Converter, vehicle-mounted charging system and vehicle

Abstract

The utility model relates to a converter, a vehicle-mounted charging system and a vehicle. The converter comprises an alternating current transmission port, a first full-bridge circuit unit, a half-bridge circuit unit, a first filter circuit unit, a resonance circuit unit and a second full-bridge circuit unit, the first end of the alternating current transmission port is connected with the first full-bridge circuit unit, the second end of the alternating current transmission port is connected with the half-bridge circuit unit, the alternating current transmission port is used for transmitting alternating current signals, and the first full-bridge circuit unit, the half-bridge circuit unit and the first filter circuit unit are connected in parallel; the resonance circuit unit is connected with the first full-bridge circuit unit and the second full-bridge circuit unit. And the target power device in the second full-bridge circuit unit is in a normally-off state. Thus, in the charging stage, the problem that the charging efficiency is poor due to the fact that the electric quantity in the battery flows backwards to the converter can be avoided, and the reliability of the converter is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of vehicle technology, and in particular to a converter, a vehicle-mounted charging system and a vehicle. Background Art

[0002] The on-board charger OBC of electric vehicles is used to convert AC power into DC power to charge the vehicle's power battery. The on-board charger OBC has a built-in converter for converting AC power into DC power. At present, isolated AC-DC converters usually adopt a two-stage structure, consisting of two independent single-stage converters. The first stage is a power factor correction AC-DC converter, and the second stage is an isolated DC-DC converter. An electrolytic capacitor is connected between the first and second stages, and the electrolytic capacitor is used for energy buffering. However, the two-stage AC-DC converter has the problem of more components and higher hardware cost.

[0003] At present, the market and academia are promoting the evolution of two-stage AC-DC converters towards a single-stage topology, so that the single-stage AC-DC converter can not only save electrolytic capacitors but also reduce the number of power electronic switching devices on the basis of achieving the above functions. Compared with the two-stage AC-DC converter, the single-stage AC-DC converter is smaller in size, more efficient, lower in cost, and has a significantly improved service life. Utility Model Content

[0004] In order to overcome the problems existing in the related art, the present disclosure provides a converter, an on-board charging system and a vehicle.

[0005] According to a first aspect of an embodiment of the present disclosure, there is provided a converter, comprising: an AC power transmission port, a first full-bridge circuit unit, a half-bridge circuit unit, a first filter circuit unit, a resonant circuit unit, and a second full-bridge circuit unit;

[0006] The first end of the AC power transmission port is connected to the first full-bridge circuit unit, the second end of the AC power transmission port is connected to the half-bridge circuit unit, and the AC power transmission port is used to transmit an AC signal:

[0007] The first full-bridge circuit unit, the half-bridge circuit unit and the first filter circuit unit are connected in parallel;

[0008] The resonant circuit unit is connected to the first full-bridge circuit unit and the second full-bridge circuit unit respectively;

[0009] The target power device in the second full-bridge circuit unit is in a normally-off state.

[0010] Optionally, the second full-bridge circuit unit includes a first bridge arm and a second bridge arm, the first bridge arm includes a first power device and a second power device, the second bridge arm includes a third power device and a fourth power device, the first power device is located at an upper bridge arm of the first bridge arm, the second power device is located at a lower bridge arm of the first bridge arm, the third power device is located at an upper bridge arm of the second bridge arm, and the fourth power device is located at a lower bridge arm of the second bridge arm;

[0011] The target power device includes the first power device and the third power device; or, the target power device includes the second power device and the fourth power device.

[0012] Optionally, the converter further comprises a drive signal generating unit and a control unit;

[0013] The drive signal generating unit is used to generate a first type of drive signal for controlling the operation of the second full-bridge circuit unit, wherein the first type of drive signal includes a second drive signal for controlling the target power device to be in a normally-off state and a first drive signal for controlling other power devices in the second full-bridge circuit unit except the target power device;

[0014] The control unit is used to control the target power device to be in a normally-off state using the second drive signal, and to control other power devices in the second full-bridge circuit unit except the target power device to operate using the first drive signal.

[0015] Optionally, other power devices of the second full-bridge circuit unit except the target power device include a first target power device and a second target power device, and the first drive signal includes a first sub-drive signal for controlling the first target power device to work and a second sub-drive signal for controlling the second target power device to work;

[0016] The driving signal generating unit includes a first comparator, a first inverter and a second comparator;

[0017] The positive input terminal of the first comparator is used to input a reference signal, the negative input terminal of the first comparator is used to input a second reference carrier signal, and the output terminal of the first comparator is used to output the first sub-driving signal, wherein the second reference carrier signal is obtained by shifting the first reference carrier signal by a preset phase, the first reference carrier signal is generated according to the current voltage value of the battery, the target voltage value of the battery and the alternating current signal, and the reference signal is generated according to a preset duty cycle of the driving signal and the first reference carrier signal;

[0018] The input end of the first inverter is connected to the output end of the first comparator and is used to input the first sub-driving signal, and the output end of the first inverter is used to output the second sub-driving signal;

[0019] The positive input terminal of the second comparator is used for a preset signal, the negative input terminal of the second comparator is used for inputting the first reference carrier signal, and the output terminal of the second comparator is used for outputting a second driving signal.

