Charging circuit and electric equipment

Abstract

The invention relates to a charging circuit and electric equipment. The charging circuit comprises a power supply circuit unit, a power inductance circuit unit and a power factor correction circuit unit. The power supply circuit unit is connected with the power inductance circuit unit and is used for selecting a target power supply from a direct-current power supply and an alternating-current power supply which are connected with each other and inputting an electric signal provided by the target power supply to the power inductance circuit unit; and the power factor correction circuit unit is connected with the power inductance circuit unit and is used for boosting the electric signal output by the power inductance circuit unit to obtain a first electric signal and supplying power to the power battery and / or the high-voltage accessory by using the first electric signal when the charging mode is a direct-current boosting charging mode. Therefore, the multiplexing AC charging power factor correction circuit unit performs boosting processing on the electric signal, so that the electrical integration is high, the problems of charging port electrification and high-voltage safety risk caused by electrical coupling can be avoided, and the charging safety is improved.

Description

Technical Field

[0001] The present disclosure relates to the field of charging technology, and in particular to a charging circuit and an electric device. Background Art

[0002] At present, the charging of electric vehicles is mainly divided into two modes: AC slow charging and DC fast charging. AC slow charging is often achieved by converting AC into DC to charge the on-board high-voltage battery through the on-board charger OBC. The charging power is usually divided into two levels of 7kW and 11kW. Among them, the charging power of slow charging using single-phase AC is usually 7kW, and the charging power of slow charging using three-phase AC is usually 11kW. In addition, according to the voltage specifications of the high-voltage battery on the vehicle side and the voltage specifications of the DC charging pile, the DC fast can be fully divided into two methods: DC direct charging and DC boost charging. At present, the vast majority of new energy vehicles on the market have a 400V electrical architecture, while the voltage specifications of DC charging piles are basically 500V, 750V, and 1000V, so the 400V electrical architecture can adopt the DC direct charging method. However, as users have higher and higher requirements for charging performance, the shorter the charging time, the better. The high-voltage and high-power charging methods that come with it are getting more and more attention from vehicle manufacturers. At present, the high-voltage and high-power DC fast charging on the vehicle side is generally 800V. Therefore, for 500V and 750V DC charging piles, the voltage on the charging pile side needs to be boosted to charge the power battery. Summary of the invention

[0003] In order to overcome the problems existing in the related art, the present disclosure provides a charging circuit and an electric device.

[0004] According to a first aspect of an embodiment of the present disclosure, there is provided a charging circuit, comprising: a power supply circuit unit, a power inductor circuit unit and a power factor correction circuit unit;

[0005] The power supply circuit unit is connected to the power inductor circuit unit, and is used to select a target power supply from the connected DC power supply and AC power supply, and input an electrical signal provided by the target power supply to the power inductor circuit unit;

[0006] The power factor correction circuit unit is connected to the power inductance circuit unit, and is used to boost the electrical signal output by the power inductance circuit unit to obtain a first electrical signal, and when the charging mode is a DC boost charging mode, use the first electrical signal to power the power battery and / or high-voltage accessories.

[0007] Optionally, the target power supply further includes an AC power supply; the charging circuit further includes: a primary circuit unit of a resonant converter, a first secondary circuit unit of a resonant converter and a first DC charging control unit;

[0008] The first DC charging control unit is connected to the power factor correction circuit unit, and is used to control the power factor correction circuit unit to be connected to the power battery and / or the high-voltage accessory when the charging mode is the DC boost charging mode, so as to use the first electrical signal to power the power battery and / or the high-voltage accessory;

[0009] The primary circuit unit of the resonant converter is connected to the power factor correction circuit unit, and is used to obtain the first electrical signal, and when the target power source is the AC power source, the first electrical signal is processed in combination with the first secondary circuit unit of the resonant converter to obtain a second electrical signal, so as to use the second electrical signal to power the power battery and / or the high-voltage accessory;

[0010] Wherein, when the target power source is the AC power source, the first secondary circuit unit of the resonant converter is in an on state, and when the target power source is the DC power source, the first secondary circuit unit of the resonant converter is in an off state.

[0011] Optionally, the power circuit unit includes a first selection relay for selecting a DC power source, a second selection relay and a third selection relay for selecting an AC power source;

[0012] The first selection relay includes a first relay and a second relay, wherein a first end of the first relay is connected to a positive electrode of a DC power supply, and a second end of the first relay is connected to a midpoint of a first bridge arm of the power factor correction circuit unit; a first end of the second relay is connected to a negative electrode of the DC power supply, and a second end of the second relay is connected to a second end of the power factor correction circuit unit;

[0013] The second selection relay includes three live wire relays and one neutral wire relay, the power inductor circuit unit includes three power inductors connected in parallel, and the power factor correction circuit unit includes a first bridge arm, a second bridge arm and a third bridge arm;

[0014] The first ends of the three live wire relays are respectively connected to the phase lines of the AC power supply, the second ends of the three live wire relays are respectively connected to the first ends of the three power inductors, and the second ends of the three power inductors are respectively connected to the midpoints of the first bridge arm, the second bridge arm and the third bridge arm;

[0015] The first end of the zero line relay is connected to the zero line of the AC power supply, and the second end of the zero line relay is connected to the midpoint of the third bridge arm;

[0016] The third selection relay includes a third relay and a fourth relay, wherein two ends of the third relay are respectively connected to the midpoint of the first bridge arm and the midpoint of the second bridge arm, and two ends of the fourth relay are respectively connected to the midpoint of the first bridge arm and the midpoint of the third bridge arm.

