Power supply circuit, power system, control method and vehicle

Abstract

The invention relates to a power supply circuit, a power system, a control method and a vehicle. The power supply circuit comprises a first switch element and an inductive element. The first switch element and the inductive element are connected in series between the direct-current power supply and the capacitive element to form a current loop between the direct-current power supply and the capacitive element; and the inductive element is used for forming alternating current between the direct-current power supply and the capacitive element according to the on-off of the first switch element. Firstly, the alternating current can enable the internal resistor of the direct-current power supply to generate heat, so that self-heating of the direct-current power supply is realized; and secondly, when the current flows to the capacitive element from the direct-current power supply, the capacitive element can be pre-charged due to the hindering effect of the inductive element on the current, so that the aim of soft start is fulfilled.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to a power supply circuit, a power system, a control method and a vehicle. Background Art

[0002] In new energy vehicles, the DC power supply typically outputs electrical energy through capacitive components. During the startup phase, a pre-charge circuit consisting of a pre-charge resistor and a pre-charge contactor between the DC power supply and the capacitive component can be turned on before the main contactor between the DC power supply and the capacitive component. This current-blocking effect of the pre-charge resistor can be used to limit the charging current of the capacitive component, achieving a soft start.

[0003] Furthermore, DC power supplies typically require suitable operating temperature conditions. When the temperature of a DC power supply is low, its performance is significantly affected. During use, heating can be achieved by placing a heating film between adjacent battery modules within the DC power supply.

[0004] The existing technology uses independent circuits or structures to realize precharging of the capacitive element and heating of the DC power supply, which has a complex architecture, a large volume and high cost. Summary of the Invention

[0005] Embodiments of the present application provide a power supply circuit, a power system, a control method, and a vehicle, wherein a power supply circuit having a first switching element and an inductive element as the main body is provided, which is connected in series between a DC power supply and a capacitive element to form a current loop. Based on the energy storage and release of the inductive element, an alternating current can be generated between the DC power supply and the capacitive element when the first switching element is turned on, thereby at least partially solving the above-mentioned technical problems.

[0006] In order to achieve the above object, according to a first aspect of the present application, there is provided a power supply circuit, comprising a first switching element and an inductive element;

[0007] The first switch element and the inductive element are used to be connected in series between the DC power supply and the capacitive element to form a current loop between the DC power supply and the capacitive element;

[0008] The inductive element is used to form an alternating current between the direct current power supply and the capacitive element according to the on-off switching of the first switching element.

[0009] Optionally, the first access terminal of the first switching element is used to be electrically connected to the positive electrode of the DC power supply, and the second access terminal of the first switching element is used to be electrically connected to the first end of the capacitive element through the inductive element; or,

[0010] The second access end of the first switching element is used to be electrically connected to the negative electrode of the DC power supply, and the first access end of the first switching element is used to be electrically connected to the second end of the capacitive element through the inductive element.

[0011] Optionally, the power supply circuit further includes a freewheeling diode;

[0012] The cathode of the freewheeling diode is electrically connected to the second access terminal of the first switching element and the inductive element respectively, and the anode of the freewheeling diode is electrically connected to the second end of the capacitive element; or,

[0013] The anode of the freewheeling diode is electrically connected to the first access terminal of the first switch element and the inductive element respectively, and the cathode of the freewheeling diode is used to be electrically connected to the first end of the capacitive element.

[0014] Optionally, the inductive element includes a transformer, the transformer includes a primary winding and a secondary winding; the power supply circuit further includes a second switching element;

[0015] The first end of the primary winding is electrically connected to the second access terminal of the first switching element and the cathode of the freewheeling diode, respectively; the second end of the primary winding is electrically connected to the first end of the secondary winding and is used to be electrically connected to the first end of the capacitive element; the second end of the secondary winding is electrically connected to the first access terminal of the second switching element, the second access terminal of the second switching element is electrically connected to the anode of the freewheeling diode and is used to be electrically connected to the second end of the capacitive element; or,

[0016] The second end of the primary winding is respectively connected to the first access terminal of the first switching element and the anode of the freewheeling diode, the cathode of the freewheeling diode is electrically connected to the first end of the secondary winding and is used to be electrically connected to the first end of the capacitive element, the second end of the secondary winding is electrically connected to the first access terminal of the second switching element, and the second access terminal of the second switching element is used to be electrically connected to the second end of the capacitive element.

[0017] Optionally, the inductive element includes an inductor.

[0018] Optionally, the power supply circuit further includes a second switching element and a freewheeling diode;

[0019] The first access terminal of the second switching element is electrically connected to the second access terminal of the first switching element and the cathode of the freewheeling diode through an inductor, and is electrically connected to the first end of the capacitive element; the second access terminal of the second switching element is electrically connected to the anode of the freewheeling diode and is electrically connected to the second end of the capacitive element; or,

[0020] The second access end of the second switching element is electrically connected to the first access end of the first switching element and the anode of the freewheeling diode through an inductor and is used to be electrically connected to the second end of the capacitive element. The first access end of the second switching element is used to be electrically connected to the first end of the capacitive element.

