Single-stage three-port magnetic integration topology, on-board charger, and control method thereof

Abstract

The present application provides a single-stage three-port magnetic integrated topology, an on-board charger and a control method thereof, in which the AC side conversion circuit in the single-stage three-port magnetic integrated topology realizes voltage polarity conversion processing for the AC side of the single-stage three-port magnetic integrated topology, and adopts a matrix conversion structure to realize the power factor correction function instead of the additional PFC rectifier circuit in the prior art, and further, the PFC rectifier circuit and the corresponding PFC inductor and the large-capacity electrolytic capacitor between the positive and negative poles of the intermediate busbar in the subsequent stage in the prior art can be omitted, thereby reducing the number of devices and increasing the power density, and the single-stage conversion structure without the PFC rectifier circuit can reduce one stage of power conversion compared with the prior art, further improving the conversion efficiency and simplifying the control scheme. Furthermore, the high-voltage side can be controlled to realize transport voltage clamping through a low impedance design, thereby realizing port power decoupling and reducing the complexity of control.

Description

[Technical field]

[0001] The present application relates to the field of power electronics technology, and in particular to a single-stage three-port magnetic integration topology, an on-board charger, and a control method thereof.

[0002] This application claims priority to a Chinese patent application bearing application number 202310248243.6 and entitled "Single-stage three-port magnetic integrated topology, on-board charger, and control method thereof" filed with the State Intellectual Property Office of the People's Republic of China on March 10, 2023, the entire contents of which are incorporated herein by reference. [Background technology]

[0003] With the rapid development of new energy vehicles, the market share of electric vehicles is increasing. In the current passenger vehicle field, on-board chargers are an important component of electric vehicles. High integration is the trend of development. Traditional magnetic integration technology integrates two voltage level outputs supplied to high-voltage batteries, low-voltage batteries and low-voltage electrical equipment, and the front-stage PFC (Power Factor Correction) rectifier circuit and rear-stage three-port magnetic integration topology have greatly improved the utilization rate and power density of the device. Summary of the Invention [Problem to be solved by the invention]

[0004] However, this method adopts a two-stage cascade structure, which has the disadvantages of many devices, low efficiency, and complex control.

[0005] The present application provides a single-stage three-port magnetic integrated topology, an on-board charger, and a control method thereof, which reduces devices, simultaneously improves conversion efficiency, and simplifies control schemes. [Means for solving the problem]

[0006] To achieve the above objectives, the present application provides the following technical solutions:

[0007] A first aspect of the present application provides a single-stage three-port magnetic integrated topology, including a transformer, an AC side conversion circuit, a high-side conversion circuit, and a low-side conversion circuit; One side of the AC side conversion circuit is used as the AC side of the single-stage three-port magnetic integrated topology; The other side of the AC side conversion circuit is connected to the primary winding of the transformer, The AC side of the high-voltage side conversion circuit is connected to one secondary winding of the transformer; The DC side of the high-side converter circuit is used as the high-side DC side of the single-stage three-port magnetic integrated topology; The AC side of the low-voltage side conversion circuit is connected to another secondary winding of the transformer, The DC side of the low-side converter circuit is used as the low-voltage DC side of the single-stage three-port magnetic integrated topology; The AC side conversion circuit is a matrix conversion structure to realize the voltage polarity conversion process and power factor correction function for the AC side of the single-stage three-port magnetic integrated topology.

[0008] Preferably, the matrix conversion structure is a three-phase structure, a full-bridge structure, or a half-bridge structure.

[0009] Preferably, the controlled half-bridge arm in the AC side conversion circuit includes two bidirectional switches connected in series, and the bidirectional switch includes two switching tubes connected in reverse series; When the matrix transformation structure is a three-phase structure or a full-bridge structure, a corresponding filter capacitor is further installed between each phase on the AC side of the single-stage three-port magnetic integration topology; When the matrix conversion structure is a half-bridge structure, the AC side conversion circuit further includes two filter capacitors connected in series, the series-connected connection point is used to connect the primary winding, and both ends of the series connection are connected to the AC side of the single-stage three-port magnetic integrated topology in parallel with the half-bridge arm.

[0010] Preferably, the high-voltage side converter circuit is a full-bridge circuit or a half-bridge circuit.

[0011] Preferably, the low-voltage side conversion circuit is a full-bridge circuit or a full-wave rectifier circuit and a step-down circuit that are cascaded together.

[0012] Preferably, the method further includes a first impedance, a second impedance, and a third impedance; the first impedance and the primary winding are connected in series to a corresponding side of the AC side conversion circuit; The second impedance and the corresponding secondary winding are connected in series to the AC side of the high voltage side conversion circuit; The third impedance and the corresponding secondary winding are connected in series to the AC side of the low-voltage side conversion circuit.

[0013] Preferably, at a switching frequency of the single-stage three-port magnetic integrated topology, the impedance value of the second impedance is smaller than the impedance value of the first impedance and the impedance value of the third impedance, and a difference value between the impedance value of the second impedance and any one of the impedances of the first impedance and the third impedance is greater than a preset threshold value.