[0017] Optionally, the charging circuit further includes a second secondary circuit unit of the resonant converter;

[0018] The primary circuit unit of the resonant converter is connected to the second secondary circuit unit of the resonant converter, and is used to process the first electrical signal in combination with the second secondary circuit unit of the resonant converter to obtain a third electrical signal, and use the third electrical signal to power the low-voltage load.

[0019] Optionally, the charging circuit further includes a filter capacitor, and the power factor correction circuit unit, the filter capacitor, and the primary circuit unit of the resonant converter are connected in parallel in sequence.

[0020] Optionally, the first secondary circuit unit of the resonant converter includes a first secondary winding, a fifth relay, a full-bridge circuit, and a first capacitor; the full-bridge circuit includes a fourth bridge arm and a fifth bridge arm;

[0021] The first end of the first secondary winding is connected to the first end of the fifth relay, the second end of the fifth relay is connected to the midpoint of the fourth bridge arm, and the second end of the first secondary winding is connected to the midpoint of the fifth bridge arm;

[0022] The first capacitor is connected in parallel with the full-bridge circuit, and the first end of the first capacitor is connected to the positive electrode of the power battery and / or the high-voltage accessory, and the second end of the first capacitor is connected to the negative electrode of the power battery and / or the high-voltage accessory.

[0023] Optionally, the second secondary circuit unit of the resonant converter includes a second secondary winding, a first power device, a second power device, a third power device, a fourth power device, a first inductor and a second capacitor;

[0024] The first end of the second secondary winding is connected to the first end of the first power device, the second end of the first power device is connected to the second end of the second power device, and the first end of the second power device is connected to the second end of the second secondary winding;

[0025] The first end of the third power device is connected to the midpoint of the second secondary winding, and the second end of the third power device is connected to the first end of the fourth power device and the first end of the first inductor respectively;

[0026] The second end of the fourth power device is connected to the second end of the second power device and the second end of the second capacitor respectively;

[0027] The second end of the first inductor is connected to the first end of the second capacitor, and the first end of the second capacitor is used to be connected to the positive electrode of the low-voltage load, and the second end of the second capacitor is used to be connected to the negative electrode of the low-voltage load.

[0028] Optionally, the first DC charging control unit includes a sixth relay and a seventh relay;

[0029] The first end of the sixth relay is connected to the first end of the power factor correction circuit unit, and the second end of the sixth relay is connected to the positive electrode of the power battery and / or the high-voltage accessory;

[0030] The first end of the seventh relay is connected to the second end of the power factor correction circuit unit, and the second end of the seventh relay is connected to the negative electrode of the power battery and / or the high-voltage accessory;

[0031] Wherein, when the charging mode is the DC boost charging mode, the sixth relay and the seventh relay are closed.

[0032] Optionally, the charging circuit further includes a second DC charging control unit; the second DC charging control unit includes an eighth relay and a ninth relay;

[0033] The first end of the eighth relay is connected to the positive electrode of the DC power supply, and the second end of the eighth relay is connected to the positive electrode of the power battery and / or the high-voltage accessory;

[0034] The first end of the ninth relay is connected to the negative electrode of the DC power supply, and the second end of the ninth relay is connected to the negative electrode of the power battery and / or the high-voltage accessory;

[0035] Wherein, when the charging mode is the DC direct charging mode, the eighth relay and the ninth relay are closed.

[0036] According to a second aspect of an embodiment of the present disclosure, there is provided an electric device, the electric device comprising: the charging circuit, the power battery and / or the high-voltage accessories provided in the first aspect of the present disclosure;

[0037] The charging circuit is connected to the power battery and / or the high-voltage accessory, and is used to supply power to the power battery and / or the high-voltage accessory.

[0038] The technical solution provided by the embodiments of the present disclosure may include the following beneficial effects: by adopting the above technical solution, during DC boost charging, the power factor correction circuit unit of AC charging is reused to boost the electrical signal, and the boosted electrical signal is used to power the power battery and / or high-voltage accessories. In this way, there is no need to design additional booster circuits and EDS circuits for DC boost charging, which effectively reduces the number of power devices and reduces hardware costs. In addition, the power factor correction circuit unit of AC charging is reused to boost the electrical signal, making the electrical system highly integrated, thereby avoiding the problems of charging port charging and high-voltage safety risks caused by electrical coupling, and improving charging safety.

[0039] 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

[0040] 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.

[0041] Figure 1 is a circuit diagram of a Buck-Boost circuit in a related art according to an exemplary embodiment.

[0042] Figure 2 is a block diagram of a charging circuit according to an exemplary embodiment.

[0043] Figure 3 is a block diagram of another charging circuit according to an exemplary embodiment.

[0044] Figure 4 is a circuit diagram of a charging circuit according to an exemplary embodiment. DETAILED DESCRIPTION

[0045] 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.

[0046] It should be noted that all actions of acquiring signals, information or data in this application are carried out in compliance with the relevant data protection laws and policies of the country where they are located, and with the authorization given by the owner of the corresponding device.

