Charger, charger control method, and vehicle

Abstract

The charger includes a controller (1), an AC-side capacitor assembly (2), a power factor correction circuit (3), a bus capacitor assembly (4), and a DC-DC converter (5). The bus capacitor assembly (4) includes a first capacitor (C1) and a second capacitor (C2). The AC-side capacitor assembly (4) is connected to both the first capacitor (C1) and the second capacitor (C2). When the charger is in a single-phase AC charging mode, the controller (1) dynamically adjusts the on-duty ratio of the high-frequency bridge arm of the power factor correction circuit (3) according to the AC voltage to discharge the voltage of the AC-side capacitor assembly (4), perform power factor correction for the AC, and input the DC output from the power factor correction circuit to the DC-DC converter (5). A charger control method and a vehicle are also provided.

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This disclosure claims priority to Chinese Patent Application No. 202211050020.0, entitled "CHARGER, CHARGER CONTROL METHOD, AND VEHICLE," filed on August 30, 2022. The entire contents of the above-referenced application are incorporated herein by reference.

[0002] The present disclosure relates to the field of power electronics technology, and more particularly to a charger, a control method for a charger, and a vehicle. [Background technology]

[0003] A charger is a power system that converts alternating current (AC) to direct current (DC). It typically includes a power factor correction (PFC) circuit at the front end and a DC-DC converter at the back end. A bus capacitor, configured to balance the instantaneous power difference between the AC and DC sides, is placed between the PFC circuit and the DC-DC converter. During charger operation, common-mode current leakage issues arise. Therefore, bus capacitors and AC-side capacitors are added to the charger. The midpoint of the bus capacitor is shorted to the midpoint of the AC-side capacitor to mitigate the common-mode current leakage issue during three-phase charging. However, shorting the midpoint of the bus capacitor to the midpoint of the AC-side capacitor introduces new problems. For example, when the charger is in single-phase AC charging mode, the input current becomes distorted when the input voltage crosses zero. In other words, when the input voltage crosses zero, the current has large positive pulse peaks or large negative pulse peaks, or the current waveform is severely distorted and unable to properly track the input voltage. Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a charger, a method for controlling a charger, and a vehicle to overcome problems existing in the related art. [Means for solving the problem]

[0005] To achieve the above object, according to a first aspect, the present disclosure provides a charger including an alternating current (AC) side capacitor assembly, a power factor correction (PFC) circuit, a direct current-direct current (DC-DC) converter, a bus capacitor assembly, and a controller.

[0006] One end of the AC side capacitor assembly is adapted to connect to an AC power source.

[0007] A first end of the PFC circuit is configured to connect to an AC power source and to an end of the AC-side capacitor assembly.

[0008] The bus capacitor assembly includes a first capacitor and a second capacitor.

[0009] One end of the first capacitor is connected to both the second end of the PFC circuit and one end of the DC-DC converter.

[0010] One end of the second capacitor is connected to the other end of the first capacitor, and the other end of the second capacitor is connected to both the third end of the PFC circuit and the other end of the DC-DC converter.

[0011] The controller is connected to both the PFC circuit and the DC-DC converter, and is configured to, when the charger is in a single-phase AC charging mode, dynamically adjust the duty ratio of the high-frequency bridge arms of the PFC circuit based on the voltage of the AC power source, discharge the voltage of the AC-side capacitor assembly to perform PFC on the AC power source, input the DC output from the PFC circuit to the DC-DC converter, enable the DC-DC converter to perform voltage conversion on the DC, and output the DC to the device to be charged.

[0012] The other end of the first capacitor and the other end of the second capacitor are both connected to the other end of the AC-side capacitor assembly.

[0013] The PFC circuit optionally includes an M-phase high frequency bridge arm, M coils, and a power frequency bridge arm.

[0014] The first bus terminal of the M-phase high-frequency bridge arm is connected to a first capacitor. The second bus terminal of the M-phase high-frequency bridge arm is connected to a second capacitor.

[0015] The first ends of the M coils are connected to the midpoints of the M-phase high-frequency bridge arms in a one-to-one correspondence, and the second ends of the M coils are connected to the live wires of the AC power supply.

[0016] One end of the power frequency bridge arm is connected to both the first bus terminal and the first capacitor. The other end of the power frequency bridge arm is connected to both the second bus terminal and the second capacitor. The midpoint of the power frequency bridge arm is configured to be connected to the neutral conductor of the AC power source.

[0017] M≧1, and the AC-side capacitor assembly includes M third capacitors. First ends of the M third capacitors are connected to second ends of the M coils in a one-to-one correspondence. Second ends of the M third capacitors are connected together to form a neutral point. The neutral point is connected to both the first capacitor and the second capacitor via a resistor.

[0018] A controller is optionally connected to each of the M-phase high frequency bridge arms and configured as follows: controlling a target high frequency bridge arm to be turned off when the absolute value of the voltage of the AC power source is equal to or less than a first preset voltage, wherein the target high frequency bridge arm includes one or more high frequency bridge arms used in a single-phase AC charging mode; When the input voltage of the charger is in a positive half cycle, if the voltage is greater than a first preset voltage and less than a second preset voltage, control the upper bridge arm of the target high-frequency bridge arm to be turned off and the lower bridge arm to be turned on with a first duty ratio to discharge the voltage of the AC-side capacitor assembly; if the voltage is greater than a second preset voltage, control the lower bridge arm to be turned on with a second duty ratio to perform PFC for the AC power source, where the first preset voltage is less than the second preset voltage; When the input voltage of the charger is in a negative half cycle, if the absolute value of the voltage is greater than a first preset voltage and less than a second preset voltage, the lower bridge arm of the target high-frequency bridge arm is controlled to be turned off and the upper bridge arm is controlled to be turned on with a first duty ratio to discharge the voltage of the AC-side capacitor assembly, and if the absolute value of the voltage is greater than a second preset voltage, the upper bridge arm of the target high-frequency bridge arm is controlled to be turned on with a second duty ratio to perform PFC for the AC power source.

