A charging system and an electric vehicle

Abstract

The application provides a charging system and an electric vehicle, the charging system comprising a motor controller MCU and a first inductor, a first bridge arm in the MCU and the first inductor constituting a voltage conversion circuit, the MCU can perform step-up conversion on a power supply voltage through the voltage conversion circuit when the power supply voltage is less than a minimum charging voltage of a power battery, and output the step-up converted power supply voltage as a first output voltage to the power battery, the first output voltage being not less than the minimum charging voltage. The application can reduce the space and cost occupied by the charging system while performing step-down conversion on the power supply voltage.

Description

A charging system and an electric vehicle

[0001] This application is a divisional application. The original application has the application number 202110083917.2 and the original application date is January 21, 2021. The entire contents of the original application are incorporated herein by reference. Technical Field

[0002] This application relates to the field of new energy vehicle technology, and in particular to a charging system and an electric vehicle. Background Technology

[0003] With the development of new energy technologies, electric vehicles have received increasing attention. Electric vehicles are equipped with power batteries that can receive and store electrical energy provided by charging stations. During operation, the power battery releases the stored energy to power the electric vehicle.

[0004] To improve the charging speed of electric vehicles, an increasing number of electric vehicles are using 800V high-voltage power batteries. The maximum voltage of a power battery is 800V, but the required charging voltage may exceed 800V. However, most DC fast charging stations on the market currently have an output voltage of 500V. These charging stations cannot directly charge 800V high-voltage power batteries, causing charging difficulties for electric vehicles equipped with high-voltage power batteries and hindering user experience.

[0005] Therefore, charging solutions for electric vehicles still require further research. Summary of the Invention

[0006] In view of this, this application provides a charging system and an electric vehicle that, when the power supply voltage is less than the minimum charging voltage of the power battery, enables the electric vehicle to still support the power supply voltage for charging the power battery.

[0007] Firstly, this application provides a charging system, including a motor controller (MCU) and a first inductor. The MCU includes N bridge arms, where N is an integer greater than or equal to 1. The high-potential terminals of the N bridge arms are connected to a first power supply terminal and a first battery terminal of the charging system. The first power supply terminal can be connected to the positive terminal of a DC power supply, and the first battery terminal can be connected to the positive terminal of a power battery. The DC power supply can output a power supply voltage, and the power battery can receive a first output voltage from the charging system. The low-potential terminals of the N bridge arms are connected to a second battery terminal of the charging system, which can be connected to the negative terminal of the power battery. One end of the first inductor is connected to the second power supply terminal, and the other end of the first inductor is connected to the midpoint of the first bridge arm. The second power supply terminal can be connected to the negative terminal of the DC power supply. The first bridge arm can be any one of the N bridge arms. The N bridge arms of the MCU and the first inductor constitute a voltage conversion circuit. When the power supply voltage is less than the minimum charging voltage of the power battery, the MCU can boost the power supply voltage through the voltage conversion circuit and output the boosted power supply voltage as the first output voltage to the power battery. The first output voltage is not less than the minimum charging voltage.

[0008] In summary, this application implements a charging system by reusing an MCU. When the power supply voltage is lower than the minimum charging voltage of the power battery, the charging system can boost the power supply voltage to obtain a first output voltage that is not lower than the aforementioned minimum charging voltage. This first output voltage can be adapted to the power battery, thereby charging the power battery. Furthermore, this application reuses an MCU commonly found in electric vehicles, which also helps to reduce the space and cost occupied by the charging system.

[0009] For example, the first aspect of this application provides the following example for illustration:

[0010] Example 1

[0011] The aforementioned first bridge arm includes a first switch and a second switch. The first electrode of the first switch is connected to both the first battery terminal and the first power supply terminal, and the second electrode of the first switch is connected to the first electrode of the second switch. The midpoint of the first bridge arm is located between the first and second switches. When the power supply voltage is lower than the minimum charging voltage, the MCU can turn on the first switch to charge the first inductor. The MCU can also turn off the first switch to discharge the first inductor.

[0012] Specifically, when the MCU turns on the first switching transistor, current flows from the positive terminal of the DC power supply, through the first switching transistor, and to the first inductor, charging it. When the MCU turns off the first switching transistor, the first inductor begins to discharge. Current flows from the end of the first inductor closest to the second power supply terminal, through the DC power supply, the power battery, and the diode in the second switching transistor, before flowing back to the end of the first inductor closest to the second switching transistor. During this process, the DC power supply and the first inductor discharge in series, and the first output voltage is the sum of the power supply voltage and the voltage of the first inductor. Obviously, the first output voltage is greater than the power supply voltage, thus enabling boost conversion.

[0013] It is understood that the power supply voltage provided by the DC power source may also be within the charging voltage range of the power battery, i.e., the power supply voltage is compatible with the power battery. To accommodate this scenario, the charging system in this application may further include a first switch, with a first terminal connected to the second battery terminal and a second terminal connected to the second power supply terminal. The MCU may also turn on the first switch when the power supply voltage is within the charging voltage range of the power battery, and turn off the first switch when the power supply voltage is outside the charging voltage range of the power battery.

[0014] Specifically, when the first switch is on, the power battery can be directly connected to the DC power supply, thus directly receiving the power voltage provided by the DC power supply to complete charging. Therefore, the first switch can be turned on when the power voltage is within the charging voltage range of the power battery. When the first switch is off, the MCU can convert the power voltage and provide the converted power voltage as the first output voltage to the power battery. Therefore, the first switch can be turned off when the power voltage is outside the charging voltage range of the power battery.

[0015] To adapt to high-power scenarios, the charging system may include N first inductors and N third switches. One end of each of the N third switches is connected to a second power supply terminal, and the other end of each of the N third switches is connected to one end of each of the N first inductors. The other end of each of the N first inductors is connected to one of each of the N bridge arms. The N third switches can be turned on when receiving power supply voltage and turned off when receiving power supply voltage stops.

[0016] Specifically, when N third switches are on, the charging and discharging of N first inductors can be controlled separately through N bridge arms. In other words, the N first inductors can transmit power in parallel, thus adapting to high-power scenarios. Turning off the N third switches when the power supply voltage is stopped ensures that the N first inductors are mutually disconnected, which helps reduce the impact of the N first inductors on the MCU's inverter function.

[0017] Example 2

[0018] It is foreseeable that in some scenarios, the power supply voltage may exceed the maximum charging voltage of the power battery. Therefore, in this application, the MCU can also perform a voltage conversion circuit to step down the power supply voltage when it exceeds the maximum charging voltage of the power battery, and output the stepped-down voltage as the first output voltage to the power battery. This first output voltage is not greater than the maximum charging voltage. In this case, the electric vehicle can receive a larger power supply voltage, which, after conversion, can then be used to charge the power battery, thus improving charging convenience.

[0019] For example, the first bridge arm includes a first switch and a second switch, wherein the first electrode of the first switch is connected to the first battery terminal and the first power supply terminal respectively, the second electrode of the first switch is connected to the first electrode of the second switch, and the midpoint of the first bridge arm is located between the first switch and the second switch. The charging system may further include a first switch and a second switch, wherein the first end of the first switch is connected to the second battery terminal, the second end of the first switch is connected to the second power supply terminal, the first end of the second switch is connected to the first battery terminal, the second end of the second switch is connected to one end of a first inductor, and the third end of the second switch is connected to the first power supply terminal.

[0020] Based on this charging system, when the power supply voltage is greater than the maximum charging voltage, the MCU can turn on the first switch and the first and second terminals of the second switch. The MCU turns on the first switch to charge the first inductor. The MCU turns off the first switch to discharge the first inductor.

[0021] Specifically, when the MCU turns on the first switching transistor, it can charge the first inductor. At this time, the first output voltage is the voltage difference between the power supply voltage and the voltage of the first inductor. When the MCU turns off the first switching transistor, it can discharge the first inductor. At this time, the first output voltage is the voltage of the first inductor. Therefore, the first output voltage is always less than the power supply voltage, so the charging system can perform voltage step-down conversion on the power supply voltage.

[0022] It should be noted that the charging system provided in Example 2 can also perform voltage boost conversion on the power supply. For example, the charging system may further include a third switch, with its first terminal connected to one end of the first inductor and its second terminal connected to a second power supply terminal. When the power supply voltage is lower than the minimum charging voltage, the MCU can turn on the first and third terminals of the second switch, thus turning on the third switch and turning off the first switch. The MCU turns on the first switch transistor to charge the first inductor. The MCU turns off the first switch transistor to discharge the first inductor.

[0023] Specifically, when the MCU turns on the first switching transistor, it can charge the first inductor. When the MCU turns off the first switching transistor, it can discharge the first inductor. At this time, the first output voltage is the sum of the voltage of the first inductor and the power supply voltage. Therefore, the first output voltage is greater than the power supply voltage, so the charging system can perform boost conversion on the power supply voltage.

[0024] Furthermore, the charging system provided in Example 2 can also perform buck-boost conversion on the power supply voltage. Exemplarily, the charging system may further include a third switch, the first terminal of which is connected to one end of the first inductor, and the second terminal of which is connected to a second power supply terminal. The MCU can turn on the first and second terminals of the second switch, as well as the third switch. The MCU turns on the first switch transistor to charge the first inductor. It turns off the first switch transistor to discharge the first inductor.

[0025] Specifically, when the MCU turns on the first switching transistor, it can charge the first inductor. When the MCU turns off the first switching transistor, it can discharge the first inductor. At this time, the first output voltage is the voltage of the first inductor. The voltage of the first inductor depends on the charging time of the first inductor. Therefore, by adjusting the charging time of the first inductor, the magnitude of the first output voltage can be adjusted. This first output voltage may be greater than the power supply voltage (boost conversion) or less than the power supply voltage (buck conversion).