[0021] Optionally, the power supply circuit further includes a rectifier diode;

[0022] The anode of the rectifier diode is electrically connected to the first access terminal of the second switch element and the inductor respectively, and the cathode of the rectifier diode is electrically connected to the first end of the capacitive element; or,

[0023] The cathode of the rectifier diode is electrically connected to the second access terminal of the second switch element and the inductor respectively, and the anode of the rectifier diode is used to be electrically connected to the second end of the capacitive element.

[0024] According to a second aspect of the present application, there is provided a power system comprising a DC power supply, a main positive switching element, a main negative switching element, a capacitive element, and the power supply circuit in any one of the above embodiments;

[0025] The positive electrode of the DC power supply is electrically connected to the first end of the capacitive element through the main positive switch element, and the negative electrode of the DC power supply is electrically connected to the second end of the capacitive element through the main negative switch element.

[0026] According to a third aspect of the present application, a control method is provided, which is applied to the power system in any of the above embodiments. The control method includes:

[0027] The first switch element is controlled to be on and off so that an alternating current is formed between the direct current power supply and the capacitive element.

[0028] Optionally, the first access terminal of the first switching element is electrically connected to the positive electrode of the DC power supply, and the second access terminal of the first switching element is electrically connected to the first end of the capacitive element via the inductive element; and controlling the first switching element to be on and off includes:

[0029] The first switching element and the main negative switching element are controlled to be turned on, so that an alternating current is formed between the direct current power supply and the capacitive element.

[0030] Optionally, the power supply circuit further includes a freewheeling diode, wherein a cathode of the freewheeling diode is electrically connected to the second access terminal of the first switching element and the inductive element, respectively, and an anode of the freewheeling diode is electrically connected to the second end of the capacitive element; controlling the first switching element and the main negative switching element to be conductive so that an alternating current is formed between the DC power supply and the capacitive element includes:

[0031] Controlling the first switching element and the main negative switching element to be turned on so that the DC power supply precharges the capacitive element and stores energy in the inductive element;

[0032] Controlling the first switch element to be disconnected, so that the inductive element releases energy through the freewheeling diode and charges the capacitive element;

[0033] Controlling the first switching element to be turned on so that the capacitive element reversely charges the DC power supply and the inductive element stores energy;

[0034] The first switch element is controlled to remain turned on, so that the inductive element releases energy and charges the DC power supply.

[0035] Optionally, the inductive element includes a transformer, the transformer includes a primary winding and a secondary winding, the power supply circuit further includes a second switching element, the first end of the primary winding is electrically connected to the second access end of the first switching element, the second end of the primary winding is electrically connected to the first end of the secondary winding and to the first end of the capacitive element, the second end of the secondary winding is electrically connected to the first access end of the second switching element, and the second access end of the second switching element is electrically connected to the second end of the capacitive element; controlling the first switching element and the main negative switching element to conduct so that an alternating current is formed between the DC power supply and the capacitive element, includes:

[0036] Controlling the first switching element and the main negative switching element to be turned on, so that the DC power supply pre-charges the capacitive element and stores energy in the primary winding, and causing the primary winding to release energy after storing energy to recharge the capacitive element;

[0037] Controlling the main positive switching element and the second switching element to be turned on so that the capacitive element reversely charges the DC power supply and stores energy in the secondary winding;

[0038] The second switching element is controlled to be disconnected, so that the secondary winding releases energy through the primary winding and the freewheeling diode and charges the DC power supply.

[0039] Optionally, the inductive element includes an inductor, and the power supply circuit further includes a second switching element, wherein a first access terminal of the second switching element is electrically connected to a second access terminal of the first switching element and a cathode of a freewheeling diode, and to a first end of a capacitive element, respectively, through the inductor, and a second access terminal of the second switching element is electrically connected to a second end of the capacitive element; and controlling the first switching element and the main negative switching element to conduct so that an alternating current is formed between the DC power supply and the capacitive element includes:

[0040] Controlling the first switching element and the main negative switching element to be turned on so that the DC power supply pre-charges the capacitive element and stores energy in the inductor; the inductor is used to release energy after storing energy to recharge the capacitive element;

[0041] Controlling the main positive switch element and the second switch element to be turned on so that the inductor stores energy;

[0042] The first switching element and / or the second switching element are controlled to be disconnected, so that the inductor releases energy and reverse charges the DC power supply.

[0043] According to a fourth aspect of the present application, a vehicle is provided, characterized in that it includes the power supply circuit in any one of the above embodiments, or includes the power system in any one of the above embodiments.

[0044] The power supply circuit of the embodiment of the present application is mainly composed of a first switching element and an inductive element, which are used to be connected in series between a DC power supply and a capacitive element to form a current loop. Based on the energy storage and release of the inductive element, alternating current can be generated between the DC power supply and the capacitive element when the first switching element is turned on; first, the alternating current can cause the internal resistance of the DC power supply to generate heat, thereby achieving self-heating of the DC power supply; second, when current flows from the DC power supply to the capacitive element, due to the obstruction of the inductive element to the current, the capacitive element can also be pre-charged to achieve the purpose of soft starting.

[0045] Other features and advantages of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] To more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present application. Those skilled in the art can also derive other drawings based on these drawings without inventive effort.

[0047] In order to more completely understand the present application and its beneficial effects, the following description will be given in conjunction with the accompanying drawings, wherein the same drawing numbers represent the same parts in the following description.