[0019] The controller is optionally further configured as follows. controlling the upper and lower bridge arms of the target high frequency bridge arm to be alternately turned on after the lower bridge arm of the target high frequency bridge arm has been continuously turned on for a preset period at a second duty ratio; After the upper bridge arm of the target high-frequency bridge arm is continuously turned on for a preset period at a second duty ratio, the upper bridge arm and the lower bridge arm of the target high-frequency bridge arm are controlled to be turned on alternately.

[0020] The subject radio frequency bridge arms optionally include a plurality of radio frequency bridge arms.

[0021] The controller is configured to control the upper bridge arm of the target high-frequency bridge arm to be turned off and the lower bridge arm to be turned on alternately at a preset angle and a first duty ratio, and to control the lower bridge arm of the target high-frequency bridge arm to be turned off and the upper bridge arm to be turned on alternately at a preset angle and a first duty ratio.

[0022] The controller is optionally connected to the power frequency bridge arms and configured to control the lower bridge arm of the power frequency bridge arms to be on and the upper bridge arm to be off when the input voltage of the charger is in a positive half cycle, and to control the upper bridge arm of the power frequency bridge arms to be on and the lower bridge arm to be off when the input voltage of the charger is in a negative half cycle.

[0023] According to a second aspect, the present disclosure provides a charger control method including the following steps.

[0024] When the charger is in single-phase AC charging mode, the duty cycle of the high-frequency bridge arm of the PFC circuit is dynamically adjusted based on the voltage of the AC power source to discharge the voltage of the AC-side capacitor assembly and perform PFC on the AC power source.

[0025] The DC output from the PFC circuit is input to a DC-DC converter, which performs voltage conversion on the DC, enabling the DC to be output to the device to be charged.

[0026] The charger includes an AC-side capacitor assembly, a PFC circuit, a bus capacitor assembly, and a DC-DC converter. A first end of the PFC circuit is configured to connect to an AC power source. The bus capacitor assembly includes a first capacitor and a second capacitor. One end of the first capacitor is connected to both a second end of the PFC circuit and one end of the DC-DC converter. The other end of the first capacitor is connected to one end of the second capacitor. The other end of the second capacitor is connected to both a third end of the PFC circuit and the other end of the DC-DC converter. One end of the AC-side capacitor assembly is connected to both the AC power source and the first end of the PFC circuit, and the other end of the AC-side capacitor assembly is connected to both the first capacitor and the second capacitor.

[0027] The PFC circuit optionally includes an M-phase high frequency bridge arm, M coils, and a power frequency bridge arm, where M≧1.

[0028] The first bus terminal of the M-phase high frequency bridge arm is connected to the first capacitor. The second bus terminal of the M-phase high frequency bridge arm is connected to the second capacitor. The first ends of the M coils are connected to the midpoints of the M-phase high frequency bridge arms in a one-to-one correspondence. The second ends of the M coils are connected to the live conductor of the AC power supply. One end of the power frequency bridge arm is connected to both the first bus terminal and the first capacitor, and the other end of the power frequency bridge arm is connected to both the second bus terminal and the second capacitor. The midpoint of the power frequency bridge arm is configured to be connected to the neutral conductor of the AC power supply. The AC-side capacitor assembly includes M third capacitors. The first ends of the M third capacitors are connected to the second ends of the M coils in a one-to-one correspondence. The second ends of the M third capacitors are connected together to form a neutral point. The neutral point is connected to both the first capacitor and the second capacitor via a resistor.

[0029] Dynamically adjusting the duty ratio of the high frequency bridge arm of the PFC circuit based on the voltage of the AC power source to discharge the voltage of the AC side capacitor assembly and performing PFC on the AC power source includes the following steps:

[0030] When the absolute value of the voltage of the AC power source is equal to or less than a first preset voltage, the target high frequency bridge arms are controlled to be turned off. The target high frequency bridge arms include one or more high frequency bridge arms used in a single-phase AC charging mode.

[0031] When the charger input voltage is in a positive half cycle, the upper bridge arm of the target high-frequency bridge arm is controlled to be turned off, and the lower bridge arm is controlled to be turned on with a first duty ratio to discharge the voltage of the AC-side capacitor assembly if the voltage is greater than a first preset voltage and less than a second preset voltage, and the lower bridge arm is controlled to be turned on with a second duty ratio to perform PFC for the AC power source if the voltage is greater than the second preset voltage and the first preset voltage is less than the second preset voltage.

[0032] When the input voltage of the charger is in a negative half cycle, the lower bridge arm of the target high-frequency bridge arm is controlled to be turned off, and the upper bridge arm is controlled to be turned on with a first duty ratio when the absolute value of the voltage is greater than a first preset voltage and less than a second preset voltage, to discharge the voltage of the AC-side capacitor assembly, and the upper bridge arm is controlled to be turned on with a second duty ratio when the absolute value of the voltage is greater than the second preset voltage, to perform PFC for the AC power source.