[0047] In the relevant technology, the charging circuit that supports the three functions of AC charging, DC direct charging, and DC boost charging is mainly composed of four power modules: on-board charger OBC + DC converter DCDC + electric drive system EDS + booster Booster. Among them, OBC is a power converter for AC slow charging, which converts 220V AC into about 800V DC, and then converts 800V DC into battery charging voltage and charges the battery. DCDC converts high voltage electricity into low voltage electricity, and supplies power to the low-voltage network of the whole vehicle, including low-voltage batteries and low-voltage loads. At present, passenger cars on the market all use 12V low-voltage electrical architecture. Booster+EDS realizes the DC boost charging function. At present, the boost charging power can generally reach 120kW and above. The Booster circuit mainly includes electromagnetic compatibility inductors, X capacitors, Y capacitors, and relays, which are used to realize electromagnetic compatibility protection and on-off control of the DC charging port voltage. The EDS circuit is a motor controller under driving conditions, but in charging mode, it is equivalent to a bidirectional Buck-Boost circuit, which can realize the conversion of two different DC voltage levels. That is, the characteristic of EDS topology is used to achieve the purpose of boosting and charging the 800V power battery at the vehicle end using a 500V or 750V DC charging pile.

[0048] When the voltage specification of the DC charging pile is judged to be 500V or 750V on the vehicle side, and the voltage specification of the power battery on the vehicle side is 800V, the charging mode is considered to be a DC boost charging model. At this time, the relay inside the Booster circuit is closed first, and the power battery uses the EDS circuit to work in the buck mode to pre-charge the voltage of the charging port. For example, the charging port voltage is pre-charged to the voltage range that the 500V / 750V DC charging pile can output. After the vehicle and the charging pile confirm that charging is ready through interaction, the charging pile closes the relay on the charging pile side and starts to output DC charging power based on the charging current request on the vehicle side, which is used to power the high-voltage battery and other loads on the vehicle side (DCDC, air conditioning, etc.).

[0049] Figure 1 FIG. 1 is a circuit diagram of a Buck-Boost circuit in a related art according to an exemplary embodiment. Figure 1 As shown, the Buck-Boost circuit may include a capacitor C low , capacitor C high , inductor L, power device Q1 and power device Q2, wherein the connection relationship of the above-mentioned devices is as follows: Figure 1 As shown, no further description is given here. Figure 1 In the example, high / low voltage conversion can be achieved by controlling the conduction state of power device Q1 and power device Q2. low Convert to U high , you can also use Uhigh Convert to U low .

[0050] It can be seen that the rechargeable batteries in the related technology are relatively independent in terms of architecture, and a large number of power devices are used. In order to achieve boost charging, the Booster circuit includes a large number of capacitors, filter inductors, relay switches, etc., and the hardware cost is extremely high. In addition, due to the large number of power devices, if the circuit design is unreasonable, it will cause electrical coupling with the EDS or BMS circuit, resulting in problems such as charging port being charged, causing high-voltage safety risks, and also causing DC charging failure. Therefore, the design requirements for the Booster circuit are extremely high.

[0051] In view of this, the present disclosure provides a charging circuit and an electric device. During DC boost charging, the power factor correction circuit unit of AC charging is reused to boost the electrical signal, and the boosted electrical signal is used to power the power battery and / or high-voltage accessories. In this way, there is no need to design additional booster circuits and EDS circuits for DC boost charging, which effectively reduces the number of power devices and reduces hardware costs. In addition, the power factor correction circuit unit of AC charging is reused to boost the electrical signal, making the electrical system highly integrated, thereby avoiding the problem of charging port charging and high-voltage safety risks caused by electrical coupling, and improving charging safety.

[0052] Figure 2 FIG. 1 is a block diagram of a charging circuit according to an exemplary embodiment. Figure 2 As shown, the charging circuit may include a power circuit unit 10, a power inductor circuit unit 20 and a power factor correction circuit unit 30. The power circuit unit 10 is used to connect to a DC power supply and an AC power supply and select a target power supply from them. The power circuit unit 10 is also connected to the power inductor circuit unit 20 to input an electrical signal provided by the target power supply to the power inductor circuit unit 20. The power inductor circuit unit 20 performs filtering processing on the electrical signal provided by the target power supply and caches the released energy.

[0053] The power factor correction circuit unit 30 is connected to the power inductor circuit unit 20, and is used to boost the electrical signal output by the power inductor circuit unit 20 to obtain a first electrical signal, and when the charging mode is a DC boost charging mode, use the first electrical signal to power the power battery and / or high-voltage accessories.

[0054] It should be understood that when the target power source is a DC power source, the charging mode may include DC boost charging and DC direct charging. For example, the vehicle-side battery management system BMS can determine whether the charging mode is DC boost charging or DC direct charging based on the voltage specification of the DC power source and the voltage specification of the vehicle-side power battery and / or high-voltage accessories. For example, if the voltage specification of the DC power source is less than the voltage specification of the vehicle-side power battery and / or high-voltage accessories, the charging mode is determined to be DC boost charging. If the voltage specification of the DC power source is greater than or equal to the voltage specification of the vehicle-side power battery and / or high-voltage accessories, the charging mode is determined to be DC direct charging. Afterwards, if the charging mode is determined to be a DC boost charging mode, the first electrical signal output by the power factor correction circuit unit 30 is directly used to power the power battery and / or high-voltage accessories.