[0014] Preferably, the impedance value of the first impedance is zero, or the first impedance is at least one of an inductor and a capacitor; The impedance value of the second impedance is zero, or the second impedance is at least one of an inductor and a capacitor; The impedance value of the third impedance is zero, or the third impedance is at least one of an inductor and a capacitor.

[0015] Preferably, the impedance value of the second impedance is zero, or the second impedance is a capacitor having a capacitance larger than a preset capacitance.

[0016] Preferably, the inductors in the first impedance and the third impedance are single inductors or integrated inductors or leakage inductors of the transformer.

[0017] A second aspect of the present application provides an on-board charger, comprising a controller and a single-stage, three-port magnetic integrated topology according to any one of the first aspects above; The single stage three port magnetic integration topology is controlled by the controller.

[0018] A third aspect of the present application provides a control method for an on-board charger that is applied to the controller of the on-board charger according to the second aspect, the control method comprising: Obtaining detection parameters of a single-stage three-port magnetic integration topology in the on-board charger, and determining a required power transmission direction for the single-stage three-port magnetic integration topology; determining control parameters of the single-stage three-port magnetic integrated topology based on the detection parameters and the power transmission direction, the control parameters including an outward phase shift angle and a switching frequency; generating and outputting a drive signal for each switching tube in the single-stage three-port magnetic integrated topology based on the control parameters.

[0019] Preferably, the outward phase shift angle, in the single-stage three-port magnetic integrated topology, a first angular phase difference existing between the drive signals of the AC side conversion circuit and the high voltage side conversion circuit; a second angular phase difference existing between the drive signals of the AC side conversion circuit and the low voltage side conversion circuit; and a third angular phase difference existing between the drive signals of the high-voltage side converter circuit and the low-voltage side converter circuit.

[0020] Preferably, when power is transferred from the AC side to the HV DC side and the LV DC side of the single-stage three-port magnetic integrated topology, the first angular phase difference and the second angular phase difference are both greater than zero; When power is transmitted from the high voltage DC side to the low voltage DC side, the third angle phase difference is greater than zero, and the drive signal of the AC side matrix conversion circuit is off; When power is transmitted from the high voltage DC side to the AC side and the low voltage DC side, the first angular phase difference is smaller than zero and the third angular phase difference is larger than zero; When power is transmitted from the low voltage DC side to the high voltage DC side, the third angular phase difference is smaller than zero, and the drive signal of the AC side matrix conversion circuit is off.

[0021] Preferably, when the low-side converter circuit in the single-stage three-port magnetic integrated topology is a full-bridge circuit, the control parameters further include an inward phase shift angle of the low-side converter circuit.

[0022] Preferably, the high side converter circuit has no inward phase shift angle.

[0023] Preferably, in the single-stage three-port magnetic integrated topology AC side conversion circuit, each half-bridge arm includes: The anode of the Rayleigh diode is connected to the AC high voltage end of the single-stage three-port magnetic integrated topology switching tube, the driving signal of which is a constant-on signal; The anode of the flywheel diode is connected to the low voltage end of the AC side of the single-stage three-port magnetic integrated topology, and the driving signal of the switching tube is a complementary high frequency on-off signal. Effect of the Invention

[0024] The single-stage three-port magnetic integrated topology provided by the present application has an AC side conversion circuit that realizes voltage polarity conversion processing for the AC side of the single-stage three-port magnetic integrated topology, and by adopting a matrix conversion structure, can realize a power factor correction function instead of the additional PFC rectifier circuit in the prior art, and can omit the PFC rectifier circuit and the corresponding PFC inductor and the large-capacity electrolytic capacitor between the positive and negative poles of the intermediate busbar in the subsequent stage in the prior art, thereby reducing devices and increasing power density; and the single-stage conversion structure omitting the PFC rectifier circuit reduces one stage of power conversion compared to the prior art, and can further improve conversion efficiency and simplify the control scheme.

[0025] In order to more clearly describe the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below. Obviously, the drawings in the following description are merely the embodiments of the present invention, and those skilled in the art can obtain other drawings from these drawings without creative efforts. [Brief description of the drawings]