[0033] The method optionally further comprises the following steps:

[0034] After the lower bridge arm of the target high-frequency bridge arm is continuously turned on for a preset period at a second duty ratio, the upper bridge arm and the lower bridge arm of the target high-frequency bridge arm are controlled to be turned on alternately.

[0035] After the upper bridge arm of the target high-frequency bridge arm is continuously turned on for a preset period at a second duty ratio, the upper bridge arm and the lower bridge arm of the target high-frequency bridge arm are controlled to be turned on alternately.

[0036] According to a third aspect, the present disclosure provides a vehicle including the charger provided in the first aspect of the present disclosure.

[0037] In the above technical solution, when the charger is in single-phase AC charging mode, the duty ratio of the high-frequency bridge arm of the PFC circuit is dynamically adjusted based on the voltage of the AC power source, discharging the voltage of the AC-side capacitor assembly to perform PFC on the AC power source, and inputting the DC output from the PFC circuit into the DC-DC converter, which then performs voltage conversion on the DC and outputs the DC to the device being charged. In this way, when the charger is in single-phase AC charging mode, the duty ratio of the high-frequency bridge arm of the PFC circuit is dynamically adjusted to discharge the voltage of the AC-side capacitor assembly, thereby preventing current distortion when the AC crosses zero and ensuring the original PFC function.

[0038] Other features and advantages of the present disclosure will be described in detail in the remainder of the detailed description.

[0039] The accompanying drawings are intended to provide a further understanding of the disclosure and are incorporated into this specification. The accompanying drawings and the following specific embodiments do not constitute limitations of the disclosure, but rather are used together to explain the disclosure. [Brief explanation of the drawings]

[0040] [Figure 1] FIG. 2 is a block diagram of the architecture of a charger according to an exemplary embodiment. [Figure 2] 1 is a topology diagram of a circuit for a charger in accordance with an exemplary embodiment. [Figure 3] FIG. 2 is a simplified circuit topology diagram of a charger in a single-phase alternating current (AC) charging mode, according to an exemplary embodiment. [Figure 4] 1 is a flow diagram of a charger control method according to an exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0041] Specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are used merely to describe and explain the present disclosure, and are not intended to limit the present disclosure.

[0042] 1 is a block diagram of a charger architecture according to an exemplary embodiment, which includes a controller 1, an alternating current (AC) side capacitor assembly 2, a power factor correction (PFC) circuit 3, a bus capacitor assembly 4, and a direct current-to-direct current (DC-DC) converter 5, as shown in FIG.

[0043] One end of the AC-side capacitor assembly 2 is adapted to connect to an AC power source 6. A first end of the PFC circuit 3 is configured to connect to the AC power source 6 and an end of the AC-side capacitor assembly 2.

[0044] The bus capacitor assembly 4 includes a first capacitor C1 and a second capacitor C2. One end of the first capacitor C1 is connected to both the second end of the PFC circuit 3 and one end of the DC-DC converter 5. One end of the second capacitor C2 is connected to the other end of the first capacitor C1. The other end of the second capacitor C2 is connected to both the third end of the PFC circuit 3 and the other end of the DC-DC converter 5. Both the other end of the first capacitor C1 and the other end of the second capacitor C2 are connected to the other end of the AC-side capacitor assembly 2.

[0045] The controller 1 is connected to both the PFC circuit 3 and the DC-DC converter 5, and is configured to dynamically adjust the duty ratio of the high-frequency bridge arms of the PFC circuit 3 based on the voltage of the AC power source when the charger is in a single-phase AC charging mode, discharge the voltage of the AC-side capacitor assembly 2 to perform PFC on the AC power source, input the DC output from the PFC circuit 3 to the DC-DC converter 5, and enable the DC-DC converter 5 to perform voltage conversion on the DC and output the DC to the device to be charged. The device to be charged may be, for example, a power battery or a load. The AC may be sine wave AC or cosine wave AC.

[0046] In the above technical solution, when the charger is in single-phase AC charging mode, the duty ratio of the high-frequency bridge arm of the PFC circuit is dynamically adjusted based on the voltage of the AC power source, discharging the voltage of the AC-side capacitor assembly to perform PFC on the AC power source, and inputting the DC output from the PFC circuit into the DC-DC converter, which then performs voltage conversion on the DC and outputs the DC to the device being charged. In this way, when the charger is in single-phase AC charging mode, the duty ratio of the high-frequency bridge arm of the PFC circuit is dynamically adjusted to discharge the voltage of the AC-side capacitor assembly, thereby preventing current distortion when the AC crosses zero and ensuring the original PFC function.

[0047] As shown in FIG. 2, the above PFC circuit 3 may include an M-phase high-frequency bridge arm B1, M coils KM, and a power frequency bridge arm B2, where M≧1.