[0048] Figure 1 is a schematic structural diagram of a power system including a power supply circuit provided in an exemplary embodiment of the present application;

[0049] Figure 2 This is a schematic diagram of a transformer-based high-side pre-charge structure provided in an exemplary embodiment of the present application;

[0050] Figure 3 This is a schematic diagram of a transformer-based low-side pre-charge structure provided in an exemplary embodiment of the present application;

[0051] Figure 4 1 is a schematic diagram of a structure based on inductance and high-side precharging provided in an exemplary embodiment of the present application;

[0052] Figure 5 1 is a schematic diagram of a structure based on inductance and low-side pre-charging provided in an exemplary embodiment of the present application. DETAILED DESCRIPTION

[0053] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the embodiments described are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the present application.

[0054] According to the first aspect of this application, Figure 1 As shown, a power supply circuit 10 is provided, comprising a first switching element 1 and an inductive element 2 .

[0055] The first switch element 1 and the inductive element 2 are used to be connected in series between the DC power supply 3 and the capacitive element 4 to form a current loop between the DC power supply 3 and the capacitive element 4 .

[0056] Among them, Figure 1 In the embodiment, the power supply circuit 10 composed of the first switch element 1 and the inductive element 2 is electrically connected to the first end (such as the positive electrode) of the DC power supply 3 and the first end of the capacitive element 4 respectively. Figure 1 In a solution not shown, the power supply circuit 10 can also be electrically connected to the second end (e.g., the negative electrode) of the DC power supply 3 and the second end of the capacitive element 4. Both connection methods are intended to establish a feasible current loop between the DC power supply 3 and the capacitive element 4.

[0057] The inductive element 2 is used to form an alternating current between the DC power supply 3 and the capacitive element 4 according to the on / off switching of the first switching element 1 .

[0058] In addition, the positive electrode of the DC power supply 3 is also electrically connected to the first end of the capacitive element 4 through the main positive switch element 5, and the negative electrode of the DC power supply 3 is also electrically connected to the second end of the capacitive element 4 through the main negative switch element 6.

[0059] When precharging the capacitive element 4 is required, the main positive switch element 5 is turned off, the main negative switch element 6 is turned on, and the first switch element 1 is turned on. At this point, the DC power supply 3 forms a current loop with the capacitive element 4 through the power supply circuit 10 and the main negative switch element 6. The inductive element 2 blocks the current and charges the capacitive element 4 with a limited current, gradually increasing the voltage across the capacitive element 4 and achieving the purpose of precharging, or soft starting. When the capacitive element 4 is precharged and the vehicle needs to be powered on, the main positive switch element 5 and the main negative switch element 6 are turned on, and the DC power supply 3 forms a current loop with the capacitive element 4 through the main positive switch element 5 and the main negative switch element 6. The inductive element 2 is short-circuited, and energy can be transferred efficiently between the DC power supply 3 and the capacitive element 4.

[0060] Among them, when the DC power supply 3 needs to be heated, the inductive element 2 will store energy during the pre-charging process, and after the pre-charging of the capacitive element 4 is completed, the voltage on the capacitive element 4 is basically saturated, and the energy released by the inductive element 2 after the stored energy can be used to reverse charge the DC power supply 3.

[0061] When charging the capacitive element 4, the power supply circuit 10 generates a forward current flowing toward the capacitive element 4. When reverse charging the DC power supply 3, the power supply circuit 10 generates a reverse current flowing toward the DC power supply 3. The forward and reverse currents constitute the required alternating current. Since the DC power supply 3 has a corresponding internal resistance, the generated alternating current generates heat when it passes through the internal resistance, ultimately achieving the purpose of self-heating the DC power supply 3.

[0062] The power supply circuit of the embodiment of the present application is mainly composed of a first switching element and an inductive element, which are used to be connected in series between a DC power supply and a capacitive element to form a current loop. Based on the energy storage and release of the inductive element, alternating current can be generated between the DC power supply and the capacitive element when the first switching element is turned on; first, the alternating current can cause the internal resistance of the DC power supply to generate heat, thereby achieving self-heating of the DC power supply; second, when current flows from the DC power supply to the capacitive element, due to the obstruction of the inductive element to the current, the capacitive element can also be pre-charged to achieve the purpose of soft starting.

[0063] like Figure 2 As shown, optionally, the first switching element includes a first MOS tube Q1, the inductive element includes a transformer T1, the transformer T1 includes a primary winding and a secondary winding, the DC power supply includes a power battery BAT, the capacitive element includes a bus capacitor C1, the main positive switching element includes a main positive contactor K1, and the main negative switching element includes a main negative contactor K2.

[0064] The drain of the first MOS transistor Q1 is used to be electrically connected to the positive electrode of the power battery BAT, and the source of the first MOS transistor Q1 is used to be electrically connected to the first end of the bus capacitor C1 through the primary winding of the transformer T1.

[0065] When precharging the bus capacitor C1, the main positive contactor K1 is disconnected, and the main negative contactor K2 and the first MOS transistor Q1 are connected. The power battery BAT, the first MOS transistor Q1, the primary winding of the transformer T1, the bus capacitor C1, and the main negative contactor K2 form a current loop. The primary winding of the transformer T1 blocks the current flow, enabling precharging of the bus capacitor C1.

