阅读说明：本技术 具有反向预充电功能的车载dc/dc变换器及车载充电装置 (Vehicle-mounted DC/DC converter with reverse pre-charging function and vehicle-mounted charging device ) 是由 施鸿波 平定钢 刘钢 于 2020-10-30 设计创作，主要内容包括：本申请提供具有反向预充电功能的车载DC/DC变换器及车载充电装置。所述具有反向预充电功能的车载DC/DC变换器包括主变压器、第一电路、第二电路和第三电路,所述主变压器包括原边绕组和副边绕组；所述第一电路的一端连接所述原边绕组,所述第一电路的另一端连接车载充电系统的车载充电机；所述第二电路的一端连接所述副边绕组,所述第二电路的另一端连接第三电路的一端,进行电能传输；所述第三电路的另一端连接车载充电系统的低压电池；在正向充电时,从所述高压电池通过所述车载DC/DC变换器给所述低压电池充电,在反向充电时,通过控制所述第二电路和所述第三电路的开关管,使所述低压电池给所述母线电容进行反向预充电。(The application provides an on-vehicle DC/DC converter and an on-vehicle charging device with reverse precharge function. The vehicle-mounted DC/DC converter with the reverse pre-charging function comprises a main transformer, a first circuit, a second circuit and a third circuit, wherein the main transformer comprises a primary winding and a secondary winding; one end of the first circuit is connected with the primary winding, and the other end of the first circuit is connected with a vehicle-mounted charger of a vehicle-mounted charging system; one end of the second circuit is connected with the secondary winding, and the other end of the second circuit is connected with one end of the third circuit for electric energy transmission; the other end of the third circuit is connected with a low-voltage battery of the vehicle-mounted charging system; and when the high-voltage battery is charged in the forward direction, the low-voltage battery is charged from the high-voltage battery through the vehicle-mounted DC/DC converter, and when the low-voltage battery is charged in the reverse direction, the low-voltage battery is enabled to carry out reverse pre-charging on the bus capacitor by controlling the switching tubes of the second circuit and the third circuit.)

1. An on-vehicle DC/DC converter with reverse precharge function, comprising:

the main transformer comprises a primary winding and a secondary winding;

one end of the first circuit is connected with the primary winding, and the other end of the first circuit is connected with a bus capacitor and a high-voltage battery of the vehicle-mounted charging system;

one end of the second circuit is connected with the secondary winding, and the other end of the second circuit is connected with one end of the third circuit;

one end of the third circuit is connected with the second circuit, and the other end of the third circuit is connected with a low-voltage battery of the vehicle-mounted charging system;

and when the high-voltage battery is charged in the forward direction, the low-voltage battery is charged from the high-voltage battery through the vehicle-mounted DC/DC converter, and when the low-voltage battery is charged in the reverse direction, the low-voltage battery is enabled to carry out reverse pre-charging on the bus capacitor by controlling the switching tubes of the second circuit and the third circuit.

2. The vehicle-mounted DC/DC converter with reverse precharge function as claimed in claim 1, wherein the third circuit comprises:

a filter capacitor connected in parallel with the second circuit;

one end of the filter inductor is connected with the anode of the filter capacitor;

one end of the backflow prevention switch tube is connected with the other end of the filter inductor, and the other end of the backflow prevention switch tube is connected with the anode of the low-voltage battery;

the anode of the freewheeling diode is connected with the cathode of the low-voltage battery, and the cathode of the freewheeling diode is connected with the connecting end of the backflow-preventing switching tube and the filter inductor;

when the reverse charging is carried out, the anti-backflow switch tube is closed, the filter inductor and the filter capacitor are charged through the low-voltage battery, and when the anti-backflow switch tube is disconnected, the filter inductor charges the filter capacitor through the follow current of the follow current diode.

3. The vehicle-mounted DC/DC converter with reverse precharge function as claimed in claim 1, wherein the second circuit comprises:

one end of the first secondary inductor is connected with the positive electrode of one end of the third circuit, and the other end of the first secondary inductor is connected with the negative end of a secondary winding of the main transformer;

one end of the second secondary side inductor is connected with the positive electrode of one end of the third circuit, and the other end of the second secondary side inductor is connected with the positive end of the secondary side winding of the main transformer;

one end of the first secondary side switching tube is connected with the other end of the first secondary side inductor, and the other end of the first secondary side switching tube is connected with the negative electrode of the low-voltage battery;

and one end of the second secondary side switching tube is connected with the positive end of the secondary side winding of the main transformer, and the other end of the second secondary side switching tube is connected with the negative electrode of the low-voltage battery.