[0048] The first bus terminal of the M-phase high-frequency bridge arm B1 is connected to the first capacitor C1. The second bus terminal of the M-phase high-frequency bridge arm B1 is connected to the second capacitor C2. The first ends of the M coils KM are connected to the midpoint of the M-phase high-frequency bridge arm B1 in a one-to-one correspondence. The second ends of the M coils KM are connected to the live lines of the AC power source 6. (As shown in FIG. 2, the M coils KM are coils km1, km2, and km3, respectively. Here, the second end of coil km1 is connected to live line A of the AC power source 6, the second end of coil km2 is connected to live line B of the AC power source 6, and the second end of coil km3 is connected to live line C of the AC power source 6.) One end of the power frequency bridge arm B2 is connected to both the first bus terminal and the first capacitor C1. The other end of the power frequency bridge arm is connected to both the second bus terminal and the second capacitor C2. The midpoint of the power frequency bridge arm B2 is configured to be connected to the neutral wire N of the AC power source 6.

[0049] As shown in FIG. 2, the AC-side capacitor assembly 2 includes M third capacitors C3. First ends of the M third capacitors C3 are connected to second ends of the M coils KM in a one-to-one correspondence. The second ends of the M third capacitors C3 are connected together to form a neutral point. The neutral point is connected to both the first capacitor C1 and the second capacitor C2 via a resistor R.

[0050] As shown in FIG. 2, the DC-DC converter 5 includes a transformer 51, a first-stage bridge arm 52, a second-stage bridge arm 53, a third-stage bridge arm 54, a fourth-stage bridge arm 55, and a fourth capacitor C4. The midpoint of the first-stage bridge arm 52 is connected to a first end of the primary side of the transformer 51. The midpoint of the second-stage bridge arm 53 is connected to a second end of the primary side of the transformer 51. The midpoint of the third-stage bridge arm 54 is connected to a first end of the secondary side of the transformer 51. The midpoint of the fourth-stage bridge arm 55 is connected to a second end of the secondary side of the transformer 51. First bus terminals of the first-stage bridge arm 52 and the second-stage bridge arm 53 are connected to a first capacitor C1. Second bus terminals of the first-stage bridge arm 52 and the second-stage bridge arm 53 are connected to a second capacitor C2. The first bus terminals of the third-stage bridge arm 54 and the fourth-stage bridge arm 55 are connected to both one end of the fourth capacitor C4 and the positive terminal of the device to be charged, and the second bus terminals of the third-stage bridge arm 54 and the fourth-stage bridge arm 55 are connected to both the other end of the fourth capacitor C4 and the negative terminal of the device to be charged.

[0051] 2, the charger may further include a first switch K1, a second switch K2, a third switch K3, and a fourth switch K4. The fourth switch K4 includes a movable end K41, a first fixed end K42, and a second fixed end K43. The movable end K41 is configured to be selectively connected to the first fixed end K42 or the second fixed end K43.

[0052] When the first switch K1, the second switch K2, and the third switch K3 are all closed and the movable end K41 of the fourth switch K4 is connected to the second fixed end K43, the charger is in a three-phase AC charging mode.

[0053] When the first switch K1 is closed and both the second switch K2 and the third switch K3 are open, or when both the first switch K1 and the second switch K2 are closed, the third switch K3 is open, and the movable end K41 of the fourth switch K4 is connected to the first fixed end K42, the charger is in single-phase AC charging mode (as shown in FIG. 3).

[0054] Controller 1 (not shown in FIG. 2) is connected to each of the M-phase high-frequency bridge arms B1 and is configured as follows:

[0055] When the charger is in a single-phase AC charging mode, if the absolute value of the voltage of the AC power source is equal to or less than a first preset voltage, the target high-frequency bridge arm is controlled to be turned off; when the input voltage of the charger (i.e., the output voltage of the AC power source, and accordingly the voltage of the AC power source is the input voltage of the charger) is in a positive half cycle and the voltage of the AC power source is greater than zero, if the voltage is greater than the first preset voltage and less than a second preset voltage, the upper bridge arm of the target high-frequency bridge arm is controlled to be turned off and the lower bridge arm is controlled to be turned on with a first duty ratio to discharge the voltage of the AC-side capacitor assembly 2; if the voltage is greater than the second preset voltage, the target high-frequency bridge arm is controlled to be turned on with a first duty ratio. and when the charger input voltage is in the negative half cycle and the voltage of the AC power supply is less than zero, if the absolute value of the voltage is greater than the first preset voltage and less than the second preset voltage, the lower bridge arm of the target high-frequency bridge arm is turned off and the upper bridge arm is controlled to be turned on with the first duty ratio to discharge the voltage of the AC-side capacitor assembly 2, and if the absolute value of the voltage is greater than the second preset voltage, the upper bridge arm of the target high-frequency bridge arm is controlled to be turned on with the second duty ratio to perform PFC on the AC power supply.

[0056] In this disclosure, the target high-frequency bridge arm includes one or more high-frequency bridge arms used in a single-phase AC charging mode. Specifically, when the first switch K1 is closed and both the second switch K2 and the third switch K3 are open, the target high-frequency bridge arm includes the left high-frequency bridge arm of the M-phase high-frequency bridge arm B1. In other words, one target high-frequency bridge arm is arranged. When both the first switch K1 and the second switch K2 are closed, the third switch K3 is open, and the movable end K41 of the fourth switch K4 is connected to the first fixed end K42, the target high-frequency bridge arm includes the left high-frequency bridge arm of the M-phase high-frequency bridge arm B1 and the center high-frequency bridge arm. In other words, two target high-frequency bridge arms are arranged, as shown in FIG. 3.

[0057] Additionally, the first preset voltage is less than the second preset voltage, the first preset voltage is greater than or close to zero, and the second preset voltage is less than the maximum voltage of the AC power source.

