and the second voltage regulating switch S3 can be adjusted by adjusting the duty cycle, frequency and other electrical parameters of the control signals used to control the first voltage regulating switch S2 and the second voltage regulating switch S3, thereby adjusting the charging voltage and charging current transmitted to the low-voltage power battery. The set frequency and set conduction time can be set according to actual needs.

[0042] Specifically, in charging mode, the motor driver 100 can turn on the first power supply switch Q1 and the fifth power supply switch Q5, and turn off the second power supply switch Q2 and the sixth power supply switch Q6. At this time, the second motor winding L2 and the first motor winding L1 are connected in series between the charging half-bridge circuit 300 and the first power supply switch Q1, and the second motor winding L2 and the third motor winding L3 are connected in series between the charging half-bridge circuit 300 and the fifth power supply switch Q5. Alternatively, charging of the low-voltage power battery 20 can be achieved by turning on only one of the first power supply switch Q1 and the fifth power supply switch Q5.

[0043] In some embodiments, such as Figure 2As shown, the charging circuit 10 also includes a charging interface 400, which is connected to the charging half-bridge circuit 300 for docking with the high-voltage DC charging pile 30. Specifically, the first end of the first voltage regulating switch S2 can be connected to the positive terminal of the charging interface 400, thereby connecting to the positive terminal of the high-voltage DC charging pile 30 through the charging interface 400, and the second end of the second voltage regulating switch S3 can be connected to the negative terminal of the charging interface 400, thereby connecting to the negative terminal of the high-voltage DC charging pile 30 through the charging interface 400.

[0044] It should be noted that the low-voltage power battery 20 has a positive terminal and a negative terminal. The upper arm of the switching bridge arm of each motor driver is connected to the positive terminal of the low-voltage power battery 20, and the lower arm of each switching bridge arm is connected to the negative terminal of the low-voltage power battery 20. At the same time, the negative terminal of the low-voltage power battery 20 can also be connected to the negative terminal of the charging interface 400.

[0045] In one embodiment, such as Figure 5 As shown, unlike the above embodiment, the motor driver 100 includes a first switch bridge arm, a second switch bridge arm, and a third switch bridge arm, and the motor 200 includes a first motor winding L1, a second motor winding L2, and a third motor winding L3. Both ends of the first switch bridge arm are connected to the low-voltage power battery 20, and the midpoint of the first switch bridge arm is connected to the first end of the first motor winding L1. Both ends of the second switch bridge arm are connected to the low-voltage power battery 20, and the midpoint of the second switch bridge arm is connected to the first end of the second motor winding L2. Both ends of the third switch bridge arm are connected to the low-voltage power battery 20, and the midpoint of the third switch bridge arm is connected to the first end of the third motor winding L3. The second ends of the first motor winding L1, the second motor winding L2, and the third motor winding L3 are all connected to the center point of the motor and to the midpoint of the charging half-bridge circuit 300 bridge arm.

[0046] It should be noted that in this embodiment, the second end of the first motor winding L1, the second end of the second motor winding L2, and the second end of the third motor winding L3 are all connected to the center terminal of the motor 200. By connecting the center terminal to the midpoint of the bridge arm of the charging half-bridge circuit 300, each motor winding can be directly connected in series between the charging half-bridge circuit 300 and the low-voltage power battery 20.

[0047] In some embodiments, the first switch bridge arm includes a first power supply switch Q1 and a second power supply switch Q2. The first end of the first power supply switch Q1 is connected to the positive terminal of the low-voltage power battery 20, the second end of the first power supply switch Q1 is connected to the first end of the first motor winding L1, the first end of the second power supply switch Q2 is connected to the second end of the first power supply switch Q1, and the second end of the second power supply switch Q2 is connected to the negative terminal of the low-voltage power battery 20.

[0048] The second switch arm includes a third power supply switch Q3 and a fourth power supply switch Q4. The first end of the third power supply switch Q3 is connected to the positive terminal of the low-voltage power battery 20, the second end of the third power supply switch Q3 is connected to the first end of the second motor winding L2, the first end of the fourth power supply switch Q4 is connected to the second end of the third power supply switch Q3, and the second end of the fourth power supply switch Q4 is connected to the negative terminal of the low-voltage power battery 20.