[0020] Optionally, the drive signal generating unit is further used to generate a second type of drive signal for controlling the operation of the first full-bridge circuit unit according to the first reference carrier signal and the reference signal, and the first drive signal delays the second type of drive signal by a preset phase;

[0021] The control unit is further configured to control the operation of the first full-bridge circuit unit using the second type of driving signal.

[0022] Optionally, the first full-bridge circuit unit includes a first group of pairs of tubes and a second group of pairs of tubes, and the second type of driving signal includes a third sub-driving signal for controlling the operation of the first group of pairs of tubes and a fourth sub-driving signal for controlling the operation of the second group of pairs of tubes;

[0023] The driving signal generating unit further includes a third comparator and a second inverter;

[0024] The positive input terminal of the third comparator is used to input the reference signal, the negative input terminal of the third comparator is used to input the first reference carrier signal, and the output terminal of the third comparator is used to output the third sub-driving signal;

[0025] The input end of the second inverter is connected to the output end of the third comparator, and the output end of the second inverter is used to output the fourth sub-driving signal;

[0026] Among them, if the first target power device is the first power device or the fourth power device, the first group of pairs of tubes includes: a fifth power device located in the upper bridge arm of the third bridge arm in the first full-bridge circuit unit and an eighth power device located in the lower bridge arm of the fourth bridge arm in the first full-bridge circuit unit; if the first target power device is the second power device or the third power device, the first group of pairs of tubes includes: a sixth power device located in the lower bridge arm of the third bridge arm in the first full-bridge circuit unit and a seventh power device located in the upper bridge arm of the fourth bridge arm in the first full-bridge circuit unit.

[0027] Optionally, the resonant circuit unit includes a resonant inductor, a first resonant capacitor, a second resonant capacitor and a transformer; the first end of the resonant inductor is connected to the first full-bridge circuit unit, the second end of the resonant inductor is connected to the first full-bridge circuit unit via the first winding of the transformer and the first resonant capacitor, the first end of the second winding of the transformer is connected to the second full-bridge circuit unit, and the second end of the second winding is connected to the second full-bridge circuit unit via the second resonant capacitor.

[0028] Optionally, the AC power transmission port includes an AC power source, a first boost inductor and a second boost inductor;

[0029] The first ends of the first boost inductor and the second boost inductor are respectively connected to the first end of the AC power supply, and the second ends of the first boost inductor and the second boost inductor are respectively connected to the midpoint of the third bridge arm and the midpoint of the fourth bridge arm included in the first full-bridge circuit unit;

[0030] The third bridge arm includes a fifth power device located at the upper bridge arm and a sixth power device located at the lower bridge arm, and the connection point between the fifth power device and the sixth power device is the midpoint of the third bridge arm. The fourth bridge arm includes a seventh power device located at the upper bridge arm and an eighth power device located at the lower bridge arm, and the connection point between the seventh power device and the eighth power device is the midpoint of the fourth bridge arm.

[0031] Optionally, the half-bridge circuit unit includes a ninth power device and a tenth power device, and a connection point between the ninth power device and the tenth power device is a midpoint of a bridge arm of the half-bridge circuit unit;

[0032] The second end of the AC power transmission port is connected to the midpoint of the bridge arm of the half-bridge circuit unit.

[0033] Optionally, the converter further includes a second filtering circuit unit, which is connected in parallel with the second full-bridge circuit unit and is configured to filter the low-frequency signal and store the filtered electric energy.

[0034] According to a second aspect of an embodiment of the present disclosure, there is provided an on-vehicle charging system, the on-vehicle charging system comprising the converter as described in the first aspect of the present disclosure.

[0035] According to a third aspect of an embodiment of the present disclosure, a vehicle is provided, comprising the on-board charging system and a power battery as described in the second aspect of the present disclosure, wherein the on-board charging system is capable of charging the power battery.

[0036] Using the above technical solution,

[0037] The target power device in the second full-bridge circuit unit connected to the battery is controlled to be in a normally disconnected state. In this way, during the charging stage, the problem of poor charging efficiency caused by the charge in the battery being prevented from flowing back to the converter can be avoided, thereby improving the reliability of the converter.

[0038] It is to be understood that the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present disclosure and, together with the description, serve to explain the principles of the present disclosure.

[0040] Figure 1 It is a schematic diagram showing an application scenario according to an exemplary embodiment.

[0041] Figure 2 is a block diagram of a converter according to an exemplary embodiment.

[0042] Figure 3 is a schematic diagram of a converter according to an exemplary embodiment.

[0043] Figure 4 is a schematic diagram showing a method of generating a first type of driving signal according to an exemplary embodiment.

[0044] Figure 5 The diagram is a schematic diagram showing a method of generating a first reference carrier signal according to an exemplary embodiment.

[0045] Figure 6 is a schematic diagram showing a method of generating a second type of driving signal according to an exemplary embodiment.