4. The vehicle-mounted DC/DC converter with reverse precharge function as claimed in claim 1, wherein the second circuit comprises:

the secondary side inductor is connected with the positive electrode of one end of the third circuit at one end;

one end of the third secondary side switching tube is connected with the other end of the secondary side inductor, and the other end of the third secondary side switching tube is connected with the positive end of the secondary side winding of the main transformer;

and one end of the fourth secondary side switching tube is connected with the other end of the secondary side inductor, the other end of the fourth secondary side switching tube is connected with the negative end of the secondary side winding of the main transformer, and the midpoint of the secondary side winding of the main transformer is connected with the negative electrode of the low-voltage battery.

5. The vehicle-mounted DC/DC converter with reverse precharge function as claimed in claim 1, wherein the first circuit comprises:

one end of the first primary side switching tube is connected with the positive end of the primary side winding of the main transformer, and the other end of the first primary side switching tube is connected with the anode of the high-voltage battery;

one end of the second primary side switching tube is connected with the positive end of the primary side winding of the main transformer, and the other end of the second primary side switching tube is connected with the negative electrode of the high-voltage battery;

one end of the first primary side capacitor is connected with the anode of the high-voltage battery, and the other end of the first primary side capacitor is connected with the negative end of the primary side winding of the main transformer;

and one end of the second primary side capacitor is connected with the negative electrode of the high-voltage battery, and the other end of the second primary side capacitor is connected with the negative end of the primary side winding of the main transformer.

6. An in-vehicle charging device comprising: the vehicle-mounted DC/DC converter with the reverse pre-charging function, the low-voltage battery, the vehicle-mounted charger and the high-voltage battery as claimed in any one of claims 1 to 5, wherein one end of the vehicle-mounted charger is connected with the alternating current input end, and the other end of the vehicle-mounted charger is connected with the high-voltage battery.

7. The vehicle-mounted charging device according to claim 6, wherein the vehicle-mounted charger comprises:

one end of the circuit module is connected with the alternating current input end,

and one end of the second DC/DC converter is connected with the other end of the circuit module, and the other end of the second DC/DC converter is connected with the high-voltage battery.

8. The vehicle-mounted charging device according to claim 7, wherein the circuit module is a rectifying circuit or a correction circuit, and the second DC/DC converter is a bidirectional isolation DC/DC converter or a unidirectional isolation DC/DC converter.

Technical Field

The application relates to the technical field of vehicle-mounted charging, in particular to a vehicle-mounted DC/DC converter with a reverse pre-charging function and a vehicle-mounted charging device.

Background

In the charging process of the vehicle-mounted charging device, if the charging voltage is too high, the charging current is very large, and a bus and a capacitor may be damaged, so in the prior art, in order to limit the charging current, a pre-charging process is usually added in the vehicle-mounted charging device, and the purpose of protecting a circuit is achieved.

Because an electrolytic capacitor with a large capacitance value is arranged On a bus of an On Board Charger (OBC) to realize a voltage stabilizing function, a conventional pre-charging circuit usually pre-charges the bus capacitor before the On board charger is started, so as to suppress input pulse current, wherein the pre-charging circuit is composed of a relay and a resistor; or on the bus bar on the high-voltage battery side, a group of pre-charging circuits is added for preventing surge current.

However, the pre-charging circuit is additionally arranged, so that the circuit safety is guaranteed, but the problems that the vehicle-mounted charger is large in size, high in cost and the like are caused.

Disclosure of Invention

The embodiment of the application provides a vehicle-mounted DC/DC converter with a reverse pre-charging function, which comprises a main transformer, a first circuit, a second circuit and a third circuit, wherein the main transformer comprises a primary winding and a secondary winding; one end of the first circuit is connected with the primary winding, and the other end of the first circuit is connected with a bus capacitor and a high-voltage battery of the vehicle-mounted charging system; one end of the second circuit is connected with the secondary winding, and the other end of the second circuit is connected with one end of a third circuit; one end of the third circuit is connected with the second circuit, and the other end of the third circuit is connected with a low-voltage battery of the vehicle-mounted charging system; and when the high-voltage battery is charged in the forward direction, the low-voltage battery is charged from the high-voltage battery through the vehicle-mounted DC/DC converter, and when the low-voltage battery is charged in the reverse direction, the low-voltage battery is enabled to carry out reverse pre-charging on the bus capacitor by controlling the switching tubes of the second circuit and the third circuit.