[0049] The third switch bridge arm includes a fifth power supply switch Q5 and a sixth power supply switch Q6. The first end of the fifth power supply switch Q5 is connected to the positive terminal of the low-voltage power battery 20, the second end of the fifth power supply switch Q5 is connected to the first end of the third motor winding L3, the first end of the sixth power supply switch Q6 is connected to the second end of the fifth power supply switch Q5, and the second end of the sixth power supply switch Q6 is connected to the negative terminal of the low-voltage power battery 20.

[0050] In one embodiment, the charging half-bridge circuit 300 includes a first voltage regulating switch S2, a second voltage regulating switch S3, and a charging input capacitor C2. The first terminal of the first voltage regulating switch S2 is connected to the positive terminal of the high-voltage DC charging pile 30, and the second terminal of the first voltage regulating switch S2 is connected to the center terminal of the motor 200. The first terminal of the second voltage regulating switch S3 is connected to the center terminal of the motor 200, and the second terminal of the second voltage regulating switch S3 is connected to the negative terminal of the high-voltage DC charging pile 30. The two ends of the charging input capacitor C2 are connected to the first terminal of the first voltage regulating switch S2 and the second terminal of the second voltage regulating switch S3.

[0051] In one embodiment, the charging circuit 10 is configured such that, in discharge mode, the first voltage regulating switch S2 and the second voltage regulating switch S3 are turned off, and the motor driver 100 drives the motor 200 to operate based on the electrical energy provided by the low-voltage power battery 20. In charging mode, the upper arms of the first switch bridge arm, the second switch bridge arm, and the third switch bridge arm are turned on, and the other voltage regulating switches of the motor driver 100 are all turned off (i.e., the lower arms of the first switch bridge arm, the second switch bridge arm, and the third switch bridge arm are turned off). The first voltage regulating switch S2 and the second voltage regulating switch S3 periodically turn on and off at a set frequency and a set on duration.

[0052] In charging mode, the motor driver 100 can turn on the first power supply switch Q1, the third power supply switch Q3, and the fifth power supply switch Q5, and turn off the second power supply switch Q2, the fourth power supply switch Q4, and the sixth power supply switch Q6. At this time, the first motor winding L1 is connected in series between the midpoint of the charging half-bridge circuit 300 arm and the first power supply switch Q1, the second motor winding L2 is connected in series between the midpoint of the charging half-bridge circuit 300 arm and the third power supply switch Q3, and the third motor winding L3 is connected in series between the midpoint of the charging half-bridge circuit 300 arm and the fifth power supply switch Q5. Alternatively, only one of the first power supply switch Q1, the third power supply switch Q3, or the fifth power supply switch Q5 can be turned on to charge the low-voltage power battery 20.

[0053] The specific working principle of the charging half-bridge circuit 300 has been explained in the above embodiments, and will not be repeated in this embodiment.

[0054] In one embodiment, such as Figure 5 As shown, the motor driver 100 includes a filter capacitor C1, the two ends of which are used to connect to the positive and negative terminals of the low-voltage power battery 20, respectively.

[0055] For example, the charging circuit 10 provides the low-voltage power battery 20 with a charging voltage such as... Figure 6 As shown, the filter capacitor C1 can filter and regulate the voltage transmitted to the low-voltage power battery 20 to provide a stable voltage to the low-voltage power battery 20.

[0056] One embodiment of this application provides a charging method applicable to any of the above embodiments, including steps S100 to S200.

[0057] Step S100: Turn on the upper arm of the switching bridge arm of at least one motor driver to connect at least one motor winding in series between the charging half-bridge circuit and the low-voltage power battery.

[0058] Step S200: The charging half-bridge circuit, in conjunction with the motor windings and the charging half-bridge circuit C2 of the motor driver, reduces the input high voltage provided by the high-voltage DC charging pile to output charging voltage to the low-voltage power battery.

