Vehicle-mounted charger circuit and charging device

Abstract

The invention discloses a vehicle-mounted charger circuit and a charging device, and relates to the technical field of vehicle-mounted chargers, the vehicle-mounted charger circuit comprises a rectification module, a bus capacitor, a power conversion module and a control module, the rectification module, the bus capacitor and the power conversion module are connected in sequence, the control module is connected with the rectification module and the power conversion module, and the power conversion module is connected with a plurality of battery packs; wherein the control module is used for controlling the power conversion module through a single-phase-shift wave-sending control strategy, an extended phase-shift control strategy or a triple-phase-shift control strategy, so that the power conversion module performs power factor correction and power conversion on the received direct current and correspondingly provides multiple paths of different outputs to the battery packs. The technical effects of reducing the circuit board occupation area of the vehicle-mounted charger, reducing the size and cost of the whole machine, prolonging the service life of the vehicle-mounted charger and improving the reliability of the vehicle-mounted charger are achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of on-board chargers, and particularly relates to an on-board charger circuit and a charging device. BACKGROUND

[0002] In a new energy vehicle, a traditional on-board charger generally adopts a two-stage topology composed of a PFC (Power Factor Correction) and an HVDC (High Voltage Direct Current). The two-stage topology structure has defects of a large number of tubes, a large volume, low efficiency, and high cost. In addition, an electrolytic capacitor included in the PFC topology not only has a large volume, but also affects the service life of the product.

[0003] Therefore, how to effectively reduce the volume and cost of the on-board charger to improve the efficiency of the on-board charger is a technical problem to be solved. SUMMARY

[0004] The main purpose of the present application is to provide an on-board charger circuit and a charging device, and to solve the technical problems of a large volume, high cost, and low efficiency of an on-board charger in the related art.

[0005] To achieve the above purpose, the present application provides an on-board charger circuit, which comprises a rectifier module, a bus capacitor, and a power conversion module connected in sequence, and a control module connected with the rectifier module and the power conversion module respectively, and the power conversion module is connected with a plurality of battery groups.

[0006] The control module is configured to control the power conversion module by a single-phase-shift control strategy, an extended phase-shift control strategy, or a triple phase-shift control strategy, so that the power conversion module performs power factor correction and power conversion on the received direct current, and provides a plurality of different outputs to the plurality of battery groups.

[0007] In an embodiment, the power conversion module comprises a primary bridge arm unit, a multi-winding transformer, and a plurality of secondary bridge arm units. The primary bridge arm unit is connected with the bus capacitor. The primary winding of the multi-winding transformer is connected with the primary bridge arm unit. The plurality of secondary windings of the multi-winding transformer are connected with the plurality of secondary bridge arm units correspondingly. The plurality of secondary bridge arm units are connected with the plurality of battery groups correspondingly. The primary bridge arm unit and the plurality of secondary bridge arm units are connected with the control module respectively.

[0008] The control module is specifically configured to generate the primary-side switch driving signal based on a single-phase-shift control strategy, an extended phase-shift control strategy, or a triple phase-shift control strategy, and output the primary-side switch driving signal to the primary-side bridge arm unit; and generate a plurality of secondary-side switch driving signals based on a phase of the primary-side switch driving signal and a plurality of preset phase-shift angles in the single-phase-shift control strategy, the extended phase-shift control strategy, or the triple phase-shift control strategy, and output the plurality of secondary-side switch driving signals to the corresponding plurality of secondary-side bridge arm units.

[0009] In an embodiment, the multi-winding transformer is a three-winding transformer, and the plurality of secondary-side bridge arm units includes a first secondary-side bridge arm unit and a second secondary-side bridge arm unit, a first secondary-side winding of the three-winding transformer is connected to the first secondary-side bridge arm unit, and a second secondary-side winding of the three-winding transformer is connected to the second secondary-side bridge arm unit.

[0010] The control module is further configured to generate the first secondary-side switch driving signal based on the phase of the primary-side switch driving signal and a first phase-shift angle, and output the first secondary-side switch driving signal to the first secondary-side bridge arm unit; and generate the second secondary-side switch driving signal based on the phase of the primary-side switch driving signal and a second phase-shift angle, and output the second secondary-side switch driving signal to the second secondary-side bridge arm unit.

[0011] In an embodiment, the plurality of battery packs includes a high-voltage battery pack and a low-voltage battery pack, the first secondary-side bridge arm unit is connected to the high-voltage battery pack, and the second secondary-side bridge arm unit is connected to the low-voltage battery pack.

[0012] The first secondary-side bridge arm unit is configured to convert a voltage transmitted by the three-winding transformer based on the first secondary-side switch driving signal, output a first charging voltage to the high-voltage battery pack to charge the high-voltage battery pack, and convert a voltage provided by the high-voltage battery pack based on the first secondary-side switch driving signal, and output a first discharging voltage to the three-winding transformer.

[0013] The second secondary-side bridge arm unit is configured to convert a voltage transmitted by the three-winding transformer based on the second secondary-side switch driving signal, output a second charging voltage to the low-voltage battery pack to charge the low-voltage battery pack, and convert a voltage provided by the low-voltage battery pack based on the second secondary-side switch driving signal, and output a second discharging voltage to the three-winding transformer.

[0014] In an embodiment, the power conversion module further includes a resonant inductor Lr1, a capacitor Cr1, and a capacitor Cr2, the resonant inductor Lr1 and the capacitor Cr1 are connected in series between the primary-side winding of the three-winding transformer and the primary-side bridge arm unit, and the capacitor Cr2 is connected in series between the first secondary-side winding of the three-winding transformer and the first secondary-side bridge arm unit.