[0066] After precharging the bus capacitor C1, its voltage is essentially equal to that of the power battery BAT. However, during the precharging process, the primary winding of the transformer T1 stores energy. If the first MOS transistor Q1 remains conductive, the primary winding of the transformer T1 will continue to charge the bus capacitor C1 based on the current loop established during precharging, causing the voltage on the bus capacitor C1 to increase slightly. At this point, the voltage on the bus capacitor C1 is higher than the power battery BAT, causing the bus capacitor C1 to reverse charge the power battery BAT based on the current loop established during precharging. Similarly, after reverse charging of the bus capacitor C1 is complete, its voltage is essentially equal to that of the power battery BAT. However, during the reverse charging process, the primary winding of the transformer T1 also stores energy. If the first MOS transistor Q1 remains conductive, the primary winding of the transformer T1 will continue to reverse charge the power battery BAT based on the current loop established during precharging, causing the voltage on the power battery BAT to increase slightly. At this time, the voltage on the power battery BAT is higher than the bus capacitor C1, and a charge and discharge cycle is completed. Based on the energy storage and release of the primary winding of the transformer T1, alternating current is generated, and ultimately the power battery BAT is self-heated.

[0067] like Figure 3 As shown, optionally, the source of the first MOS transistor Q1 is used to be electrically connected to the negative electrode of the power battery BAT, and the drain of the first MOS transistor Q1 is used to be electrically connected to the second end of the bus capacitor C1 through the primary winding of the transformer T1.

[0068] Among them, different from Figure 2 In the corresponding embodiment, the first MOS tube Q1 and the primary winding of the transformer T1 are connected in series and are electrically connected to the negative electrode of the power battery BAT and the second end of the bus capacitor C1 respectively. The principle of pre-charging and self-heating is the same as that of FIG. Figure 2 The corresponding embodiments are basically the same, and the specific details can be referred to Figure 2 The corresponding embodiments will not be described in detail here.

[0069] As a supplement, when precharging the bus capacitor C1 is necessary, the main negative contactor K2 can be disconnected, while the main positive contactor K1 and the first MOS transistor Q1 are turned on. The power battery BAT, the main positive contactor K1, the bus capacitor C1, the primary winding of the transformer T1, and the first MOS transistor Q1 form a current loop. The primary winding of the transformer T1 blocks the current flow, enabling precharging of the bus capacitor C1. Once the bus capacitor C1 is precharged, the energy stored and released by the primary winding of the transformer T1 reverses the charge of the power battery BAT, ultimately generating alternating current and enabling self-heating of the power battery BAT.

[0070] like Figure 2 As shown, optionally, the power supply circuit further includes a freewheeling diode D1.

[0071] The cathode of the freewheeling diode D1 is electrically connected to the source of the first MOS transistor Q1 and the primary winding of the transformer T1 respectively, and the anode of the freewheeling diode D1 is electrically connected to the second end of the bus capacitor C1.

[0072] Among them, the above embodiment has mentioned that after the bus capacitor C1 is pre-charged, the current loop constructed by the pre-charge can be used to release the energy of the primary winding of the transformer T1. However, in this current loop, the energy stored and released by the primary winding of the transformer T1 will continue to decrease, and ultimately, the voltage difference between the power battery BAT and the bus capacitor C1 will no longer be formed. Therefore, in this embodiment, a freewheeling diode D1 is added so that after the bus capacitor C1 is pre-charged, the first MOS transistor Q1 is disconnected. At this time, the primary winding of the transformer T1, the bus capacitor C1, and the freewheeling diode D1 form a current loop. The primary winding of the transformer T1 releases energy through this current loop to recharge the bus capacitor C1.

[0073] The current loop constructed by the freewheeling diode D1 can enable the primary winding of the transformer T1 to maintain its energy level during continuous energy storage and release.

[0074] like Figure 3 As shown, optionally, the anode of the freewheeling diode D1 is electrically connected to the drain of the first MOS transistor Q1 and the primary winding of the transformer T1 respectively, and the cathode of the freewheeling diode D1 is electrically connected to the first end of the bus capacitor C1.

[0075] Similarly, after the first MOS tube Q1 is disconnected, the freewheeling diode D1 forms a current loop with the primary winding of the transformer T1 and the bus capacitor C1. For details, please refer to Figure 2 The corresponding embodiments will not be described in detail here.

[0076] like Figure 2 As shown, optionally, the power supply circuit further includes a second switch element, and the second switch element includes a second MOS transistor Q2.

[0077] A first end of the primary winding of the transformer T1 is electrically connected to the source of the first MOS transistor Q1 and the cathode of the freewheeling diode D1, respectively. A second end of the primary winding of the transformer T1 is electrically connected to the first end of the secondary winding of the transformer T1 and is used to be electrically connected to the first end of the bus capacitor C1. A second end of the secondary winding of the transformer T1 is electrically connected to the drain of the second MOS transistor Q2. A source of the second MOS transistor Q2 is electrically connected to the anode of the freewheeling diode D1 and is used to be electrically connected to the second end of the bus capacitor C1.

[0078] The above embodiment has already mentioned that the power battery BAT can be reverse-charged directly through the primary winding of transformer T1 and the first MOS transistor Q1, but this is premised on the main positive contactor K1 not being turned on. However, when the vehicle enters the driving phase rather than the parking phase, the main positive contactor K1 is turned on, and the first MOS transistor Q1 and the primary winding of transformer T1 are short-circuited, making it impossible to reverse-charge the power battery BAT through the primary winding of transformer T1 and the first MOS transistor Q1. Therefore, in this embodiment, a second MOS transistor Q2 is added to control the energy storage and release of the secondary winding of transformer T1, thereby utilizing the principle of electromagnetic induction to reverse-charge the power battery BAT through the primary winding of transformer T1.