[0055] By adopting the above technical solution, during DC boost charging, the power factor correction circuit unit of AC charging is reused to boost the electrical signal, and the boosted electrical signal is used to power the power battery and / or high-voltage accessories. In this way, there is no need to design additional booster circuits and EDS circuits for DC boost charging, which effectively reduces the number of power devices and hardware costs. In addition, the power factor correction circuit unit of AC charging is reused to boost the electrical signal, making the electrical system highly integrated, thereby avoiding the problem of charging port charging and high-voltage safety risks caused by electrical coupling, and improving charging safety.

[0056] In addition, in order to meet the AC charging requirements, the charging circuit may further include a circuit unit for implementing AC charging. In one embodiment, the target power source may further include an AC power source; accordingly, Figure 3 As shown, the charging circuit may further include: a resonant converter primary circuit unit 40 , a resonant converter first secondary circuit unit 50 , and a first DC charging control unit 60 .

[0057] The first DC charging control unit 60 is connected to the power factor correction circuit unit 30, and is used to control the power factor correction circuit unit 30 to be connected to the power battery and / or high-voltage accessories when the charging mode is the DC boost charging mode, so as to power the power battery and / or high-voltage accessories using the first electrical signal.

[0058] The primary circuit unit 40 of the resonant converter is connected to the power factor correction circuit unit 30, and is used to obtain a first electrical signal, and when the target power supply is an AC power supply, the first electrical signal is processed in combination with the first secondary circuit unit 50 of the resonant converter to obtain a second electrical signal, so as to use the second electrical signal to power the power battery and / or high-voltage accessories. When the target power supply is an AC power supply, the first secondary circuit unit of the resonant converter is in an on state, and when the target power supply is a DC power supply, the first secondary circuit unit of the resonant converter is in a disconnected state.

[0059] Among them, the primary circuit unit 40 of the resonant converter and the first secondary circuit unit 50 of the resonant converter work together. On the one hand, the voltage value of the first electrical signal can be adjusted to obtain a second electrical signal consistent with the voltage specification of the power battery and / or high-voltage accessories. On the other hand, it can also achieve the function of isolating AC and DC.

[0060] In this way, the charging circuit provided by the present invention can meet the needs of DC boost charging as well as the needs of AC charging, and the same power factor correction circuit unit is used for DC boost charging and AC charging, without the need to additionally design a booster circuit and an EDS circuit for DC boost charging, thereby effectively reducing the number of power devices and reducing hardware costs. In addition, the power factor correction circuit unit of AC charging is reused to perform voltage boost processing on the electrical signal, making the electrical system highly integrated, thereby avoiding the problems of charging port charging and high voltage safety risks caused by electrical coupling, thereby improving charging safety.

[0061] In addition, if Figure 3 As shown, the charging circuit may further include a resonant converter second secondary circuit unit 70, and the resonant converter primary circuit unit 40 is connected to the resonant converter second secondary circuit unit 70. It should be understood that the connection between the resonant converter primary circuit unit 40 and the resonant converter second secondary circuit unit 70 means that the two are electrically connected, and similarly, the connection between the resonant converter primary circuit unit 40 and the resonant converter first secondary circuit unit 50 also means that the two are electrically connected.

[0062] The resonant converter primary circuit unit 40 combines with the resonant converter second secondary circuit unit 70 to process the first electrical signal to obtain a third electrical signal, and uses the third electrical signal to power the low-voltage load.

[0063] For example, the first electrical signal output by the power factor correction circuit unit 30 is usually 800 V, while the voltage specification of the low-voltage load is usually 12 V, 24 V, or 48 V. Therefore, the resonant converter primary circuit unit 40 and the resonant converter second secondary circuit unit 70 cooperate to convert the 800 V first electrical signal into a second electrical signal consistent with the voltage specification of the low-voltage load, and use the third electrical signal to power the low-voltage load.

[0064] By adopting the above charging circuit, during the DC boost charging process or the AC charging process, it is also possible to supply power to the low-voltage load, thereby further improving the degree of electrical integration.

[0065] In practical applications, considering that subsequent charging is mainly based on high voltage and high power, the voltage specification of the subsequent charging pile can be 1000V. The future DC charging trend may be dominated by 1000V DC fast charging, that is, the charging mode can be a DC direct charging mode. Therefore, Figure 3 As shown, the charging circuit may further include a second DC charging control unit 80, which is connected to the DC power supply, and is used to control the DC power supply to directly supply power to the power battery and / or high-voltage accessories when the charging mode is the DC direct charging mode. For example, Figure 3 As shown, the second DC charging control unit 80 can be connected to the power circuit unit 10, the power battery and / or the high-voltage accessories respectively.

[0066] In order to facilitate those skilled in the art to better understand the charging circuit provided by the present disclosure, Figure 3 The specific structure of each circuit unit is described.

[0067] Figure 4 FIG. 1 is a circuit diagram of a charging circuit according to an exemplary embodiment. Figure 4 As shown, the power circuit unit 10 may include a first selection relay for selecting a DC power source, a second selection relay for selecting an AC power source, and a third selection relay. The DC power source may be used as the target power source by controlling the closing and opening of the first selection relay, and the AC power source may be used as the target power source by controlling the closing and opening of the second selection relay.