[0015] In an embodiment, the power conversion module further comprises a resonant inductor Lr2 and a resonant inductor Lr3, the resonant inductor Lr2 is connected in series between the capacitor Cr2 and the first secondary bridge arm unit, and the resonant inductor Lr3 is connected in series between the second secondary winding of the three-winding transformer and the second secondary bridge arm unit.

[0016] In an embodiment, the on-board charger circuit further comprises an EMI filter module, an input end of the EMI filter module is connected with the power grid, and an output end of the EMI filter module is connected with the rectifier module.

[0017] The EMI filter module is configured to perform low-pass filtering on the alternating current provided by the power grid, output the power frequency alternating current to the rectifier module, and provide surge protection.

[0018] In an embodiment, the rectifier module comprises a power frequency rectifier bridge, an input end of the power frequency rectifier bridge is connected with the output end of the EMI filter module, an output end of the power frequency rectifier bridge is connected with the power conversion module, and a control end of the power frequency rectifier bridge is connected with the control module.

[0019] The control module is further configured to generate a rectification driving signal according to the frequency and phase of the power grid and output the rectification driving signal to the power frequency rectifier bridge, so that the power frequency rectifier bridge converts the power frequency alternating current into direct current according to the rectification driving signal.

[0020] In an embodiment, a capacitor unit is connected between the power conversion module and each battery pack.

[0021] The capacitor unit is configured to filter the output of the power conversion module and provide power decoupling between the power conversion module and the battery pack.

[0022] To achieve the above-mentioned purposes, the application further provides a charging device comprising the on-board charger circuit as described above.

[0023] The one or more technical solutions provided by the application have at least the following technical effects:

[0024] A vehicle-mounted charger circuit is proposed, comprising a rectifier module, a bus capacitor, and a power conversion module connected in sequence, and a control module connected to the rectifier module and the power conversion module respectively. The power conversion module is connected to multiple battery packs. The control module controls the power conversion module through a single-phase-shift waveform control strategy, an extended phase-shift control strategy, or a triple phase-shift control strategy. This enables the power conversion module to perform power factor correction and power conversion on the received DC power, and then provide multiple different outputs to multiple battery packs, achieving the purpose of charging multiple battery packs with different charging needs. Compared with the vehicle-mounted chargers using a two-stage topology in related technologies, this circuit achieves power factor correction and power conversion with only one power conversion module and provides multiple different outputs, which greatly reduces the circuit board area of ​​the vehicle-mounted charger, eliminates electrolytic capacitors, reduces the overall size and cost, and avoids the impact of electrolytic capacitors on product life, thus improving the lifespan and reliability of the vehicle-mounted charger. Attached Figure Description

[0025] 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.

[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0027] Figure 1 This is a connection diagram of an embodiment of the on-board charger circuit of this application;

[0028] Figure 2 This is a detailed connection diagram of the power conversion module in another embodiment of the on-board charger circuit of this application;

[0029] Figure 3 This is a circuit topology diagram of yet another embodiment of the on-board charger circuit of this application;

[0030] Figure 4 for Figure 3 The waveform diagrams of some switching devices in the rectifier module and power conversion module are shown.

[0031] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with the embodiments and accompanying drawings. Detailed Implementation

[0032] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative effort belong to the scope of protection of the present application.

[0033] It should be noted that if the present application has a description of "first", "second" and the like, the description of "first", "second" and the like is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implicitly indicating the number of the indicated technical features. Therefore, the features limited by "first", "second" can be explicitly or implicitly included at least one of the features. In addition, if "and / or" or "and / or" appears throughout the text, it means that the three parallel schemes include "A and / or B", which includes A scheme, or B scheme, or A and B scheme. In addition, the technical solutions of each embodiment can be combined with each other, but it must be based on the fact that a person of ordinary skill in the art can realize it, and when the combination of technical solutions appears contradictory or unachievable, it should be considered that the combination of technical solutions does not exist, nor is it within the scope of protection claimed in the present application.

[0034] In new energy vehicles, the traditional on-board charger generally adopts a two-stage topology composed of PFC (Power Factor Correction) and HVDC (High Voltage Direct Current), which includes bus electrolytic capacitor, OBC (On-board Charger) main transformer and DCDC (Direct Current-Direct Current) main transformer and other main devices. Such two-stage topology structure has the defects of large number of tubes, large volume, low efficiency, high cost and the like.

[0035] In addition, the electrolytic capacitor included in the PFC topology has a large volume, so that the overall volume of the on-board charger cannot be reduced, and the layout of the electrolytic capacitor is also a design difficulty. If the current distribution of the electrolytic capacitor is uneven due to the influence of the layout, the service life of the electrolytic capacitor will be reduced. Therefore, the electrolytic capacitor not only has a large volume, but also affects the service life of the product.

[0036] The PFC topology also includes a PFC inductor, which is affected by the direct current bias, and its volume and cost are the main part of the on-board charger; the OBC battery side tube and the DCDC tube, the OBC main transformer and the DCDC main transformer in the on-board charger have capacity redundancy, causing waste of volume and cost of the on-board charger.

[0037] Therefore, how to effectively reduce the size and cost of the vehicle charger to improve the efficiency of the vehicle charger and ensure the service life of the product is a technical problem to be solved.

[0038] To solve the above problems, the application provides a vehicle charger circuit and a charging device.

[0039] The application provides a vehicle charger (OBC) circuit.