[0026] It is understood that the charging system provided in Example 2 of this application is also compatible with scenarios where the power supply voltage matches the power battery. For example, the MCU can also turn on the first and third terminals of the second switch, as well as the first switch, when the power supply voltage is within the charging voltage range of the power battery. In this case, the power battery is directly connected to the DC power supply and can directly receive the power supply voltage to complete charging.

[0027] Secondly, this application also provides a charging system, mainly including a motor controller (MCU) and a first inductor. The MCU includes N bridge arms, where N is an integer greater than or equal to 1. The high-potential terminals of the N bridge arms of the MCU are connected to a first power supply terminal and a first battery terminal of the charging system. The first power supply terminal can be connected to the positive terminal of a DC load, and the first battery terminal can be connected to the positive terminal of a power battery. The DC load can receive a second output voltage from the charging system, and the power battery can output a battery voltage to the charging system. The low-potential terminals of the N bridge arms of the MCU are connected to a second battery terminal of the charging system, which can be connected to the negative terminal of the power battery. One end of the first inductor is connected to the second power supply terminal, and the other end of the first inductor is connected to a first bridge arm. The second power supply terminal can be connected to the negative terminal of the DC load, and the first bridge arm can be any one of the N bridge arms. The first bridge arm and the first inductor constitute a voltage conversion circuit. When the battery voltage is greater than the maximum operating voltage of the DC load, the MCU can perform step-down conversion on the battery voltage through the voltage conversion circuit and output the step-down battery voltage as the second output voltage to the DC load. The second output voltage is not greater than the maximum operating voltage.

[0028] In summary, this application implements a charging system by reusing an MCU. When the battery voltage exceeds the maximum operating voltage of the DC load, the charging system can step down the battery voltage to obtain a second output voltage that is no greater than the aforementioned maximum operating voltage. This second output voltage can be adapted to the DC load, thereby supplying power to the DC load. Furthermore, this application reuses an MCU commonly found in electric vehicles, which also helps reduce the space and cost occupied by the charging system.

[0029] For example, the second aspect of this application provides the following example for illustration:

[0030] Example 1

[0031] For example, the first bridge arm includes a first switch and a second switch. The first electrode of the first switch is connected to the first battery terminal and the first power supply terminal, respectively. The second electrode of the first switch is connected to the first electrode of the second switch. The midpoint of the first bridge arm is located between the first switch and the second switch. When the battery voltage is greater than the maximum operating voltage, the MCU can turn on the second switch to charge the first inductor. The MCU turns off the second switch to discharge the first inductor.

[0032] Specifically, when the MCU turns on the second switch, it can charge the first inductor. At this time, the first output voltage is the voltage difference between the power supply voltage and the voltage of the first inductor. When the MCU turns off the second switch, it can discharge the first inductor. At this time, the first output voltage is the voltage of the first inductor. Therefore, the first output voltage is always less than the battery voltage. Thus, the charging system provided in Example 1 of this application can achieve step-down conversion of the battery voltage.

[0033] It is understandable that the battery voltage of the power battery may also be compatible with a DC load. To accommodate this scenario, the charging system may also include a first switch, with a first terminal connected to a second battery terminal and a second terminal connected to a second power supply terminal. The MCU may also turn on the first switch when the battery voltage is within the operating voltage range of the DC load, and turn off the first switch when the battery voltage is outside the operating voltage range of the DC load.

[0034] When the first switch is on, the power battery can be directly connected to the DC load to directly supply power to the DC load. When the first switch is off, the MCU can convert the battery voltage and use the converted battery voltage as the second output voltage to supply the DC load.

[0035] To adapt to high-power scenarios, the charging system may include N first inductors and N third switches. One end of each of the N third switches is connected to the second power supply terminal, and the other end of each of the N third switches is connected to one end of each of the N first inductors. The other ends of the N first inductors are connected to each of the N bridge arms. The N third switches can be turned on when the second output voltage is output and turned off when the second output voltage is stopped.

[0036] Specifically, when N third switches are on, the charging and discharging of N first inductors can be controlled separately through N bridge arms. In other words, the N first inductors can transmit power in parallel, thus adapting to high-power scenarios. Turning off the N third switches when the power supply voltage is stopped ensures that the N first inductors are mutually disconnected, which helps reduce the impact of the N first inductors on the MCU's inverter function.

[0037] Example 2

[0038] It is foreseeable that in some scenarios, the battery voltage may be lower than the minimum operating voltage of the DC load. In view of this, the MCU in this application can also perform voltage conversion on the battery voltage through a voltage conversion circuit when the battery voltage is lower than the minimum operating voltage of the DC load, and output the boosted battery voltage as a second output voltage to the DC load. This second output voltage is not lower than the minimum operating voltage.

[0039] For example, the first bridge arm in the MCU includes a first switch and a second switch, wherein the first electrode of the first switch is connected to a first battery terminal and a first power supply terminal, respectively, the second electrode of the first switch is connected to the first electrode of the second switch, and the midpoint of the first bridge arm is located between the first switch and the second switch. The charging system may also include a first switch and a second switch, wherein the first end of the first switch is connected to the second battery terminal, the second end of the first switch is connected to the second power supply terminal, the first end of the second switch is connected to the first battery terminal, the second end of the second switch is connected to one end of a first inductor, and the third end of the second switch is connected to the first power supply terminal.

[0040] Based on this charging system, when the battery voltage is lower than the minimum operating voltage, the MCU can turn on the first switch and the first and second terminals of the second switch. The MCU turns on the second switch to charge the first inductor. The MCU turns off the second switch to discharge the first inductor.

[0041] Specifically, when the MCU turns on the second switch, it can charge the first inductor. When the MCU turns off the second switch, it can discharge the first inductor. At this time, the second output voltage is the sum of the battery voltage and the voltage of the first inductor. Therefore, the second output voltage is greater than the battery voltage, and thus the charging system can perform a boost conversion on the battery voltage.

[0042] It should be noted that the charging system provided in Example 2 can also perform step-down conversion of the battery voltage. For example, the charging system may further include a third switch, the first terminal of which is connected to one end of the first inductor, and the second terminal of the third switch is connected to a second power supply terminal. When the battery voltage is greater than the maximum operating voltage, the MCU can turn on the first and third terminals of the second switch, thus turning on the third switch and turning off the first switch. The MCU turns on the second switch to charge the first inductor. The MCU turns off the second switch to discharge the first inductor.

[0043] Specifically, when the MCU turns on the second switch, it can charge the first inductor, and the second output voltage is the voltage difference between the battery voltage and the voltage of the first inductor. When the MCU turns off the second switch, it can discharge the first inductor, and the second output voltage is the voltage of the first inductor. Therefore, the second output voltage is always less than the battery voltage, thus the charging system can perform a step-down conversion of the battery voltage.

[0044] Furthermore, the charging system provided in Example 2 can also perform buck-boost conversion on the battery voltage. Exemplarily, the charging system may further include a third switch, the first terminal of which is connected to one end of the first inductor, and the second terminal of which is connected to a second power supply terminal. The MCU can turn on the first and second terminals of the second switch, as well as the third switch. The MCU turns on the second switch to charge the first inductor. The MCU turns off the second switch to discharge the first inductor.

[0045] Specifically, when the MCU turns on the second switch, it can charge the first inductor. When the MCU turns off the second switch, it can discharge the first inductor. At this time, the second output voltage is the voltage of the first inductor. The voltage of the first inductor depends on the charging time of the first inductor. Therefore, by adjusting the charging time of the first inductor, the magnitude of the second output voltage can be adjusted. This second output voltage may be greater than the battery voltage (boost conversion) or less than the battery voltage (buck conversion).

[0046] It is understood that the charging system provided in Example 2 of this application is also compatible with scenarios where the battery voltage matches the DC load. For example, the MCU can also turn on the first and third terminals of the second switch, as well as the first switch, when the battery voltage is within the operating voltage range of the power battery. In this case, the power battery is directly connected to the DC load and can directly supply power to the DC load.

[0047] Thirdly, this application provides a charging system, mainly including a motor controller (MCU) and a first inductor. The MCU includes N bridge arms, where N is an integer greater than or equal to 1. The high-potential terminals of the N bridge arms are connected to a first battery terminal of the charging system. The first battery terminal can be connected to the positive terminal of a power battery, which can receive a first output voltage from the charging system. The low-potential terminals of the N bridge arms are connected to a second battery terminal and a second power supply terminal of the charging system. The second battery terminal can be connected to the negative terminal of the power battery, and the second power supply terminal can be connected to the negative terminal of a DC power supply, which can output a power supply voltage. One end of the first inductor is connected to the first power supply terminal, and the other end of the first inductor is connected to the midpoint of the first bridge arm. The first power supply terminal can be connected to the positive terminal of the DC power supply, and the first bridge arm can be any one of the N bridge arms. The first bridge arm and the first inductor constitute a voltage conversion circuit. When the power supply voltage is lower than the minimum charging voltage of the power battery, the MCU can use this voltage conversion circuit to boost the power supply voltage and output the boosted power supply voltage as the first output voltage to the power battery. This first output voltage is not lower than the minimum charging voltage. When the power supply voltage is higher than the maximum charging voltage of the power battery, the MCU can use this voltage conversion circuit to buck the power supply voltage and output the bucked power supply voltage as the first output voltage to the power battery. This first output voltage is not higher than the minimum charging voltage.