According to some embodiments, the third circuit comprises a filter capacitor, a filter inductor, a backflow prevention switching tube and a freewheeling diode, wherein the filter capacitor is connected in parallel with the second circuit; one end of the filter inductor is connected with the anode of the filter capacitor; one end of the backflow prevention switching tube is connected with the other end of the filter inductor, and the other end of the backflow prevention switching tube is connected with the anode of the low-voltage battery; the anode of the freewheeling diode is connected with the cathode of the low-voltage battery, and the cathode of the freewheeling diode is connected with the connecting end of the backflow-preventing switching tube and the filter inductor; when the reverse charging is carried out, the anti-backflow switch tube is closed, the filter inductor and the filter capacitor are charged through the low-voltage battery, and when the anti-backflow switch tube is disconnected, the filter inductor charges the filter capacitor through the follow current of the follow current diode.

According to some embodiments, the second circuit comprises a first secondary inductor, a second secondary inductor, a first secondary switching tube and a second secondary switching tube, one end of the first secondary inductor is connected to the positive electrode of one end of the third circuit, and the other end of the first secondary inductor is connected to the negative terminal of the secondary winding of the main transformer; one end of the second secondary side inductor is connected with the positive electrode of one end of the third circuit, and the other end of the second secondary side inductor is connected with the positive end of the secondary side winding of the main transformer; one end of the first secondary switch tube is connected with the other end of the first secondary inductor, and the other end of the first secondary switch tube is connected with the negative electrode of the low-voltage battery; one end of the second secondary side switch tube is connected with the positive end of the secondary side winding of the main transformer, and the other end of the second secondary side switch tube is connected with the negative electrode of the low-voltage battery.

According to some embodiments, the second circuit comprises a secondary side inductor, a first secondary side switching tube and a second secondary side switching tube, wherein one end of the secondary side inductor is connected with the positive electrode of one end of the third circuit; one end of the first secondary side switching tube is connected with the other end of the secondary side inductor, and the other end of the first secondary side switching tube is connected with the positive end of the secondary side winding of the main transformer; one end of the second secondary side switching tube is connected with the other end of the secondary side inductor, the other end of the second secondary side switching tube is connected with the negative end of the secondary side winding of the main transformer, and the midpoint of the secondary side winding of the main transformer is connected with the negative electrode of the low-voltage battery.

According to some embodiments, the first circuit comprises a first primary side switching tube, a second primary side switching tube, a first primary side capacitor and a second primary side capacitor, wherein one end of the first primary side switching tube is connected with the positive end of the primary side winding of the main transformer, and the other end of the first primary side switching tube is connected with the positive electrode of the high-voltage battery; one end of the second primary side switching tube is connected with the positive end of the primary side winding of the main transformer, and the other end of the second primary side switching tube is connected with the negative electrode of the high-voltage battery; one end of the first primary side capacitor is connected with the anode of the high-voltage battery, and the other end of the first primary side capacitor is connected with the negative end of the primary side winding of the main transformer; one end of the second primary side capacitor is connected with the negative electrode of the high-voltage battery, and the other end of the second primary side capacitor is connected with the negative end of the primary side winding of the main transformer.

The embodiment of the present application further provides an on-vehicle charging device, include: the vehicle-mounted DC/DC converter with the reverse pre-charging function, the low-voltage battery, the vehicle-mounted charger and the high-voltage battery are connected.

According to some embodiments, the vehicle-mounted charger comprises a circuit module and a second DC/DC converter, one end of the circuit module is connected to the alternating current input end, one end of the second DC/DC converter is connected to the other end of the circuit module, and the other end of the second DC/DC converter is connected to the high-voltage battery.

According to some embodiments, the circuit module is a rectifying circuit or a correction circuit, and the second DC/DC converter is a bidirectional isolation DC/DC converter or a unidirectional isolation DC/DC converter.