[0059] The motor winding inductance and the filter capacitor in the motor driver 100 are used as part of the charging circuit 10. Together with the charging half-bridge circuit 300, they form a BUCK circuit to regulate the charging voltage. This allows the high-voltage DC charging pile 30 to charge the low-voltage power battery 20 at high power without the need for an additional high-power DC / DC converter.

[0060] One embodiment of this application provides a low-voltage electric motorcycle, which includes a low-voltage power battery and a charging circuit as described in any of the above embodiments, the charging circuit being connected to the low-voltage power battery. The charging circuit can be connected to a high-voltage DC charging station to charge the low-voltage power battery. Since the low-voltage electric motorcycle includes the charging circuit of any of the above embodiments, it possesses the beneficial effects of the charging circuit of any of the above embodiments, which will not be elaborated further here.

[0061] Low-voltage electric motorcycles can specifically be electric motorcycles, all-terrain vehicles, electric cars, or other tools and equipment driven by electric motors.

[0062] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the above-described division of functional units and modules is merely an example. In practical applications, the above functions can be assigned to different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiments can be integrated into one processing unit, or each unit can exist physically separately, or two or more units can be integrated into one unit. The integrated unit can be implemented in hardware or as a software functional unit. Furthermore, the specific names of the functional units and modules are only for easy differentiation and are not intended to limit the scope of protection of this application. The specific working process of the units and modules in the above system can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0063] In the above embodiments, the descriptions of each embodiment have different focuses. For parts that are not described in detail or recorded in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0064] The above-described embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application, and should all be included within the protection scope of this application.

Claims

1. A charging circuit for a low-voltage electric motorcycle using a high-voltage DC charging station, wherein the low-voltage electric motorcycle includes a low-voltage power battery, a motor driver, and a motor, characterized in that, The charging circuit includes: a charging half-bridge circuit, a switching bridge arm of the motor driver, and motor windings of the motor. Both ends of each of the switch bridge arms are used to connect to the low-voltage power battery. The midpoint of at least one of the switch bridge arms is connected to the midpoint of the charging half-bridge circuit through at least one of the motor windings. Both ends of the charging half-bridge circuit are used to connect to the positive and negative terminals of the high-voltage DC charging pile. The motor driver includes a mode switching switch, a first switch bridge arm, a second switch bridge arm, and a third switch bridge arm; the motor includes a first motor winding, a second motor winding, and a third motor winding. Both ends of the first switch bridge arm are connected to the low-voltage power battery, and the midpoint of the first switch bridge arm is connected to the first end of the first motor winding. Both ends of the second switch bridge arm are connected to the low-voltage power battery, and the midpoint of the second switch bridge arm is connected to the first end of the second motor winding through the mode switching switch. Both ends of the third switch bridge arm are connected to the low-voltage power battery, and the midpoint of the third switch bridge arm is connected to the first end of the third motor winding. The second end of the first motor winding, the second end of the second motor winding, and the second end of the third motor winding are connected to each other. The first end of the second motor winding, the second end of the mode switching switch, and the midpoint of the bridge arm of the charging half-bridge circuit are connected to each other. The charging half-bridge circuit includes a first voltage regulating switch, a second voltage regulating switch, and a charging input capacitor. The first terminal of the first voltage regulating switch is connected to the positive terminal of the high-voltage DC charging pile, the second terminal of the first voltage regulating switch is connected to the first terminal of the second motor winding, the first terminal of the second voltage regulating switch is connected to the first terminal of the second motor winding, the second terminal of the second voltage regulating switch is connected to the negative terminal of the high-voltage DC charging pile, and the two ends of the charging input capacitor are connected to the first terminal of the first voltage regulating switch and the second terminal of the second voltage regulating switch.

2. The charging circuit as described in claim 1, characterized in that, The motor windings correspond one-to-one with the switch bridge arms. The first end of each motor winding is connected to the midpoint of the corresponding switch bridge arm. The second ends of each motor winding are connected to each other. At least one first end or second end of the motor winding is connected to the midpoint of the bridge arm of the charging half-bridge circuit.