[0048] For example, the first bridge arm includes a first switch and a second switch, wherein the first electrode of the first switch is connected to the first battery terminal and the first power supply terminal, respectively, the second electrode of the first switch is connected to the first electrode of the second switch, and the midpoint of the first bridge arm is located between the first switch and the second switch. The charging system also includes a sixth switch and a fifth switch, wherein the first end of the fifth switch is connected to the second battery terminal, the second end of the fifth switch is connected to the low potential terminal of the N bridge arms, the third end of the fifth switch is connected to one end of the first inductor, the first end of the sixth switch is connected to the first battery terminal, and the second end of the sixth switch is connected to the first power supply terminal.

[0049] When the power supply voltage is greater than the maximum charging voltage, the MCU can turn on the sixth switch, and turn on the first and third terminals of the fifth switch. The MCU then turns on the second switch to charge the first inductor. The MCU turns off the second switch to discharge the first inductor.

[0050] Specifically, when the MCU turns on the second switch, it can charge the first inductor, and the first output voltage is the voltage difference between the power supply voltage and the voltage of the first inductor. When the MCU turns off the second switch, it can discharge the first inductor, and the first output voltage is the voltage of the first inductor. Therefore, the first output voltage is always less than the power supply voltage, thus the charging system can perform a step-down conversion of the power supply voltage.

[0051] It should be noted that the charging system provided in the third aspect of this application can also perform boost conversion of the power supply voltage. For example, the charging system may further include a fourth switch, with a first terminal connected to one end of the first inductor and a second terminal connected to the first power supply terminal. When the power supply voltage is less than the minimum charging voltage, the MCU can turn on the first and second terminals of the fifth switch, turn on the fourth switch, and turn off the sixth switch. The MCU turns on the second switch transistor to charge the first inductor. The MCU turns off the second switch transistor to discharge the first inductor.

[0052] Specifically, when the MCU turns on the second switch, it can charge the first inductor. When the MCU turns off the second switch, it can discharge the first inductor. At this time, the first output voltage is the sum of the voltage of the first inductor and the power supply voltage. Therefore, the first output voltage is greater than the power supply voltage, so the charging system can perform boost conversion on the power supply voltage.

[0053] Furthermore, the charging system provided in the third aspect of this application can also perform buck-boost conversion on the power supply voltage. Exemplarily, the charging system may further include a fourth switch, with a first terminal connected to one end of a first inductor and a second terminal connected to a first power supply terminal. The MCU can turn on the first and third terminals of a fifth switch, as well as the fourth switch. The MCU turns on a second switch to charge the first inductor. The MCU turns off the second switch to discharge the first inductor.

[0054] Specifically, when the MCU turns on the second switch, it can charge the first inductor. When the MCU turns off the second switch, it can discharge the first inductor. At this time, the first output voltage is the voltage of the first inductor. The voltage of the first inductor depends on the charging time of the first inductor. Therefore, by adjusting the charging time of the first inductor, the magnitude of the first output voltage can be adjusted. This first output voltage may be greater than the power supply voltage (boost conversion) or less than the power supply voltage (buck conversion).

[0055] It is understood that the charging system provided in the third aspect of this application is also compatible with scenarios where the power supply voltage matches the power battery. For example, the MCU can also turn on the first and second terminals of the fifth switch, and the sixth switch, when the power supply voltage is within the charging voltage range of the power battery. In this case, the power battery is directly connected to the DC power supply and can directly receive the power supply voltage to complete charging.

[0056] Fourthly, this application provides a charging system, mainly including a motor controller (MCU) and a first inductor. The MCU includes N bridge arms, where N is an integer greater than or equal to 1. The high-potential terminals of the N bridge arms are connected to a first battery terminal of the charging system. The first battery terminal can be connected to the positive terminal of a power battery, and the power battery can output battery voltage to the charging system. The low-potential terminals of the N bridge arms are connected to a second battery terminal and a second power supply terminal of the charging system. The second battery terminal can be connected to the negative terminal of the power battery, and the second power supply terminal can be connected to the negative terminal of a DC load, which can receive a second output voltage from the charging system. One end of the first inductor is connected to the first power supply terminal, and the other end of the first inductor is connected to the midpoint of the first bridge arm. The first power supply terminal can be connected to the positive terminal of the DC load. The first bridge arm can be any one of the N bridge arms. The first bridge arm and the first inductor can form a voltage conversion circuit. When the battery voltage is greater than the maximum operating voltage of the DC load, the MCU can use the voltage conversion circuit to step down the battery voltage and output the step-down battery voltage as the second output voltage to the DC load. The second output voltage is not greater than the maximum operating voltage. When the battery voltage is less than the minimum operating voltage of the DC load, the voltage conversion circuit can use the voltage conversion circuit to step up the battery voltage and output the step-up battery voltage as the second output voltage to the DC load. The second output voltage is not less than the minimum operating voltage.

[0057] For example, the first bridge arm of the MCU includes a first switch and a second switch, wherein the first electrode of the first switch is connected to the first battery terminal and the first power supply terminal, respectively, and the second electrode of the first switch is connected to the first electrode of the second switch, with the midpoint located between the first and second switches. The charging system also includes a sixth switch and a fifth switch, wherein the first terminal of the fifth switch is connected to the second battery terminal, the second terminal of the fifth switch is connected to the low potential terminal of the N bridge arms, the third terminal of the fifth switch is connected to one end of the first inductor, the first terminal of the sixth switch is connected to the first battery terminal, and the second terminal of the sixth switch is connected to the first power supply terminal.

[0058] Based on this charging system, when the battery voltage is lower than the minimum operating voltage, the MCU can turn on the sixth switch, and turn on the first and third terminals of the fifth switch. The MCU then turns on the first switch to charge the first inductor. The MCU turns off the first switch to discharge the first inductor.

[0059] Specifically, when the MCU turns on the first switching transistor, it can charge the first inductor. When the MCU turns off the first switching transistor, it can discharge the first inductor. At this time, the second output voltage is the sum of the battery voltage and the voltage of the first inductor. Therefore, the second output voltage is greater than the battery voltage, so the charging system can perform boost conversion on the battery voltage.

[0060] It should be noted that the charging system provided in the fourth aspect of this application can also perform step-down conversion of the battery voltage. For example, the charging system may further include a fourth switch, the first terminal of which is connected to one end of a first inductor, and the second terminal of which is connected to a first power supply terminal. When the battery voltage is greater than the maximum operating voltage, the MCU can turn on the first and second terminals of a fifth switch, turn on the fourth switch, and turn off the sixth switch. The MCU turns on a second switch transistor to charge the first inductor. The MCU turns off the second switch transistor to discharge the first inductor.

[0061] Specifically, when the MCU turns on the first switch, it can charge the first inductor, and the second output voltage is the voltage difference between the battery voltage and the voltage of the first inductor. When the MCU turns off the first switch, it can discharge the first inductor, and the second output voltage is the voltage of the first inductor. Therefore, the second output voltage is always less than the battery voltage, thus the charging system can perform a step-down conversion of the battery voltage.

[0062] Furthermore, the charging system provided in the fourth aspect of this application can also perform buck-boost conversion on the battery voltage. Exemplarily, the charging system may further include a fourth switch, the first terminal of which is connected to one end of a first inductor, and the second terminal of which is connected to a first power supply terminal. The MCU can turn on the first and third terminals of a fifth switch, as well as the fourth switch. The MCU turns on the first switch transistor to charge the first inductor. The MCU turns off the first switch transistor to discharge the first inductor.

[0063] Specifically, when the MCU turns on the first switching transistor, it can charge the first inductor. When the MCU turns off the first switching transistor, it can discharge the first inductor. At this time, the second output voltage is the voltage of the first inductor. The voltage of the first inductor depends on the charging time of the first inductor. Therefore, by adjusting the charging time of the first inductor, the magnitude of the second output voltage can be adjusted. This second output voltage may be greater than the battery voltage (boost conversion) or less than the battery voltage (buck conversion).

[0064] It is understood that the charging system provided in the fourth aspect of this application is also compatible with scenarios where the battery voltage matches the DC load. For example, the MCU can also turn on the first and second terminals of the fifth switch, and the sixth switch, when the battery voltage is within the operating voltage range of the DC load. In this case, the power battery is directly connected to the DC load and can directly supply power to the DC load.

[0065] Fifthly, this application provides an electric vehicle, which mainly includes a power battery and a charging system as provided in any one of the first to fourth aspects above, the charging system being able to charge the power battery.