[0068] like Figure 4 As shown, the first selection relay includes a first relay K1 and a second relay K2, wherein the first end of the first relay K1 is connected to the positive pole of the DC power supply, and the second end of the first relay K1 is connected to the midpoint of the first bridge arm of the power factor correction circuit unit; the first end of the second relay K2 is connected to the negative pole of the DC power supply, and the second end of the second relay K2 is connected to the second end of the power factor correction circuit unit.

[0069] In practical applications, the AC power supply is usually a single-phase AC power supply or a multi-phase AC power supply. Therefore, in order to ensure that the charging circuit provided by the present disclosure can be adapted to both a single-phase AC power supply and a multi-phase AC power supply, the second selection relay may include three live wire relays and one neutral wire relay. It should be understood that when the AC power supply has a larger number of phase wires, the second selection relay may also include a larger number of live wire relays, and the present disclosure does not specifically limit this.

[0070] In the present disclosure, for the convenience of description, an AC power supply is taken as a three-phase AC power supply as an example. Accordingly, the second selection relay includes three live wire relays and one neutral wire relay, the power inductor circuit unit includes three power inductors connected in parallel, and the power factor correction circuit unit includes a first bridge arm, a second bridge arm, and a third bridge arm.

[0071] First, the specific structure of the power inductor circuit unit is described. Figure 4 As shown, the power inductor circuit unit is a first full-bridge circuit, and the first full-bridge circuit includes a first bridge arm, a second bridge arm, and a third bridge arm. The first bridge arm includes a power device S1 and a power device S2 connected in series, and the connection point between the power device S1 and the power device S2 is the midpoint of the first bridge arm; the second bridge arm includes a power device S3 and a power device S4 connected in series, and the connection point between the power device S3 and the power device S4 is the midpoint of the second bridge arm; the third bridge arm includes a power device S5 and a power device S6 connected in series, and the connection point between the power device S5 and the power device S6 is the midpoint of the third bridge arm.

[0072] The power device may be a MOS tube, or a device composed of a MOS tube and a body diode of the MOS tube connected in parallel, which is not limited in the present disclosure. Figure 4 In the description, the above power devices are all NMOS tubes and MOS tubes whose body diodes are connected in parallel. The drain of the NMOS tube is connected to the cathode of the body diode, and the source of the NMOS tube is connected to the anode of the body diode. It should be understood that the MOS tube used in the present disclosure may also be a PMOS tube, and the present disclosure does not limit this.

[0073] like Figure 4 As shown, in the first bridge arm, the source of the power device S1 is connected to the drain of the power device S2, in the second bridge arm, the source of the power device S3 is connected to the drain of the power device S4, and in the third bridge arm, the source of the power device S5 is connected to the drain of the power device S6. In addition, the drains of the power devices S1, S3, and S5 are connected as the first end of the power inductor circuit unit, and the sources of the power devices S2, S4, and S6 are connected as the second end of the power inductor circuit unit. The power inductor circuit unit includes three parallel power inductors, namely, inductor L g1 、Inductance L g2 and inductor L g3 .

[0074] The three live relays in the second selection relay are respectively denoted as relay RL1, relay RL2 and relay RL3, and the neutral relay is denoted as relay RLN. Figure 4As shown, the first ends of the relays RL1, RL2 and RL3 are connected to the phase lines of the AC power supply respectively, and the second ends of the relays RL1, RL2 and RL3 are connected to the inductor L respectively. g1 、Inductance L g2 and inductor L g3 The first end of the corresponding connection, and the inductor L g1 、Inductance L g2 and inductor L g3 The second end of the relay RLN is connected to the midpoint of the first bridge arm, the midpoint of the second bridge arm and the midpoint of the third bridge arm respectively. The first end of the relay RLN is connected to the neutral line of the AC power supply, and the second end of the relay RLN is connected to the midpoint of the third bridge arm.

[0075] The third selection relay includes a third relay and a fourth relay. Two ends of the third relay K3 are respectively connected to the midpoint of the first bridge arm and the midpoint of the second bridge arm. Two ends of the fourth relay K4 are respectively connected to the midpoint of the first bridge arm and the midpoint of the third bridge arm.

[0076] In addition, the primary circuit unit 40 of the resonant converter is a second full-bridge circuit, a second inductor L2, a third capacitor C3 and a primary winding Z1. Among them, the second full-bridge circuit includes a sixth bridge arm and a seventh bridge arm, the sixth bridge arm includes a power device S7 and a power device S8 connected in series, the connection point of the power device S7 and the power device S8 is the midpoint of the sixth bridge arm, and the seventh bridge arm includes a power device S9 and a power device S10 connected in series, and the connection point of the power device S9 and the power device S10 is the midpoint of the seventh bridge arm. Among them, the specific connection of the above four power devices is similar to the above, and will not be repeated here. The first end of the primary winding Z1 is connected to the midpoint of the sixth bridge arm via the second inductor L2, and the second end of the primary winding Z1 is connected to the midpoint of the seventh bridge arm via the third capacitor C3.

[0077] In addition, a filter capacitor is provided between the power factor correction circuit unit 30 and the resonant converter primary circuit unit 40, and the power factor correction circuit unit, the filter capacitor, and the resonant converter primary circuit unit are sequentially connected in parallel. Figure 4 As shown, the filter capacitor includes two capacitors connected in series, namely a fourth capacitor C4 and a fifth capacitor C5, which are used to process the first electrical signal output by the power factor correction circuit unit to ensure the stability of the first electrical signal.