[0046] Figure 7 is a schematic diagram of a driving signal according to an exemplary embodiment. DETAILED DESCRIPTION

[0047] Exemplary embodiments will be described in detail herein, examples of which are shown in the accompanying drawings. When the following description refers to the drawings, the same numbers in different drawings represent the same or similar elements unless otherwise indicated. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present disclosure. Instead, they are merely examples of devices and methods consistent with some aspects of the present disclosure as detailed in the appended claims.

[0048] It should be noted that all actions of acquiring signals, information or data in the present disclosure are carried out in compliance with the relevant data protection laws and policies of the country where the device is located and with the authorization given by the owner of the corresponding device.

[0049] Currently, during the operation of a single-stage AC-DC converter, for example, during the charging stage, the power in the battery may flow back into the converter, resulting in poor charging efficiency and poor reliability of the converter.

[0050] In view of this, the present disclosure provides a converter, an on-board charging system and a vehicle, which control the target power device in the second full-bridge circuit unit connected to the battery to be in a normally disconnected state. In this way, during the charging stage, it is possible to avoid the problem of the power in the battery flowing back to the converter, thereby causing poor charging efficiency, thereby improving the reliability of the converter.

[0051] Figure 1 is a schematic diagram showing an application scenario according to an exemplary embodiment. Figure 1 As shown, an onboard charger OBC is provided in the vehicle, and the onboard charger OBC includes a single-stage AC-DC converter. When charging is required, the charging gun is inserted into the AC charging pile, after which the onboard charger OBC receives the AC charging instruction, and then under the monitoring of the battery management system BMS, the onboard charger OBC charges the battery on the vehicle. For example, the onboard charger OBC converts the AC power provided by the AC charging pile into DC power for battery charging.

[0052] Figure 2 FIG. 1 is a block diagram of a converter according to an exemplary embodiment. Figure 2 As shown, the converter may include: an AC power transmission port 10 , a first full-bridge circuit unit 20 , a half-bridge circuit unit 30 , a first filter circuit unit 40 , a resonant circuit unit 50 and a second full-bridge circuit unit 60 .

[0053] The first end of the AC power transmission port 10 is connected to the first full-bridge circuit unit 20 , the second end of the AC power transmission port 10 is connected to the half-bridge circuit unit 30 , and the AC power transmission port 10 is used to transmit AC signals.

[0054] The first full-bridge circuit unit 20, the half-bridge circuit unit 30 and the first filter circuit unit 40 are connected in parallel. The first full-bridge circuit unit 20, the half-bridge circuit unit 30 and the first filter circuit unit 40 work together to convert the AC signal transmitted by the AC transmission port 10 into a DC signal. Among them, the first filter circuit unit 40 can perform high-frequency filtering on the electrical signal. For example, the first filter circuit unit 40 is a first filter capacitor, and the first filter capacitor Cc can be a film capacitor or a ceramic capacitor.

[0055] The resonant circuit unit 50 is connected to the first full-bridge circuit unit 20 and the second full-bridge circuit unit 60 respectively.

[0056] In the present disclosure, the second full-bridge circuit unit 60 is used to transmit the DC signal converted by the first full-bridge circuit unit 20, the half-bridge circuit unit 30, the first filter circuit unit 40, and the resonant circuit unit 50. For example, when the converter operates in the rectification mode, the second full-bridge circuit unit 60 rectifies the converted DC signal and transmits the rectified DC signal to the power battery of the vehicle.

[0057] In the present disclosure, the converter operates in a rectification mode, and the first full-bridge circuit unit 20, the half-bridge circuit unit 30 and the first filter circuit unit 40 cooperate to convert alternating current into direct current, and transmit the direct current to the resonant circuit unit 50. Thereafter, the resonant circuit unit 50 adjusts the voltage of the direct current according to actual needs, and outputs the direct current with adjusted voltage to the second full-bridge circuit unit 60. The second full-bridge circuit unit 60 rectifies the direct current and outputs a rectified direct current signal, for example, inputting the rectified direct current signal into the power battery of the vehicle.

[0058] In the charging stage, since the target power device in the second full-bridge circuit unit 60 is in a normally-off state, its corresponding body diode is in a freewheeling state, thus preventing the reverse flow of power in the battery to the converter, thereby causing poor charging efficiency.

[0059] By adopting the above technical solution, the target power device in the second full-bridge circuit unit connected to the battery is controlled to be in a normally disconnected state. In this way, during the charging stage, the problem of poor charging efficiency caused by the power in the battery being reversely flowed to the converter can be avoided, thereby improving the reliability of the converter.

[0060] In the present disclosure, the resonant circuit unit includes a resonant inductor, a first resonant capacitor, a second resonant capacitor and a transformer; the first end of the resonant inductor is connected to the first full-bridge circuit unit, the second end of the resonant inductor is connected to the first full-bridge circuit unit via the first winding of the transformer and the first resonant capacitor, the first end of the second winding of the transformer is connected to the second full-bridge circuit unit, and the second end of the second winding is connected to the second full-bridge circuit unit via the second resonant capacitor.