[0026] [Figure 1] FIG. 2 is a schematic diagram of a single-stage three-port magnetic integration topology provided by an embodiment of the present application. [Diagram 2] FIG. 2 is a schematic diagram of an AC side conversion circuit in a single-stage three-port magnetic integrated topology provided by an embodiment of the present application. [Diagram 3] FIG. 2 is another schematic diagram of an AC side conversion circuit in a single-stage three-port magnetic integrated topology provided by an embodiment of the present application. [Figure 4] FIG. 2 is another schematic diagram of an AC side conversion circuit in a single-stage three-port magnetic integrated topology provided by an embodiment of the present application. [Diagram 5] FIG. 2 is a schematic diagram of a high-side or low-side converter circuit in a single-stage three-port magnetic integrated topology provided by an embodiment of the present application. [Figure 6] FIG. 2 is another schematic diagram of a high-side converter circuit in a single-stage three-port magnetic integrated topology provided by an embodiment of the present application. [Figure 7] FIG. 2 is another schematic diagram of a low-side converter circuit in a single-stage three-port magnetic integrated topology provided by an embodiment of the present application. [Figure 8] 2 is a flowchart of a method for controlling an in-vehicle charger provided by an embodiment of the present application. [Figure 9] FIG. 2 is a circuit diagram of a single-stage three-port magnetic integration topology provided by an embodiment of the present application. [Figure 10] FIG. 13 is a driving signal waveform diagram of the single-stage three-port magnetic integrated topology provided by an embodiment of the present application when the power grid voltage is positive. [Figure 11] FIG. 2 is another circuit diagram of a single-stage three-port magnetic integration topology provided by an embodiment of the present application. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, the technical solutions in the embodiments of the present invention will be described clearly and completely with reference to the drawings in the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and are not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative efforts belong to the scope of protection of the present invention.

[0028] In this application, the terms "comprise", "comprises", or any other variation thereof, are intended to cover a non-exclusive inclusion such that a process, method, product, or device that includes a set of elements includes not only those elements, but also other elements not expressly listed or inherent to such process, method, product, or device. In the absence of further limitations, an element defined by the phrase "comprises one" does not exclude the presence of other identical elements in the process, method, product, or device that includes the element.

[0029] The present application provides a single-stage, three-port magnetic integrated topology that reduces devices, increases conversion efficiency, and simplifies control schemes.

[0030] As shown in FIG. 1, this single-stage three-port magnetic integrated topology includes a transformer T, an AC side conversion circuit 10, a high-voltage side conversion circuit 20, and a low-voltage side conversion circuit 30, one side of the AC side conversion circuit 10 is used as the AC side AC of the single-stage three-port magnetic integrated topology, and is used to connect a power grid, such as a single-phase or three-phase power grid, and the other side of the AC side conversion circuit 10 is connected to the primary winding of the transformer T directly or through a first impedance Z1.

[0031] The AC side of the high-voltage side conversion circuit 20 is connected to one secondary winding of the transformer T directly or via a second impedance Z2, and the DC side of the high-voltage side conversion circuit 20 is used as the high-voltage DC side HV of the single-stage three-port magnetic integrated topology, and can be connected to the high-voltage battery of the electric vehicle.

[0032] The AC side of the low-voltage side conversion circuit 30 is connected to another secondary winding of the transformer T directly or via a third impedance Z3, and the DC side of the low-voltage side conversion circuit 30 is used as the low-voltage DC side LV of the single-stage three-port magnetic integrated topology, and can be connected to the low-voltage battery and low-voltage electrical equipment of the electric vehicle.

[0033] That is, this single-stage three-port magnetic integration topology mainly includes a power grid side matrix conversion circuit (i.e., AC side conversion circuit 10), a first impedance Z1, a high-voltage side conversion circuit 20, a second impedance Z2, a low-voltage side conversion circuit 30, a third impedance Z3, and a three-port high-frequency transformer T, which connects the AC side AC, the high-voltage DC side HV, and the low-voltage DC side LV.

[0034] The AC side conversion circuit 10 is a single-stage three-port magnetic integrated topology, and has a matrix conversion structure for realizing voltage polarity conversion processing and power factor correction function for the AC side.

[0035] In practical application, the matrix conversion structure realizing the AC side conversion circuit 10 may be specifically a three-phase structure (shown in FIG. 2), a full-bridge structure (shown in FIG. 3), or a half-bridge structure (shown in FIG. 4). Regardless of which structure is adopted, the matrix conversion structure takes a controlled half-bridge arm as a basic unit, and the half-bridge arm is formed by connecting two of four switching tubes back to back to form two bidirectional switches, which are then connected in series, that is, each half-bridge arm includes two bidirectional switches, and each bidirectional switch is respectively configured by connecting two corresponding switching tubes in series in the opposite direction (i.e., back to back). Take the full-bridge structure shown in FIG. 3 as an example, the power grid is connected to both ends of the half-bridge arm, and the midpoint of the half-bridge arm is used to connect the impedance (i.e., Z1 in FIG. 1) and the transformer T network. Regarding control, in the bidirectional switch, the switching tube whose anode of the flywheel diode corresponds to the high-voltage end of the voltage across the half-bridge arm is driven to be always on, and the switching tube whose anode of the flywheel diode corresponds to the low-voltage end of the voltage across the half-bridge arm is turned on and off in a high-frequency manner, and performs complementary operation, and the duty ratio is 50%. Furthermore, when the matrix conversion structure is a three-phase structure or a full-bridge structure, a corresponding filter capacitor is further installed between each phase on the AC side of the single-stage three-port magnetic integrated topology, and when the matrix conversion structure is a half-bridge structure, the AC side conversion circuit 10 further includes two filter capacitors connected in series, the connection point of the two filter capacitors connected in series is used to connect the primary winding, and the two ends of the two filter capacitors connected in series are connected in parallel with the half-bridge arm to the AC side of the single-stage three-port magnetic integrated topology.

