On-vehicle charger, primary-side circuit, and vehicle
By using a single-stage topology and a bias suppression module, the problems of large size and low efficiency of traditional on-board chargers are solved, resulting in a smaller, more efficient, and more reliable charger design.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- SUZHOU INOSA UNITED POWER SYST CO LTD
- Filing Date
- 2026-03-06
- Publication Date
- 2026-07-03
AI Technical Summary
Traditional on-board chargers are bulky, inefficient, costly, and unreliable due to the inclusion of electrolytic capacitors and PFC power inductors.
It adopts a single-stage topology structure, converts the power frequency voltage into a high-frequency voltage through the primary circuit, and uses a transformer to transmit the voltage to the secondary circuit for charging. It eliminates the PFC inductor and electrolytic capacitor, and uses a bias magnetic suppression module and a two-phase bridge circuit structure.
It effectively reduces the footprint and volume of the on-board charger, improves efficiency, extends lifespan, reduces costs, and enhances reliability.
Smart Images
Figure CN122323809A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of vehicle technology, and more particularly to an on-board charger, primary circuit, and vehicle. Background Technology
[0002] With the increasing popularity of new energy vehicles, electricity consumption is also rising continuously. On-board chargers are used to charge the batteries in new energy vehicles and are an important component of these vehicles.
[0003] Traditional on-board charger technology employs PFC (Power Factor Correction) and HVDC (High Voltage Direct Current Converter) methods, including a PFC rectifier bridge arm, PFC power inductor, electrolytic capacitor, HV AC side H-bridge, resonant inductor, transformer, and HV DC side H-bridge. The front-stage PFC performs power factor correction, while the rear-stage regulates the output voltage and current.
[0004] In the above scheme, the presence of electrolytic capacitors and PFC power inductors results in a relatively large size of the on-board charger. Summary of the Invention
[0005] This application provides an on-board charger, a primary circuit, and a vehicle to achieve the effect of eliminating electrolytic capacitors and PFC power inductors, thereby reducing the size of the on-board charger.
[0006] In a first aspect, embodiments of this application provide an on-board charger, including: a primary circuit, a transformer, and a secondary circuit;
[0007] The primary circuit is used to convert the power frequency voltage provided by the AC power supply into a high frequency voltage, which is then transmitted to the secondary circuit via a transformer.
[0008] The primary-side circuit includes: a first two-phase bridge circuit, a second two-phase bridge circuit, and a bias suppression module; the first two-phase bridge circuit and the second two-phase bridge circuit are connected through the bias suppression module.
[0009] The first two-phase bridge circuit includes a first bridge arm and a second bridge arm connected in parallel, and the second two-phase bridge circuit includes a third bridge arm and a fourth bridge arm connected in parallel.
[0010] The midpoints of the first and fourth bridge arms are both connected to the first terminal of the AC power supply.
[0011] The midpoint of the second bridge arm is connected to the first end of the transformer, the midpoint of the third bridge arm is connected to the second end of the transformer, and the third end of the transformer is connected to the second end of the AC power supply.
[0012] In one possible implementation, the bias magnetic suppression module includes a first bias magnetic suppression unit and a second bias magnetic suppression unit;
[0013] The first bias magnetic suppression unit and the first two-phase bridge circuit are connected in parallel, and the second bias magnetic suppression unit and the second two-phase bridge circuit are connected in parallel.
[0014] The first bias suppression unit is connected to the second bias suppression unit.
[0015] In one possible implementation, the first bias suppression unit includes a first capacitor and a second capacitor connected in series, and the second bias suppression unit includes a third capacitor and a fourth capacitor connected in series.
[0016] The connection point between the first and second capacitors is connected to the connection point between the third and fourth capacitors.
[0017] In one possible implementation, the first bridge arm includes a first rectifier tube and a second rectifier tube connected in series, and the second bridge arm includes a first DAB tube and a second DAB tube connected in series.
[0018] The first and second rectifier diodes, the first and second DAB diodes, and the first and second capacitors are connected in parallel, all connected in series.
[0019] The connection point between the first rectifier tube and the second rectifier tube is connected to the midpoint of the fourth bridge arm and the first end of the AC power supply, respectively.
[0020] The connection point of the first DAB tube and the second DAB tube is connected to the first end of the transformer.
[0021] In one possible implementation, the third bridge arm includes a third DAB tube and a fourth DAB tube connected in series, and the fourth bridge arm includes a third rectifier tube and a fourth rectifier tube connected in series.
[0022] The third and fourth capacitors are connected in series, the third and fourth DAB transistors are connected in series, and the third and fourth rectifier transistors are connected in parallel.
[0023] The connection point between the third and fourth rectifier tubes is connected to the connection point between the first and second rectifier tubes and the first end of the AC power supply, respectively.
[0024] The connection point between the third and fourth DAB tubes is connected to the second end of the transformer.
[0025] In one possible implementation, the transformer includes a first primary winding, a second primary winding, and a secondary winding;
[0026] The first end of the first primary winding is connected to the connection point between the first DAB tube and the second DAB tube.
[0027] The second end of the first primary winding and the first end of the second primary winding are both connected to the second end of the AC power supply.
[0028] The second end of the second primary winding is connected to the connection point between the third and fourth DAB tubes.
[0029] In one possible implementation, the secondary-side circuit includes a fifth and a sixth bridge arm, a fifth capacitor, and a sixth capacitor connected in parallel.