[0061] Figure 3 FIG. 1 is a schematic diagram of a converter according to an exemplary embodiment. Figure 3 As shown, the resonant circuit unit 50 includes a resonant inductor Ls, a first resonant capacitor Cr, a second resonant capacitor Cs and a transformer T. The resonant inductor Ls is connected to the first resonant capacitor Cr and the second resonant capacitor Cs via the transformer T, respectively, the resonant inductor Ls and the first resonant capacitor Cr are connected to the first full-bridge circuit unit 20, respectively, and the transformer T and the second resonant capacitor Cs are connected to the second full-bridge circuit unit 60, respectively.

[0062] For example, the transformer T includes a first winding and a second winding. The first end of the resonant inductor Ls is connected to the first full-bridge circuit unit 20, and the second end of the resonant inductor Ls is connected to the first resonant capacitor Cr via the first winding; the first end of the second winding is connected to the second full-bridge circuit unit 60, and the second end of the second winding is connected to the second full-bridge circuit unit 60 via the second resonant capacitor Cs.

[0063] By selecting appropriate inductance values ​​of the resonant inductor, capacitance values ​​of the first resonant capacitor, and capacitance values ​​of the second resonant capacitor, the converter can be operated in a resonant state. In addition, the resonant inductor may include one or more inductors connected in series and parallel, and the first resonant capacitor and the second resonant capacitor may also include one or more capacitors connected in series and parallel. Figure 3 In the description, the resonant inductor includes an inductor, and the first resonant capacitor and the second resonant capacitor each include a capacitor. In one embodiment, the first resonant capacitor and the second resonant capacitor may be a film capacitor or a ceramic capacitor. Since the film capacitor or the ceramic capacitor has a low cost and a small volume, the hardware cost of the converter can be reduced, and the converter volume can be further reduced, and the space occupied by the converter can be reduced.

[0064] In the present disclosure, by selecting the inductance value of the resonant inductor, the capacitance value of the first resonant capacitor, and the capacitance value of the second resonant capacitor in the resonant circuit unit, the converter can be operated in a resonant state. On the one hand, the electromagnetic compatibility design can be optimized. On the other hand, while keeping the total amount of power devices unchanged, the resonant circuit unit enables the power devices to have a wider soft switching range, reduce the switching loss of high-frequency devices, and improve the working efficiency of the converter. In addition, since the converter can operate in a resonant state, the voltage transmission range is wider. At low voltage input, energy transmission is easier, and there is no need to introduce additional complex control strategies.

[0065] In the present disclosure, since the converter can operate in a resonant state, the frequencies of the drive signal for driving the first full-bridge circuit unit and the drive signal for driving the second full-bridge circuit unit can be changed, that is, the frequencies of the drive signals are different at different times. In this way, the converter can operate in a variable frequency resonant state. It should be understood that the drive signal for driving the first full-bridge circuit unit and the drive signal for driving the second full-bridge circuit unit can both be generated by a microprocessor. The specific method of generating the drive signal will be described in detail below.

[0066] In one embodiment, the second full-bridge circuit unit 60 includes a first bridge arm 601 and a second bridge arm 602, the first bridge arm 601 includes a first power device S1 and a second power device S2, the second bridge arm 602 includes a third power device S3 and a fourth power device S4, the first power device S1 is located at the upper bridge arm of the first bridge arm 601, the second power device S2 is located at the lower bridge arm of the first bridge arm 601, the source of the first power device S1 is connected to the drain of the second power device S2, and the connection point is recorded as the midpoint c of the first bridge arm 601. The third power device S3 is located at the upper bridge arm of the second bridge arm 602, and the fourth power device S4 is located at the lower bridge arm of the second bridge arm 602. The source of the third power device S3 is connected to the drain of the fourth power device S4, and the connection point is recorded as the midpoint d of the second bridge arm 602. The first end of the second winding of the transformer T is connected to the midpoint c of the first bridge arm 601 , and the second end of the second winding of the transformer T is connected to the midpoint d of the second bridge arm 602 via the second resonant capacitor Cs.

[0067] The target power device in the normally-off state may include a first power device S1 and a third power device S3 located in an upper bridge arm; or, the target power device in the normally-off state may include a second power device S2 and a fourth power device S4 located in a lower bridge arm.

[0068] In addition, since the first power device S1 and the third power device S3 located in the upper bridge arm are connected to the positive electrode of the battery, in order to further prevent the power in the battery from flowing back to the converter, preferably, the target power device may include the first power device S1 and the third power device S3 located in the upper bridge arm.

[0069] Correspondingly, the converter further includes a drive signal generating unit and a control unit. The drive signal generating unit is used to generate a first type of drive signal for controlling the operation of the second full-bridge circuit unit, wherein the first type of drive signal includes a second drive signal for controlling the target power device to be in a normally disconnected state and a first drive signal for controlling other power devices in the second full-bridge circuit unit except the target power device; the control unit is used to control the target power device to be in a normally disconnected state using the second drive signal, and to control the operation of other power devices in the second full-bridge circuit unit except the target power device using the first drive signal.

[0070] For example, the drive signal generating unit is connected to the control unit, and the control unit is connected to the second full-bridge circuit unit. That is, the drive signal generating unit sends the first drive signal and the second drive signal generated by it to the control unit, and then the control unit uses the second drive signal to control the target power device to be in a normally disconnected state, and uses the first drive signal to control the other power devices in the second full-bridge circuit unit 60 except the target power device to work.