[0078] Among them, the first end of the fourth capacitor C4 is connected to the drain of the power device S1, the power device S3 and the power device S5, the second end of the fourth capacitor C4 is connected to the first end of the fifth capacitor C5, and the second end of the fifth capacitor C5 is connected to the source of the power device S2, the power device S4 and the power device S6.

[0079] like Figure 4As shown, the first secondary circuit unit 50 of the resonant converter includes a first secondary winding Z2, a fifth relay K5, a full-bridge circuit, and a first capacitor C1, wherein the full-bridge circuit includes a fourth bridge arm and a fifth bridge arm, wherein the fourth bridge arm includes a power device S11 and a power device S12 connected in series, and the connection point of the power device S11 and the power device S12 is the midpoint of the fourth bridge arm, and the fifth bridge arm includes a power device S13 and a power device S14 connected in series, and the connection point of the power device S13 and the power device S14 is the midpoint of the fifth bridge arm.

[0080] The first end of the first secondary winding Z2 is connected to the first end of the fifth relay K5, the second end of the fifth relay K5 is connected to the midpoint of the fourth bridge arm, and the second end of the first secondary winding Z2 is connected to the midpoint of the fifth bridge arm; the first capacitor C1 is connected in parallel with the full-bridge circuit, and the first end of the first capacitor C1 is connected to the positive electrode of the power battery and / or the high-voltage accessory, and the second end of the first capacitor is connected to the negative electrode of the power battery and / or the high-voltage accessory.

[0081] like Figure 4 As shown, the second secondary circuit unit 70 of the resonant converter includes a second secondary winding Z3, a first power device S15, a second power device S16, a third power device S17, a fourth power device S18, a first inductor L1 and a second capacitor C2. The first end of the second secondary winding Z3 is connected to the first end of the first power device S15, the second end of the first power device S15 is connected to the second end of the second power device S16, and the first end of the second power device S16 is connected to the second end of the second secondary winding Z2; the first end of the third power device S17 is connected to the midpoint of the second secondary winding Z2, and the second end of the third power device S17 is respectively connected to the first end of the fourth power device S18 and the first end of the first inductor L1; the second end of the fourth power device S18 is respectively connected to the second end of the second power device S16 and the second end of the second capacitor C2; the second end of the first inductor L1 is connected to the first end of the second capacitor C2, and the first end of the second capacitor C2 is used to be connected to the positive electrode of the low-voltage load, and the second end of the second capacitor C2 is used to be connected to the negative electrode of the low-voltage load.

[0082] First, it should be understood that the first end of the above-mentioned power device is the drain of the power device, and the second end is the source of the power device. Secondly, it should be understood that in the present disclosure, the gate of each power device is used to input a drive signal, and the drive signal is used to drive the corresponding power device to turn on and off. Among them, the drive signal can be a pulse width modulation PWM signal.

[0083] exist Figure 4In the embodiment, the first DC charging control unit 60 includes a sixth relay K6 and a seventh relay K7, wherein the first end of the sixth relay K6 is connected to the first end of the power factor correction circuit unit, that is, connected to the drain of the power device S1, the power device S3 and the power device S5, and the second end of the sixth relay K6 is connected to the positive electrode of the power battery and / or the high-voltage accessory. The first end of the seventh relay K7 is connected to the second end of the power factor correction circuit unit, that is, connected to the source of the power device S2, the power device S4 and the power device S6, and the second end of the seventh relay K7 is connected to the negative electrode of the power battery and / or the high-voltage accessory. When the charging mode is the DC boost charging mode, the sixth relay and the seventh relay are closed.

[0084] The second DC charging control unit 80 includes an eighth relay and a ninth relay. Figure 4 As shown, the first end of the eighth relay K8 is connected to the positive electrode of the DC power supply, and the second end of the eighth relay K8 is connected to the positive electrode of the power battery and / or the high-voltage accessory; the first end of the ninth relay K9 is connected to the negative electrode of the DC power supply, and the second end of the ninth relay K9 is connected to the negative electrode of the power battery and / or the high-voltage accessory. When the charging mode is the DC direct charging mode, the eighth relay and the ninth relay are closed.

[0085] It should be understood that initially Figure 4 All relays are in the disconnected state.

[0086] Below Figure 4 The working principle of the charging circuit shown is described.

[0087] In one embodiment, when the vehicle side identifies that the charging mode is the AC charging mode, if the AC power supply is a single-phase AC power supply, the relay RL1, the third relay K3, the relay RLN and the fifth relay K5 are closed, and the other relays are in the disconnected state. At this time, the power factor correction circuit unit converts the 220V AC power into 800V DC power, and the fourth capacitor C4 and the fifth capacitor C5 maintain the DC voltage stability. After that, the 800V DC power is converted into an electrical signal with the voltage specification of the power battery and / or the high-voltage accessories through the coordinated action of the primary circuit unit of the resonant converter and the first secondary circuit unit of the resonant converter to supply power to the power battery and / or the high-voltage accessories. At the same time, the 800V DC power can also be converted into an electrical signal with a voltage value consistent with the voltage specification of the low-voltage load through the coordinated action of the primary circuit unit of the resonant converter and the second secondary circuit unit of the resonant converter to supply power to the low-voltage load.