[0030] The midpoint of the fifth bridge arm is connected to the midpoint of the sixth bridge arm through the secondary winding and the fifth capacitor;
[0031] The sixth capacitor is connected in parallel with both the fifth and sixth bridge arms.
[0032] In one possible implementation, the fifth bridge arm includes a first switch and a second switch connected in series, and the sixth bridge arm includes a third switch and a fourth switch connected in series.
[0033] The connection point between the first and second switching transistors is connected to the first end of the secondary winding, and the second end of the secondary winding is connected to the connection point between the third and fourth switching transistors through the fifth capacitor.
[0034] or,
[0035] The connection point between the first and second switching transistors is connected to the first end of the secondary winding via the fifth capacitor, and the second end of the secondary winding is connected to the connection point between the third and fourth switching transistors.
[0036] In one possible implementation, the on-board charger further includes a controller for controlling the switching sequence of each switching transistor in the primary and secondary circuits, and adjusting the first phase angle and the second phase angle.
[0037] Wherein, the first phase angle is the phase difference between the second voltage and the first voltage, the first voltage is the voltage between the midpoint of the second bridge arm and the midpoint of the third bridge arm, and the second voltage is the voltage between the midpoint of the fifth bridge arm and the midpoint of the sixth bridge arm.
[0038] The second phase angle is the phase difference between the voltage at the midpoint of the sixth bridge arm and the voltage at the midpoint of the fifth bridge arm.
[0039] In one possible implementation, the on-board charger further includes a resonant inductor, which is a discrete inductor or a coupled inductor, including a first inductor and a second inductor.
[0040] The connection point between the first DAB transistor and the second DAB transistor is connected to the first end of the first primary winding through the first inductor.
[0041] The connection point between the third DAB transistor and the fourth DAB transistor is connected to the second end of the second primary winding through the second inductor.
[0042] In one possible implementation, the on-board charger further includes a resonant inductor, and the connection point between the first and second switching transistors is connected to the first end of the secondary winding through the resonant inductor; or, the connection point between the third and fourth switching transistors is connected to the second end of the secondary winding through the resonant inductor.
[0043] Secondly, embodiments of this application provide a primary-side circuit, which is connected to the secondary-side circuit via a transformer, for converting the power frequency voltage provided by the AC power supply into a high-frequency voltage and transmitting it to the secondary-side circuit via the transformer.
[0044] The primary-side circuit includes: a first two-phase bridge circuit, a second two-phase bridge circuit, and a bias suppression module; the first two-phase bridge circuit and the second two-phase bridge circuit are connected through the bias suppression module.
[0045] The first two-phase bridge circuit includes a first bridge arm and a second bridge arm connected in parallel, and the second two-phase bridge circuit includes a third bridge arm and a fourth bridge arm connected in parallel.
[0046] The midpoints of the first and fourth bridge arms are both connected to the first terminal of the AC power supply.
[0047] The midpoint of the second bridge arm is connected to the first end of the transformer, the midpoint of the third bridge arm is connected to the second end of the transformer, and the third end of the transformer is connected to the second end of the AC power supply.
[0048] Thirdly, embodiments of this application provide a vehicle including an on-board charger according to any of the first aspects or a primary-side circuit according to the second aspect.
[0049] This application provides an on-board charger, a primary-side circuit, and a vehicle. The on-board charger includes a first two-phase bridge circuit, a second two-phase bridge circuit, and a magnetic bias suppression module. The first and second two-phase bridge circuits are connected via the magnetic bias suppression module. The first two-phase bridge circuit includes a first and a second bridge arm connected in parallel, and the second two-phase bridge circuit includes a third and a fourth bridge arm connected in parallel. The midpoints of the first and fourth bridge arms are both connected to the first terminal of an AC power supply. The midpoint of the second bridge arm is connected to the first terminal of a transformer, and the midpoint of the third bridge arm is connected to the second terminal of the transformer. The third terminal of the transformer is connected to the second terminal of the AC power supply. The on-board charger of this application adopts a single-stage topology. The primary-side circuit converts the power frequency voltage provided by the AC power supply into a high-frequency voltage, which is then transmitted to the secondary-side circuit via a transformer. The secondary-side circuit charges the battery, eliminating the PFC inductor and bus capacitor, effectively reducing the board area, volume, and cost of the on-board charger, and also effectively improving efficiency. Simultaneously, the lifespan and reliability of the on-board charger are also improved due to the elimination of electrolytic capacitors. Attached Figure Description
[0050] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this application and, together with the description, serve to explain the principles of this application.
[0051] Figure 1 A schematic diagram of a vehicle charging scenario provided in an embodiment of this application;
[0052] Figure 2 A schematic diagram of the structure of an on-board charger provided in this application embodiment. Figure 1 ;
[0053] Figure 3 A schematic diagram of the structure of an on-board charger provided in this application embodiment. Figure 2 ;
[0054] Figure 4 A schematic diagram of the structure of an on-board charger provided in this application embodiment. Figure 3 ;
[0055] Figure 5 A schematic diagram of the structure of an on-board charger provided in this application embodiment. Figure 4 ;
[0056] Figure 6 A schematic diagram of the structure of an on-board charger provided in this application embodiment. Figure 5 ;
[0057] Figure 7 A schematic diagram of the positive half-cycle waveform generation timing of an on-board charger provided in an embodiment of this application;
[0058] Figure 8 This is a schematic diagram of the negative half-cycle waveform generation timing of an on-board charger provided in an embodiment of this application.