[0066] These or other aspects of this application will become more apparent from the description of the following embodiments. Attached Figure Description

[0067] Figure 1 is a schematic diagram of an electric vehicle charging scenario;

[0068] Figure 2 is a schematic diagram of an electric drive system;

[0069] Figure 3 is a schematic diagram of a charging system provided in an embodiment of this application;

[0070] Figure 4 shows one of the boost conversion states of the charging system provided in the embodiments of this application;

[0071] Figure 5 shows the second boost conversion state of the charging system provided in the embodiment of this application;

[0072] Figure 6 is a schematic diagram of a specific charging system provided in an embodiment of this application;

[0073] Figure 7 is a schematic diagram of a specific charging system provided in an embodiment of this application;

[0074] Figure 8 shows one of the buck conversion states of the charging system provided in the embodiments of this application;

[0075] Figure 9 shows the second step-down conversion state of the charging system provided in the embodiment of this application;

[0076] Figure 10 is a schematic diagram of a specific charging system provided in an embodiment of this application;

[0077] Figure 11 shows one of the switching states of the charging system provided in the embodiment of this application;

[0078] Figure 12 shows the third step-down conversion state of the charging system provided in the embodiment of this application;

[0079] Figure 13 shows the fourth step-down conversion state of the charging system provided in the embodiment of this application;

[0080] Figure 14 shows a second switching state of the charging system provided in an embodiment of this application;

[0081] Figure 15 shows a third switching state of the charging system provided in the embodiment of this application;

[0082] Figure 16 shows one of the buck-boost transition states of the charging system provided in the embodiments of this application;

[0083] Figure 17 shows the second buck-boost transition state of the charging system provided in the embodiment of this application;

[0084] Figure 18 shows the third boost conversion state of the charging system provided in the embodiment of this application;

[0085] Figure 19 shows the fourth boost conversion state of the charging system provided in the embodiment of this application;

[0086] Figure 20 shows the third buck-boost transition state of the charging system provided in the embodiment of this application;

[0087] Figure 21 shows the fourth buck-boost transition state of the charging system provided in the embodiment of this application;

[0088] Figure 22 is a schematic diagram of another charging system provided in an embodiment of this application;

[0089] Figure 23 shows a fourth switching state of the charging system provided in an embodiment of this application;

[0090] Figure 24 shows the fifth step-down conversion state of the charging system provided in the embodiment of this application;

[0091] Figure 25 shows the sixth step-down conversion state of the charging system provided in the embodiment of this application;

[0092] Figure 26 shows a fifth switching state of the charging system provided in an embodiment of this application;

[0093] Figure 27 shows a sixth switching state of the charging system provided in an embodiment of this application;

[0094] Figure 28 shows the fifth buck-boost transition state of the charging system provided in the embodiment of this application;

[0095] Figure 29 shows the sixth buck-boost transition state of the charging system provided in the embodiment of this application;

[0096] Figure 30 shows the fifth boost conversion state of the charging system provided in the embodiment of this application;

[0097] Figure 31 shows the sixth boost conversion state of the charging system provided in the embodiment of this application;

[0098] Figure 32 shows the seventh buck-boost transition state of the charging system provided in the embodiment of this application;

[0099] Figure 33 shows the eighth buck-boost transition state of the charging system provided in the embodiments of this application. Detailed Implementation

[0100] To make the objectives, technical solutions, and advantages of this application clearer, the application will be further described in detail below with reference to the accompanying drawings. The specific operational methods in the method embodiments can also be applied to the device embodiments or system embodiments. It should be noted that in the description of this application, "at least one" refers to one or more, where "multiple" refers to two or more. Therefore, in the embodiments of this invention, "multiple" can also be understood as "at least two". "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / ", unless otherwise specified, generally indicates that the preceding and following related objects have an "or" relationship. Furthermore, it should be understood that in the description of this application, terms such as "first" and "second" are only used for distinguishing the descriptive purpose and should not be construed as indicating or implying relative importance or order.

[0101] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings.

[0102] Electric vehicles, also known as new energy vehicles, are automobiles powered by electricity. As shown in Figure 1, an electric vehicle 10 mainly includes a power battery 12, a motor 13, and wheels 14. The power battery 12 is a high-capacity, high-power storage battery. When the electric vehicle 10 is in motion, the power battery 12 supplies power to the motor 13 via a motor control unit (MCU) 111. The motor 13 converts the electrical energy provided by the power battery 12 into mechanical energy, thereby driving the wheels 14 to rotate and enabling the vehicle to move.

[0103] When charging electric vehicle 10, it can generally be charged through charging pile 20. As shown in Figure 1, charging pile 20 mainly includes power circuit 21 and charging gun 22. One end of power circuit 21 is connected to the power grid 30, and the other end is connected to charging gun 22 via a cable. Currently, most charging piles 20 are DC charging piles, and power circuit 21 can convert the AC power provided by power grid 30 into DC power. The operator can insert charging gun 22 into the charging port of electric vehicle 10, so that charging gun 22 is connected to the power battery 12 in electric vehicle 10, and power circuit 21 of charging pile 20 can then charge power battery 12 through charging gun 22.

[0104] The output voltage of the charging pile 20 can be understood as the power supply voltage received by the electric vehicle 10. In the DC fast charging scenario, the power supply voltage received by the electric vehicle 10 is within the charging voltage range of the power battery 12, and the power battery 12 can directly use the output voltage of the charging pile 20 to complete the charging.

[0105] The lower limit of the charging voltage range of the power battery 12 is the minimum charging voltage, which can be understood as the minimum charging voltage that the power battery 12 can adapt to. The upper limit of the charging voltage range of the power battery 12 is the maximum charging voltage, which can be understood as the maximum charging voltage that the power battery 12 can adapt to.

[0106] Currently, to improve the charging speed of electric vehicles 10, the voltage level of the power battery 12 will gradually increase from the current 500V to 800V. Taking an 800V power battery 12 as an example, the battery voltage of the power battery 12 can reach 800V, and the required charging voltage is often no less than 800V. However, for the charging piles 20 that support DC fast charging on the market, their voltage level is generally 500V, meaning that the maximum output voltage of most charging piles 20 that support DC fast charging is 500V. This makes it difficult for many electric vehicles 10 equipped with high-voltage power batteries to charge.

[0107] In view of this, this application provides a charging system 11 connected to a power battery 12. When charging the electric vehicle 10, the charging system 11 can receive a power supply voltage. When the power supply voltage is lower than the minimum charging voltage of the power battery 12, the charging system 11 can perform a boost conversion on the power supply voltage and provide the boosted power supply voltage as the first output voltage to the power battery 12.

[0108] In the example above, the output voltage of the charging pile 20 is 500V, meaning the power supply voltage received by the charging system 11 is 500V. Assuming that the power battery 12 can be adapted to a charging voltage of 960V, the charging system 11 can boost and convert the power supply voltage to 960V, thereby providing the power battery 12 with a first output voltage of 960V, allowing the power battery 12 to complete charging using this first output voltage.

[0109] It should be noted that, in order to save space occupied by the charging system 11 in the electric vehicle 10 and control the cost of the charging system 11, the charging system 11 in this embodiment can be implemented based on the MCU 111 in the electric vehicle 10. The MCU 111 and the motor 13 are generally integrated into the electric drive system. That is, the charging system 11 in this embodiment can be implemented by improving a conventional electric drive system.

[0110] Specifically, motor 13 relies on electromagnetic induction to convert electrical energy into mechanical energy; therefore, motor 13 contains motor windings. Currently, motor 13 typically has three or six motor windings. Taking a three-phase motor as an example, as shown in Figure 2, MCU111 includes three bridge arms, and motor 13 includes three motor windings (N1 to N3), with each of the three bridge arms in MCU111 corresponding to one of the three motor windings in motor 13. Wherein:

[0111] The first bridge arm includes switching transistors T1 and T2. The first electrode of switching transistor T1 is connected to the positive terminal of the power battery 12, and the second electrode of switching transistor T1 is connected to the first electrode of switching transistor T2. The second electrode of switching transistor T2 is connected to the negative terminal of the power battery 12. The midpoint of the first bridge arm is the connection point between switching transistors T1 and T2. The midpoint of the first bridge arm is connected to one end of the motor winding N1.

[0112] The second bridge arm includes switching transistors T3 and T4. The first electrode of switching transistor T3 is connected to the positive terminal of the power battery 12, and the second electrode of switching transistor T3 is connected to the first electrode of switching transistor T4. The second electrode of switching transistor T4 is connected to the negative terminal of the power battery 12. The midpoint of the second bridge arm is the connection point between switching transistors T3 and T4. The midpoint of the second bridge arm is connected to one end of the motor winding N2.

[0113] The third bridge arm includes switching transistors T5 and T6. The first electrode of switching transistor T6 is connected to the positive terminal of the power battery 12. The second electrode of switching transistor T3 is connected to the first electrode of switching transistor T4, and the second electrode of switching transistor T4 is connected to the negative terminal of the power battery 12. The midpoint of the third bridge arm is the connection point between switching transistors T5 and T6. The midpoint of the third bridge arm is connected to one end of the motor winding N3, and the other ends of the three motor windings are connected...

[0114] The MCU111 also includes a control board (not shown in the figure). This control board is connected to the control electrodes of switching transistors T1 through T6, controlling their on / off states respectively. This allows the three bridge arms to convert the battery voltage output from the power battery 12 into three-phase AC power, with each bridge arm corresponding to one phase of the three-phase AC power. The MCU111 outputs the three-phase AC power to the motor 13, causing the motor windings N1 through N3 to generate a spatial rotating magnetic field, thereby driving the motor rotor to rotate and converting electrical energy into mechanical energy.

[0115] It should be noted that the switching transistors in this application embodiment can be one or more of various types of switching transistors, such as relays, metal-oxide-semiconductor field-effect transistors (MOSFETs), bipolar junction transistors (BJTs), and insulated-gate bipolar transistors (IGBTs). These types will not be listed individually in this application embodiment. Each switching transistor can include a first electrode, a second electrode, and a control electrode, wherein the control electrode is used to control the switching transistor's on or off state. When the switching transistor is on, current can be transferred between the first and second electrodes; when the switching transistor is off, no current can be transferred between the first and second electrodes. Taking an IGBT as an example, in this application embodiment, the first electrode of the switching transistor can be the collector, the second electrode can be the emitter, and the control electrode can be the gate electrode.

[0116] Generally, as shown in Figure 2, switches K2 and K5 can also be provided between the power battery 12 and the MCU 111. For example, switches K2 and K5 can be relays. Switches K2 and K5 can be integrated into the battery pack with the power battery 12, or they can be set independently; this embodiment does not impose many restrictions on this.

[0117] One end of switch K2 is connected to the anode of power battery 12, and the other end of switch K2 is connected to the high-potential terminals of the three bridge arms. One end of switch K5 is connected to the cathode of power battery 12, and the other end of switch K5 is connected to the low-potential terminals of the three bridge arms. When switches K2 and K5 are on, power battery 12 can supply power to MCU 111. When switches K2 and K5 are off, power battery 12 stops supplying power to MCU 111.