[0071] In the present disclosure, the other power devices of the second full-bridge circuit unit 60, except the target power device, include a first target power device and a second target power device. By way of example, it is assumed that the target power device includes a first power device S1 and a third power device S3. The first target power device may be a fourth power device S4, and the second target power device may be a second power device S2, or the first target power device may be a second power device S2, and the second target power device may be a fourth power device S4. Accordingly, the first drive signal includes a first sub-drive signal for controlling the operation of the first target power device and a second sub-drive signal for controlling the operation of the second target power device.

[0072] Figure 4 FIG. 1 is a schematic diagram showing a method of generating a first type of driving signal according to an exemplary embodiment. Figure 4 As shown, the driving signal generating unit may include a first comparator A1, a first inverter F1, and a second comparator A2. The positive input terminal of the first comparator A1 is used to input a reference signal b, the negative input terminal of the first comparator A1 is used to input a second reference carrier signal Fs2, and the output terminal of the first comparator A1 is used to output a first sub-driving signal, wherein the second reference carrier signal Fs2 is obtained by shifting the first reference carrier signal Fs1 by a preset phase, the first reference carrier signal Fs1 is generated according to the current voltage value of the battery, the target voltage value of the battery, and the alternating current signal, and the reference signal b is generated according to a preset duty cycle D of the driving signal and the first reference carrier signal Fs1.

[0073] For example, Figure 5 FIG. 1 is a schematic diagram showing a method of generating a first reference carrier signal according to an exemplary embodiment. Figure 5 As shown, first, the current voltage value of the battery V bat and the target voltage value V bat * Input voltage control loop, get the target current value i of voltage control loop output gd * The target voltage value refers to the target value of the battery charging, which can be obtained from the charging instruction. In addition, according to the AC signal i currently input to the AC transmission port g The current signal outputted after passing through the first full-bridge circuit unit 20 and the half-bridge circuit unit 30 and the AC signal i g , using the rotating coordinate transformation of the αβ AC current component to the dq DC component, the AC signal i is obtained g The corresponding current follows the value i gd After that, the target current value i gd * and the current follows the value i gdThe difference is input into the current control loop to obtain the frequency control parameter output by the current control loop. Finally, the frequency control parameter is input into the carrier generator, and the carrier generator generates and outputs the first reference carrier signal Fs1 according to the frequency control parameter, wherein the frequency of the first reference carrier signal Fs1 is the frequency corresponding to the frequency control parameter.

[0074] After the first reference carrier signal Fs1 is generated in the above manner, the first reference carrier signal Fs1 is phase-shifted by a preset phase to obtain a second reference carrier signal Fs2. The preset phase is determined according to the phase of the AC signal. For example, the preset phase is in a linear function relationship with the phase of the AC signal, and the specific functional relationship can be pre-calibrated by experiments. The preset phase can range from 0 to 0.5 rad.

[0075] In addition, the reference signal is generated according to the preset duty cycle D of the driving signal and the first reference carrier signal Fs1, and the amplitude of the reference signal b does not change with the phase of the AC signal. For example, the product of the duty cycle D and the maximum amplitude of the first reference carrier signal Fs1 can be determined as the reference signal b, which is a fixed value and does not change with the phase of the AC signal. For example, assuming that the duty cycle D is 50%, if the maximum amplitude of the first reference carrier signal Fs1 is 1, the reference signal b is y=0.5. If the maximum amplitude of the first reference carrier signal Fs1 is 100, the reference signal b is y=50.

[0076] It should be understood that the duty cycle may also be other values, but when the duty cycle is 50%, the energy transmitted by the converter is maximum, that is, the voltage utilization rate of the converter is highest.

[0077] return Figure 4 The output end of the first comparator A1 is connected to the first inverter F1, that is, the first sub-driving signal is input into the first inverter F1 to obtain the second sub-driving signal output by the first inverter F1 for controlling the operation of the second target power device.

[0078] The positive input terminal of the second comparator A2 is used for the preset signal c, the negative input terminal of the second comparator A2 is used for inputting the first reference carrier signal Fs1, and the output terminal of the second comparator A2 is used for outputting the second drive signal. The second drive signal is a low level 0, which is used to control the target power device to be in a normally disconnected state.

[0079] The preset signal may be a signal whose amplitude is 0, or may be any signal whose amplitude is not 0 but whose amplitude at each moment is smaller than the amplitude of the first reference carrier signal Fs1 at that moment, and the present disclosure does not make any specific limitation on this.

[0080] The drive signal generating unit can also control the first full-bridge circuit unit 20. For example, the drive signal generating unit is also used to generate a second type of drive signal for controlling the operation of the first full-bridge circuit unit according to the first reference carrier signal and the reference signal; the control unit 80 is also used to control the first full-bridge circuit unit 20 using the second type of drive signal. There is a phase delay between the second type of drive signal and the first drive signal, and the delayed phase is the above-mentioned preset phase. For example, the first drive signal delays the preset phase of the second type of drive signal.