[0058] The first duty ratio may be smaller than the second duty ratio or may be equal to or larger than the second duty ratio, but this disclosure is not specifically limited thereto. In one embodiment, the first duty ratio is smaller than the second duty ratio. The second duty ratio is approximately equal to the ratio of the output voltage to the input voltage of the PFC circuit 3.

[0059] In this embodiment, regardless of whether the charger input voltage (i.e., the output voltage of the AC power supply) is in a positive or negative half-cycle, the charger input voltage is considered to cross zero as long as the absolute value of the AC power supply voltage is equal to or less than a first preset voltage. In this case, to prevent current distortion, the target high-frequency bridge arm is first controlled to be turned off. Next, when the charger input voltage is in a positive half-cycle, if the voltage is greater than the first preset voltage and less than the second preset voltage, the lower bridge arm of the target high-frequency bridge arm is controlled to be turned on with a relatively small duty ratio (i.e., a first duty ratio smaller than the second duty ratio). During this period, the upper bridge arm of the target high-frequency bridge arm is always in an off state. In this way, the voltage of the AC-side capacitor assembly can be discharged to the second capacitor C2 at a relatively slow rate through the coil connected to the target high-frequency bridge arm and the lower bridge arm of the target high-frequency bridge arm, thereby smoothly transitioning the leakage current crossing zero and avoiding current distortion. During the negative half-cycle of the charger's input voltage, if the absolute value of the voltage is greater than the first preset voltage and less than the second preset voltage, the upper bridge arm of the target high-frequency bridge arm is controlled to be turned on with a relatively small duty cycle. During this period, the lower bridge arm of the target high-frequency bridge arm is always in an off state. In this way, the voltage of the AC-side capacitor assembly can be discharged to the first capacitor C1 at a relatively slow rate through the coil connected to the target high-frequency bridge arm and the upper bridge arm of the target high-frequency bridge arm, which allows the leakage current to smoothly transition across zero and avoids current distortion.

[0060] Next, to ensure the original PFC function, when the charger input voltage is in a positive half cycle, if the voltage is greater than a second preset voltage, the lower bridge arm of the target high-frequency bridge arm is controlled to turn on with a second duty ratio to perform PFC for the AC power supply.When the charger input voltage is in a negative half cycle, if the absolute value of the voltage is greater than the second preset voltage, the upper bridge arm of the target high-frequency bridge arm is controlled to turn on with a second duty ratio to perform PFC for the AC power supply.

[0061] Although FIG. 2 illustrates M=3, those skilled in the art will understand that the number of bridge arms, the number of coils, and the number of third capacitors in FIG. 2 are merely examples.

[0062] In addition, the upper and lower bridge arms of the power frequency bridge arm B2 may be always in the off state when the charger input voltage is in the positive half cycle or the negative half cycle. When the upper and lower bridge arms of the power frequency bridge arm B2 are always in the off state, automatic freewheeling may be implemented by using the body diodes of the bridge arms.

[0063] Because the turn-on loss of the bridge arm is smaller than the freewheeling loss of the body diode, in order to reduce the bridge arm loss of the power frequency bridge arm, the lower bridge arm of the power frequency bridge arm B2 may be turned on and the upper bridge arm may be turned off when the input voltage of the charger is in a positive half cycle, and the upper bridge arm of the power frequency bridge arm B2 may be turned on and the lower bridge arm may be turned off when the input voltage of the charger is in a negative half cycle. Specifically, the controller 1 is connected to the power frequency bridge arm B2 and is further configured to control the lower bridge arm of the power frequency bridge arm B2 to be turned on and the upper bridge arm to be turned off when the input voltage of the charger is in a positive half cycle, and to control the upper bridge arm of the power frequency bridge arm B2 to be turned on and the lower bridge arm to be turned off when the input voltage of the charger is in a negative half cycle.

[0064] In addition, when the target high-frequency bridge arm includes multiple high-frequency bridge arms, the multiple high-frequency bridge arms of the target high-frequency bridge arm are alternately turned on to reduce the offset of the input current ripple and reduce electromagnetic interference of the charger. Specifically, the controller 1 is configured to control the target high-frequency bridge arm so that an upper bridge arm is turned off and a lower bridge arm is alternately turned on at a preset angle and a first duty ratio, and to control the target high-frequency bridge arm so that a lower bridge arm is turned off and an upper bridge arm is alternately turned on at a preset angle and a first duty ratio.

[0065] The target high-frequency bridge arms illustratively include the left high-frequency bridge arm and the center high-frequency bridge arm of the M-phase high-frequency bridge arm B1, as shown in Figure 3. In this case, the preset angle may be 90 degrees.

[0066] In addition, in order to reduce switching loss in the upper bridge arm of the target high-frequency bridge arm when the input voltage of the charger is in a positive half cycle, the above-mentioned controller 1 is further configured to control the upper bridge arm and the lower bridge arm of the target high-frequency bridge arm to be alternately turned on after the lower bridge arm of the target high-frequency bridge arm is continuously turned on for a preset period with a second duty ratio.

[0067] Similarly, in order to reduce switching loss in the lower bridge arm of the target high-frequency bridge arm when the input voltage of the charger is in a negative half cycle, the above-mentioned controller 1 is further configured to control the upper bridge arm of the target high-frequency bridge arm to be turned on continuously for a preset period with a second duty ratio, and then the upper bridge arm and the lower bridge arm of the target high-frequency bridge arm are turned on alternately.