[0118] As can be seen from the above description of MCU111 and motor 13, MCU111 includes N bridge arms, where N is an integer greater than or equal to 1. It can be understood that when electric vehicle 10 is charging, electric vehicle 10 typically does not need to move; that is, MCU111 does not need to provide three-phase power to motor 13 at this time. Therefore, this embodiment of the application can achieve charging of power battery 12 based on the N bridge arms in the MCU without affecting the driving function of electric vehicle 10.

[0119] The charging system 11 provided in the embodiments of this application will be further illustrated by the following examples.

[0120] Example 1

[0121] For example, the charging system 11 provided in this application embodiment includes an MCU 111 and a motor 13. The MCU 111 includes N bridge arms, and the motor 13 includes N motor windings. The N bridge arms and the N motor windings are connected one-to-one, and N is an integer greater than or equal to 1.

[0122] Taking N=3 as an example, as shown in Figure 3, the charging system 11 includes an MCU 111 and a motor 13. The first battery terminal of the charging system 11 is connected to the positive terminal of the power battery 12, the second battery terminal is connected to the negative terminal of the power battery 12, the first power supply terminal of the charging system 11 is connected to the positive terminal of the DC power supply, and the second power supply terminal of the charging system is connected to the negative terminal of the DC power supply.

[0123] The DC power source can be a charging pile, another electric vehicle, etc., and this application embodiment does not impose many limitations on this. The DC power source can output a power supply voltage. The charging system 11 receives the power supply voltage through a first power supply terminal and a second power supply terminal, converts the power supply voltage into a first output voltage adapted to the power battery 12, and outputs it to the power battery 12 through the first battery terminal and the second battery terminal. The power battery 12 can then receive the first output voltage provided by the charging system 11, thereby completing the charging process.

[0124] Specifically, as shown in Figure 3, the MCU111 includes three bridge arms. In this embodiment, the high-potential terminals of the three bridge arms in the MCU111 are connected to the first power supply terminal, and the low-potential terminals of the three bridge arms are connected to the second battery terminal of the charging system 11. The charging system 11 also includes an inductor L1, one end of which is connected to the second power supply terminal, and the other end of an inductor L2 is connected to the midpoint of any bridge arm in the MCU11. In the specific example shown in Figure 3, the other end of the inductor L2 is connected to the midpoint of bridge arm 2 where the switching transistors T3 and T4 are located.

[0125] In this case, the three bridge arms of MCU111 and inductor L1 can form a voltage conversion circuit, so that MCU111 can control the conduction and cutoff of each of the switching transistors T1 to T6, thereby enabling the voltage conversion circuit to convert the power supply voltage.

[0126] Therefore, when the power supply voltage is less than the minimum charging voltage of the power battery 12, the MCU111 can use the voltage conversion circuit to boost the power supply voltage and output the boosted power supply voltage as the first output voltage to the power battery. The first output voltage is not less than the minimum charging voltage of the power battery 12.

[0127] For example, if the power supply voltage is 500V, the minimum charging voltage of the power battery 12 is 960V. The MCU111 can boost and convert the power supply voltage to 960V or higher, thereby providing a suitable first output voltage for the power battery 12, enabling the power battery 12 to complete charging.

[0128] Generally, as shown in Figure 3, the charging system 11 also includes switches K3 and K4. Switches K3 and K4 can also be referred to as fast contactors. One end of switch K3 is connected to the connection point of the motor windings N1 to N3, and the other end of switch K3 is connected to the second power supply terminal. One end of switch K4 is connected to the high-potential terminals of the three bridge arms, and the other end of switch K4 is connected to the first power supply terminal. When switches K3 and K4 are turned on, the DC power supply can provide power to the charging system 11. When switches K3 and K4 are turned off, the DC power supply can stop providing power to the charging system 11.

[0129] Next, taking bridge arm 2, which includes switching transistors T3 and T4, as an example, the boost conversion process will be further illustrated. The midpoint of bridge arm 2 is the connection point between switching transistors T3 and T4. One end of inductor L1 is connected to the second power supply terminal, and the other end of inductor L1 is connected to the midpoint of bridge arm 2. The boost conversion of the power supply voltage mainly includes the following two stages:

[0130] Phase 1: Inductor L1 charging

[0131] MCU111 can turn on switch T3 to charge inductor L1. Understandably, switch T4 is turned off at this time. As shown in Figure 4, current flows from the positive terminal of the DC power supply, through switch T3 and inductor L1, and then back to the negative terminal of the DC power supply, thus forming a charging circuit to charge inductor L1.

[0132] Phase 2: Inductor L1 discharges

[0133] MCU111 can turn off switch T3, preventing inductor L1 from receiving current through switch T3. Due to the freewheeling characteristic of the inductor, inductor L1 begins to discharge. As shown in Figure 5, the current is output from the end of inductor L1 closest to the second power supply terminal, and after being transmitted through the DC power supply, the power battery 12, and the diode in switch T4, it flows back to the end of inductor L1 closest to switch T4. During this process, the first output voltage of charging system 11 is the sum of the DC power supply voltage and the voltage of inductor L1. Obviously, the first output voltage is greater than the DC power supply voltage, thus achieving boost conversion.

[0134] It is understandable that when the DC power supply has a high power rating, the MCU111 can also simultaneously control multiple bridge arms for boost conversion. For example, as shown in Figure 6, the MCU111 includes three inductors (inductors L1-1 to L1-3) and three switches K3 (switches K3-1 to K3-3). One end of each switch K3-1 to K3-3 is connected to the second power supply terminal, and the other end of each switch K3-1 to K3-3 is connected to one end of each of the three inductors (inductors L1-1 to L1-3). Specifically, switch K3-1 is connected to one end of inductor L1-1, switch K3-2 is connected to one end of inductor L1-2, and switch K3-3 is connected to one end of inductor L1-3.

[0135] The three inductors are connected one-to-one with the midpoints of the three bridge arms in the MCU111. Specifically, one end of inductor L1-1 is connected to the second power supply terminal of the charging system 11, and the other end of inductor L1-1 is connected to the midpoint between switching transistors T1 and T2. One end of inductor L1-2 is connected to the second power supply terminal of the charging system 11, and the other end of inductor L1-2 is connected to the midpoint between switching transistors T3 and T4. One end of inductor L1-3 is connected to the second power supply terminal of the charging system 11, and the other end of inductor L1-3 is connected to the midpoint between switching transistors T5 and T6.

[0136] When charging the power battery 12, the MCU111 can turn on switches K3-1 to K3-3. The MCU111 can synchronously control the on and off of switches T1, T3, and T5, causing inductors L1-1 to L1-3 to charge and discharge synchronously. In this case, it is equivalent to the three inductors working in parallel, thus supporting voltage conversion in high-power scenarios. After stopping charging the power battery 12, the MCU111 can turn off switches K3-1 to K3-3. In this case, inductors L1-1 to L1-3 are open-circuited, reducing the impact of inductors L1-1 to L1-3 on the MCU111's inverter process.

[0137] In summary, the charging system 11 in this embodiment can boost the voltage of a DC power supply, thereby charging the high-voltage power battery 12 and improving the convenience of charging the high-voltage power battery 12. Furthermore, by reusing N bridge arms in the MCU 111, this embodiment also helps to reduce the space and cost occupied by the charging system 11.

[0138] It is understandable that the power supply voltage provided by the DC power supply may also be compatible with the power battery 12. For example, the charging voltage range of the power battery 12 is 700-1000V, and the power supply voltage of the DC power supply (charging pile) is 800V. In this case, there is no need to perform voltage boosting conversion.

[0139] To accommodate this scenario, as shown in Figure 7, the charging system 11 provided in this embodiment may further include a switch K1. The first terminal of switch K1 is connected to the second battery terminal, and the second terminal of switch K1 is connected to the second power supply terminal. The MCU 111 can control the on / off state of switch K1. Specifically, the MCU 111 can turn on switch K1 when the power supply voltage is within the charging voltage range of the power battery 12, and turn off switch K1 when the power supply voltage is outside the charging voltage range of the power battery 12.

[0140] The scenario where the power supply voltage is within the charging voltage range of the power battery 12 can be either the power supply voltage equal to the minimum charging voltage of the power battery 12, the power supply voltage equal to the maximum charging voltage of the power battery 12, or the power supply voltage greater than the minimum charging voltage of the power battery 12 but less than the maximum charging voltage of the power battery 12. The scenario where the power supply voltage is outside the charging voltage range of the power battery 12 can be either the power supply voltage less than the minimum charging voltage of the power battery 12 or the power supply voltage greater than the maximum charging voltage of the power battery 12.

[0141] As shown in Figure 7, switch K5 is turned on by default when the power battery 12 is charging. When switch K1 is turned on, the power battery 12 can be directly connected to the DC power supply, and therefore can directly receive the power voltage provided by the DC power supply to complete the charging process. Therefore, MCU111 can turn on switch K1 when the power supply voltage is within the charging voltage range of the power battery 12.

[0142] When switch K1 is turned off, the charging system 11 shown in Figure 7 is equivalent to the charging system 11 shown in Figure 3. MCU 111 can perform boost conversion on the power supply voltage, which will not be described in detail here.

[0143] In one possible implementation, as shown in Figure 3, the charging system 11 may further include a filter capacitor C1, one end of which is connected to the first battery terminal, and the other end of which is connected to the second battery terminal. When charging the power battery 12, the filter capacitor C1 can filter the first output voltage.