[0079] Specifically, after bus capacitor C1 is precharged and main positive contactor K1 is turned on, the second MOS transistor Q2 is turned on, and the secondary winding of transformer T1 forms a current loop through the second MOS transistor Q2 and bus capacitor C1. Bus capacitor C1 stores energy in the secondary winding of transformer T1. After the secondary winding of transformer T1 completes energy storage, the second MOS transistor Q2 is turned off, and the energy of the secondary winding of transformer T1 is transferred to the primary winding of transformer T1 through the principle of electromagnetic induction. At this time, the primary winding of transformer T1 forms a current loop through freewheeling diode D1, main negative contactor K2, power battery BAT, and main positive contactor K1. Based on the energy released by the primary winding of transformer T1, power battery BAT is reversely charged.

[0080] like Figure 3 As shown, optionally, the second end of the primary winding of the transformer T1 is respectively connected to the drain of the first MOS transistor Q1 and the anode of the freewheeling diode D1, the cathode of the freewheeling diode D1 is electrically connected to the first end of the secondary winding of the transformer T1 and is used to be electrically connected to the first end of the bus capacitor C1, the second end of the secondary winding of the transformer T1 is electrically connected to the drain of the second MOS transistor Q2, and the source of the second MOS transistor Q2 is used to be electrically connected to the second end of the bus capacitor C1.

[0081] For details, please refer to Figure 2 The corresponding embodiments will not be described in detail here.

[0082] like Figure 4 or Figure 5 As shown, optionally, the inductive element includes an inductor L1.

[0083] Among them, relative to Figure 2 In the corresponding embodiment, when the rectifier diode D2 is not provided (i.e., the inductor L1 is directly electrically connected to the bus capacitor C1), only the pre-charging process and the self-heating process during the parking phase are considered. The inductor L1 and the primary winding of the transformer T1 play basically the same role. For details, please refer to Figure 2 The corresponding embodiments will not be described in detail here.

[0084] like Figure 4 As shown, optionally, the power supply circuit further includes a second switch element and a freewheeling diode D1, and the second switch element includes a second MOS transistor Q2.

[0085] The drain of the second MOS transistor Q2 is electrically connected to the source of the first MOS transistor Q1 and the cathode of the freewheeling diode D1 through the inductor L1, and is electrically connected to the first end of the bus capacitor C1. The source of the second MOS transistor Q2 is electrically connected to the anode of the freewheeling diode D1 and is electrically connected to the second end of the bus capacitor C1.

[0086] As in the above embodiment, when the vehicle enters the driving phase, the main positive contactor K1 is turned on, short-circuiting the first MOS transistor Q1 and the inductor L1. This prevents the bus capacitor C1 from reversely charging the power battery BAT through the inductor L1 and the first MOS transistor Q1. Therefore, in this embodiment, a second MOS transistor Q2 is added. After the bus capacitor C1 is pre-charged and the main positive contactor K1 is turned on, the second MOS transistor Q2 is turned on, and the inductor L1 forms a current loop through the second MOS transistor Q2, the main negative contactor K2, the power battery BAT, and the first MOS transistor Q1, storing energy in the inductor L1. When the inductor L1 has completed energy storage, at least one of the first and second MOS transistors Q1 and Q2 is turned off. At this point, the inductor L1 forms a current loop through the main positive contactor K1, the power battery BAT, the main negative contactor K2, and the freewheeling diode D1. Based on the energy released by the inductor L1, reverse charging of the power battery BAT is achieved.

[0087] like Figure 5 As shown, optionally, the source of the second MOS transistor Q2 is electrically connected to the drain of the first MOS transistor Q1 and the anode of the freewheeling diode D1 through the inductor L1, and is used to be electrically connected to the second end of the bus capacitor C1, and the drain of the second MOS transistor Q2 is used to be electrically connected to the first end of the bus capacitor C1.

[0088] For details, please refer to Figure 4 The corresponding embodiments will not be described in detail here.

[0089] like Figure 4 As shown, optionally, the power supply circuit further includes a rectifier diode D2.

[0090] The anode of the rectifier diode D2 is electrically connected to the drain of the second MOS transistor Q2 and the inductor L1 respectively, and the cathode of the rectifier diode D2 is electrically connected to the first end of the bus capacitor C1.

[0091] The rectifier diode D2 can limit the current to flow only from the inductor L1 to the bus capacitor C1 or the power battery BAT, but not from the bus capacitor C1 or the power battery BAT to the inductor L1, thereby ensuring the output stability of the bus capacitor C1.

[0092] like Figure 5 As shown, optionally, the cathode of the rectifier diode D2 is electrically connected to the source of the second MOS transistor Q2 and the inductor L1 respectively, and the anode of the rectifier diode D2 is used to be electrically connected to the second end of the bus capacitor C1.

[0093] For details, please refer to Figure 4 The corresponding embodiments will not be described in detail here.