[0088] In another embodiment, when the vehicle side identifies that the charging mode is a DC boost charging mode, for example, the vehicle side identifies that the voltage specification of the DC charging pile is 500V or 750V, and the voltage specification of the vehicle side power battery and / or high-voltage accessories is 800V, then it is determined to be a DC boost charging mode. In this embodiment, relays K3, K4, K1, K2, K6, and K7 are closed, and other relays are in an open state. For example, if Figure 4 As shown, the power inductor circuit unit includes three bridge arms, that is, three boost circuits, and the maximum current of each boost circuit can be 16A. When DC boost charging is required, relay K3, relay K4, relay K1 and relay K2 are closed, and the maximum current that the DC charging pile can output is 48A. In addition, since the power factor correction circuit unit of AC charging is reused during DC boost charging, the rated voltage of the AC power supply is 220V, and considering the AC charging working voltage requirements and costs, the withstand voltage of the power factor correction circuit unit is lower than 800V. In order to ensure the safety of DC boost charging, the charging circuit only supports boost charging of 500V DC power supply, that is, when the DC charging pile is 500V or 750V, it is boosted and charged at 500V, that is, the DC boost charging power is: 48A*500V=24kW. It should be understood that at the beginning of DC boost charging, the power battery operates in step-down mode when relay K6 and relay K7 are closed, and the voltage of the DC charging port is pre-charged to 500V. After that, the DC charging pile with a voltage specification of 500V or 750V closes its own relay, and the vehicle end requests the charging pile charging voltage to be stabilized at 500V through message interaction. After that, the power factor correction circuit unit is used to boost the 500V DC signal to obtain an electrical signal with a voltage value consistent with the voltage specification of the power battery and / or high-voltage accessories, and the electrical signal is used to power the power battery and / or high-voltage accessories.

[0089] In addition, in this embodiment, the relay K5 in the first secondary circuit unit of the resonant converter is disconnected, which further avoids electrical coupling between the devices included in the first secondary circuit unit of the resonant converter and the devices included in the primary circuit unit of the resonant converter and the second secondary circuit unit of the resonant converter, thereby further improving charging safety.

[0090] In another embodiment, the vehicle side identifies that the charging mode is a direct DC charging mode, that is, the voltage specification of the DC charging pile is greater than or equal to the voltage specification of the power battery and / or high-voltage accessories. In this embodiment, the relay K8 and the relay K9 are closed, and the other relays are in the disconnected state, and the DC charging pile is directly used to power the power battery and / or the high-voltage accessories. At this time, the relay K8 and the relay K9 are electrically connected to the power battery, that is, the voltage across the filter capacitor (the fourth capacitor C4 and the fifth capacitor C5) is the voltage of the power battery, and then, through the coordination of the primary circuit unit of the resonant converter and the second secondary circuit unit of the resonant converter, the voltage across the filter capacitor is converted into a voltage consistent with the voltage specification of the low-voltage load, and the converted electrical signal is used to power the low-voltage load.

[0091] In another embodiment, the vehicle end is in a non-charging mode, at which time, the electrical signal provided by the power battery can also be converted to power the low-voltage load. In this embodiment, the relays K6 and K7 are closed, and the other relays are in an open state. The electrical signal output by the power battery is converted into an electrical signal having a voltage consistent with the voltage specification of the low-voltage load via the primary circuit unit of the resonant converter and the second secondary circuit unit of the resonant converter, and the converted electrical signal is used to power the low-voltage load.

[0092] Based on the same inventive concept, the present disclosure also provides an electric device, which includes: the charging circuit, power battery and / or high-voltage accessories provided in the present disclosure; the charging circuit is connected to the power battery and / or the high-voltage accessories, and is used to power the power battery and / or the high-voltage accessories.

[0093] The electric device may be a vehicle, a ship or an aircraft.

[0094] Those skilled in the art will readily appreciate other embodiments of the present disclosure after considering the specification and practicing the present disclosure. This application is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not disclosed in the present disclosure. The specification 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.

[0095] 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 charging circuit, characterized in that: include: A power supply circuit unit, a power inductor circuit unit and a power factor correction circuit unit; The power supply circuit unit is connected to the power inductor circuit unit, and is used to select a target power supply from the connected DC power supply and AC power supply, and input an electrical signal provided by the target power supply to the power inductor circuit unit; The power factor correction circuit unit is connected to the power inductance circuit unit, and is used to boost the electrical signal output by the power inductance circuit unit to obtain a first electrical signal, and when the charging mode is a DC boost charging mode, use the first electrical signal to power the power battery and / or high-voltage accessories.

2. The charging circuit according to claim 1, characterized in that: The target power supply also includes an AC power supply; the charging circuit also includes: a primary circuit unit of a resonant converter, a first secondary circuit unit of a resonant converter and a first DC charging control unit; The first DC charging control unit is connected to the power factor correction circuit unit, and is used to control the power factor correction circuit unit to be connected to the power battery and / or the high-voltage accessory when the charging mode is the DC boost charging mode, so as to use the first electrical signal to power the power battery and / or the high-voltage accessory; The primary circuit unit of the resonant converter is connected to the power factor correction circuit unit, and is used to obtain the first electrical signal, and when the target power source is the AC power source, the first electrical signal is processed in combination with the first secondary circuit unit of the resonant converter to obtain a second electrical signal, so as to use the second electrical signal to power the power battery and / or the high-voltage accessory; Wherein, when the target power source is the AC power source, the first secondary circuit unit of the resonant converter is in an on state, and when the target power source is the DC power source, the first secondary circuit unit of the resonant converter is in an off state.