3. The charging circuit as described in claim 1, characterized in that, The motor driver includes a filter capacitor, the two ends of which are respectively connected to the positive and negative terminals of the low-voltage power battery.

4. The charging circuit as described in claim 1, characterized in that, The charging circuit is configured such that, in discharge mode, the mode switching switch is turned on, and the motor driver drives the motor to work based on the electrical energy provided by the low-voltage power battery. In charging mode, the mode switching switch is off, the upper arm of the first switch bridge arm and the upper arm of the third switch bridge arm are on, the other bridge arm switches of the motor driver are all off, and the first voltage regulating switch and the second voltage regulating switch are periodically turned on and off with a set switching frequency and a set conduction duration.

5. A charging circuit for a low-voltage electric motorcycle using a high-voltage DC charging station, wherein the low-voltage electric motorcycle includes a low-voltage power battery, a motor driver, and a motor, characterized in that... The charging circuit includes: a charging half-bridge circuit, a switching bridge arm of the motor driver, and motor windings of the motor. Both ends of each of the switch bridge arms are used to connect to the low-voltage power battery. The midpoint of at least one of the switch bridge arms is connected to the midpoint of the charging half-bridge circuit through at least one of the motor windings. Both ends of the charging half-bridge circuit are used to connect to the positive and negative terminals of the high-voltage DC charging pile. The motor driver includes a first switch bridge arm, a second switch bridge arm, and a third switch bridge arm, and the motor includes a first motor winding, a second motor winding, and a third motor winding; Both ends of the first switch bridge arm are connected to the low-voltage power battery, and the midpoint of the first switch bridge arm is connected to the first end of the first motor winding. Both ends of the second switch bridge arm are connected to the low-voltage power battery, and the midpoint of the second switch bridge arm is connected to the first end of the second motor winding. Both ends of the third switch bridge arm are connected to the low-voltage power battery, and the midpoint of the third switch bridge arm is connected to the first end of the third motor winding. The second end of the first motor winding, the second end of the second motor winding, and the second end of the third motor winding are all connected to the center of the motor and to the midpoint of the bridge arm of the charging half-bridge circuit. The charging half-bridge circuit includes a first voltage regulating switch, a second voltage regulating switch, and a charging input capacitor. The first terminal of the first voltage regulating switch is connected to the positive terminal of the high-voltage DC charging pile, the second terminal of the first voltage regulating switch is connected to the center point of the motor, the first terminal of the second voltage regulating switch is connected to the center point of the motor, and the second terminal of the second voltage regulating switch is connected to the negative terminal of the high-voltage DC charging pile. The two ends of the charging input capacitor are connected to the first terminal of the first voltage regulating switch and the second terminal of the second voltage regulating switch.

6. The charging circuit as described in claim 5, characterized in that, The charging circuit is configured such that, in discharge mode, the first voltage regulator switch and the second voltage regulator switch are turned off, and the motor driver drives the motor to work based on the electrical energy provided by the low-voltage power battery. In charging mode, the upper arms of the first switch bridge arm, the second switch bridge arm, and the third switch bridge arm are turned on, while the other bridge arm switches of the motor driver are turned off. The first voltage regulator switch and the second voltage regulator switch periodically turn on and off according to a set switching frequency and a set conduction duration.

7. A charging method, characterized in that, Applied to the charging circuit as described in any one of claims 1 to 6; The charging method includes: Turn on the upper arm of the switching bridge arm of at least one motor driver to connect at least one motor winding in series between the charging half-bridge circuit and the low-voltage power battery. The charging half-bridge circuit, controlled by pulse width modulation, works with the motor windings of the motor and the charging input capacitor of the charging half-bridge circuit to step down the input high voltage provided by the high voltage DC charging pile, so as to output charging voltage to the low voltage power battery.

8. A low-voltage electric motorcycle, characterized in that, include: The low-voltage power battery, the motor driver, and the charging circuit as described in any one of claims 1 to 6.

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