[0040] In an embodiment of the vehicle charger circuit, referring to Figure 1 , Figure 1 The connection diagram of the embodiment is shown in the figure. The OBC circuit can include a rectifier module, a bus capacitor and a power conversion module connected in sequence, and a control module connected with the rectifier module and the power conversion module respectively, and the power conversion module is connected with a plurality of battery packs.

[0041] The control module is used to control the power conversion module through a single-phase-shift control strategy, an extended phase shift (EPS) control strategy or a triple phase shift (TPS) control strategy, so that the power conversion module performs power factor correction and power conversion on the received direct current, and provides a plurality of different outputs to the plurality of battery packs.

[0042] It should be noted that in the OBC circuit, the rectifier module can be connected with a power grid or an alternating current power supply to rectify the received alternating current into direct current, store energy by the bus capacitor, and output to the power conversion module, so that the power conversion module performs power factor correction on the direct current under the control of the control module, and after power conversion, outputs a plurality of different charging voltages to the corresponding plurality of different battery packs, thereby achieving charging of the plurality of different battery packs. For example, in the actual application of the OBC of an electric vehicle, two different outputs can be provided to two battery packs, such as a high-voltage power supply and a low-voltage power supply in the electric vehicle.

[0043] The rectifier module can be a conventional rectifier, a rectifier bridge or a rectifier H-bridge. The bus capacitor has a smaller volume than an electrolytic capacitor, thereby effectively reducing the overall volume of the OBC. The control module can be a programmable controller for outputting a plurality of pulse signals with a phase difference to the power conversion module according to the single-phase-shift control strategy, the EPS strategy or the TPS strategy. Specifically, the transmission power can be controlled by adjusting the phase shift angle between the output voltages on both sides of the transformer in the power conversion module, thereby achieving power factor correction and power conversion.

[0044] It should be noted that when the control module controls the power conversion module according to the single-phase-shift wave generation control strategy, better power regulation and power factor regulation can be achieved, and when the control module controls the power conversion module according to the EPS strategy and the TPS strategy, the charging efficiency and the current stress can be optimized. In actual application, selection can be made according to requirements, and the embodiment is not specifically limited.

[0045] The vehicle charger circuit provided in the embodiment includes a rectifier module, a bus capacitor and a power conversion module connected in sequence, and a control module connected with the rectifier module and the power conversion module respectively. The power conversion module is connected with a plurality of battery packs. The control module controls the power conversion module through a single-phase-shift wave generation control strategy, an extended phase-shift control strategy or a triple phase-shift control strategy, so that the power conversion module performs power factor correction on received direct current and provides a plurality of different outputs to the plurality of battery packs after power conversion, thereby achieving the purpose of charging the plurality of battery packs with different charging requirements. Compared with the vehicle charger with a two-stage topology structure in the related art, the vehicle charger circuit only needs one power conversion module to achieve power factor correction and power conversion and provide a plurality of different outputs, thereby greatly reducing the circuit board area of the vehicle charger, removing electrolytic capacitors, reducing the overall volume and cost of the vehicle charger, avoiding the influence of electrolytic capacitors on the service life of the vehicle charger, and improving the service life and reliability of the vehicle charger.

[0046] In another embodiment of the vehicle charger circuit, referring to Figure 2 , Figure 2 FIG. 6 is a detailed connection diagram of the power conversion module in the embodiment. The power conversion module includes a primary bridge arm unit, a multi-winding transformer, a plurality of secondary bridge arm units. The primary bridge arm unit is connected with the bus capacitor. The primary winding of the multi-winding transformer is connected with the primary bridge arm unit. The plurality of secondary windings of the multi-winding transformer are connected with the plurality of secondary bridge arm units correspondingly. The plurality of secondary bridge arm units are connected with the plurality of battery packs correspondingly. The primary bridge arm unit and the plurality of secondary bridge arm units are connected with the control module respectively.

[0047] The control module is specifically configured to generate a primary-side switch driving signal based on the single-phase-shift wave generation control strategy, the extended phase-shift control strategy or the triple phase-shift control strategy, and output the primary-side switch driving signal to the primary bridge arm unit; and generate a plurality of secondary-side switch driving signals based on the phase of the primary-side switch driving signal and a plurality of preset phase-shift angles in the single-phase-shift wave generation control strategy, the extended phase-shift control strategy or the triple phase-shift control strategy, and output the plurality of secondary-side switch driving signals to the corresponding plurality of secondary bridge arm units.

[0048] It should be noted that the multi-winding transformer includes one primary winding and multiple secondary windings, and the number of secondary windings is consistent with the number of secondary bridge arm units and the number of battery groups. For example, in the actual application of the OBC of the electric vehicle, the multi-winding transformer can include one primary winding and two secondary windings, i.e., the multi-winding transformer is a three-port transformer, and the number of secondary windings is consistent with the number of secondary bridge arm units and the number of battery groups, both of which are two. The primary bridge arm unit can adopt an H-bridge circuit topology formed by four switching devices, wherein the switching devices can be controllable switching tubes such as MOS (Metal-Oxide-Semiconductor Field-Effect Transistor) tubes, JFET (Junction Field-Effect Transistor) tubes, IGBT (Insulated Gate Bipolar Transistor) tubes, or power semiconductor switches (such as gallium nitride power semiconductors, silicon carbide power devices, etc.), which can be selected according to actual needs, and are not specifically limited here. The circuit topologies of the multiple secondary bridge arm units can be consistent, and each secondary bridge arm unit can also be an H-bridge circuit topology formed by four switching devices, which is different from the primary bridge arm unit in that the driving signals received from the control module are different. The phase of the primary side switching driving signal received by the primary bridge arm unit and the phase of the secondary side switching driving signal received by the secondary bridge arm unit have a phase shift angle, and the phase shift angles of the multiple secondary side switching driving signals relative to the primary side switching driving signal can be the same or different, which can be adjusted according to actual needs, and is not specifically limited here.