[0144] Similarly, as shown in Figure 3, the charging system 11 may also include a filter capacitor C2, one end of which is connected to the first power supply terminal, and the other end of which is connected to the second power supply terminal. When charging the power battery 12, the filter capacitor C2 can filter the received power supply voltage.

[0145] Example 2

[0146] With the development of electric vehicle charging and discharging technology, more and more electric vehicles 10 can also support the discharging function, that is, the electric vehicle 10 supplies power to a DC load. In some scenarios, the DC load can be another electric vehicle. For example, as shown in Figure 3, the first power supply terminal of the charging system 11 can also be connected to the positive terminal of the DC load, and the second power supply terminal of the charging system 11 can also be connected to the negative terminal of the DC load.

[0147] The power battery 12 can output battery voltage to the charging system 11. When the battery voltage of the power battery 12 is greater than the maximum operating voltage of the DC load, the charging system 11 can perform a step-down conversion on the battery voltage to obtain a second output voltage adapted to the DC load, and output the second output voltage to the DC load through the first power terminal and the second power terminal. Wherein, when the DC load is another electric vehicle, the operating voltage range of the DC load can be understood as the charging voltage range of the power battery in that other electric vehicle.

[0148] The lower limit of the operating voltage range of a DC load is the minimum operating voltage, which can be understood as the minimum operating voltage that the DC load can adapt to. The upper limit of the operating voltage range of a DC load is the maximum operating voltage, which can be understood as the maximum operating voltage that the DC load can adapt to.

[0149] For example, if the battery voltage of the power battery 12 is 800V and the operating voltage range of the DC load is 400-600V, then the MCU 111 can perform a step-down conversion on the battery voltage to obtain a second output voltage within the operating voltage range. The charging system 11 outputs the second output voltage to the DC load, thereby providing a suitable operating voltage for the DC load.

[0150] Next, taking bridge arm 2, which includes switching transistors T3 and T4 in Figure 3, as an example, we will further illustrate the boost conversion process. It is understood that switches K2 to K5 are conducting at this time, which will not be elaborated further. The buck conversion of the battery voltage mainly includes the following two stages:

[0151] Phase 1: Inductor L1 charging

[0152] MCU111 turns on switch T4, while switch T3 remains off. As shown in Figure 8, current flows from the positive terminal of power battery 12, through the DC load, inductor L1, and switch T4, before returning to the negative terminal of power battery 12. During this phase, inductor L1 is charged. The second output voltage of charging system 11 is the difference between the battery voltage and the voltage of inductor L1. Obviously, the second output voltage is less than the battery voltage, therefore charging system 11 can achieve step-down conversion of the battery voltage.

[0153] Phase 2: Inductor L1 discharges

[0154] MCU111 can turn off switch T4, thus shutting off the charging circuit of inductor L1. Due to the freewheeling characteristic of the inductor, inductor L1 begins to discharge. As shown in Figure 9, the current is output from the end of inductor L1 closest to switch T3, and after being transmitted through the diode in switch T3 and the DC load, it flows back to the end of inductor L1 closest to the second power supply terminal. During this process, the second output voltage of charging system 11 is the voltage of inductor L1. Obviously, the voltage of inductor L1 is less than the battery voltage, therefore charging system 11 can achieve step-down conversion of the battery voltage.

[0155] It is understandable that in the charging system 11 shown in Figure 6, the MCU 111 can also synchronously control multiple bridge arms for boost conversion. For example, the MCU 111 can synchronously control the on and off of switches T2, T4, and T6, so that inductors L1-1 to L1-3 are charged and discharged synchronously. In this case, it is equivalent to three inductors working in parallel, thereby supporting voltage conversion in high-power scenarios.

[0156] It should be noted that the charging system 11 shown in Figure 7 is also suitable for step-down conversion of battery voltage. When the battery voltage is within the operating voltage range of the DC load, the MCU 111 can turn on switch K1, allowing the power battery 12 to directly supply power to the DC load. When the battery voltage is outside the operating voltage range of the DC load, the MCU 111 can turn off switch K1, allowing the MCU 111 to perform voltage conversion on the battery voltage. Further details will not be elaborated upon.

[0157] The scenario where the battery voltage is within the operating voltage range of the DC load can be either the battery voltage equal to the minimum operating voltage of the DC load, the battery voltage equal to the maximum operating voltage of the DC load, or the battery voltage greater than the minimum operating voltage of the DC load but less than the maximum operating voltage of the DC load. The scenario where the battery voltage is outside the operating voltage range of the DC load can be either the battery voltage less than the minimum operating voltage of the DC load or the battery voltage greater than the maximum operating voltage of the DC load.

[0158] Example 3

[0159] As mentioned earlier, both low-voltage and high-voltage charging stations exist in the market. Electric vehicles can be equipped with either high-voltage or low-voltage power batteries. Therefore, charging low-voltage power batteries with high-voltage charging stations will be a common scenario.

[0160] In view of this, this application embodiment also provides a charging system 11. The connection relationship between the charging system 11, the DC power supply, and the power battery 12 is the same as in the above embodiments, and will not be repeated here. When the power supply voltage of the DC power supply is greater than the maximum charging voltage of the power battery 12, the charging system 11 can perform a step-down conversion of the power supply voltage. When the power supply voltage of the DC power supply is less than the minimum charging voltage of the power battery 12, the charging system 11 can perform a step-up conversion of the power supply voltage. Therefore, the charging system 11 can provide a first output voltage adapted to the power battery 12.

[0161] For example, as shown in FIG10, the charging system 11 in this embodiment may include an MCU 111 and an inductor L1. The connection relationship between the N bridge arms in the MCU 111 and the inductor L1 will not be described in detail. In addition, the charging system 11 may also include a switch K1 and a switch K2. The first end of the switch K1 is connected to the second battery terminal of the charging system 11, and the second end of the switch K1 is connected to the second power supply terminal. The switch K2 is a single-pole double-throw switch, wherein the first end of the switch K2 is connected to the first battery terminal, the second end a of the switch K2 is connected to one end of the inductor L1, and the third end b of the switch K2 is connected to the first power supply terminal.

[0162] It should be noted that switch K2 can be set independently of the power battery 12. In this case, the first terminal of switch K2 can be understood as the first battery terminal of charging system 11. It can also be understood that switch K2 can be integrated with the power battery 12 in the power battery pack. In this case, the charging system 11 provided in this application embodiment can be considered to include two first battery terminals, one of which is connected to the second terminal a of switch K2, and the other first battery terminal is connected to the third terminal b of switch K2.

[0163] Next, taking Figure 10 as an example, we will explain the buck conversion and boost conversion of the power supply voltage respectively.

[0164] I. Step-down conversion

[0165] During the buck conversion process, MCU111 can turn on switch K1, as well as the first and second terminals a of switch K2, as shown in Figure 11. It should be noted that in some scenarios, the charging system 11 can also include switches K3 to K5. In this case, switches K4 and K5 should be kept on, and switch K3 should be kept off. Based on the circuit state shown in Figure 11, taking bridge arm 2, which includes switches T3 and T4, as an example, the buck conversion process mainly includes:

[0166] Phase 1: Inductor L1 charging

[0167] MCU111 turns on switch T3 to charge inductor L1. As shown in Figure 12, current is output from the positive terminal of the DC power supply, transmitted through switch T3, inductor L1, switch K2, and power battery 12, and then flows back to the negative terminal of the DC power supply, thus forming a charging circuit to charge inductor L1. During this process, the first output voltage of charging system 11 is the difference between the power supply voltage and the voltage of inductor L1. Obviously, the first output voltage is less than the power supply voltage, therefore charging system 11 can achieve step-down conversion.

[0168] Phase 2: Inductor L1 discharges

[0169] MCU111 turns off switch T3 to discharge inductor L1. Specifically, after MCU111 turns off switch T3, the charging circuit is shut down. Due to the freewheeling characteristic of the inductor, inductor L1 discharges. As shown in Figure 13, the current is output from the end of inductor L1 closest to the second power supply terminal, and after being transmitted through switch K2, power battery 12, and diode in switch T4, it flows back to the end of inductor L1 closest to switch T4. During this process, the first output voltage of charging system 11 is the voltage of inductor L1. Obviously, the first output voltage is less than the power supply voltage, so charging system 11 can perform step-down conversion of the power supply voltage.

[0170] II. Boost Conversion

[0171] As shown in Figure 10, the charging system 11 may also include a switch K3. The first terminal of switch K3 is connected to the connection point of motor windings N1 to N3, and the second terminal of switch K3 is connected to the second power supply terminal. During the boost conversion process, MCU 111 can turn on the first and third terminals b of switch K2, turn on switch K3, and turn off switch K1. The circuit state can be as shown in Figure 14. As can be seen from Figure 14, the circuit state in this case is equivalent to the charging system 11 shown in Figure 3. Therefore, the boost conversion process provided in Embodiment 1 above can be referred to, and will not be described again.

[0172] In addition, the charging system 11 shown in Figure 10 can also support voltage conversion in buck-boost mode for the power supply voltage.

[0173] Specifically:

[0174] III. Buck-boost

[0175] During buck-boost conversion of the power supply voltage, MCU111 can turn on the first and second terminals a of switch K2, as well as switch K3, as shown in Figure 15. Based on the circuit state shown in Figure 15, buck-boost conversion mainly includes the following two stages:

[0176] Phase 1: Inductor L1 charging

[0177] MCU111 turns on switch T3 to charge inductor L1. As shown in Figure 16, current is output from the positive terminal of the DC power supply, transmitted through switch T3 and inductor L1, and then flows back to the negative terminal of the DC power supply, thus forming a charging circuit for inductor L1 to charge it.