[0059] The accompanying drawings illustrate specific embodiments of this application, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concept of this application to those skilled in the art through reference to particular embodiments. Detailed Implementation
[0060] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.
[0061] Figure 1This is a schematic diagram of a vehicle charging scenario provided in an embodiment of this application. The vehicle includes an on-board charger 110 and a battery BAT. The on-board charger 110 can receive AC power output from an AC power source and convert the AC power into DC power to charge the battery BAT.
[0062] Traditional on-board chargers use a two-stage topology to charge batteries, including a PFC inductor and electrolytic capacitors, resulting in a relatively large size. Furthermore, the large area of the electrolytic capacitors often limits the overall height of the on-board charger. This also makes the placement of the electrolytic capacitors difficult, leading to uneven current distribution and reduced capacitor lifespan, ultimately resulting in lower lifespan and reliability for the on-board charger.
[0063] Meanwhile, the two-stage topology means that the current passes through more devices during transmission, which reduces efficiency.
[0064] In addition, PFC inductors are also affected by DC bias, and PFC inductors and electrolytic capacitors also contribute to the higher cost of on-board chargers.
[0065] Based on this, this application provides an on-board charger that uses a single-stage topology to charge the battery, eliminating the PFC inductor and electrolytic capacitor, effectively reducing the on-board charger's footprint, size, and cost, while also improving efficiency. Simultaneously, the elimination of the electrolytic capacitor also improves the on-board charger's lifespan and reliability.
[0066] The technical solution of this application and how the technical solution of this application solves the above-mentioned technical problems are described in detail below with specific embodiments. These specific embodiments can be combined with each other, and the same or similar concepts or processes may not be described again in some embodiments. The embodiments of this application will be described below with reference to the accompanying drawings.
[0067] Figure 2 A schematic diagram of the structure of an on-board charger provided in this application embodiment. Figure 1 ,refer to Figure 2 As shown, the on-board charger 110 includes: a primary circuit 10, a transformer T, and a secondary circuit 20;
[0068] The primary circuit 10 is used to convert the power frequency voltage provided by the AC power supply into a high frequency voltage, and transmit it to the secondary circuit 20 via the transformer T.
[0069] The primary circuit 10 includes: a first two-phase bridge circuit 101, a second two-phase bridge circuit 102, and a bias suppression module 103; the first two-phase bridge circuit 101 and the second two-phase bridge circuit 102 are connected through the bias suppression module 103.
[0070] The first two-phase bridge circuit 101 includes a first bridge arm 1011 and a second bridge arm 1012 connected in parallel, and the second two-phase bridge circuit 102 includes a third bridge arm 1021 and a fourth bridge arm 1022 connected in parallel.
[0071] The midpoint of the first bridge arm 1011 and the midpoint of the fourth bridge arm 1022 are both connected to the first terminal of the AC power supply.
[0072] The midpoint of the second bridge arm 1012 is connected to the first end of the transformer T, the midpoint of the third bridge arm 1021 is connected to the second end of the transformer T, and the third end of the transformer T is connected to the second end of the AC power supply.
[0073] The primary circuit 10 converts the AC power supply's mains frequency voltage into a high-frequency voltage, which is then transmitted to the secondary circuit 20 via transformer T. The secondary circuit 20 is connected to both ends of the vehicle battery, converting the voltage into the DC voltage required by the battery to charge it. Figure 2 The battery is not shown in the image.
[0074] As can be seen from the above, the primary circuit 10 can be used for voltage boosting. In one implementation scenario, the power frequency voltage can be converted into a high frequency voltage by controlling the switching action of the first two-phase bridge circuit 101 and the second two-phase bridge circuit 102.
[0075] AC power can be the power grid or other sources that provide alternating current.
[0076] Still referencing Figure 2 As shown, in some embodiments, the bias suppression module 103 includes a first bias suppression unit 1031 and a second bias suppression unit 1032.
[0077] The first bias suppression unit 1031 and the first two-phase bridge circuit 101 are connected in parallel, and the second bias suppression unit 1032 and the second two-phase bridge circuit 102 are connected in parallel.
[0078] The first bias suppression unit 1031 is connected to the second bias suppression unit 1032.
[0079] In one implementation scenario, the first bias suppression unit 1031 includes a first capacitor C1 and a second capacitor C2 connected in series, and the second bias suppression unit 1032 includes a third capacitor C3 and a fourth capacitor C4 connected in series.
[0080] The connection point between the first capacitor C1 and the second capacitor C2 is connected to the connection point between the third capacitor C3 and the fourth capacitor C4.
[0081] Still referencing Figure 2 As shown, the connection point between the first capacitor C1 and the second capacitor C2 is point p, and the connection point between the third capacitor C3 and the fourth capacitor C4 is point q. Points p and q are connected.
[0082] The first capacitor C1, the second capacitor C2, the third capacitor C3, and the fourth capacitor C4 serve to filter, block DC, and suppress bias magnetization. Specifically, because capacitors can store charge, they can absorb excess charge when the bus voltage rises instantaneously and release stored charge when the bus voltage drops instantaneously, thus buffering voltage fluctuations. Simultaneously, because capacitors have low impedance to high-frequency signals, they provide a low-impedance path for high-frequency signals, thereby acting as filters.