[0049] It can be understood that, compared with the vehicle charger with a two-stage topology structure in the related art, the PFC topology does not need to be separately arranged, the OBC main transformer and the DCDC main transformer are combined, and are realized by one multi-winding transformer, the main transformer is changed from two to one, which can effectively simplify the circuit structure, reduce the size, and reduce the cost; the power tubes of the OBC battery measurement and the power tubes of the high-voltage side of the DCDC are combined, and are realized by one primary bridge arm unit, which at least reduces four power tubes, and can effectively reduce the number of devices and the cost. Therefore, in this embodiment, the circuit board area of the vehicle charger is more specifically and further reduced, the size is reduced, and the cost is reduced.

[0050] In one embodiment, the multi-winding transformer is a three-winding transformer, and the multiple secondary bridge arm units include a first secondary bridge arm unit and a second secondary bridge arm unit, the first secondary winding of the three-winding transformer is connected with the first secondary bridge arm unit, and the second secondary winding of the three-winding transformer is connected with the second secondary bridge arm unit.

[0051] The control module is further configured to generate the first secondary-side switch driving signal according to a phase of the primary-side switch driving signal and a first phase shift angle, and output the first secondary-side switch driving signal to the first secondary-side bridge arm unit; and generate the second secondary-side switch driving signal according to the phase of the primary-side switch driving signal and a second phase shift angle, and output the second secondary-side switch driving signal to the second secondary-side bridge arm unit.

[0052] It should be noted that the above-mentioned primary-side bridge arm unit, multi-winding transformer and first secondary-side bridge arm unit can form a dual active bridge (DAB) conversion circuit. Specifically, in the DAB conversion circuit, in one case, the primary-side bridge arm unit converts the direct current output by the rectifier module into alternating current, and after being transformed by the multi-winding transformer, the first secondary-side bridge arm unit converts the transformed alternating current into direct current, i.e., obtains and outputs the first charging voltage; in another case, the first secondary-side bridge arm unit can convert the received direct current into alternating current, and after being transformed by the multi-winding transformer, the primary-side bridge arm unit converts the transformed alternating current into direct current and outputs it, thereby realizing bidirectional DCDC conversion. Similarly, the primary-side bridge arm unit, multi-winding transformer and second secondary-side bridge arm unit can also form a DAB conversion circuit. Specifically, in the DAB conversion circuit, in one case, the primary-side bridge arm unit converts the direct current output by the rectifier module into alternating current, and after being transformed by the multi-winding transformer, the second secondary-side bridge arm unit converts the transformed alternating current into direct current, i.e., obtains and outputs the second charging voltage; in another case, the second secondary-side bridge arm unit can convert the received direct current into alternating current, and after being transformed by the multi-winding transformer, the primary-side bridge arm unit converts the transformed alternating current into direct current and outputs it, thereby also realizing bidirectional DCDC conversion.

[0053] In a specific application, in most electric vehicles, the battery pack mainly includes a high-voltage battery pack and a low-voltage battery pack, and correspondingly, the multi-winding transformer can specifically adopt a three-winding transformer, which includes a primary winding and two secondary windings, i.e., a first secondary winding and a second secondary winding. When the control module generates the first secondary-side switch driving signal according to the phase of the primary-side switch driving signal and the first phase shift angle, and generates the second secondary-side switch driving signal according to the phase of the primary-side switch driving signal and the second phase shift angle, the first phase shift angle and the second phase shift angle are different, but the specific sizes of the first phase shift angle and the second phase shift angle can be set or adjusted according to actual needs. For example, the control module can adjust the sizes of the phase shift angles according to a preset single-phase-shift wave generation control strategy, so as to adjust the duty ratio and frequency of the secondary-side switch driving signal output to each secondary-side bridge arm unit, so that each switching device in the corresponding secondary-side bridge arm unit can be quickly switched according to the duty ratio and frequency of the secondary-side switch driving signal, thereby adjusting the phase and amplitude of the input current to match the waveform of the input voltage, i.e., to realize different power factor corrections of different secondary-side bridge arm units, so as to output different charging voltages to charge different battery packs.

[0054] In an embodiment, the plurality of battery packs includes a high-voltage battery pack and a low-voltage battery pack, the first secondary side bridge arm unit is connected to the high-voltage battery pack, and the second secondary side bridge arm unit is connected to the low-voltage battery pack.

[0055] The first secondary side bridge arm unit is configured to convert a voltage transmitted by the three-winding transformer according to the first secondary side switch driving signal, output a first charging voltage to the high-voltage battery pack to charge the high-voltage battery pack, and convert a voltage provided by the high-voltage battery pack according to the first secondary side switch driving signal, output a first discharging voltage to the three-winding transformer; and the second secondary side bridge arm unit is configured to convert a voltage transmitted by the three-winding transformer according to the second secondary side switch driving signal, output a second charging voltage to the low-voltage battery pack to charge the low-voltage battery pack, and convert a voltage provided by the low-voltage battery pack according to the second secondary side switch driving signal, output a second discharging voltage to the three-winding transformer.

[0056] It should be noted that the high-voltage battery pack and the low-voltage battery pack differ in that the charging voltages received by the two are different and the voltages provided to the load are also different, and the charging voltage and the discharging voltage of the high-voltage battery pack can both be greater than the charging voltage and the discharging voltage of the low-voltage battery pack. Based on the difference between the first secondary side switch driving signal and the second secondary side switch driving signal, the first secondary side bridge arm unit and the second secondary side bridge arm unit each actually output different first charging voltages and second charging voltages during system charging, and each actually output different first discharging voltages and second discharging voltages during system discharging. The sizes of the first phase shift angle and the second phase shift angle can be determined according to the power of the battery pack.