[0178] Phase 2: Inductor L1 discharges

[0179] MCU111 turns off switch T3 to discharge inductor L1. As shown in Figure 17, current flows from the end of inductor L1 closest to the second power supply terminal, through switch K2, power battery 12, and the diode in switch T4, before returning to the end of inductor L1 closest to switch T4. Therefore, the first output voltage of charging system 11 is equal to the voltage of inductor L1. By controlling the charging time of inductor L1 in stage one, MCU111 can control the voltage of inductor L1, thereby controlling the magnitude of the first output voltage, which may be greater than or less than the power supply voltage.

[0180] Similar to Embodiment 1, when the DC power supply voltage is within the charging voltage range of the power battery 12, the MCU 111 can also turn on the first and third terminals b of switch K2, as well as switch K1, so that the power battery 12 can directly receive the power supply voltage and thus complete charging. For specific implementation details, please refer to Embodiment 1; further explanation is not provided here.

[0181] Example 4

[0182] It should be noted that the charging system 11 shown in Figure 10 can also support the discharge function of the electric vehicle 10. When the electric vehicle 10 is discharging, the connection relationship between the charging system 11, the power battery 12, and the DC load is similar to that in Embodiment 2, and will not be described again.

[0183] The difference from Embodiment 2 is that the charging system 11 provided in Figure 10 can not only perform step-down conversion of battery voltage, but also step-up conversion of battery voltage, so that the battery voltage output by both high-voltage and low-voltage power batteries can be adapted to DC loads with different operating voltage ranges.

[0184] Next, taking Figure 10 as an example, we will explain the boost and buck conversion of battery voltage respectively.

[0185] I. Boost Conversion

[0186] During the boost conversion process, MCU111 can turn on switch K1, as well as the first and second terminals a of switch K2, as shown in Figure 11. Based on the circuit state shown in Figure 11, taking bridge arm 2, which includes switching transistors T3 and T4, as an example, the boost conversion process mainly includes:

[0187] Phase 1: Inductor L1 charging

[0188] MCU111 turns on switch T4 to charge inductor L1. As shown in Figure 18, current is output from the positive terminal of power battery 12, transmitted through switch K2, inductor L1 and switch T4, and then flows back to the negative terminal of power battery 12, thus forming a charging circuit to charge inductor L1.

[0189] Phase 2: Inductor L1 discharges

[0190] MCU111 turns off switch T4, causing inductor L1 to discharge. After MCU111 turns off switch T4, the charging circuit is shut off. Due to the freewheeling characteristic of the inductor, inductor L1 discharges. As shown in Figure 19, current flows from the positive terminal of power battery 12, through switch K2, inductor L1, the diode in switch T3, and the DC load, before returning to the negative terminal of power battery 12. During this process, the second output voltage of charging system 11 is the sum of the battery voltage of power battery 12 and the voltage of inductor L1. Obviously, the second output voltage is greater than the battery voltage, therefore charging system 11 can perform boost conversion of the battery voltage.

[0191] II. Voltage Reduction Conversion

[0192] As shown in Figure 10, the charging system 11 may also include a switch K3. The first terminal of switch K3 is connected to the connection point of motor windings N1 to N3, and the second terminal of switch K3 is connected to the second power supply terminal. During the buck conversion process, MCU 111 can turn on the first and third terminals b of switch K2, turn on switch K3, and turn off switch K1. The circuit state can be as shown in Figure 14. As can be seen from Figure 14, the circuit state in this case is equivalent to the charging system 11 shown in Figure 3. Therefore, the buck conversion process provided in Embodiment 2 above can be referred to, and will not be described again.

[0193] Furthermore, the charging system 11 shown in Figure 10 can also support buck-boost mode voltage conversion for the battery voltage. Specifically:

[0194] III. Buck-boost

[0195] When performing buck-boost conversion on the battery voltage, MCU111 can turn on the first and second terminals a of switch K2, as well as switch K3, as shown in Figure 15. Based on the circuit state shown in Figure 15, the buck-boost conversion mainly includes the following two stages:

[0196] Phase 1: Inductor L1 charging

[0197] MCU111 turns on switch T4 to charge inductor L1. As shown in Figure 20, current is output from the positive terminal of power battery 12, transmitted through switch K2, inductor L1 and switch T4, and then flows back to the negative terminal of power battery 12, thus forming a charging circuit for inductor L1.

[0198] Phase 2: Inductor L1 discharges

[0199] MCU111 turns off switch T4 to discharge inductor L1. As shown in Figure 21, current flows out from the end of inductor L1 closest to switch T3, through the diode in switch T3 and the DC load, and then back to the end of inductor L1 closest to the second power supply terminal. Therefore, the second output voltage of charging system 11 is equal to the voltage of inductor L1. By controlling the charging time of inductor L1 in stage one, MCU111 can control the voltage of inductor L1, thereby controlling the magnitude of the second output voltage, which may be greater than or less than the battery voltage.

[0200] Similar to Embodiment 2, when the battery voltage of the power battery 12 is within the operating voltage range of the DC load, the MCU 111 can also turn on the first and third terminals b of switch K2, as well as switch K1, so that the power battery 12 can directly supply power to the DC load. For specific implementation details, please refer to Embodiment 2, which will not be repeated here.

[0201] Example 5

[0202] In embodiments three and four, inductor L1 is connected to the second power supply terminal. Based on a similar concept, inductor L1 can also be connected to the first power supply terminal, in which case the charging system 11 can be as shown in Figure 22.

[0203] The charging system 11 also includes switches K5 and K6. Switch K5 is a single-pole double-throw switch. The first terminal of switch K5 is connected to the second battery terminal, the second terminal a of switch K5 is connected to the low-potential terminals of the N bridge arms, and the third terminal b of switch K5 is connected to one end of inductor L1. The second terminal of switch K6 is connected to the second power supply terminal, and the first terminal of switch K6 is connected to both the first battery terminal and the first power supply terminal.

[0204] It should be noted that switch K5 can be set independently of the power battery 12. In this case, the first terminal of switch K5 can be understood as the second battery terminal of charging system 11. It can also be understood that switch K5 can be integrated with the power battery 12 in the power battery pack. In this case, the charging system 11 provided in this application embodiment can be considered to include two second battery terminals, one of which is connected to the second terminal a of switch K5, and the other second battery terminal is connected to the third terminal b of switch K5.

[0205] Next, taking Figure 22 as an example, we will explain the buck conversion and boost conversion of the power supply voltage respectively.

[0206] I. Step-down conversion

[0207] When the power supply voltage is greater than the maximum charging voltage, MCU111 can perform a step-down conversion of the power supply voltage. During the step-down conversion process, MCU111 can turn on switch K6, as well as the first and third terminals b of switch K5, and the circuit state can be shown in Figure 23. It should be noted that in some scenarios, switches K2 to K4 can also be set in the charging system 11. In this case, switches K2 and K3 should be kept on, and switch K4 should be kept off. Based on the circuit state shown in Figure 23, taking bridge arm 2 including switch T3 and switch T4 as an example, the step-down conversion process mainly includes:

[0208] Phase 1: Inductor L1 charging

[0209] MCU111 turns on switch T4 to charge inductor L1. As shown in Figure 24, current is output from the positive terminal of the DC power supply, transmitted through the power battery 12, switch K5, inductor L1, and switch T4, and then flows back to the negative terminal of the DC power supply, thus forming a charging circuit to charge inductor L1. During this process, the first output voltage of the charging system 11 is the difference between the power supply voltage and the voltage of inductor L1. Obviously, the first output voltage is less than the power supply voltage, therefore the charging system 11 can achieve step-down conversion.

[0210] Phase 2: Inductor L1 discharges

[0211] MCU111 turns off switch T4 to discharge inductor L1. The second switch is also turned off to discharge inductor L1. Specifically, after MCU111 turns off switch T4, the charging circuit is shut down. Due to the freewheeling characteristic of the inductor, inductor L1 discharges. As shown in Figure 25, current is output from the end of inductor L1 closest to switch T3, and after passing through the diode in switch T3, the power battery 12, and switch K5, it flows back to the end of inductor L1 closest to the first power supply terminal. During this process, the first output voltage of the charging system 11 is the voltage of inductor L1. Obviously, the first output voltage is less than the power supply voltage, therefore the charging system 11 can perform a step-down conversion of the power supply voltage.

[0212] II. Boost Conversion

[0213] As shown in Figure 22, the charging system 11 may also include a switch K4. The first terminal of switch K4 is connected to the connection terminals of the N motor windings, and the second terminal of switch K4 is connected to the first power supply terminal. During the boost conversion process, MCU 111 can turn on the first and second terminals a of switch K5, turn on switch K4, and turn off switch K6. The circuit state can be as shown in Figure 26. As can be seen from Figure 26, the circuit state in this case is equivalent to the charging system 11 shown in Figure 3. Therefore, the boost conversion process provided in Embodiment 1 above can be referred to, and will not be repeated here.

[0214] In addition, the charging system 11 shown in Figure 22 can also support voltage conversion in buck-boost mode for the power supply voltage.

[0215] Specifically:

[0216] III. Buck-boost

[0217] During buck-boost conversion of the power supply voltage, MCU111 can turn on the first and third terminals b of switch K5, as well as switch K4, as shown in Figure 27. Based on the circuit state shown in Figure 27, buck-boost conversion mainly includes the following two stages:

[0218] Phase 1: Inductor L1 charging

[0219] MCU111 turns on switch T4 to charge inductor L1. As shown in Figure 28, the current is output from the positive terminal of the DC power supply, transmitted through switch T4 and inductor L1, and then flows back to the negative terminal of the DC power supply, thus forming a charging circuit for inductor L1.