[0036] The high-voltage side conversion circuit 20 may be a full-bridge circuit (shown in FIG. 5) or a half-bridge circuit (shown in FIG. 6). The switching tubes of the half-bridge arms in the high-voltage side conversion circuit 20 are complementarily turned on, the duty ratio is 50%, and the frequency is the same as that of the high-frequency switching tubes in the AC side conversion circuit 10, and the midpoint of the bridge arms generates a square wave voltage with symmetrical positive and negative polarities.

[0037] The low-voltage side conversion circuit 30 may be a full-bridge circuit as shown in Fig. 5. When the low-voltage side conversion circuit 30 is a full-bridge circuit, the switching tubes of its half-bridge arms are complementarily turned on, the duty ratio is 50%, the frequency is the same as that of the high-frequency switching tube of the AC side conversion circuit 10, and the midpoint of the bridge arms generates a three-level voltage having positive and negative symmetrical square wave voltage or zero voltage according to the voltage relationship between the high-voltage DC side HV and the low-voltage DC side LV.

[0038] 7, the low-voltage side conversion circuit 30 includes a full-wave rectifier circuit 201 and a step-down circuit (i.e., a Buck circuit) 202 connected in cascade, and in this case, the secondary winding to which the low-voltage side conversion circuit 30 is connected is a center-tapped winding. When the low-voltage side conversion circuit 30 is the full-wave rectifier circuit 201 and the step-down circuit 202 shown in FIG. 7, the on and off times of the full-wave rectifier switching tube are in phase with the switching tube in the high-voltage side conversion circuit 20, and the output voltage of the low-voltage DC side LV is controlled by changing the duty ratio of the switching tube in the step-down circuit 202.

[0039] Power transmission between the three ports of this single-stage three-port magnetic integrated topology is realized by controlling the phase angle changes of the switching tubes in the AC side conversion circuit 10, the switching tubes in the high-voltage side conversion circuit 20, and the switching tubes in the low-voltage side conversion circuit 30.

[0040] The single-stage three-port magnetic integrated topology provided by this embodiment realizes voltage polarity conversion processing for the AC side of the single-stage three-port magnetic integrated topology in its AC side conversion circuit 10, and adopts a matrix conversion structure to realize power factor correction function instead of the additional PFC rectifier circuit in the prior art, and further omits the PFC rectifier circuit and the corresponding large-capacity electrolytic capacitor between the positive and negative poles of the subsequent intermediate busbar in the prior art, thereby reducing devices and increasing power density. Moreover, the single-stage conversion structure without the PFC rectifier circuit reduces one stage of power conversion compared with the prior art, further improving conversion efficiency and simplifying the control scheme.

[0041] In practical applications, the AC side AC, the high voltage DC side HV, and the low voltage DC side LV of this single-stage three-port magnetic integrated topology may further be provided with corresponding filter circuits, which can be determined according to the specific application environment and is not limited here.

[0042] In addition, each switching tube in the AC side conversion circuit 10 and the high voltage side conversion circuit 20 may be a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), for example, a SiC (Silicon Carbide) MOSFET, an IGBT (Insulated Gate Bipolar Transistor) with an anti-parallel diode, or GaN (Gallium Nitride), etc., and is not limited here. In addition, the packaging of each device is not limited, and the bidirectional switch in the AC side conversion circuit 10 may be an integrated module type package or a single tube connection configuration. Each switching tube in the low voltage side conversion circuit 30 may be a MOSFET, but is not limited thereto, and can be determined according to the specific application environment.

[0043] Based on the previous embodiment, the single-stage three-port magnetic integrated topology provided by this embodiment can be configured with multiple implementations, for example, the impedance of the first impedance Z1 is zero, or the first impedance Z1 can be at least one of an inductor and a capacitor, the impedance of the second impedance Z2 is zero, or the second impedance Z2 can be at least one of an inductor and a capacitor, and the impedance of the third impedance Z3 is zero, or the third impedance Z3 can be at least one of an inductor and a capacitor. That is, the impedances Z1, Z2 and Z3 are a combination of an inductor and a capacitor, or one or none of an inductor and a capacitor (i.e., directly short-circuited, the impedance value is zero).

[0044] Preferably, at the switching frequency of this single-stage three-port magnetic integrated topology, the impedance value of the second impedance Z2 is smaller than the impedance value of the first impedance Z1 and the impedance value of the third impedance Z3, and the difference between the impedance value of either the first impedance Z1 or the third impedance Z3 and the impedance value of the second impedance Z2 is greater than a preset threshold, that is, the impedance value of the second impedance Z2 can be set to be much smaller than the first impedance Z1 and the third impedance Z3.