[0057] In this embodiment, a single-stage bidirectional three-port OBC circuit is specifically proposed, which does not require a PFC inductor and an electrolytic capacitor, can significantly reduce the volume of the OBC, and can avoid the influence caused by the electrolytic capacitor; by replacing the two-stage transformer in the related art with one three-winding transformer, the first secondary side bridge arm unit and the second secondary side bridge arm unit share one magnetic core in the three-winding transformer, reducing the number of tubes, greatly improving the power density, efficiency and reliability of the OBC, and greatly reducing the cost of devices. In addition, not only can the battery pack be charged, but also the battery pack can be discharged, one circuit realizes two purposes, and has high applicability.

[0058] In a feasible embodiment, the OBC circuit can further include an EMI (Electromagnetic Interference) filtering module, an input end of the EMI filtering module is connected to the power grid, and an output end of the EMI filtering module is connected to the rectifying module.

[0059] The EMI filter module is used to perform low-pass filtering on the AC power provided by the power grid, output the power frequency AC power to the rectifier module, and provide surge protection.

[0060] It should be noted that electromagnetic interference can cause a decrease in circuit efficiency, affect the normal operation of the device, and even cause damage to the components in the circuit. Therefore, an EMI filter module can be added between the power grid and the rectifier module to reduce electromagnetic interference and provide surge protection for the circuit, thereby further improving the reliability of the OBC circuit.

[0061] In a possible implementation, the rectifier module can include a power frequency rectifier bridge, the input end of the power frequency rectifier bridge is connected to the output end of the EMI filter module, the output end of the power frequency rectifier bridge is connected to the power conversion module, and the control end of the power frequency rectifier bridge is connected to the control module.

[0062] The control module is also used to generate a rectifier drive signal according to the frequency and phase of the power grid and output the rectifier drive signal to the power frequency rectifier bridge, so that the power frequency rectifier bridge converts the power frequency AC power into DC power according to the rectifier drive signal; the DC power output by the power frequency rectifier bridge can be stored by the bus capacitor C0, and then received by the power conversion module for power factor correction and power conversion.

[0063] It should be noted that the power frequency rectifier bridge can be composed of diodes or switching devices, and can be an H-bridge topology. In actual applications, the power frequency rectifier bridge can be used to directly rectify the AC power provided by the power grid, or to rectify the power frequency AC power output by the EMI filter module.

[0064] It can be understood that the rectifier module selects the power frequency rectifier bridge because it has high current and voltage bearing capacity, so that the rectifier module can meet the rectification requirements of the power frequency AC power and improve stability to ensure stable operation during the charging process.

[0065] In a possible implementation, the power conversion module is connected to each battery pack through a capacitor unit.

[0066] The capacitor unit is used to filter the output of the power conversion module and provide power decoupling between the power conversion module and the battery pack.

[0067] It should be noted that the capacitor unit can be one capacitor device, or a unit composed of multiple capacitor devices in series or parallel, or a filter circuit composed of inductors and capacitors, which is not specifically limited here. One capacitor unit can be connected between the first secondary side bridge arm unit and the high-voltage battery pack, and one capacitor unit can be connected between the second secondary side bridge arm unit and the low-voltage battery pack, that is, the OBC circuit can specifically include a capacitor unit consistent with the number of battery packs, for example, two capacitor units are included to achieve output filtering of the secondary side bridge arm unit and provide power decoupling between the secondary side bridge arm unit and the battery pack.

[0068] In another embodiment of the on-board charger circuit, a specific example of the OBC circuit is proposed, referring to Figure 3 , Figure 3 The circuit topology of this embodiment is shown in the figure. The OBC circuit includes an AC source AC, an EMI filter module, a power frequency rectifier bridge, a bus capacitor C0, a primary side bridge arm unit, a three-winding transformer T1, a first secondary side bridge arm unit, and a second secondary side bridge arm unit.

[0069] The power frequency rectifier bridge includes four switching devices to form an H-bridge topology, specifically including IGBT tubes G1-G4. The common connection point of the emitter of G1 and the collector of G2 is connected to the positive output end of the EMI filter module, and the common connection point of the emitter of G3 and the collector of G4 is connected to the negative output end of the EMI filter module. The common connection point of the collector of G1 and the collector of G3 is connected to one end of C0 and the positive bus input end of the primary side bridge arm unit, respectively. The common connection point of the emitter of G2 and the emitter of G4 is connected to the other end of C0 and the negative bus input end of the primary side bridge arm unit, respectively.

[0070] The bus capacitor C0 is used for energy storage, and the voltage across it is the DC voltage Vbus received by the power conversion module. The power conversion module includes the primary side bridge arm unit, the three-winding transformer T1, the first secondary side bridge arm unit, and the second secondary side bridge arm unit.

[0071] The primary side bridge arm unit includes four switching devices to form an H-bridge topology, specifically including IGBT tubes P1-P4. The common connection point of the collector of P1 and the collector of P3 is connected to one end of C0, and the common connection point of the emitter of P2 and the emitter of P4 is connected to the other end of C0. The common connection point a of the emitter of P1 and the collector of P2 is connected to one end of the primary winding of T1, and the common connection point b of the emitter of P3 and the collector of P4 is connected to the other end of the primary winding of T1.