[0220] Phase 2: Inductor L1 discharges

[0221] MCU111 turns off switch T3 to discharge inductor L1. As shown in Figure 29, current flows from the end of inductor L1 closest to switch T3, through the diode in switch T3, the power battery 12, and switch K5, before returning to the end of inductor L1 closest to the first power supply terminal. Therefore, the first output voltage of charging system 11 is equal to the voltage of inductor L1. By controlling the charging time of inductor L1 in stage one, MCU111 can control the voltage of inductor L1, thereby controlling the magnitude of the first output voltage, which may be greater than or less than the power supply voltage.

[0222] Similar to Embodiment 1, when the DC power supply voltage is within the charging voltage range of the power battery 12, the MCU 111 can also turn on the first and second terminals a of switch K5, as well as switch K6, so that the power battery 12 can directly receive the power supply voltage and thus complete charging. For specific implementation details, please refer to Embodiment 1; further elaboration will not be repeated here.

[0223] Example 6

[0224] It should be noted that the charging system 11 shown in Figure 22 can not only perform step-down conversion of battery voltage, but also step-up conversion of battery voltage, so that the battery voltage output by both high-voltage and low-voltage power batteries can be adapted to DC loads with different operating voltage ranges.

[0225] Next, taking Figure 22 as an example, we will explain the boost and buck conversion of battery voltage respectively.

[0226] I. Boost Conversion

[0227] During the boost conversion process, MCU111 can turn on switch K6, as well as the first and third terminals b of switch K5, and the circuit state can be as shown in Figure 23. Based on the circuit state shown in Figure 23, taking bridge arm 2, which includes switching transistors T3 and T4, as an example, the boost conversion process mainly includes:

[0228] Phase 1: Inductor L1 charging

[0229] MCU111 turns on switch T3 to charge inductor L1. As shown in Figure 30, current is output from the positive terminal of power battery 12, transmitted through switch T3, inductor L1 and switch K5, and then flows back to the negative terminal of power battery 12, thus forming a charging circuit to charge inductor L1.

[0230] Phase 2: Inductor L1 discharges

[0231] MCU111 turns off switch T3 to discharge inductor L1. After MCU111 turns off switch T3, the charging circuit is shut off. Due to the freewheeling characteristic of the inductor, inductor L1 discharges. As shown in Figure 32, current is output from the positive terminal of power battery 12, and after passing through the DC load, the diode in switch T4, inductor L1, and switch K5, it flows back to the negative terminal of power battery 12. During this process, the second output voltage of charging system 11 is the sum of the battery voltage of power battery 12 and the voltage of inductor L1. Obviously, the second output voltage is greater than the battery voltage, so charging system 11 can perform boost conversion of the battery voltage.

[0232] II. Voltage Reduction Conversion

[0233] As shown in Figure 22, the charging system 11 may further include a switch K4. The first terminal of switch K4 is connected to the connection point of the N motor windings, and the second terminal of switch K4 is connected to the first power supply terminal. During the buck conversion process, MCU 111 can turn on the first and second terminals a of switch K5, turn on switch K4, and turn off switch K6. The circuit state can be as shown in Figure 26. As can be seen from Figure 26, the circuit state in this case is equivalent to the charging system 11 shown in Figure 3. Therefore, the buck conversion process provided in Embodiment 2 above can be referred to, and will not be repeated here.

[0234] Furthermore, the charging system 11 shown in Figure 22 can also support buck-boost mode voltage conversion for the battery voltage. Specifically:

[0235] III. Buck-boost

[0236] During buck-boost conversion of the battery voltage, MCU111 can turn on the first and third terminals b of switch K5, as well as switch K4, as shown in Figure 27. Based on the circuit state shown in Figure 27, buck-boost conversion mainly includes the following two stages:

[0237] Phase 1: Inductor L1 charging

[0238] MCU111 turns on switch T3 to charge inductor L1. As shown in Figure 32, current is output from the positive terminal of power battery 12, transmitted through switch T3, inductor L1 and switch K5, and then flows back to the negative terminal of power battery 12, thus forming a charging circuit for inductor L1.

[0239] Phase 2: Inductor L1 discharges

[0240] MCU111 turns off switch T3 to discharge inductor L1. As shown in Figure 33, current flows out from the end of inductor L1 closest to the first power supply, passes through the DC load and the diode in switch T4, and then flows back to the end of inductor L1 closest to switch T4. Therefore, the second output voltage of charging system 11 is equal to the voltage of inductor L1. By controlling the charging time of inductor L1 in stage one, MCU111 can control the voltage of inductor L1, thereby controlling the magnitude of the second output voltage, which may be greater than or less than the battery voltage.

[0241] Similar to Embodiment 2, when the battery voltage of the power battery 12 is within the operating voltage range of the DC load, the MCU 111 can also turn on the first and second terminals a of switch K5, as well as switch K6, so that the power battery 12 can directly supply power to the DC load. For specific implementation details, please refer to Embodiment 2, which will not be repeated here.

[0242] Obviously, those skilled in the art can make various modifications and variations to this application without departing from the spirit and scope of this application. Therefore, if such modifications and variations fall within the scope of the claims of this application and their equivalents, this application also intends to include such modifications and variations.

Claims

1. A charging system, characterized in that, The charging system includes a motor controller, at least one inductor, a first switch, a second switch, a third switch, a fourth switch, and a fifth switch. The motor controller includes three bridge arms. The three bridge arms, the at least one inductor, the first switch, the second switch, the third switch, the fourth switch, and the fifth switch constitute a voltage conversion circuit. The voltage conversion circuit is used to boost or buck the power supply voltage output from the DC power supply. Specifically: one end of each of the three bridge arms is connected to the positive terminal of the DC power supply and the positive terminal of the power battery via the fourth switch; the other end of each of the three bridge arms is connected to the negative terminal of the DC power supply and the negative terminal of the power battery via the first switch; one end of the at least one inductor is connected to the midpoint of one of the three bridge arms; and the other end of the at least one inductor is connected to the DC power supply via the third switch. One of the positive or negative terminals of the power source; the first switch is used to connect or disconnect the connection between the other end of each of the three bridge arms and the negative terminal of the DC power supply, and the fifth switch is used to connect or disconnect the connection between the other end of each of the three bridge arms and the negative terminal of the power battery; the motor controller is used to: during the voltage conversion circuit's step-down conversion of the power supply voltage, turn off the third switch, turn on the first switch and the fourth switch, control the fifth switch to connect the other end of each of the three bridge arms to the negative terminal of the power battery and control the second switch to connect the positive terminal of the power battery to the other end of at least one inductor, or control the second switch to connect the other end of each of the three bridge arms to the positive terminal of the power battery and control the fifth switch to connect the negative terminal of the power battery to the other end of at least one inductor.

2. The charging system according to claim 1, characterized in that, The second switch is a single-pole double-throw switch, which is used to selectively connect the positive terminal of the power battery to one end of each of the three bridge arms or to the other end of the at least one inductor.

3. The charging system according to claim 1 or 2, characterized in that, The fifth switch is a single-pole double-throw switch, which is used to selectively connect the negative terminal of the power battery to the other end of each of the three bridge arms or to the other end of the at least one inductor.

4. The charging system according to claim 1, characterized in that, The charging system also includes a filter capacitor, the two ends of which are respectively used to connect to the positive and negative terminals of the DC power supply.

5. The charging system according to claim 1, characterized in that, The motor controller is configured to selectively perform boost or buck conversion on the DC power supply voltage based on the relationship between the DC power supply voltage and the charging voltage of the power battery when the power supply voltage is outside the charging voltage range of the power battery. Specifically, the motor controller is configured to: when the DC power supply voltage is less than the minimum charging voltage of the power battery, perform boost conversion on the DC power supply voltage plus the voltage of at least one inductor through the voltage conversion circuit, and output the boosted voltage as the first output voltage to the power battery; when the power supply voltage is greater than the maximum charging voltage of the power battery, perform buck conversion on the power supply voltage through the voltage conversion circuit, and output the bucked voltage as the first output voltage to the power battery.

6. The charging system according to claim 1, characterized in that, The motor controller is further configured to: during the process of the voltage conversion circuit boosting the power supply voltage, turn off the first switch, turn on the third switch, control the fifth switch to connect the negative terminal of the power battery to the other end of each of the three bridge arms, and control the second switch to connect one end of each of the three bridge arms to the positive terminal of the power battery.

7. The charging system according to claim 1, characterized in that, The motor controller is further configured to: when the power supply voltage is within the charging voltage range of the power battery, turn on the first switch, turn off the third switch, control the fifth switch to connect the negative terminal of the power battery to the other end of each of the three bridge arms, and control the second switch to connect one end of each of the three bridge arms to the positive terminal of the power battery, so that the DC power supply directly supplies power to the power battery.

8. The charging system according to claim 6, characterized in that, One bridge arm used to connect the at least one inductor is the first bridge arm. During the process of the voltage conversion circuit boosting the DC power supply voltage, the motor controller is specifically used to: turn on the upper bridge arm switch of the first bridge arm so that the DC power supply charges the at least one inductor; and turn off the upper bridge arm switch of the first bridge arm so that the DC power supply and the at least one inductor charge the power battery together.

9. The charging system according to claim 1, characterized in that, One bridge arm used to connect the at least one inductor is the first bridge arm. During the process of the voltage conversion circuit performing step-down conversion of the DC power supply voltage, the motor controller is specifically used to: turn on the upper bridge arm switch of the first bridge arm so that the DC power supply charges the at least one inductor and the power battery; and turn off the upper bridge arm switch of the first bridge arm so that the at least one inductor charges the power battery.

10. An electric vehicle, characterized in that, It includes a power battery and a charging system as described in any one of claims 1 to 9, wherein the charging system is used to charge the power battery.

Images