[0068] 4 is a flowchart of a charger control method according to an exemplary embodiment. As shown in FIG. 4, the method may include the following steps S401 and S402.

[0069] In S401, when the charger is in a single-phase AC charging mode, the duty ratio of the high-frequency bridge arm of the PFC circuit is dynamically adjusted based on the voltage of the AC power source to discharge the voltage of the AC-side capacitor assembly and perform PFC on the AC power source.

[0070] In S402, the DC output from the PFC circuit is input to the DC-DC converter, and the DC-DC converter performs voltage conversion on the DC, enabling the DC to be output to the device to be charged.

[0071] The charger includes an AC-side capacitor assembly, a PFC circuit, a bus capacitor assembly, and a DC-DC converter. A first end of the PFC circuit is configured to connect to an AC power source. The bus capacitor assembly includes a first capacitor and a second capacitor. One end of the first capacitor is connected to both a second end of the PFC circuit and one end of the DC-DC converter. The other end of the first capacitor is connected to one end of the second capacitor. The other end of the second capacitor is connected to both a third end of the PFC circuit and the other end of the DC-DC converter. One end of the AC-side capacitor assembly is connected to both the AC power source and the first end of the PFC circuit, and the other end of the AC-side capacitor assembly is connected to both the first capacitor and the second capacitor.

[0072] In the above technical solution, when the charger is in single-phase AC charging mode, the duty ratio of the high-frequency bridge arm of the PFC circuit is dynamically adjusted based on the voltage of the AC power source, discharging the voltage of the AC-side capacitor assembly to perform PFC on the AC power source, and inputting the DC output from the PFC circuit into the DC-DC converter, which then performs voltage conversion on the DC and outputs the DC to the device being charged. In this way, when the charger is in single-phase AC charging mode, the duty ratio of the high-frequency bridge arm of the PFC circuit is dynamically adjusted to discharge the voltage of the AC-side capacitor assembly, thereby preventing current distortion when the AC crosses zero and ensuring the original PFC function.

[0073] The PFC circuit optionally includes an M-phase high frequency bridge arm, M coils, and a power frequency bridge arm, where M≧1.

[0074] The first bus terminal of the M-phase high frequency bridge arm is connected to the first capacitor. The second bus terminal of the M-phase high frequency bridge arm is connected to the second capacitor. The first ends of the M coils are connected to the midpoints of the M-phase high frequency bridge arms in a one-to-one correspondence. The second ends of the M coils are connected to the live conductor of the AC power source. One end of the power frequency bridge arm is connected to the first bus terminal and the first capacitor. The other end of the power frequency bridge arm is connected to the second bus terminal and the second capacitor. The midpoint of the power frequency bridge arm is configured to be connected to the neutral conductor of the AC power source. The AC-side capacitor assembly includes M third capacitors. The first ends of the M third capacitors are connected to the second ends of the M coils in a one-to-one correspondence. The second ends of the M third capacitors are connected together to form a neutral point. The neutral point is connected to both the first capacitor and the second capacitor via a resistor.

[0075] Dynamically adjusting the duty ratio of the high frequency bridge arm of the PFC circuit based on the voltage of the AC power source to discharge the voltage of the AC side capacitor assembly and performing PFC on the AC power source includes the following steps:

[0076] When the absolute value of the voltage of the AC power source is equal to or less than a first preset voltage, the target high frequency bridge arms are controlled to be turned off. The target high frequency bridge arms include one or more high frequency bridge arms used in a single-phase AC charging mode.

[0077] When the charger input voltage is in a positive half cycle, the upper bridge arm of the target high-frequency bridge arm is controlled to be turned off, and the lower bridge arm is controlled to be turned on with a first duty ratio to discharge the voltage of the AC-side capacitor assembly when the voltage is greater than a first preset voltage and less than a second preset voltage, and the lower bridge arm is controlled to be turned on with a second duty ratio to perform PFC for the AC power source when the voltage is greater than the second preset voltage and the first preset voltage is less than the second preset voltage.

[0078] When the input voltage of the charger is in a negative half cycle, the lower bridge arm of the target high-frequency bridge arm is controlled to be turned off, and the upper bridge arm is controlled to be turned on with a first duty ratio when the absolute value of the voltage is greater than a first preset voltage and less than a second preset voltage, to discharge the voltage of the AC-side capacitor assembly, and the upper bridge arm is controlled to be turned on with a second duty ratio when the absolute value of the voltage is greater than the second preset voltage, to perform PFC for the AC power source.

[0079] The method optionally further comprises the following steps:

[0080] After the lower bridge arm of the target high-frequency bridge arm is continuously turned on for a preset period at a second duty ratio, the upper bridge arm and the lower bridge arm of the target high-frequency bridge arm are controlled to be turned on alternately.

[0081] After the upper bridge arm of the target high-frequency bridge arm is continuously turned on for a preset period at a second duty ratio, the upper bridge arm and the lower bridge arm of the target high-frequency bridge arm are controlled to be turned on alternately.

[0082] The subject radio frequency bridge arms optionally include a plurality of radio frequency bridge arms.

[0083] Controlling the upper bridge arm of a target high frequency bridge arm to be turned off and the lower bridge arm to be turned on at a first duty ratio includes the following steps.

[0084] The upper bridge arm of the target high frequency bridge arm is controlled to be turned off, and the lower bridge arm is controlled to be alternately turned on at a preset angle and a first duty ratio.