[0045] For example, the second impedance Z2 can be realized by selecting a direct short circuit, in which case the impedance value is zero, or the second impedance Z2 can be realized by selecting a capacitor with a larger capacity than a preset capacity, i.e. a large-capacity block capacitor, which plays the role of DC isolation, and the voltage across it is small and does not change much, and can be regarded as a short circuit during analysis. If the first impedance Z1 and the third impedance Z3 have an inductor, the inductor can be realized by selecting a single inductor, or an integrated inductor or a leakage inductor of a transformer T.

[0046] When the second impedance Z2 is small, the port voltage of the corresponding secondary winding of the transformer T can be approximated to the AC side voltage of this high-side conversion circuit 20, that is, the midpoint voltage of its bridge arm. Therefore, when the midpoint voltage of the bridge arm of this high-side conversion circuit 20 is a square wave voltage with positive and negative symmetry, the port voltage waveform of the other winding of the transformer T is also a square wave voltage with positive and negative symmetry, and the ratio between its amplitude and the port voltage amplitude of the secondary winding to which this high-side conversion circuit 20 is connected is the turns ratio of the corresponding winding.

[0047] The single-stage three-port magnetic integrated topology provided by this embodiment not only realizes three-port power transmission through a single-stage structure, but also realizes clamping of the transformer T-winding port voltage through the high-voltage side low impedance design, and realizes power decoupling between different ports, which is advantageous for realizing control simplification.

[0048] Another embodiment of the present application also provides an on-board charger, including a controller and the single-stage three-port magnetic integration topology according to any of the above embodiments, where the single-stage three-port magnetic integration topology is controlled by the controller.

[0049] The structure and principle of this single-stage three-port magnetic integration topology can be referred to the above embodiment, and will not be described here. The specific structure and functions of this controller can be referred to the prior art, and will not be described here.

[0050] The on-board charger provided in this embodiment adopts this single-stage three-port magnetic integration topology to realize the AC side conversion circuit 10 with a matrix conversion structure, thereby realizing AC voltage polarity conversion processing and power factor correction functions. In addition, the high-voltage side is designed with low impedance, and the high-voltage side conversion circuit 20 can be controlled to realize transformer T port voltage clamping, thereby realizing port power decoupling and reducing control complexity.

[0051] Another embodiment of the present application also provides a method for controlling an on-board charger, which is applied to the controller of the on-board charger described in the above embodiment. As shown in Figure 8, the method includes the following steps:

[0052] S101, obtaining detection parameters of a single-stage three-port magnetic integration topology in an on-board charger, and determining a power transmission direction required for the single-stage three-port magnetic integration topology.

[0053] Referring to FIG. 1, this single-stage three-port magnetic integrated topology can realize charging power transmission from the AC side to the high voltage DC side HV and / or the low voltage DC side LV, can realize discharging power transmission from the high voltage DC side HV to the AC side AC and / or the low voltage DC side LV, and can also realize power transmission from the low voltage DC side LV to the high voltage DC side HV, which can be determined according to the specific application environment, and all are within the protection scope of the present application.

[0054] Specifically, after receiving a charge / discharge command, the on-board charger can detect the electrical parameters of the corresponding port, such as voltage detection, and at the same time, determine the required power transmission direction based on the charge / discharge command.

[0055] S102, determining a control parameter of the single-stage three-port magnetic integrated topology based on the detection parameter and the power transmission direction.

[0056] The control parameters may include the outward phase shift angle and the switching frequency.

[0057] When this single-stage three-port magnetic integration topology includes the AC side conversion circuit 10, the high-voltage side conversion circuit 20, and the low-voltage side conversion circuit 30 shown in FIG. 1 , this outward phase shift angle specifically includes a first angle phase difference existing between the drive signals of the AC side conversion circuit 10 and the high-voltage side conversion circuit 20, a second angle phase difference existing between the drive signals of the AC side conversion circuit 10 and the low-voltage side conversion circuit 30, and a third angle phase difference existing between the drive signals of the high-voltage side conversion circuit 20 and the low-voltage side conversion circuit 30.

[0058] Specifically, when power is transmitted from the AC side AC of the single-stage three-port magnetic integrated topology to the high voltage DC side HV and the low voltage DC side LV, the first angle phase difference and the second angle phase difference are both greater than zero; when power is transmitted from the high voltage DC side HV to the low voltage DC side LV, the third angle phase difference is greater than zero and the drive signal of the AC side matrix conversion circuit is off; when power is transmitted from the high voltage DC side HV to the AC side AC and the low voltage DC side LV, the first angle phase difference is less than zero and the third angle phase difference is greater than zero; when power is transmitted from the low voltage DC side LV to the high voltage DC side HV, the third angle phase difference is less than zero and the drive signal of the AC side matrix conversion circuit is off.

[0059] The switching frequencies of the AC side conversion circuit 10, the high voltage side conversion circuit 20, and the low voltage side conversion circuit 30 may be the same, and the duty ratios of all three may be 50%, but are not limited to this. When the low voltage side conversion circuit 30 includes the full wave rectifier circuit 201 and the step-down circuit 202 shown in Fig. 7, the duty ratio of the switching tube in the step-down circuit 202 becomes adjustable, and the output voltage of the low voltage DC side LV can be controlled.