[0072] The first secondary bridge arm unit includes four switching devices, forming an H-bridge topology. Specifically, it includes IGBT transistors S11-S14. The common connection point c of the emitter of S11 and the collector of S12 is connected to one end of the first secondary winding of T1. The common connection point d of the emitter of S13 and the collector of S14 is connected to the other end of the first secondary winding of T1. The common connection point of the collector of S11 and the collector of S13 is connected to one end of capacitor C1 and the positive terminal of high-voltage battery HVBat, respectively. The common connection point of the emitter of S12 and the emitter of S14 is connected to the other end of C1 and the negative terminal of high-voltage battery HVBat, respectively.

[0073] The second secondary bridge arm unit includes four switching devices, forming an H-bridge topology. Specifically, it includes IGBT transistors S21-S24. The common connection point e of the emitter of S21 and the collector of S22 is connected to one end of the second secondary winding of T1. The common connection point f of the emitter of S23 and the collector of S24 is connected to the other end of the second secondary winding of T1. The common connection point of the collector of S21 and the collector of S23 is connected to one end of capacitor C2 and the positive terminal of the low-voltage battery LVBat, respectively. The common connection point of the emitter of S22 and the emitter of S24 is connected to the other end of C2 and the negative terminal of the low-voltage battery LVBat, respectively.

[0074] The gates of all the above IGBT transistors are connected to the control module. Figure 3 (not shown in the diagram) to receive the rectifier drive signal output by the control module to the power frequency rectifier bridge, the primary-side switch drive signal to the primary-side bridge arm unit, the first secondary-side switch drive signal to the first secondary-side bridge arm unit, and the second secondary-side switch drive signal to the second secondary-side bridge arm unit.

[0075] Optionally, a fuse F1 is connected between the AC source and the EMI filter module to provide overcurrent protection; a switch S1 is connected between the EMI filter module and the power frequency rectifier bridge. One end of S1 is specifically connected to the positive output terminal of the EMI filter module, and the other end of S1 is specifically connected to the common junction of the emitter of G1 and the collector of G2. S1 can be a manual switch or an automatic switch controlled by the control module. The trigger condition can be that the control module controls the disconnection when it detects a circuit fault, so as to avoid causing more device failures.

[0076] In one feasible implementation, the power conversion module may further include a resonant inductor Lr1, a capacitor Cr1, and a capacitor Cr2. The resonant inductor Lr1 and the capacitor Cr1 are connected in series between the primary winding of the three-winding transformer and the primary bridge arm unit, and the capacitor Cr2 is connected in series between the first secondary winding of the three-winding transformer and the first secondary bridge arm unit.

[0077] It should be noted that the resonant inductor Lr1 can be a discrete inductor or a transformer leakage inductance; the capacitor Cr1 and the capacitor Cr2 can be a DC blocking capacitor or a resonant capacitor, which is not specifically limited here.

[0078] As shown in the example, Figure 3 As shown in the example,

[0079] In a specific embodiment, the power conversion module can further include a resonant inductor Lr2 and a resonant inductor Lr3, the resonant inductor Lr2 being connected in series between the capacitor Cr2 and the first secondary bridge arm unit, and the resonant inductor Lr3 being connected in series between the second secondary winding of the three-winding transformer and the second secondary bridge arm unit.

[0080] It should be noted that the resonant inductor Lr2 and the resonant inductor Lr3 can be a discrete inductor or a transformer leakage inductance, which is not specifically limited here.

[0081] As shown in the example, Figure 3 As shown in the example,

[0082] In the above specific example, G1-G4 is different from the PFC of the two-stage topology in the related art, and the switching devices in the power frequency rectifier bridge can reduce switching loss; the power factor correction and power transmission are achieved between the primary bridge arm unit and the first secondary bridge arm unit and the second secondary bridge arm unit, and the control module can specifically adjust the phase shift angle between the primary side switching drive signal and the first secondary side switching drive signal and the second secondary side switching drive signal to achieve free distribution of each secondary power output.

[0083] The control module controls G1-G4 in the power frequency rectifier bridge, P1-P4 in the primary bridge arm unit, S11-S14 in the first secondary bridge arm unit, and S21-S24 in the second secondary bridge arm unit. The control of G1-G4 in the power frequency rectifier bridge can be wave emission with the frequency and phase of the power grid, i.e. the AC source AC; the single phase shift wave emission mode is used for wave emission of P1-P4 in the primary bridge arm unit; in actual application, all the upper and lower tubes of the H-bridge are complementarily emitted with 50% duty cycle.

[0084] As shown in the example, Figure 4 As shown in the example, Figure 3Fig. 6 is a waveform diagram of some switching devices in the rectifier module and the power conversion module, wherein the horizontal axis represents time and the vertical axis represents the waveforms of signals, and specifically shows the waveforms of rectification driving signals received by G1-G4 in the power frequency rectifier bridge, the waveforms of primary-side switching driving signals received by P1 and P4 in the primary-side bridge arm unit, the waveforms of first secondary-side switching driving signals received by S11 and S14 in the first secondary-side bridge arm unit, and the waveforms of second secondary-side switching driving signals received by S21 and S24 in the second secondary-side bridge arm unit, wherein the phase shift angle between the primary-side switching driving signals received by P1-P4 and the first secondary-side switching driving signals received by S11-S14 is set as a1, and the phase shift angle between the primary-side switching driving signals received by P1-P4 and the second secondary-side switching driving signals received by S21 and S24 is set as a2.