[0083] Furthermore, because capacitors present high impedance to DC signals, they can block DC components, thus achieving DC blocking. Moreover, based on the DC blocking effect of capacitors, the saturation of the transformer core (T) caused by DC components is effectively prevented, thereby suppressing bias magnetization.
[0084] In some embodiments, the first bridge arm 1011 includes a first rectifier P1 and a second rectifier P2 connected in series, and the second bridge arm 1012 includes a first DAB tube M1 and a second DAB tube M2 connected in series.
[0085] The first rectifier P1 and the second rectifier P2 are connected in series, the first DAB transistor M1 and the second DAB transistor M2 are connected in series, and the first capacitor C1 and the second capacitor C2 are connected in parallel.
[0086] The connection point between the first rectifier P1 and the second rectifier P2 is connected to the midpoint of the fourth bridge arm 1022 and the first end of the AC power supply, respectively.
[0087] The connection point of the first DAB tube M1 and the second DAB tube M2 is connected to the first end of the transformer T.
[0088] The first rectifier P1 and the second rectifier P2, connected in series, form the first bridge arm 1011. The midpoint of the first bridge arm 1011 is a connection point between the first rectifier P1 and the second rectifier P2. Figure 2 Point m is shown.
[0089] The first DAB tube M1 and the second DAB tube M2, connected in series, form the second bridge arm 1012. The midpoint of the second bridge arm 1012 is a connection point between the first DAB tube M1 and the second DAB tube M2, i.e. Figure 2 Point a is shown.
[0090] In some embodiments, the third bridge arm 1021 includes a third DAB tube M3 and a fourth DAB tube M4 connected in series, and the fourth bridge arm 1022 includes a third rectifier tube P3 and a fourth rectifier tube P4 connected in series.
[0091] The third capacitor C3 and the fourth capacitor C4 are connected in series, the third DAB transistor M3 and the fourth DAB transistor M4 are connected in series, and the third rectifier transistor P3 and the fourth rectifier transistor P4 are connected in parallel.
[0092] The connection point between the third rectifier P3 and the fourth rectifier P4 is connected to the connection point between the first rectifier P1 and the second rectifier P2, and the first end of the AC power supply, respectively.
[0093] The connection point between the third DAB tube M3 and the fourth DAB tube M4 is connected to the second end of the transformer T.
[0094] The third DAB tube M3 and the fourth DAB tube M4 form the third bridge arm 1021. The midpoint of the third bridge arm 1021 is a connection point between the third DAB tube M3 and the fourth DAB tube M4, i.e. Figure 2 Point b is shown.
[0095] The third rectifier tube P3 and the fourth rectifier tube P4 form the fourth bridge arm 1022. The midpoint of the fourth bridge arm 1022 is a connection point between the third rectifier tube P3 and the fourth rectifier tube P4, i.e. Figure 2 The n points shown.
[0096] The first DAB transistor M1 to the fourth DAB transistor M4 form an H-bridge. In one implementation scenario, the first DAB transistor M1 to the fourth DAB transistor M4 can be fast transistors, where fast transistors refer to fast-switching semiconductor power devices.
[0097] Specifically, the first DAB transistor M1 to the fourth DAB transistor M4 and the first rectifier transistor P1 to the fourth rectifier transistor P4 can be MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), combinations of IGBTs (Insulated Gate Bipolar Transistors) and FRDs (Fast Recovery Diodes), SiC (Silicon Carbide) MOSFETs, etc. This application does not limit the specific types of the first rectifier transistor P1 to the fourth rectifier transistor P4 and the first DAB transistor M1 to the fourth DAB transistor M4.
[0098] This application provides an on-board charger 110, including a first two-phase bridge circuit 101, a second two-phase bridge circuit 102, and a bias suppression module 103. The first two-phase bridge circuit 101 and the second two-phase bridge circuit 102 are connected through the bias suppression module 103. The first two-phase bridge circuit 101 includes a first bridge arm 1011 and a second bridge arm 1012 connected in parallel, and the second two-phase bridge circuit 102 includes a third bridge arm 1021 and a fourth bridge arm 1022 connected in parallel. The midpoints of the first bridge arm 1011 and the fourth bridge arm 1022 are both connected to the first terminal of an AC power supply, the midpoint of the second bridge arm 1012 is connected to the first terminal of a transformer T, the midpoint of the third bridge arm 1021 is connected to the second terminal of the transformer T, and the third terminal of the transformer T is connected to the second terminal of the AC power supply. The on-board charger 110 of this application adopts a single-stage topology. The primary circuit 10 converts the AC power supply's mains frequency voltage into a high-frequency voltage, which is then transmitted to the secondary circuit 20 via transformer T. The secondary circuit 20 charges the battery, eliminating the PFC inductor and bus capacitor, effectively reducing the board area, size, and cost of the on-board charger 110, and also effectively improving efficiency. At the same time, the elimination of electrolytic capacitors also improves the lifespan and reliability of the on-board charger 110.
[0099] Based on the above embodiments, the following embodiment is provided to illustrate the structure of transformer T and secondary circuit 20.