[0081] like Figure 3 As shown, the first full-bridge circuit unit 20 includes a third bridge arm 201 and a fourth bridge arm 202, wherein the third bridge arm 201 includes a fifth power device S5 and a sixth power device S6, and the fourth bridge arm 202 includes a seventh power device S7 and an eighth power device S8. The fifth power device S5 and the eighth power device S8 form a group of pairs of tubes, and the sixth power device S6 and the seventh power device S7 form a group of pairs of tubes. The second type of driving signal includes a third sub-driving signal for controlling the operation of the first group of pairs of tubes and a fourth sub-driving signal for controlling the operation of the second group of pairs of tubes. Accordingly, the driving signal generating unit also includes a third comparator and a second inverter.

[0082] Figure 6 FIG. 1 is a schematic diagram showing a method of generating a second type of driving signal according to an exemplary embodiment. Figure 6 As shown, the positive input terminal of the third comparator A3 is used to input the reference signal b, the negative input terminal of the third comparator A3 is used to input the first reference carrier signal Fs1, and the output terminal of the third comparator A3 is used to output the third sub-driving signal. The input terminal of the second inverter F2 is connected to the output terminal of the third comparator A3, and the output terminal of the second inverter F2 is used to output the fourth sub-driving signal.

[0083] Among them, if the first target power device is the first power device or the fourth power device, the first group of pairs of tubes includes: a fifth power device located at the upper bridge arm of the third bridge arm in the first full-bridge circuit unit and an eighth power device located at the lower bridge arm of the fourth bridge arm in the first full-bridge circuit unit; if the first target power device is the second power device or the third power device, the first group of pairs of tubes includes: a sixth power device located at the lower bridge arm of the third bridge arm in the first full-bridge circuit unit and a seventh power device located at the upper bridge arm of the fourth bridge arm in the first full-bridge circuit unit.

[0084] In one possible manner, assuming that the target power devices in the normally-off state are the second power device S2 and the fourth power device S4, if the first target power device is the first power device S1, the first group of pairs of tubes includes the fifth power device S5 and the eighth power device S8, and the second group of pairs of tubes includes the sixth power device S6 and the seventh power device S7; if the first target power device is the third power device S3, the first group of pairs of tubes includes the sixth power device S6 and the seventh power device S7, and the second group of pairs of tubes includes the fifth power device S5 and the eighth power device S8.

[0085] In another possible manner, assuming that the target power devices in the normally-off state are the first power device S1 and the third power device S3, if the first target power device is the fourth power device S4, the first group of pairs of tubes includes the fifth power device S5 and the eighth power device S8, and the second group of pairs of tubes includes the sixth power device S6 and the seventh power device S7; if the first target power device is the second power device S2, the first group of pairs of tubes includes the sixth power device S6 and the seventh power device S7, and the second group of pairs of tubes includes the fifth power device S5 and the eighth power device S8.

[0086] Figure 7 FIG. 1 is a schematic diagram showing a driving signal according to an exemplary embodiment. Figure 7 As shown, there is a delay of a preset phase φ between the first sub-drive signal output by the first comparator A1 and the third sub-drive signal output by the third comparator A3, and there is a delay of a preset phase φ between the second sub-drive signal output by the first inverter F1 and the fourth sub-drive signal output by the second inverter F2. That is, the power devices corresponding to the primary and secondary sides of the transformer are not turned on at the same time, and there is a certain phase delay. For example, assuming that the target power devices in the normally off state are the first power device S1 and the third power device S3, the fifth power device S5 and the eighth power device S8 on the primary side of the transformer and the fourth power device S4 on the secondary side of the transformer are not turned on at the same time, and there is a certain phase delay.

[0087] Among them, Figure 7 As shown, the duty cycles of the first to fourth sub-driving signals are all 50%.

[0088] Combination Figure 3In the converter shown, it is assumed that the first power device S1 and the third power device S3 are in a normally disconnected state, and the first full-bridge circuit unit 20 works under the drive of the second type of driving signal, and stores the AC power grid energy in the resonant circuit unit 50. Afterwards, after a preset phase delay, when the fourth power device S4 is turned on and the second power device S2 is turned off, the resonant power energy is stored in the resonant circuit unit 50. In addition, when the second power device S2 is turned on and the fourth power device S4 is turned off, the negative electrode of the battery is connected to one end of the second winding of the transformer T via the second power device S2 and the midpoint c, and the other end of the second winding of the transformer T is connected to the positive electrode of the battery via the midpoint d and the body diode of the fourth power device S4, so as to charge the battery with the AC power grid energy and the resonant power energy stored in the resonant circuit unit 50. In this way, the gain of the converter output voltage is improved, thereby improving the charging efficiency.

[0089] By adopting the above technical solution, the target power device in the second full-bridge circuit unit is in a normally disconnected state, and the other power devices in the second full-bridge circuit unit are in a modulation state, and there is a phase delay between the drive signal used when modulating other power devices and the drive signal used when modulating the power device on the primary side of the transformer. In this way, the output voltage gain and charging efficiency are improved while preventing the reverse flow of battery energy and improving the reliability of the converter.