[0060] Preferably, when the low-side converter circuit in the single-stage three-port magnetic integrated topology is a full-bridge circuit, the control parameters further include an inward phase shift angle of the low-side converter circuit.

[0061] Moreover, this high voltage side conversion circuit has no inward phase shift angle, and the AC side outputs a square wave voltage that is symmetrical in positive and negative directions.

[0062] S103, generating and outputting driving signals for each switching tube in the single-stage three-port magnetic integrated topology according to the control parameters.

[0063] According to the control parameters, the driving signals of each circuit can be generated by corresponding PWM (pulse width modulation) algorithms, which will not be described again here.

[0064] In practical application, in this single-stage three-port magnetic integrated topology AC side conversion circuit, in each half-bridge arm, the switching tube with the anode of the flywheel diode pointing to the AC side high voltage end of the single-stage three-port magnetic integrated topology has a driving signal that is always on, and the switching tube with the anode of the flywheel diode pointing to the AC side low voltage end of the single-stage three-port magnetic integrated topology has a driving signal that is a complementary high frequency on-off signal with a duty ratio of 50%.

[0065] The switching tubes of the half-bridge arms in this high-voltage side conversion circuit are turned on complementarily, the duty ratio is 50%, and the frequency is the same as that of the high-frequency switching tubes in the AC side conversion circuit, and a positive and negative symmetrical square wave voltage is generated at the midpoint of the bridge arms.

[0066] When the low-voltage side conversion circuit is a full-bridge circuit, the switching tubes of the half-bridge arms are turned on complementarily, the duty ratio is 50%, the frequency is the same as that of the high-frequency switching tube of the AC side conversion circuit, and the midpoint of the bridge arms generates a three-level voltage with positive and negative symmetrical square wave voltage or zero voltage according to the voltage relationship between the high-voltage side and the low-voltage side.When the low-voltage side conversion circuit includes a full-wave rectifier circuit and a step-down circuit connected in cascade, the on and off times of the full-wave rectifier switching tube are in phase with the switching tube in the high-voltage side conversion circuit, and the control of the output voltage on the low-voltage side is realized by changing the duty ratio of the switching tube in the step-down circuit.

[0067] By changing the phase angles of the three in-circuit switching tubes, the power transfer among the three ports of this single-stage three-port magnetic integrated topology can be realized.

[0068] Hereinafter, the driving logic will be described in detail by taking the topology of a single-stage three-port charger in a single-phase power grid shown in FIG. 9 as an example. Referring to FIG. 9, its AC side is connected to single-phase electricity, and the AC side conversion circuit is a full-bridge structure, and in one half-bridge arm, switching tubes S1 and S2 are connected back to back to form one bidirectional switch, and switching tubes S3 and S4 are connected back to back to form another bidirectional switch. The other half-bridge arm is the same. The high-voltage side conversion circuit is a full-bridge structure, and one half-bridge arm includes switching tubes Q1 and Q2, and the other half-bridge arm includes switching tubes Q3 and Q4. The low-voltage side conversion circuit is a full-bridge structure, and one half-bridge arm includes switching tubes M1 and M2, and the other half-bridge arm includes switching tubes M3 and M4. The first impedance Z1 and the third impedance Z3 are single inductors, or are integrated inductors or leakage inductors of a transformer T. The second impedance Z2 is a large capacitance capacitor that acts as a DC isolation, and the voltage across it is small and does not change significantly, so it can be considered a short circuit during analysis.

[0069] When the power grid voltage LN is positive, the anodes of the flywheel diodes of the switching tubes S2 and S4 point to the L terminal, so the switching tubes S2 and S4 remain driven on all the time, and the anodes of the flywheel diodes of the switching tubes S1 and S3 point to the N terminal, so the switching tubes S1 and S3 turn on and off at high frequency. When the power grid voltage LN is negative, the switching tubes S2 and S4 turn on and off at high frequency, and the switching tubes S1 and S3 remain driven on all the time.

[0070] When the power grid voltage LN is positive, there is an α angle phase difference (i.e., the first angle phase difference described above) between the driving signals of the switching tubes S1 and Q1, there is a β angle phase difference (i.e., the second angle phase difference described above) between the driving signals of the switching tubes S1 and M1, there is a γ angle phase difference (i.e., the third angle phase difference described above) between the driving signals of the switching tubes Q1 and M1, and the driving signal of the switching tube M1 leads the driving signal of the switching tube M4 by an δ angle (i.e., the inward phase shift angle described above). By adjusting the α, β, and γ angles, the energy control between the three ports of this single-stage three-port magnetic integrated topology can be realized, and at the same time, by adjusting the δ angle, the effective current on the transformer T winding can be reduced when transmitting the same power, and the conduction loss of the transformer T and the power tube can be reduced, thereby improving the efficiency of the charger. When the power grid voltage LN is positive, the corresponding driving signal logic is shown in Figure 10. Here, VCD is the midpoint voltage of the bridge arm of the high-voltage side conversion circuit (i.e., the AC side voltage, the voltage between two points C and D shown in Figure 9), VEF is the midpoint voltage of the bridge arm of the low-voltage side conversion circuit (i.e., the AC side voltage, the voltage between two points E and F shown in Figure 9), and VAN is the voltage difference between the midpoint of the corresponding half-bridge arm in the AC side conversion circuit (midpoint A of the half-bridge arm where switching tubes S1 to S4 are located shown in Figure 9) and the N line on the AC side.