[0100] Figure 3 A schematic diagram of the structure of an on-board charger provided in this application embodiment. Figure 2 ,refer to Figure 3 As shown, in some embodiments, the transformer T includes a first primary winding V1, a second primary winding V2, and a secondary winding V3;
[0101] The first end of the first primary winding V1 is connected to the connection point between the first DAB tube M1 and the second DAB tube M2.
[0102] The second end of the first primary winding V1 and the first end of the second primary winding V2 are both connected to the second end of the AC power supply AC.
[0103] The second end of the second primary winding V2 is connected to the connection point between the third DAB tube M3 and the fourth DAB tube M4.
[0104] The first end of the first primary winding V1 is connected to the connection point between the first DAB tube M1 and the second DAB tube M2, that is, it is connected to point a.
[0105] The second end of the second primary winding V2 is connected to the connection point between the third DAB tube M3 and the fourth DAB tube M4, that is, connected to point b.
[0106] In one implementation scenario, the on-board charger 110 also includes an output differential mode filter Lf. The second end of the first primary winding V1 and the first end of the second primary winding V2 are both connected to the second end of the AC power supply AC through the output differential mode filter Lf, so that the AC power is filtered by the output differential mode filter Lf and then output to the transformer T.
[0107] Meanwhile, the on-board charger 110 of this application effectively reduces the size of the output differential filter Lf by interleaving the input current.
[0108] In some embodiments, the secondary circuit 20 includes a fifth bridge arm 201 and a sixth bridge arm 202 connected in parallel, a fifth capacitor Cb and a sixth capacitor Co;
[0109] The midpoint of the fifth bridge arm 201 is connected to the midpoint of the sixth bridge arm 202 through the secondary winding V3 and the fifth capacitor Cb.
[0110] The sixth capacitor Co is connected in parallel with the fifth bridge arm 201 and the sixth bridge arm 202.
[0111] Among them, the fifth capacitor Cb can be a DC blocking capacitor or a resonant capacitor.
[0112] In one implementation scenario, the midpoint of the fifth bridge arm 201 is connected to the first end of the secondary winding V3, and the second end of the secondary winding V3 is connected to the midpoint of the sixth bridge arm 202 through the fifth capacitor Cb. Figure 3 As shown.
[0113] In another implementation scenario, the midpoint of the fifth bridge arm 201 is connected to the first end of the secondary winding V3 through the fifth capacitor Cb, and the second end of the secondary winding V3 is connected to the midpoint of the sixth bridge arm 202. See reference [link / reference needed] for details. Figure 4 As shown, Figure 4 A schematic diagram of the structure of an on-board charger provided in this application embodiment. Figure 3 .
[0114] The sixth capacitor Co is connected in parallel with both the fifth bridge arm 201 and the sixth bridge arm 202 for filtering. The two ends of the sixth capacitor Co are also connected to the positive and negative terminals of the battery, which is... Figure 3 and Figure 4 The BAT shown in the image.
[0115] Still referencing Figure 3 As shown, in some embodiments, the fifth bridge arm 201 includes a first switch S1 and a second switch S2 connected in series, and the sixth bridge arm 202 includes a third switch S3 and a fourth switch S4 connected in series.
[0116] The connection point between the first switch S1 and the second switch S2 is connected to the first end of the secondary winding V3. The second end of the secondary winding V3 is connected to the connection point between the third switch S3 and the fourth switch S4 through the fifth capacitor Cb.
[0117] or,
[0118] The connection point between the first switch S1 and the second switch S2 is connected to the first end of the secondary winding V3 through the fifth capacitor Cb, and the second end of the secondary winding V3 is connected to the connection point between the third switch S3 and the fourth switch S4.
[0119] The first switch S1 to the fourth switch S4 form an H-bridge, wherein the first switch S1 and the second switch S2 form the fifth bridge arm 201, and the midpoint of the fifth bridge arm 201 is a connection point between the first switch S1 and the second switch S2, i.e. Figure 3 Point c is shown.
[0120] The third switch S3 and the fourth switch S4 form the sixth bridge arm 202. The midpoint of the sixth bridge arm 202 is a connection point between the third switch S3 and the fourth switch S4, i.e. Figure 3 Point d is shown.
[0121] Points c and d are connected via the secondary winding V3 and the fifth capacitor Cb. In one implementation scenario, such as... Figure 3 As shown, point c is connected to the first end of the secondary winding V3, and the second end of the secondary winding V3 is connected to point d through the fifth capacitor Cb.
[0122] In another implementation scenario, such as Figure 4 As shown, point c is connected to the first end of the secondary winding V3 through the fifth capacitor Cb, and the second end of the secondary winding V3 is connected to point d.
[0123] Normally, the fifth bridge arm 201 is the leading arm, and the sixth bridge arm 202 is the lagging arm.
[0124] The first switching transistor S1 to the fourth switching transistor S4 can be MOSFET, IGBT, SiC MOSFET, etc. This application does not limit the specific type of the first switching transistor S1 to the fourth switching transistor S4.
[0125] Still referencing Figure 3 As shown, in some embodiments, the on-board charger 110 further includes a resonant inductor, which is a discrete inductor or a coupled inductor, including a first inductor and a second inductor.
[0126] The connection point between the first DAB transistor M1 and the second DAB transistor M2 is connected to the first end of the first primary winding V1 through the first inductor.
[0127] The connection point between the third DAB tube M3 and the fourth DAB tube M4 is connected to the second end of the second primary winding V2 through the second inductor.