[0094] like Figure 1 As shown, according to the second aspect of the present application, a power system is provided, comprising a DC power supply 3, a main positive switching element 5, a main negative switching element 6, a capacitive element 4, and a power supply circuit 10 in any one of the above embodiments;

[0095] The positive electrode of the DC power supply 3 is electrically connected to the first end of the capacitive element 4 through the main positive switch element 5 , and the negative electrode of the DC power supply 3 is electrically connected to the second end of the capacitive element 4 through the main negative switch element 6 .

[0096] The power supply circuit in the power system of the embodiment of the present application is mainly composed of a first switching element and an inductive element, which are used to be connected in series between the DC power supply and the capacitive element to form a current loop. Based on the energy storage and release of the inductive element, alternating current can be generated between the DC power supply and the capacitive element when the first switching element is turned on; first, the alternating current can cause the internal resistance of the DC power supply to generate heat, thereby realizing self-heating of the DC power supply; secondly, when the current flows from the DC power supply to the capacitive element, due to the obstruction of the inductive element to the current, the capacitive element can also be pre-charged to achieve the purpose of soft starting.

[0097] According to a third aspect of the present application, a control method is provided, which is applied to the power system in any of the above embodiments. The control method includes:

[0098] The first switch element is controlled to be on and off so that an alternating current is formed between the direct current power supply and the capacitive element.

[0099] When only the pre-charging and self-heating during the parking phase are considered, it is only necessary to control the first switching element to remain turned on.

[0100] Among them, reference Figure 2 、 Figure 3 、 Figure 4 or Figure 5 , controlling the first MOS tube Q1 to be turned on, and controlling the main negative contactor K2 or the main positive contactor K1 to be turned on, forming a pre-charge current loop through the first MOS tube Q1 and the primary winding of the transformer T1 or the inductor L1.

[0101] During the pre-charging process, the magnitude of the pre-charging current can be controlled by controlling the conduction frequency and conduction depth of the first MOS transistor Q1.

[0102] Optionally, the specific structure of the power system; controlling the on-off of the first switching element includes:

[0103] The first switching element and the main negative switching element are controlled to be turned on, so that an alternating current is formed between the direct current power supply and the capacitive element.

[0104] Specifically, refer to Figure 2 or Figure 4 , controls the first MOS tube Q1 and the main negative contactor K2 to be turned on, so that an alternating current is formed between the power battery BAT and the bus capacitor C1.

[0105] The specific principles can be referred to the relevant embodiments of the above power supply circuit, which will not be described in detail here.

[0106] In other embodiments, the specific structure of the power system to which the control method is applied can also refer to Figure 3 or Figure 5 The difference is that the application Figure 3 or Figure 5 In the power system shown, it is necessary to control the first MOS tube Q1 and the main positive contactor K1 to be turned on.

[0107] Optional, see Figure 2 or Figure 4 When the power supply circuit further includes a freewheeling diode D1; controlling the first switching element and the main negative switching element to be turned on so that an alternating current is formed between the DC power supply and the capacitive element, including:

[0108] The first MOS tube Q1 and the main negative contactor K2 are controlled to be turned on, so that an alternating current is formed between the power battery BAT and the bus capacitor C1.

[0109] Specifically:

[0110] Step 1: Control the first MOS tube Q1 and the main negative contactor K2 to be turned on, so that the power battery BAT pre-charges the bus capacitor C1 and stores energy in the primary winding of the transformer T1 or the inductor L1.

[0111] Step 2: Control the first MOS transistor Q1 to be turned off, so that the primary winding or inductor L1 of the transformer T1 releases energy through the freewheeling diode D1 and charges the bus capacitor C1.

[0112] Step 3: Control the first MOS tube Q1 to be turned on, so that the bus capacitor C1 reverse charges the power battery BAT and stores energy in the primary winding of the transformer T1 or the inductor L1.

[0113] Step 4: Control the first MOS tube Q1 to remain turned on, so that the primary winding of the transformer T1 or the inductor L1 releases energy and charges the power battery BAT.

[0114] In other embodiments, the specific structure of the power system to which the control method is applied can also refer to Figure 3 or Figure 5 The difference is that the application Figure 3 or Figure 5 In the power system shown, it is necessary to control the first MOS tube Q1 and the main positive contactor K1 to be turned on.

[0115] Optional, see Figure 2 When the inductive element includes a transformer T1 and the power supply circuit further includes a second switching element; controlling the first switching element and the main negative switching element to be turned on so that an alternating current is formed between the DC power supply and the capacitive element, including:

[0116] The first MOS tube Q1 and the main negative contactor K2 are controlled to be turned on, so that an alternating current is formed between the power battery BAT and the bus capacitor C1.

[0117] Specifically:

[0118] Step 1: Control the first MOS tube Q1 and the main negative contactor K2 to be turned on, so that the power battery BAT pre-charges the bus capacitor C1 and stores energy in the primary winding of the transformer T1, and releases energy after storing energy in the primary winding of the transformer T1 to charge the bus capacitor C1.

[0119] Step 2: Control the main positive contactor K1 and the second MOS tube Q2 to be turned on, so that the bus capacitor C1 reverse charges the power battery BAT and stores energy in the secondary winding of the transformer T1.

[0120] Step 3: Control the second MOS tube Q2 to be disconnected, so that the secondary winding of the transformer T1 releases energy through the primary winding of the transformer T1 and the freewheeling diode D1 and charges the power battery BAT.