[0071] It can be seen that the midpoint voltage VCD of the bridge arm of the high-side transformer circuit is ± the high-voltage DC side HV voltage, and when the second impedance Z2 is small, the transformer T winding port voltage connected to the high-side transformer circuit is close to the midpoint voltage of the bridge arm of the high-side transformer circuit. Therefore, the port voltage waveform of the other winding of the transformer T is also a positive and negative square wave voltage, and the ratio between its amplitude and the transformer T winding port voltage amplitude connected to the high-side transformer circuit is the turn ratio of the corresponding winding. By controlling the corresponding driving signal angle, the corresponding positive and negative square wave voltage is converted into a port voltage, thereby realizing the control of the magnitude and direction of the power.

[0072] In addition, when the power grid voltage LN is negative, the switching tubes S2 and S4 are turned on and off at high frequency, there is an α angle phase difference (i.e., the first angle phase difference mentioned above) between the driving signals of the switching tubes S4 and Q1, there is a β angle phase difference (i.e., the second angle phase difference mentioned above) between the driving signals of the switching tubes S4 and M1, and the switching tubes S1 and S3 remain driven on all the time. The driving logic is similar to that when the power grid voltage LN is positive, and will not be described or shown in detail here.

[0073] Figure 11 shows the topology of a single-stage three-port charger in a three-phase power grid, the driving logic of which can be inferred and will not be described here repeatedly. The driving logic of any other circuit structure will not be described one by one either, and all of them can realize the control of the magnitude and direction of the power by controlling the phase angle of the power device between different ports, thereby reducing the control complexity.

[0074] The same parts and similar parts between the embodiments in this specification may be referred to each other, and each embodiment focuses on the differences from other embodiments. In particular, the system or system embodiment is basically similar to the method embodiment, so the description is relatively simple, and the relevant points may be referred to the partial description of the method embodiment. The above-mentioned system and system embodiments are merely schematic, and the units described as separate components above may or may not be physically separated, and the components shown as units may or may not be physical units, and may be located in one place or distributed to multiple network elements. Some or all of the modules can be selected to achieve the purpose of the present embodiment according to actual needs. Those skilled in the art can understand and implement it without any creative effort.

[0075] Those skilled in the art may further recognize that the units and algorithm steps of each example described in connection with the embodiments disclosed herein may be realized by electronic hardware, computer software, or a combination of both, and in order to clearly explain the interchangeability of hardware and software, the above description generally describes the configurations and steps of each example functionally. Whether these functions are performed in a hardware or software manner depends on the specific application and design constraints of the technical proposal. Those skilled in the art may use different methods to realize the described functions for each specific application, but such realization should not be considered to go beyond the scope of the present invention.

[0076] With respect to the above description of the disclosed embodiments, the features described in each embodiment herein may be substituted or combined with each other so that those skilled in the art can realize or use the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Thus, the present invention is not intended to be limited to these embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A single stage three port magnetic integrated topology comprising: The present invention includes a transformer, an AC side conversion circuit, a high voltage side conversion circuit, and a low voltage side conversion circuit, One side of the AC side conversion circuit is used as the AC side of the single-stage three-port magnetic integrated topology; The other side of the AC side conversion circuit is connected to the primary winding of the transformer, The AC side of the high-voltage side conversion circuit is connected to one secondary winding of the transformer, The DC side of the high-side converter circuit is used as the high-side DC side of the single-stage three-port magnetic integrated topology; The AC side of the low-voltage side conversion circuit is connected to another secondary winding of the transformer, The DC side of the low-side converter circuit is used as the low-voltage DC side of the single-stage three-port magnetic integrated topology; The AC side conversion circuit is a matrix conversion structure for realizing voltage polarity conversion processing and power factor correction function for the AC side of the single-stage three-port magnetic integrated topology. A single-stage three-port magnetic integration topology.

2. The matrix conversion structure is a three-phase structure, a full-bridge structure, or a half-bridge structure.

2. The single-stage, three-port magnetic integration topology of claim 1.

3. The controlled half-bridge arm in the AC side conversion circuit includes two bidirectional switches connected in series, and the bidirectional switch includes two switching tubes connected in reverse series; When the matrix transformation structure is a three-phase structure or a full-bridge structure, a corresponding filter capacitor is further installed between each phase on the AC side of the single-stage three-port magnetic integration topology; When the matrix conversion structure is a half-bridge structure, the AC side conversion circuit further includes two filter capacitors connected in series, and the series-connected connection point is used to connect the primary winding, and both ends connected in series are connected to the AC side of the single-stage three-port magnetic integrated topology in parallel with the half-bridge arm.