3. The charging circuit according to claim 1, characterized in that: The power circuit unit includes a first selection relay for selecting a DC power source, a second selection relay and a third selection relay for selecting an AC power source; The first selection relay includes a first relay and a second relay, wherein a first end of the first relay is connected to a positive electrode of a DC power supply, and a second end of the first relay is connected to a midpoint of a first bridge arm of the power factor correction circuit unit; a first end of the second relay is connected to a negative electrode of the DC power supply, and a second end of the second relay is connected to a second end of the power factor correction circuit unit; The second selection relay includes three live wire relays and one neutral wire relay, the power inductor circuit unit includes three power inductors connected in parallel, and the power factor correction circuit unit includes a first bridge arm, a second bridge arm and a third bridge arm; The first ends of the three live wire relays are respectively connected to the phase lines of the AC power supply, the second ends of the three live wire relays are respectively connected to the first ends of the three power inductors, and the second ends of the three power inductors are respectively connected to the midpoints of the first bridge arm, the second bridge arm and the third bridge arm; The first end of the zero line relay is connected to the zero line of the AC power supply, and the second end of the zero line relay is connected to the midpoint of the third bridge arm; The third selection relay includes a third relay and a fourth relay, wherein two ends of the third relay are respectively connected to the midpoint of the first bridge arm and the midpoint of the second bridge arm, and two ends of the fourth relay are respectively connected to the midpoint of the first bridge arm and the midpoint of the third bridge arm.

4. The charging circuit according to claim 2, characterized in that: The charging circuit also includes a second secondary circuit unit of the resonant converter; The primary circuit unit of the resonant converter is connected to the second secondary circuit unit of the resonant converter, and is used to process the first electrical signal in combination with the second secondary circuit unit of the resonant converter to obtain a third electrical signal, and use the third electrical signal to power the low-voltage load.

5. The charging circuit according to claim 2, characterized in that: The charging circuit also includes a filter capacitor, and the power factor correction circuit unit, the filter capacitor, and the resonant converter primary circuit unit are sequentially connected in parallel.

6. The charging circuit according to claim 2, characterized in that: The first secondary circuit unit of the resonant converter includes a first secondary winding, a fifth relay, a full-bridge circuit, and a first capacitor; the full-bridge circuit includes a fourth bridge arm and a fifth bridge arm; The first end of the first secondary winding is connected to the first end of the fifth relay, the second end of the fifth relay is connected to the midpoint of the fourth bridge arm, and the second end of the first secondary winding is connected to the midpoint of the fifth bridge arm; The first capacitor is connected in parallel with the full-bridge circuit, and the first end of the first capacitor is connected to the positive electrode of the power battery and / or the high-voltage accessory, and the second end of the first capacitor is connected to the negative electrode of the power battery and / or the high-voltage accessory.

7. The charging circuit according to claim 4, characterized in that: The second secondary circuit unit of the resonant converter includes a second secondary winding, a first power device, a second power device, a third power device, a fourth power device, a first inductor and a second capacitor; The first end of the second secondary winding is connected to the first end of the first power device, the second end of the first power device is connected to the second end of the second power device, and the first end of the second power device is connected to the second end of the second secondary winding; The first end of the third power device is connected to the midpoint of the second secondary winding, and the second end of the third power device is connected to the first end of the fourth power device and the first end of the first inductor respectively; The second end of the fourth power device is connected to the second end of the second power device and the second end of the second capacitor respectively; The second end of the first inductor is connected to the first end of the second capacitor, and the first end of the second capacitor is used to be connected to the positive electrode of the low-voltage load, and the second end of the second capacitor is used to be connected to the negative electrode of the low-voltage load.

8. The charging circuit according to claim 2, characterized in that: The first DC charging control unit includes a sixth relay and a seventh relay; The first end of the sixth relay is connected to the first end of the power factor correction circuit unit, and the second end of the sixth relay is connected to the positive electrode of the power battery and / or the high-voltage accessory; The first end of the seventh relay is connected to the second end of the power factor correction circuit unit, and the second end of the seventh relay is connected to the negative electrode of the power battery and / or the high-voltage accessory; Wherein, when the charging mode is the DC boost charging mode, the sixth relay and the seventh relay are closed.

9. The charging circuit according to any one of claims 1 to 8, characterized in that: The charging circuit further includes a second DC charging control unit; the second DC charging control unit includes an eighth relay and a ninth relay; The first end of the eighth relay is connected to the positive electrode of the DC power supply, and the second end of the eighth relay is connected to the positive electrode of the power battery and / or the high-voltage accessory; The first end of the ninth relay is connected to the negative electrode of the DC power supply, and the second end of the ninth relay is connected to the negative electrode of the power battery and / or the high-voltage accessory; Wherein, when the charging mode is the DC direct charging mode, the eighth relay and the ninth relay are closed.

10. An electric device, characterized in that: The electric device comprises: a charging circuit, a power battery and / or a high-voltage accessory as claimed in any one of claims 1 to 9; The charging circuit is connected to the power battery and / or the high-voltage accessory, and is used to supply power to the power battery and / or the high-voltage accessory.

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