[0090] In addition, if Figure 3 As shown, the AC power transmission port 10 includes an AC power source v g , a first boost inductor L1 and a second boost inductor L2, one end of the first boost inductor L1 and the second boost inductor L2 are both connected to an AC power source v g The first boost inductor L1 and the second boost inductor L2 are connected to the positive terminal of the third bridge arm 201, and the other ends of the first boost inductor L1 and the second boost inductor L2 are respectively connected to the midpoint a of the third bridge arm 201 and the midpoint b of the fourth bridge arm 202. The third bridge arm includes a fifth power device S5 located in the upper bridge arm and a sixth power device S6 located in the lower bridge arm, and the connection point of the fifth power device S5 and the sixth power device S6 is the midpoint a of the third bridge arm. The fourth bridge arm includes a seventh power device S7 located in the upper bridge arm and an eighth power device S8 located in the lower bridge arm, and the connection point of the seventh power device S7 and the eighth power device S8 is the midpoint b of the fourth bridge arm.

[0091] In addition, the half-bridge circuit unit includes a ninth power device and a tenth power device, and the connection point between the ninth power device and the tenth power device is the midpoint of the bridge arm of the half-bridge circuit unit. Figure 3As shown, the half-bridge circuit unit 30 includes a ninth power device S9 and a tenth power device S10, the ninth power device S9 is located at the upper arm of the half-bridge circuit unit 30, the tenth power device S10 is located at the lower arm of the half-bridge circuit unit 30, and the connection point between the ninth power device S9 and the tenth power device S10 is the midpoint e of the half-bridge circuit unit 30. AC power supply source v g The negative terminal of is connected to the midpoint e of the half-bridge circuit unit 30.

[0092] The control unit is used to control the tenth power device S10 to be turned on and the ninth power device S9 to be turned off during the positive half cycle of the AC signal, and to control the tenth power device S10 to be turned off and the ninth power device S9 to be turned on during the negative half cycle of the AC signal.

[0093] exist Figure 3 In the embodiment, the third bridge arm, the fourth bridge arm and the half-bridge circuit unit form a single-phase interleaved totem pole PFC topology structure, which can improve the conversion efficiency, reduce the current ripple of the input alternating current, and improve the quality of the input alternating current.

[0094] The power device may be a MOS tube, an IGBT or a diode, which is not limited in the present disclosure. Figure 3 In the description, it is taken that the above power devices are all MOS tubes as an example.

[0095] The converter may further include a second filter circuit unit, which is connected in parallel with the second full-bridge circuit unit 60 and is used for energy storage filtering of the DC signal. Figure 3 As shown, the second filter circuit unit may include a second filter capacitor Cf. The first end of the second filter capacitor Cf is connected to the drain of the first power device S1 and the third power device S3, and the second end of the second filter capacitor Cf is connected to the source of the second power device S2 and the fourth power device S4. Figure 3 In the embodiment, the second filter capacitor Cf filters the low-frequency signal and then outputs a filtered direct current signal Vdc.

[0096] Based on the same concept, the present disclosure also provides an on-vehicle charging system, which includes the converter provided by the present disclosure.

[0097] Based on the same concept, the present disclosure also provides a vehicle, which includes the on-board charging system and a power battery provided by the present disclosure, and the on-board charging system can charge the power battery.

[0098] For example, the vehicle may be a pure electric vehicle or a hybrid vehicle.

[0099] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the present disclosure. The present disclosure is intended to cover any variations, uses or adaptations of the present disclosure that follow the general principles of the present disclosure and include common knowledge or customary techniques in the art that are not disclosed in the present disclosure. The description and examples are to be considered as exemplary only, and the true scope and spirit of the present disclosure are indicated by the following claims.

[0100] It should be understood that the present disclosure is not limited to the exact structures that have been described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present disclosure is limited only by the appended claims.

Claims

1. A converter, characterized in that: include: An alternating current transmission port, a first full-bridge circuit unit, a half-bridge circuit unit, a first filter circuit unit, a resonant circuit unit, and a second full-bridge circuit unit; The first end of the AC power transmission port is connected to the first full-bridge circuit unit, the second end of the AC power transmission port is connected to the half-bridge circuit unit, and the AC power transmission port is used to transmit an AC signal: The first full-bridge circuit unit, the half-bridge circuit unit and the first filter circuit unit are connected in parallel; The resonant circuit unit is connected to the first full-bridge circuit unit and the second full-bridge circuit unit respectively; The target power device in the second full-bridge circuit unit is in a normally-off state.

2. The converter according to claim 1, characterized in that The second full-bridge circuit unit includes a first bridge arm and a second bridge arm, the first bridge arm includes a first power device and a second power device, the second bridge arm includes a third power device and a fourth power device, the first power device is located at an upper bridge arm of the first bridge arm, the second power device is located at a lower bridge arm of the first bridge arm, the third power device is located at an upper bridge arm of the second bridge arm, and the fourth power device is located at a lower bridge arm of the second bridge arm; The target power device includes the first power device and the third power device; or, the target power device includes the second power device and the fourth power device.

3. The converter according to claim 2, characterized in that The converter also includes a drive signal generating unit and a control unit; The drive signal generating unit is used to generate a first type of drive signal for controlling the operation of the second full-bridge circuit unit, wherein the first type of drive signal includes a second drive signal for controlling the target power device to be in a normally-off state and a first drive signal for controlling other power devices in the second full-bridge circuit unit except the target power device; The control unit is used to control the target power device to be in a normally-off state using the second drive signal, and to control other power devices in the second full-bridge circuit unit except the target power device to operate using the first drive signal.