[0128] At this point, the resonant inductor is located on the primary side and can be either a discrete inductor or a coupled inductor. When the resonant inductor is a coupled inductor, it can cancel the DC bias.
[0129] In another implementation scenario, the resonant inductor can also be located on the secondary side; for details, please refer to [reference needed]. Figure 5 As shown, Figure 5 A schematic diagram of the structure of an on-board charger provided in this application embodiment. Figure 4 The on-board charger 110 also includes a resonant inductor. The connection point between the first switch S1 and the second switch S2 is connected to the first end of the secondary winding V3 through the resonant inductor. Alternatively, the connection point between the third switch S3 and the fourth switch S4 is connected to the second end of the secondary winding V3 through the resonant inductor.
[0130] refer to Figure 5 As shown, in one implementation scenario, when the connection point c between the first switch S1 and the second switch S2 is connected to the first end of the secondary winding V3 through a resonant inductor, the second end of the secondary winding V3 can be connected to the connection point d between the third switch S3 and the fourth switch S4 through the fifth capacitor Cb.
[0131] Figure 6 A schematic diagram of the structure of an on-board charger provided in this application embodiment. Figure 5 ,refer to Figure 6 As shown, in another implementation scenario, the connection point c between the first switch S1 and the second switch S2 is connected to the first end of the secondary winding V3 through the fifth capacitor Cb, and the second end of the secondary winding V3 is connected to the connection point d between the third switch S3 and the fourth switch S4 through the resonant inductor.
[0132] Meanwhile, since the resonant inductor is located on the secondary side, the connection point a between the first DAB transistor M1 and the second DAB transistor M2 can be directly connected to the first end of the first primary winding V1, and the connection point b between the third DAB transistor M3 and the fourth DAB transistor M4 can be directly connected to the second end of the second primary winding V2.
[0133] In summary, after the primary circuit 10 converts the power frequency voltage into a high frequency voltage and outputs it to the transformer T, the transformer T can transmit the high frequency voltage provided by the primary circuit 10 to the secondary circuit 20. The secondary circuit 20 can then convert the high frequency voltage into the DC voltage required by the battery to charge the battery.
[0134] Based on the above embodiments, the control process of the first rectifier P1 to the second rectifier P2, the first DAB tube M1 to the fourth DAB tube M4, and the first switch tube S1 and the fourth switch tube S4 in the on-board charger 110 will be described below.
[0135] In some embodiments, the on-board charger 110 further includes a controller for controlling the switching timing of each switching transistor in the primary circuit and the secondary circuit, and adjusting the first phase angle and the second phase angle.
[0136] Wherein, the first phase angle is the phase difference between the second voltage and the first voltage, the first voltage is the voltage between the midpoint of the second bridge arm 1012 and the midpoint of the third bridge arm 1021, and the second voltage is the voltage between the midpoint of the fifth bridge arm 201 and the midpoint of the sixth bridge arm 202.
[0137] The second phase angle is the phase difference between the voltage at the midpoint of the sixth bridge arm 202 and the voltage at the midpoint of the fifth bridge arm 201.
[0138] The primary circuit 10 includes rectifier transistors P1 to P4 and DAB transistors M1 to M4. The secondary circuit 20 includes rectifier transistors S1 to S4.
[0139] The second voltage may lag behind or lead the first phase angle α relative to the first voltage. Typically, the on-board charger 110 can operate in both charging and discharging modes. In charging mode, the second voltage lags behind the first voltage by the first phase angle α; in discharging mode, the second voltage leads the first voltage by the first phase angle α.
[0140] The second phase angle β is the phase difference between the voltage at the midpoint of the sixth bridge arm 202 and the voltage at the midpoint of the fifth bridge arm 201. Specifically, it is the phase difference between the voltage at the connection point of the third switch S3 and the fourth switch S4 and the voltage at the connection point of the first switch S1 and the second switch S2. Normally, the voltage at the midpoint of the sixth bridge arm 202 lags behind the voltage at the midpoint of the fifth bridge arm 201 by the second phase angle β.
[0141] Power factor correction and output power modulation can be achieved by adjusting the values of the first phase angle α and the second phase angle β.
[0142] In one implementation scenario, the controller is connected to the first rectifier P1 to the fourth rectifier P4, the first DAB tube M1 to the fourth DAB tube M4, and the first switch tube S1 to the fourth switch tube S4 respectively. It provides corresponding drive signals to the first rectifier P1 to the fourth rectifier P4, the first DAB tube M1 to the fourth DAB tube M4, and the first switch tube S1 to the fourth switch tube S4 to achieve control. By turning the first rectifier P1 to the fourth rectifier P4, the first DAB tube M1 to the fourth DAB tube M4, and the first switch tube S1 to the fourth switch tube S4 on and off according to certain rules, it achieves control of output power and power factor correction.
[0143] Figure 7 This is a schematic diagram of the positive half-cycle waveform generation timing of an on-board charger provided in an embodiment of this application. Figure 8 This is a schematic diagram of the negative half-cycle waveform generation timing of an on-board charger provided in an embodiment of this application, combined with... Figure 7 and Figure 8 As shown, the AC power supply can output an AC sine wave, including the positive half-cycle and the negative half-cycle.