[0085] It can be known that the working principle of the OBC circuit is as follows: Figure 4

[0086] In the battery charging state, when G1 and G4 in the power frequency rectifier bridge are turned on and G2 and G3 are turned off, the power frequency rectifier bridge works normally; the direct current output by the power frequency rectifier bridge is given to the primary-side bridge arm unit, when P1 and P4 in the primary-side bridge arm unit are turned on and P2 and P3 are turned off, the primary-side bridge arm unit works to convert the received direct current into alternating current and outputs the alternating current to the three-winding transformer T1; after the three-winding transformer T1 processes the alternating current, the three-winding transformer T1 transmits electric energy to the first secondary-side bridge arm unit through the primary-side winding and the first secondary-side winding of the three-winding transformer T1, when S11 and S14 in the first secondary-side bridge arm unit are turned on and S12 and S13 are turned off, the first secondary-side bridge arm unit works to convert the processed alternating current into direct current, i.e., the first charging voltage is obtained and output to charge the high-voltage battery HVBat; at the same time, the three-winding transformer T1 transmits electric energy to the second secondary-side bridge arm unit through the primary-side winding and the second secondary-side winding of the three-winding transformer T1, when S21 and S24 in the second secondary-side bridge arm unit are turned on and S22 and S23 are turned off, the second secondary-side bridge arm unit works to convert the processed alternating current into direct current, i.e., the second charging voltage is obtained and output to charge the low-voltage battery LVBat.

[0087] ​When the battery is in discharging state, the high-voltage direct current output by the high-voltage battery HVBat is given to the first secondary side bridge arm unit, when S12 and S13 are turned on and S11 and S14 are turned off, the first secondary side bridge arm unit works, converts the received high-voltage direct current into alternating current, and outputs a first discharging voltage to the three-winding transformer T1; after the three-winding transformer T1 processes the first discharging voltage, the processed voltage is transmitted to the primary side bridge arm unit, when P2 and P3 are turned on and P1 and P4 are turned off, the primary side bridge arm unit works, converts the received processed first discharging voltage into direct current, and outputs a first direct current to the bus capacitor C0 for energy storage or after rectification by the power frequency rectifier bridge. Alternatively, the low-voltage direct current output by the low-voltage battery LVBat is given to the second secondary side bridge arm unit, when S22 and S23 are turned on and S21 and S24 are turned off, the second secondary side bridge arm unit works, converts the received low-voltage direct current into alternating current, and outputs a second discharging voltage to the three-winding transformer T1; after the three-winding transformer T1 processes the second discharging voltage, the processed voltage is transmitted to the primary side bridge arm unit, when P2 and P3 are turned on and P1 and P4 are turned off, the primary side bridge arm unit works, converts the received processed second discharging voltage into direct current, and outputs a second direct current to the bus capacitor C0 for energy storage or after rectification by the power frequency rectifier bridge.

[0088] It should be noted that in the above OBC circuit example, the power frequency rectifier bridge is only used for power frequency rectification and does not involve power factor correction. The power conversion module connected after the bus capacitor C0 implements power factor correction and power conversion and transmission.

[0089] The vehicle-mounted charger circuit proposed in this embodiment adopts a single-stage bidirectional three-port topology, removes the PFC inductor and electrolytic capacitor, and uses a magnetic core shared by the low-voltage DCDC main transformer and the high-voltage DCDC main transformer, thereby reducing the number of tubes, greatly improving the power density, efficiency, and reliability, and greatly reducing the cost. The number of DCDC high-voltage side power tubes and a main transformer is reduced, thereby reducing the size and cost of the vehicle-mounted charger. In addition, since the electrolytic capacitor is removed, the service life and reliability are also improved.

[0090] The application also proposes a charging device, which can include a vehicle-mounted charger circuit. The vehicle-mounted charger circuit has a plurality of outputs connected to a plurality of battery packs, which can be connected to high-voltage battery packs and low-voltage battery packs in an electric vehicle.

[0091] It should be noted that the specific structure of the vehicle-mounted charger circuit can refer to the above embodiments. Since the charging device adopts all the technical solutions of the above embodiments, it at least has all the beneficial effects brought by the technical solutions of the above embodiments, which will not be repeated here.

[0092] The above merely illustrates some embodiments of the present application, and does not limit the patent scope of the present application, and any equivalent structural transformation, direct / indirect application in other related technical fields based on the technical concept of the present application, and using the content of the present application specification and drawings are included in the patent protection scope of the present application.

Claims

1. A vehicle-mounted charger circuit, characterized in that, The power conversion module is connected with a plurality of battery groups; The control module is configured to generate a primary side switch driving signal based on the single-phase control strategy, the extended phase-shift control strategy or the triple phase-shift control strategy, and output the primary side switch driving signal to the primary side bridge arm unit; and generate a plurality of secondary side switch driving signals based on phases of the primary side switch driving signal and a plurality of preset phase-shift angles in the single-phase control strategy, the extended phase-shift control strategy or the triple phase-shift control strategy, and output the plurality of secondary side switch driving signals to the plurality of secondary side bridge arm units.

2. The on-board charger circuit of claim 1, wherein, The multi-winding transformer is a three-winding transformer, and the plurality of secondary side bridge arm units include a first secondary side bridge arm unit and a second secondary side bridge arm unit, a first secondary side winding of the three-winding transformer is connected with the first secondary side bridge arm unit, and a second secondary side winding of the three-winding transformer is connected with the second secondary side bridge arm unit. The control module is further configured to generate a first secondary side switch driving signal based on a phase of the primary side switch driving signal and a first phase-shift angle, and output the first secondary side switch driving signal to the first secondary side bridge arm unit; and generate a second secondary side switch driving signal based on the phase of the primary side switch driving signal and a second phase-shift angle, and output the second secondary side switch driving signal to the second secondary side bridge arm unit.