4. The converter according to claim 3, characterized in that The other power devices of the second full-bridge circuit unit except the target power device include a first target power device and a second target power device, and the first driving signal includes a first sub-driving signal for controlling the operation of the first target power device and a second sub-driving signal for controlling the operation of the second target power device; The driving signal generating unit includes a first comparator, a first inverter and a second comparator; The positive input terminal of the first comparator is used to input a reference signal, the negative input terminal of the first comparator is used to input a second reference carrier signal, and the output terminal of the first comparator is used to output the first sub-driving signal, wherein the second reference carrier signal is obtained by shifting the first reference carrier signal by a preset phase, the first reference carrier signal is generated according to the current voltage value of the battery, the target voltage value of the battery and the alternating current signal, and the reference signal is generated according to a preset duty cycle of the driving signal and the first reference carrier signal; The input end of the first inverter is connected to the output end of the first comparator and is used to input the first sub-driving signal, and the output end of the first inverter is used to output the second sub-driving signal; The positive input terminal of the second comparator is used for a preset signal, the negative input terminal of the second comparator is used for inputting the first reference carrier signal, and the output terminal of the second comparator is used for outputting a second driving signal.

5. The converter according to claim 4, characterized in that The driving signal generating unit is further used to generate a second type of driving signal for controlling the operation of the first full-bridge circuit unit according to the first reference carrier signal and the reference signal, wherein the first driving signal delays the second type of driving signal by a preset phase; The control unit is further configured to control the operation of the first full-bridge circuit unit using the second type of driving signal.

6. The converter according to claim 5, characterized in that The first full-bridge circuit unit includes a first group of pairs of tubes and a second group of pairs of tubes, and the second type of driving signal includes a third sub-driving signal for controlling the operation of the first group of pairs of tubes and a fourth sub-driving signal for controlling the operation of the second group of pairs of tubes; The driving signal generating unit further includes a third comparator and a second inverter; The positive input terminal of the third comparator is used to input the reference signal, the negative input terminal of the third comparator is used to input the first reference carrier signal, and the output terminal of the third comparator is used to output the third sub-driving signal; The input end of the second inverter is connected to the output end of the third comparator, and the output end of the second inverter is used to output the fourth sub-driving signal; Among them, if the first target power device is the first power device or the fourth power device, the first group of pairs of tubes includes: a fifth power device located in the upper bridge arm of the third bridge arm in the first full-bridge circuit unit and an eighth power device located in the lower bridge arm of the fourth bridge arm in the first full-bridge circuit unit; if the first target power device is the second power device or the third power device, the first group of pairs of tubes includes: a sixth power device located in the lower bridge arm of the third bridge arm in the first full-bridge circuit unit and a seventh power device located in the upper bridge arm of the fourth bridge arm in the first full-bridge circuit unit.

7. The converter according to any one of claims 1 to 6, characterized in that: The resonant circuit unit includes a resonant inductor, a first resonant capacitor, a second resonant capacitor and a transformer; the first end of the resonant inductor is connected to the first full-bridge circuit unit, the second end of the resonant inductor is connected to the first full-bridge circuit unit via the first winding of the transformer and the first resonant capacitor, the first end of the second winding of the transformer is connected to the second full-bridge circuit unit, and the second end of the second winding is connected to the second full-bridge circuit unit via the second resonant capacitor.

8. The converter according to claim 1, characterized in that The AC power transmission port includes an AC power source, a first boost inductor and a second boost inductor; The first ends of the first boost inductor and the second boost inductor are respectively connected to the first end of the AC power supply, and the second ends of the first boost inductor and the second boost inductor are respectively connected to the midpoint of the third bridge arm and the midpoint of the fourth bridge arm included in the first full-bridge circuit unit; The third bridge arm includes a fifth power device located at the upper bridge arm and a sixth power device located at the lower bridge arm, and the connection point between the fifth power device and the sixth power device is the midpoint of the third bridge arm. The fourth bridge arm includes a seventh power device located at the upper bridge arm and an eighth power device located at the lower bridge arm, and the connection point between the seventh power device and the eighth power device is the midpoint of the fourth bridge arm.

9. The converter according to claim 8, characterized in that The half-bridge circuit unit includes a ninth power device and a tenth power device, and a connection point between the ninth power device and the tenth power device is a midpoint of a bridge arm of the half-bridge circuit unit; The second end of the AC power transmission port is connected to the midpoint of the bridge arm of the half-bridge circuit unit.

10. The converter according to claim 1, characterized in that The converter further includes a second filtering circuit unit, which is connected in parallel with the second full-bridge circuit unit and is used for filtering the low-frequency signal and storing the filtered electric energy.

11. A vehicle charging system, characterized in that: The on-vehicle charging system comprises the converter according to any one of claims 1-10.

12. A vehicle, characterized in that: The vehicle comprises the on-board charging system as claimed in claim 11 and a power battery, and the on-board charging system is capable of charging the power battery.

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