[0144] In one implementation scenario, during charging and discharging modes, the first DAB transistor M1 to the fourth DAB transistor M4 can adopt a complementary waveform generation method, for example, 50% complementary waveform generation, and the first DAB transistor M1 and the fourth DAB transistor M4 are turned on and off simultaneously, as are the second DAB transistor M2 and the third DAB transistor M3; the first switch transistor S1 and the second switch transistor S2 generate complementary waveforms, and the third switch transistor S3 and the fourth switch transistor S4 generate complementary waveforms.
[0145] When the first DAB transistor M1 to the fourth DAB transistor M4 use 50% complementary waveform generation, the bus voltage is twice the input voltage. The input voltage is the instantaneous value of the grid voltage, and the bus voltage is the voltage across the first capacitor C1 and the second capacitor C2 connected in series.
[0146] One expression for bus voltage is shown below:
[0147]
[0148] Where Vac(t) is the input voltage and Vbus(t) is the bus voltage.
[0149] An expression for output power is shown below:
[0150]
[0151] In the above formula, Pout represents the output power, Vac is the input voltage, Vo is the output voltage, Lr is the inductance value of the resonant inductor, fs is the switching frequency of the first DAB transistor M1 to the fourth DAB transistor M4, Nps is the turns ratio of the transformer T, α is the first phase angle, and β is the second phase angle.
[0152] Where α > 0 corresponds to the charging mode, and α < 0 corresponds to the discharging mode. The switching frequencies of the first DAB transistor M1 to the fourth DAB transistor M4 are the same.
[0153] As shown in the above formula, the output power can be adjusted by regulating the first phase angle α and the second phase angle β. In one implementation scenario, the first phase angle α and the second phase angle β can be adjusted within their respective preset ranges. For example, the preset range for the first phase angle α is -0.5° to 0.5°, and the preset range for the second phase angle β is 0° to 0.5°.
[0154] In summary, the controller can achieve power factor correction and output power modulation by adjusting the first phase angle and the second phase angle. There is no need to set up PFC inductors and electrolytic capacitors, which effectively reduces the size and board area of the on-board charger 110. At the same time, the elimination of electrolytic capacitors improves the lifespan and reliability of the on-board charger 110, and also effectively reduces costs.
[0155] This application provides a primary circuit 10, which is connected to a secondary circuit 20 via a transformer T. The primary circuit 10 is used to convert the power frequency voltage provided by the AC power supply into a high frequency voltage, and then transmit it to the secondary circuit 20 via the transformer T.
[0156] The primary circuit 10 includes: a first two-phase bridge circuit 101, a second two-phase bridge circuit 102, and a bias suppression module 103; the first two-phase bridge circuit 101 and the second two-phase bridge circuit 102 are connected through the bias suppression module 103.
[0157] The first two-phase bridge circuit 101 includes a first bridge arm 1011 and a second bridge arm 1012 connected in parallel, and the second two-phase bridge circuit 102 includes a third bridge arm 1021 and a fourth bridge arm 1022 connected in parallel.
[0158] The midpoint of the first bridge arm 1011 and the midpoint of the fourth bridge arm 1022 are both connected to the first terminal of the AC power supply.
[0159] The midpoint of the second bridge arm 1012 is connected to the first end of the transformer T, the midpoint of the third bridge arm 1021 is connected to the second end of the transformer T, and the third end of the transformer T is connected to the second end of the AC power supply.
[0160] The structure and principle of the primary-side circuit 10 provided in this embodiment are the same as those of the primary-side circuit 10 in the on-board charger 110 provided in the above embodiment, and will not be described again here.
[0161] This application provides a vehicle, including the on-board charger 110 provided in any of the above embodiments or the primary-side circuit 10 provided in any of the above embodiments. The specific structures of the on-board charger 110 and the primary-side circuit 10 can be referred to the above embodiments, and will not be described in detail here.
[0162] Finally, it should be noted that other embodiments of the invention will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This invention is intended to cover any variations, uses, or adaptations of the invention that follow the general principles of the invention and include common knowledge or customary techniques in the art not disclosed herein, and is not limited to the precise structures described above and shown in the accompanying drawings, and various modifications and changes can be made without departing from its scope. The scope of the invention is limited only by the appended claims.
Claims
1. An on-board charger, characterized in that, include: Primary circuit, transformer, and secondary circuit; The primary circuit is used to convert the power frequency voltage provided by the AC power supply into a high frequency voltage, and transmit it to the secondary circuit via the transformer. The primary-side circuit includes: a first two-phase bridge circuit, a second two-phase bridge circuit, and a bias suppression module; The first two-phase bridge circuit and the second two-phase bridge circuit are connected through the bias suppression module; The first two-phase bridge circuit includes a first bridge arm and a second bridge arm connected in parallel, and the second two-phase bridge circuit includes a third bridge arm and a fourth bridge arm connected in parallel. The midpoint of the first bridge arm and the midpoint of the fourth bridge arm are both connected to the first end of the AC power supply. The midpoint of the second bridge arm is connected to the first end of the transformer, the midpoint of the third bridge arm is connected to the second end of the transformer, and the third end of the transformer is connected to the second end of the AC power supply.
2. The on-board charger according to claim 1, characterized in that, The bias magnetic suppression module includes a first bias magnetic suppression unit and a second bias magnetic suppression unit; The first bias magnetic suppression unit and the first two-phase bridge circuit are connected in parallel, and the second bias magnetic suppression unit and the second two-phase bridge circuit are connected in parallel. The first bias suppression unit is connected to the second bias suppression unit.