3. The on-board charger circuit of claim 2, wherein, The plurality of battery groups include a high-voltage battery group and a low-voltage battery group, the first secondary side bridge arm unit is connected with the high-voltage battery group, and the second secondary side bridge arm unit is connected with the low-voltage battery group. The first secondary side bridge arm unit is configured to convert a voltage transmitted by the three-winding transformer based on the first secondary side switch driving signal, output a first charging voltage to the high-voltage battery group to charge the high-voltage battery group, and convert a voltage provided by the high-voltage battery group based on the first secondary side switch driving signal, and output a first discharging voltage to the three-winding transformer. ​ 4. The vehicle-mounted charger circuit of claim 3, wherein, ​ ​ The second auxiliary side bridge arm unit is configured to convert the voltage transmitted by the three-winding transformer according to the second auxiliary side switch driving signal, output a second charging voltage to the low-voltage battery pack to charge the low-voltage battery pack, and convert the voltage provided by the low-voltage battery pack according to the second auxiliary side switch driving signal, output a second discharging voltage to the three-winding transformer.

5. The vehicle-mounted charger circuit of claim 3, wherein, The power conversion module further comprises a resonant inductor Lr1, a capacitor Cr1 and a capacitor Cr2, the resonant inductor Lr1 and the capacitor Cr1 are connected in series between the primary winding of the three-winding transformer and the primary bridge arm unit, and the capacitor Cr2 is connected in series between the first auxiliary winding of the three-winding transformer and the first auxiliary bridge arm unit.

6. The vehicle-mounted charger circuit of claim 5, wherein, The power conversion module further comprises a resonant inductor Lr2 and a resonant inductor Lr3, the resonant inductor Lr2 is connected in series between the capacitor Cr2 and the first auxiliary bridge arm unit, and the resonant inductor Lr3 is connected in series between the second auxiliary winding of the three-winding transformer and the second auxiliary bridge arm unit.

7. The on-board charger circuit of any one of claims 1 to 6, wherein, The on-board charger circuit further comprises an EMI filtering module, an input end of the EMI filtering module is connected with a power grid, and an output end of the EMI filtering module is connected with the rectification module. The EMI filtering module is configured to perform low-pass filtering processing on the alternating current provided by the power grid, output a power frequency alternating current to the rectification module, and provide surge protection.

8. The vehicle-mounted charger circuit of claim 7, wherein, The rectification module comprises a power frequency rectification bridge, an input end of the power frequency rectification bridge is connected with the output end of the EMI filtering module, an output end of the power frequency rectification bridge is connected with the power conversion module, and a control end of the power frequency rectification bridge is connected with the control module. The control module is further configured to generate a rectification driving signal according to the frequency and phase of the power grid, and output the rectification driving signal to the power frequency rectification bridge, so that the power frequency rectification bridge converts the power frequency alternating current into the direct current according to the rectification driving signal.

9. The on-board charger circuit of any one of claims 1 to 6, wherein, A capacitor unit is connected between the power conversion module and each battery pack. The capacitor unit is configured to filter the output of the power conversion module, and provide power decoupling between the power conversion module and the battery pack.

10. A charging device, characterized by An on-board charger circuit is provided. The on-board charger circuit comprises a power grid connection module, a rectification module, a power conversion module, a control module and a plurality of battery packs. The power grid connection module is configured to provide an alternating current to the rectification module. The rectification module is configured to convert the alternating current into a direct current according to a rectification driving signal, and output the direct current to the power conversion module. The power conversion module is configured to convert the direct current into a plurality of charging voltages according to a plurality of switch driving signals, and output the charging voltages to the plurality of battery packs. The control module is configured to generate the rectification driving signal and the plurality of switch driving signals according to the frequency and phase of the power grid, and output the rectification driving signal and the plurality of switch driving signals to the rectification module and the power conversion module respectively. The plurality of battery packs are connected in series between the power conversion module and the control module. The plurality of battery packs are configured to provide a plurality of charging voltages to the power conversion module, and provide a plurality of discharging voltages to the power conversion module. The on-board charger circuit further comprises a plurality of auxiliary bridge arm units, each auxiliary bridge arm unit is connected between the power conversion module and one of the plurality of battery packs. The plurality of auxiliary bridge arm units are configured to convert the charging voltage provided by the power conversion module into a charging voltage of the corresponding battery pack, and convert the discharging voltage provided by the corresponding battery pack into a discharging voltage of the power conversion module. The on-board charger circuit further comprises a plurality of auxiliary windings of the three-winding transformer, each auxiliary winding is connected between the power conversion module and one of the plurality of battery packs. The plurality of auxiliary windings are configured to transmit the charging voltage provided by the power conversion module to the corresponding battery pack, and transmit the discharging voltage provided by the corresponding battery pack to the power conversion module. The on-board charger circuit further comprises a plurality of auxiliary switch units, each auxiliary switch unit is connected between the power conversion module and one of the plurality of battery packs. The plurality of auxiliary switch units are configured to convert the charging voltage provided by the power conversion module into a charging voltage of the corresponding battery pack, and convert the discharging voltage provided by the corresponding battery pack into a discharging voltage of the power conversion module. The on-board charger circuit further comprises a plurality of auxiliary switch driving signals, each auxiliary switch driving signal is generated by the control module according to the frequency and phase of the power grid, and is output to the corresponding auxiliary switch unit. The plurality of auxiliary switch driving signals are configured to control the corresponding auxiliary switch unit to convert the charging voltage provided by the power conversion module into the charging voltage of the corresponding battery pack, and convert the discharging voltage provided by the corresponding battery pack into the discharging voltage of the power conversion module.

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