[0121] In other embodiments, the specific structure of the power system to which the control method is applied can also refer to Figure 3 The difference is that the application Figure 3 In the power system shown, it is necessary to first control the first MOS tube Q1 and the main positive contactor K1 to be turned on, and then control the second MOS tube Q2 and the main negative contactor K2 to be turned on.

[0122] Optional, see Figure 4 When the inductive element includes the inductor L1 and the power supply circuit further includes a second switching element; controlling the first switching element and the main negative switching element to be turned on so that an alternating current is formed between the DC power supply and the capacitive element, including:

[0123] The first MOS tube Q1 and the main negative contactor K2 are controlled to be turned on, so that an alternating current is formed between the power battery BAT and the bus capacitor C1.

[0124] Specifically:

[0125] Step 1: Control the first MOS tube Q1 and the main negative contactor K2 to be turned on, so that the power battery BAT pre-charges the bus capacitor C1 and stores energy in the inductor L1; the inductor L1 is used to release energy after storing energy to charge the bus capacitor C1.

[0126] Step 2: Control the main positive contactor K1 and the second MOS tube Q2 to be turned on, so that the inductor L1 can store energy.

[0127] Step 3: Control the first MOS transistor Q1 and / or the second MOS transistor Q2 to be disconnected, so that the inductor L1 releases energy and reverse charges the power battery BAT.

[0128] In other embodiments, the specific structure of the power system to which the control method is applied can also refer to Figure 5 The difference is that the application Figure 5 In the power system shown, it is necessary to first control the first MOS tube Q1 and the main positive contactor K1 to be turned on, and then control the second MOS tube Q2 and the main negative contactor K2 to be turned on.

[0129] According to a fourth aspect of the present application, a vehicle is provided, characterized in that it includes the power supply circuit in any one of the above embodiments, or includes the power system in any one of the above embodiments.

[0130] The power supply circuit in the vehicle of the embodiment of the present application is mainly composed of a first switching element and an inductive element, which are used to be connected in series between a DC power supply and a capacitive element to form a current loop. Based on the energy storage and release of the inductive element, alternating current can be generated between the DC power supply and the capacitive element when the first switching element is turned on; first, the alternating current can cause the internal resistance of the DC power supply to generate heat, thereby realizing self-heating of the DC power supply; secondly, when the current flows from the DC power supply to the capacitive element, due to the obstruction of the inductive element to the current, the capacitive element can also be pre-charged to achieve the purpose of soft starting.

[0131] The vehicle may be a pure electric vehicle, a plug-in hybrid vehicle, a range-extended hybrid vehicle or other new energy vehicle, and this application does not make any specific restrictions on this.

[0132] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "plurality" means two or more, unless otherwise specifically defined.

[0133] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0134] The embodiments, implementation methods and related technical features of the present application can be combined and replaced with each other without conflict.

[0135] The above are only preferred embodiments of the present application and do not constitute any form of limitation to the present application. In the embodiments of the present application, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, please refer to the relevant content of other embodiments. However, any brief modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present application without departing from the content of the technical solution of the present application are still within the scope of the technical solution of the present application.

Claims

1. A power supply circuit, characterized in that: comprising a first switching element and an inductive element; The first switching element and the inductive element are used to be connected in series between a DC power supply and a capacitive element to form a current loop between the DC power supply and the capacitive element; The inductive element is used to form an alternating current between the direct current power supply and the capacitive element according to the switching of the first switching element.

2. The power supply circuit according to claim 1, wherein: The first access end of the first switching element is used to be electrically connected to the positive electrode of the DC power supply, and the second access end of the first switching element is used to be electrically connected to the first end of the capacitive element through the inductive element; or, The second access end of the first switching element is used to be electrically connected to the negative electrode of the DC power supply, and the first access end of the first switching element is used to be electrically connected to the second end of the capacitive element through the inductive element.

3. The power supply circuit according to claim 2, wherein: The power supply circuit also includes a freewheeling diode; The cathode of the freewheeling diode is electrically connected to the second access terminal of the first switching element and the inductive element respectively, and the anode of the freewheeling diode is electrically connected to the second end of the capacitive element; or, The anode of the freewheeling diode is electrically connected to the first access terminal of the first switching element and the inductive element respectively, and the cathode of the freewheeling diode is electrically connected to the first end of the capacitive element.

4. The power supply circuit according to claim 3, characterized in that: The inductive element includes a transformer, and the transformer includes a primary winding and a secondary winding; the power supply circuit also includes a second switching element; The first end of the primary winding is electrically connected to the second access terminal of the first switching element and the cathode of the freewheeling diode, respectively; the second end of the primary winding is electrically connected to the first end of the secondary winding and is used to be electrically connected to the first end of the capacitive element; the second end of the secondary winding is electrically connected to the first access terminal of the second switching element; the second access terminal of the second switching element is electrically connected to the anode of the freewheeling diode and is used to be electrically connected to the second end of the capacitive element; or, The second end of the primary winding is electrically connected to the first access end of the first switching element and the anode of the freewheeling diode respectively, the cathode of the freewheeling diode is electrically connected to the first end of the secondary winding and is used to be electrically connected to the first end of the capacitive element, the second end of the secondary winding is electrically connected to the first access end of the second switching element, the second access end of the second switching element is electrically connected to the first end of the primary winding and is used to be electrically connected to the second end of the capacitive element.