3. The on-board charger according to claim 2, characterized in that, The first bias suppression unit includes a first capacitor and a second capacitor connected in series, and the second bias suppression unit includes a third capacitor and a fourth capacitor connected in series. The connection point between the first capacitor and the second capacitor is connected to the connection point between the third capacitor and the fourth capacitor.
4. The on-board charger according to claim 3, characterized in that, The first bridge arm includes a first rectifier tube and a second rectifier tube connected in series, and the second bridge arm includes a first DAB tube and a second DAB tube connected in series. The first and second rectifier diodes connected in series, the first and second DAB diodes connected in series, and the first and second capacitors connected in series are connected in parallel. The connection point between the first rectifier tube and the second rectifier tube is connected to the midpoint of the fourth bridge arm and the first end of the AC power supply, respectively. The connection point of the first DAB tube and the second DAB tube is connected to the first end of the transformer.
5. The on-board charger according to claim 4, characterized in that, The third bridge arm includes a third DAB tube and a fourth DAB tube connected in series, and the fourth bridge arm includes a third rectifier tube and a fourth rectifier tube connected in series. The third and fourth capacitors connected in series, the third and fourth DAB transistors connected in series, and the third and fourth rectifier transistors connected in series are connected in parallel. The connection point between the third rectifier tube and the fourth rectifier tube is connected to the connection point between the first rectifier tube and the second rectifier tube, and the first end of the AC power supply, respectively. The connection point between the third DAB tube and the fourth DAB tube is connected to the second end of the transformer.
6. The on-board charger according to claim 5, characterized in that, The transformer includes a first primary winding, a second primary winding, and a secondary winding; The first end of the first primary winding is connected to the connection point between the first DAB tube and the second DAB tube; The second end of the first primary winding and the first end of the second primary winding are both connected to the second end of the AC power supply; The second end of the second primary winding is connected to the connection point between the third DAB tube and the fourth DAB tube.
7. The on-board charger according to claim 6, characterized in that, The secondary circuit includes a fifth and a sixth bridge arm connected in parallel, a fifth capacitor, and a sixth capacitor; The midpoint of the fifth bridge arm is connected to the midpoint of the sixth bridge arm through the secondary winding and the fifth capacitor; The sixth capacitor is connected in parallel with both the fifth and sixth bridge arms.
8. The on-board charger according to claim 7, characterized in that, The fifth bridge arm includes a first switch and a second switch connected in series, and the sixth bridge arm includes a third switch and a fourth switch connected in series. The connection point between the first switch and the second switch is connected to the first end of the secondary winding, and the second end of the secondary winding is connected to the connection point between the third switch and the fourth switch through the fifth capacitor; or, The connection point between the first switch and the second switch is connected to the first end of the secondary winding through the fifth capacitor, and the second end of the secondary winding is connected to the connection point between the third switch and the fourth switch.
9. The on-board charger according to claim 7, characterized in that, The on-board charger also includes a controller for controlling the switching sequence of each switching transistor in the primary circuit and the secondary circuit, and adjusting the first phase angle and the second phase angle. Wherein, the first phase angle is the phase difference of the second voltage relative to the first voltage, the first voltage is the voltage between the midpoint of the second bridge arm and the midpoint of the third bridge arm, and the second voltage is the voltage between the midpoint of the fifth bridge arm and the midpoint of the sixth bridge arm; The second phase angle is the phase difference between the voltage at the midpoint of the sixth bridge arm and the voltage at the midpoint of the fifth bridge arm.
10. The on-board charger according to any one of claims 6-9, characterized in that, The on-board charger also includes a resonant inductor, which is a discrete inductor or a coupled inductor, including a first inductor and a second inductor. The connection point between the first DAB transistor and the second DAB transistor is connected to the first end of the first primary winding through the first inductor. The connection point between the third DAB tube and the fourth DAB tube is connected to the second end of the second primary winding through the second inductor.
11. The on-board charger according to claim 8, characterized in that, The on-board charger also includes a resonant inductor; The connection point between the first switch and the second switch is connected to the first end of the secondary winding through the resonant inductor; or, the connection point between the third switch and the fourth switch is connected to the second end of the secondary winding through the resonant inductor.
12. A primary-side circuit, characterized in that, The primary circuit and the secondary circuit are connected by a transformer, which is used to convert the power frequency voltage provided by the AC power supply into a high frequency voltage and transmit it to the secondary circuit through the transformer. The primary-side circuit includes: a first two-phase bridge circuit, a second two-phase bridge circuit, and a bias suppression module; the first two-phase bridge circuit and the second two-phase bridge circuit are connected through the bias suppression module. The first two-phase bridge circuit includes a first bridge arm and a second bridge arm connected in parallel, and the second two-phase bridge circuit includes a third bridge arm and a fourth bridge arm connected in parallel. The midpoint of the first bridge arm and the midpoint of the fourth bridge arm are both connected to the first end of the AC power supply. The midpoint of the second bridge arm is connected to the first end of the transformer, the midpoint of the third bridge arm is connected to the second end of the transformer, and the third end of the transformer is connected to the second end of the AC power supply.
13. A vehicle, characterized in that, Includes the on-board charger as described in any one of claims 1-11 or the primary-side circuit as described in claim 12.