3. The single-stage, three-port magnetic integration topology of claim 2.

4. The high-voltage side conversion circuit is a full-bridge circuit or a half-bridge circuit.

2. The single-stage, three-port magnetic integration topology of claim 1.

5. The low-voltage side conversion circuit is a full-bridge circuit or a cascade-connected full-wave rectifier circuit and a step-down circuit.

2. The single-stage, three-port magnetic integration topology of claim 1.

6. further comprising a first impedance, a second impedance, and a third impedance; the first impedance and the primary winding are connected in series to a corresponding side of the AC side conversion circuit; The second impedance and the corresponding secondary winding are connected in series to an AC side of the high voltage side conversion circuit; The third impedance and the corresponding secondary winding are connected in series to the AC side of the low-voltage side conversion circuit. A single-stage three-port magnetic integrated topology according to any one of claims 1 to 5.

7. At a switching frequency of the single-stage three-port magnetic integrated topology, an impedance value of the second impedance is smaller than an impedance value of the first impedance and an impedance value of the third impedance, and a difference between an impedance value of the second impedance and an impedance value of either the first impedance or the third impedance is larger than a preset threshold value.

7. The single-stage, three-port magnetic integration topology of claim 6.

8. The impedance value of the first impedance is zero, or the first impedance is at least one of an inductor and a capacitor; The impedance value of the second impedance is zero, or the second impedance is at least one of an inductor and a capacitor; The impedance value of the third impedance is zero, or the third impedance is at least one of an inductor and a capacitor.

7. The single-stage, three-port magnetic integration topology of claim 6.

9. The impedance value of the second impedance is zero, or the second impedance is a capacitor having a capacitance larger than a preset capacitance.

9. The single-stage, three-port magnetic integration topology of claim 8.

10. The inductors in the first impedance and the third impedance are a single inductor or an integrated inductor or a leakage inductor of the transformer.

9. The single-stage, three-port magnetic integration topology of claim 8.

11. An in-vehicle charger, A single-stage, three-port magnetic integrated topology comprising a controller and the single-stage, three-port magnetic integrated topology of any one of claims 1 to 10, the single stage three port magnetic integration topology is controlled by the controller; The in-vehicle charger is characterized by the above.

12. A method for controlling an on-board charger, which is applied to the controller of the on-board charger according to claim 11, comprising: Obtaining detection parameters of a single-stage three-port magnetic integration topology in the on-board charger, and determining a required power transmission direction for the single-stage three-port magnetic integration topology; determining control parameters of the single-stage three-port magnetic integrated topology based on the detection parameters and the power transmission direction, the control parameters including an outward phase shift angle and a switching frequency; generating and outputting a driving signal for each switching tube in the single-stage three-port magnetic integrated topology based on the control parameters; The method according to claim 1, further comprising:

13. The outward phase shift angle is, in the single-stage three-port magnetic integrated topology, a first angular phase difference existing between the drive signals of the AC side conversion circuit and the high voltage side conversion circuit; a second angular phase difference existing between the drive signals of the AC side conversion circuit and the low voltage side conversion circuit; a third angular phase difference existing between the drive signals of the high-voltage side converter circuit and the low-voltage side converter circuit; The method for controlling an in-vehicle charger according to claim 12, further comprising:

14. when power is transferred from the AC side to the HV DC side and the LV DC side of the single-stage three-port magnetic integrated topology, the first angular phase difference and the second angular phase difference are both greater than zero; When power is transmitted from the high voltage DC side to the low voltage DC side, the third angle phase difference is greater than zero, and the drive signal of the AC side matrix conversion circuit is off; When power is transmitted from the high voltage DC side to the AC side and the low voltage DC side, the first angular phase difference is smaller than zero and the third angular phase difference is larger than zero; When power is transmitted from the low-voltage DC side to the high-voltage DC side, the third angle phase difference is smaller than zero, and the drive signal of the AC side matrix conversion circuit is off. The method for controlling an in-vehicle charger according to claim 13 .

15. When the low-side converter circuit in the single-stage three-port magnetic integrated topology is a full-bridge circuit, the control parameters further include an inner phase shift angle of the low-side converter circuit. The method for controlling an in-vehicle charger according to claim 12 .

16. The high-voltage side converter circuit has no inward phase shift angle. The method for controlling an in-vehicle charger according to claim 12 .

17. In the single-stage three-port magnetic integrated topology AC side converter circuit, each half-bridge arm includes: The anode of the flywheel diode is connected to the AC high voltage end of the single-stage three-port magnetic integrated topology switching tube, and the driving signal is a normally-on signal; The anode of the flywheel diode is connected to the AC low-voltage end of the single-stage three-port magnetic integrated topology switching tube, and the driving signal is a complementary high-frequency on-off signal; The method for controlling an in-vehicle charger according to any one of claims 12 to 16.

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