5. The power supply circuit according to claim 2, characterized in that: The inductive element includes an inductor.

6. The power supply circuit according to claim 5, characterized in that: The power supply circuit further includes a second switching element and a freewheeling diode; The first access terminal of the second switching element is electrically connected to the second access terminal of the first switching element and the cathode of the freewheeling diode through the inductor, and is used to be electrically connected to the first end of the capacitive element; the second access terminal of the second switching element is electrically connected to the anode of the freewheeling diode and is used to be electrically connected to the second end of the capacitive element; or, The second access end of the second switching element is electrically connected to the first access end of the first switching element and the anode of the freewheeling diode through the inductor, and is used to be electrically connected to the second end of the capacitive element. The first access end of the second switching element is electrically connected to the cathode of the freewheeling diode and is used to be electrically connected to the first end of the capacitive element.

7. The power supply circuit according to claim 6, characterized in that: The power supply circuit also includes a rectifier diode; The anode of the rectifier diode is electrically connected to the first access terminal of the second switch element and the inductor respectively, and the cathode of the rectifier diode is electrically connected to the first end of the capacitive element; or, The cathode of the rectifier diode is electrically connected to the second access terminal of the second switch element and the inductor respectively, and the anode of the rectifier diode is used to be electrically connected to the second end of the capacitive element.

8. A power system, characterized in that: comprising a DC power supply, a main positive switching element, a main negative switching element, a capacitive element, and the power supply circuit according to any one of claims 1 to 7; The positive electrode of the DC power supply is electrically connected to the first end of the capacitive element through the main positive switch element, and the negative electrode of the DC power supply is electrically connected to the second end of the capacitive element through the main negative switch element.

9. A control method, characterized in that: Applied to the power system according to claim 8, the control method includes: The first switch element is controlled to be on and off so that an alternating current is formed between the direct current power supply and the capacitive element.

10. The control method according to claim 9, characterized in that: The first access end of the first switching element is electrically connected to the positive electrode of the DC power supply, and the second access end of the first switching element is electrically connected to the first end of the capacitive element through the inductive element; The controlling the first switching element to be on and off includes: The first switching element and the main negative switching element are controlled to be turned on, so that an alternating current is formed between the direct current power supply and the capacitive element.

11. The control method according to claim 10, characterized in that: The power supply circuit further includes a freewheeling diode, wherein a cathode of the freewheeling diode is electrically connected to the second access terminal of the first switching element and the inductive element respectively, and an anode of the freewheeling diode is electrically connected to the second end of the capacitive element; The controlling the first switching element and the main negative switching element to be turned on so that an alternating current is formed between the direct current power supply and the capacitive element includes: controlling the first switching element and the main negative switching element to be turned on so that the DC power supply precharges the capacitive element and stores energy in the inductive element; controlling the first switch element to be disconnected, so that the inductive element releases energy through the freewheeling diode and charges the capacitive element; controlling the first switching element to be turned on so that the capacitive element reversely charges the DC power supply and the inductive element stores energy; The first switch element is controlled to remain turned on, so that the inductive element releases energy and charges the DC power supply.

12. The control method according to claim 11, characterized in that: The inductive element includes a transformer, the transformer includes a primary winding and a secondary winding, the power supply circuit further includes a second switching element, the first end of the primary winding is electrically connected to the second access end of the first switching element, the second end of the primary winding is electrically connected to the first end of the secondary winding and to the first end of the capacitive element, the second end of the secondary winding is electrically connected to the first access end of the second switching element, and the second access end of the second switching element is electrically connected to the second end of the capacitive element; The controlling the first switching element and the main negative switching element to be turned on so that an alternating current is formed between the direct current power supply and the capacitive element includes: controlling the first switching element and the main negative switching element to be turned on, so that the DC power supply pre-charges the capacitive element and stores energy in the primary winding, and causes the primary winding to release energy after storing energy, so as to recharge the capacitive element; Controlling the main positive switch element and the second switch element to be turned on, so that the capacitive element reversely charges the DC power supply and stores energy in the secondary winding; The second switching element is controlled to be disconnected, so that the secondary winding releases energy through the primary winding and the freewheeling diode and charges the DC power supply.

13. The control method according to claim 11, characterized in that: The inductive element includes an inductor, and the power supply circuit further includes a second switching element, wherein a first access terminal of the second switching element is electrically connected to a second access terminal of the first switching element and to a first end of the capacitive element via the inductor, and a second access terminal of the second switching element is electrically connected to a second end of the capacitive element; The controlling the first switching element and the main negative switching element to be turned on so that an alternating current is formed between the direct current power supply and the capacitive element includes: Controlling the first switching element and the main negative switching element to be turned on, so that the DC power supply pre-charges the capacitive element and causes the inductor to store energy; the inductor is used to release energy after storing energy to recharge the capacitive element; controlling the main positive switch element and the second switch element to be turned on so that the inductor stores energy; The first switching element and / or the second switching element are controlled to be disconnected, so that the inductor releases energy and reverse charges the DC power supply.

14. A vehicle, characterized in that: The power supply circuit comprises any one of claims 1 to 7, or the power system comprises the power system according to claim 8.

Images