[0085] Controlling the lower bridge arm of a target high frequency bridge arm to be turned off and the upper bridge arm to be turned on at a first duty ratio includes the following steps.

[0086] The lower bridge arm of the target high frequency bridge arm is controlled to be turned off, and the upper bridge arm is controlled to be alternately turned on at a preset angle and a first duty ratio.

[0087] The method optionally further comprises the following steps:

[0088] When the charger input voltage is in a positive half cycle, the lower bridge arm of the power frequency bridge arm is controlled to be turned on, and the upper bridge arm of the power frequency bridge arm is controlled to be turned off.

[0089] When the charger input voltage is in a negative half cycle, the upper bridge arm of the power frequency bridge arm is controlled to be turned on, and the lower bridge arm of the power frequency bridge arm is controlled to be turned off.

[0090] Regarding the charger control method in the embodiments of the present disclosure, the specific implementation of the steps is described in detail in the embodiments related to the charger, and the details are not described here.

[0091] The present disclosure further provides a vehicle including the above charger provided in accordance with the present disclosure.

[0092] The preferred embodiments of the present disclosure have been described in detail above with reference to the accompanying drawings. However, the present disclosure is not limited to the specific details of the above embodiments. A number of simple variations may be made to the technical solutions of the present disclosure within the scope of the technical concept of the present disclosure, and these simple variations are encompassed within the protection scope of the present disclosure.

[0093] In addition, it should be noted that the specific technical features described in the above specific embodiments may be combined in any suitable manner unless there is a contradiction, and in order to avoid unnecessary repetition, the present disclosure does not describe various possible combination manners.

[0094] Additionally, various different embodiments of the present disclosure may also be combined in different ways without departing from the spirit of the present disclosure, and the combinations shall still be considered as disclosed in the present disclosure.

Claims

1. A charger comprising: an alternating current (AC) side capacitor assembly (2), one end of which is adapted to connect to an AC power source (6); a power factor correction (PFC) circuit (3), a first end of the PFC circuit (3) configured to connect to the AC power source (6) and the end of the AC-side capacitor assembly (2); Direct current-direct current (DC-DC) converter (5), A bus capacitor assembly (4), comprising: a first capacitor (C1), one end of which is connected to both a second end of the PFC circuit (3) and one end of the DC-DC converter (5); a second capacitor (C2), one end of which is connected to the other end of the first capacitor (C1), and the other end of which is connected to both a third end of the PFC circuit (3) and the other end of the DC-DC converter (5); a bus capacitor assembly (4) comprising: a controller (1) connected to both the PFC circuit (3) and the DC-DC converter (5), and configured to dynamically adjust a duty ratio of a high-frequency bridge arm of the PFC circuit (3) based on the voltage of the AC power source (6) when the charger is in a single-phase AC charging mode, discharge the voltage of the AC-side capacitor assembly (2) to perform PFC on the AC power source (6), input DC output from the PFC circuit (3) to the DC-DC converter (5), enable the DC-DC converter (5) to perform voltage conversion on the DC, and output the DC to a device to be charged; and wherein the other end of the first capacitor (C1) and the end of the second capacitor (C2) are both connected to the other end of the AC-side capacitor assembly (2).

2. The PFC circuit (3) an M-phase high frequency bridge arm (B1), a first bus terminal of the M-phase high frequency bridge arm (B1) connected to the first capacitor (C1) and a second bus terminal of the M-phase high frequency bridge arm (B1) connected to the second capacitor (C2); M coils (KM), each having a first end connected to a midpoint of the M-phase high frequency bridge arm (B1) in a one-to-one correspondence, and a second end connected to a live line of the AC power source (6); a power frequency bridge arm (B2), one end of which is connected to both the first bus terminal and the first capacitor (C1), the other end of which is connected to both the second bus terminal and the second capacitor (C2), and a midpoint of which is connected to a neutral line (N) of the AC power source (6); 2. The charger of claim 1, wherein M≧1, and the AC-side capacitor assembly (2) comprises M third capacitors (C3), first ends of the M third capacitors (C3) are connected to the second ends of the M coils (KM) in a one-to-one correspondence, and second ends of the M third capacitors (C3) are connected together to form a neutral point, and the neutral point is connected to both the first capacitor (C1) and the second capacitor (C2) via a resistor.

3. The controller (1) is connected to each of the M-phase high frequency bridge arms (B1), If the absolute value of the voltage of the AC power source is equal to or less than a first preset voltage, control a target high frequency bridge arm to be turned off, the target high frequency bridge arm comprising one or more high frequency bridge arms used in the single-phase AC charging mode; When the input voltage of the charger is in a positive half cycle, if the voltage is greater than the first preset voltage and less than a second preset voltage, control the upper bridge arm of the target high frequency bridge arm to be turned off and the lower bridge arm to be turned on with a first duty ratio to discharge the voltage of the AC side capacitor assembly (2); if the voltage is greater than the second preset voltage, control the lower bridge arm to be turned on with a second duty ratio to perform the PFC on the AC power source; and if the first preset voltage is less than the second preset voltage, When the input voltage of the charger is in a negative half cycle, if the absolute value of the voltage is greater than the first preset voltage and less than the second preset voltage, the lower bridge arm of the target high frequency bridge arm is controlled to be turned off and the upper bridge arm is controlled to be turned on with the first duty ratio to discharge the voltage of the AC-side capacitor assembly (2), and if the absolute value of the voltage is greater than the second preset voltage, the upper bridge arm of the target high frequency bridge arm is controlled to be turned on with the second duty ratio to perform the PFC on the AC power source. The charger of claim 2 , configured to:

4. The controller (1) further comprises: controlling the upper and lower bridge arms of the target high frequency bridge arm to be alternately turned on after the lower bridge arm of the target high frequency bridge arm has been continuously turned on for a preset period at the second duty ratio; After the upper bridge arm of the target high frequency bridge arm has been continuously turned on for the preset period at the second duty ratio, the upper bridge arm and the lower bridge arm of the target high frequency bridge arm are controlled to be alternately turned on. The charger of claim 3 , configured to:

5. the target high frequency bridge arm comprises a plurality of high frequency bridge arms; the controller (1) is configured to control the upper bridge arm of the target high frequency bridge arm to be turned off and the lower bridge arm to be turned on alternately at a preset angle and the first duty ratio, and to control the lower bridge arm of the target high frequency bridge arm to be turned off and the upper bridge arm to be turned on alternately at the preset angle and the first duty ratio; 5. The charger according to claim 3 or 4.

6. 6. The charger according to claim 3, wherein the controller (1) is connected to the power frequency bridge arm (B2) and is configured to control a lower bridge arm of the power frequency bridge arm (B2) to be on and an upper bridge arm to be off when the input voltage of the charger is in the positive half cycle, and to control the upper bridge arm of the power frequency bridge arm (B2) to be on and the lower bridge arm to be off when the input voltage of the charger is in the negative half cycle.

7. When the charger is in a single-phase AC charging mode, dynamically adjust a duty ratio of a high frequency bridge arm of the PFC circuit based on a voltage of the AC power source to discharge a voltage of the AC side capacitor assembly and perform PFC on the AC power source; inputting the DC output from the PFC circuit into a DC-DC converter, and enabling the DC-DC converter to perform voltage conversion on the DC and output the DC to a device to be charged; a first end of the PFC circuit configured to connect to the AC power source; the bus capacitor assembly including a first capacitor and a second capacitor; one end of the first capacitor connected to both a second end of the PFC circuit and one end of the DC-DC converter; the other end of the first capacitor connected to one end of the second capacitor; and the other end of the second capacitor connected to both a third end of the PFC circuit and the other end of the DC-DC converter; one end of the AC side capacitor assembly connected to both the AC power source and the first end of the PFC circuit; and the other end of the AC side capacitor assembly connected to both the first capacitor and the second capacitor.

8. the PFC circuit comprises an M-phase high frequency bridge arm, M coils, and a power frequency bridge arm, where M≧1; a first bus terminal of the M-phase high frequency bridge arm is connected to the first capacitor, a second bus terminal of the M-phase high frequency bridge arm is connected to the second capacitor, first ends of the M coils are connected to midpoints of the M-phase high frequency bridge arms in a one-to-one correspondence, second ends of the M coils are connected to live lines of the AC power supply, one end of the power frequency bridge arm is connected to the first bus terminal and the first capacitor, the other end of the power frequency bridge arm is connected to the second bus terminal and the second capacitor, and the midpoint of the power frequency bridge arm is connected to a neutral line of the AC power supply; the AC-side capacitor assembly comprises M third capacitors, first ends of the M third capacitors are connected to the second ends of the M coils in a one-to-one correspondence, and second ends of the M third capacitors are connected together to form a neutral point, and the neutral point is connected to both the first capacitor and the second capacitor via a resistor; dynamically adjusting a duty ratio of a high frequency bridge arm of the PFC circuit based on a voltage of the AC power source to discharge a voltage of the AC side capacitor assembly and perform PFC on the AC power source; controlling a target high frequency bridge arm to be turned off if the absolute value of the voltage of the AC power source is equal to or less than a first preset voltage, wherein the target high frequency bridge arm comprises one or more high frequency bridge arms used in the single-phase AC charging mode; and When the input voltage of the charger is in a positive half cycle, if the voltage is greater than the first preset voltage and less than a second preset voltage, controlling an upper bridge arm of the target high frequency bridge arm to be turned off and a lower bridge arm to be turned on with a first duty ratio to discharge the voltage of the AC side capacitor assembly; and if the voltage is greater than the second preset voltage, controlling the lower bridge arm to be turned on with a second duty ratio to perform the PFC on the AC power source; When the input voltage of the charger is in a negative half cycle, if the absolute value of the voltage is greater than the first preset voltage and less than the second preset voltage, controlling the lower bridge arm of the target high frequency bridge arm to be turned off and the upper bridge arm to be turned on with the first duty ratio to discharge the voltage of the AC side capacitor assembly; and if the absolute value of the voltage is greater than the second preset voltage, controlling the upper bridge arm to be turned on with the second duty ratio to perform the PFC on the AC power source.

8. The method of claim 7, wherein the first preset voltage is less than the second preset voltage.

9. controlling the upper and lower bridge arms of the target high frequency bridge arm to be alternately turned on after the lower bridge arm of the target high frequency bridge arm has been continuously turned on for a preset period at the second duty ratio; controlling the upper bridge arm of the target high frequency bridge arm to be turned on alternately after the upper bridge arm of the target high frequency bridge arm has been turned on continuously for the preset period at the second duty ratio; The method of claim 8 further comprising:

10. A vehicle comprising a charger according to any one of claims 1 to 6.

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