The technical scheme that this application embodiment provided can realize that on-vehicle machine of charging charges for low-voltage battery 140's forward, also can realize that low-voltage battery to on-vehicle machine of charging's reverse charge to realize low-voltage battery to the pre-charge function of OBC generating line and whole car high-voltage battery side, save the pre-charge circuit of OBC and high-voltage battery side, when improving the power density and the security of OBC, also reduced the cost of OBC and whole car.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

Fig. 1 is a schematic structural diagram of an on-vehicle DC/DC converter with a reverse precharge function according to an embodiment of the present application.

Fig. 2 is a schematic structural diagram of another vehicle-mounted DC/DC converter with a reverse precharge function according to an embodiment of the present application.

Fig. 3 is a schematic structural diagram of an in-vehicle charging device according to an embodiment of the present application.

Fig. 4 is a second schematic structural diagram of an in-vehicle charging device according to an embodiment of the present application.

Fig. 5 is a third schematic structural diagram of a vehicle-mounted charging device according to an embodiment of the present application.

Fig. 6 is a fourth schematic structural diagram of an in-vehicle charging device according to an embodiment of the present application.

Fig. 7 is a fifth schematic structural diagram of an in-vehicle charging device according to an embodiment of the present application.

Fig. 8 is a sixth schematic structural view of an in-vehicle charging device according to an embodiment of the present application.

Fig. 9 is a seventh schematic structural diagram of an in-vehicle charging device according to an embodiment of the present application.

Fig. 10 is an eighth schematic structural diagram of an in-vehicle charging device according to an embodiment of the present application.

Fig. 11 is a schematic structural diagram of an in-vehicle charging system according to an embodiment of the present application.

Detailed Description

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, and it is obvious that the described embodiments are some, but not all, embodiments of the present application. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It should be understood that the terms "first", "second", etc. in the claims, description, and drawings of the present application are used for distinguishing between different objects and not for describing a particular order. The terms "comprises" and "comprising," when used in the specification and claims of this application, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Fig. 1 is a schematic structural diagram of an on-vehicle DC/DC converter with a reverse precharge function according to an embodiment of the present application.

As shown in fig. 1, the on-vehicle DC/DC converter 100 having the reverse precharge function may be a high-power DC/DC converter including a main transformer 130, a first circuit 120 located on a primary side of the main transformer 130, a second circuit 110 located on a secondary side of the main transformer 130, and a third circuit 160.

The main transformer 130 includes a primary winding and a secondary winding. One end of the first circuit 120 is connected to the primary winding, and the other end of the first circuit 120 is connected to a bus capacitor C4 of the vehicle charging system and the high voltage battery 150. One end of the second circuit 110 is connected to the secondary winding, and the other end of the second circuit 110 is connected to one end of the third circuit 160 for power transmission. The other end of the third circuit 160 is connected to the low-voltage battery 140 of the vehicle charging system. During forward charging, the low-voltage battery 140 is charged from the high-voltage battery 150 through the in-vehicle DC/DC converter 100 having the reverse precharge function, and during reverse charging, the low-voltage battery 140 is reversely precharged to the bus capacitor C4 by controlling the switching tubes of the second circuit 110 and the third circuit 160.

The first DC power supply terminal and the second DC power supply terminal are respectively connected in parallel with a capacitor for filtering and stabilizing the input and output voltages of the vehicle-mounted DC/DC converter 100 having the reverse precharge function.

The first circuit 120 includes a first primary side switching tube P₁A second primary side switch tube P₂A first primary side capacitor C₁And a second primary capacitor C₂。

First primary side switch tube P₁One end of which is connected to the positive terminal of the primary winding of the main transformer 130 and the other end of which is connected to the positive terminal of the high voltage battery 150. Second primary side switch tube P₂One end of which is connected to the positive terminal of the primary winding of the main transformer 130 and the other end of which is connected to the negative terminal of the high voltage battery 150. First primary side capacitor C₁One end of which is connected to the positive terminal of the high voltage battery 150 and the other end of which is connected to the negative terminal of the primary winding of the main transformer 130. Second primary side capacitor C₂One end of which is connected to the negative terminal of the high voltage battery 150 and the other end of which is connected to the negative terminal of the primary winding of the main transformer 130.

The second circuit 110 comprises a first secondary inductance L₁And a second secondary side inductor L₂A first secondary switch tube SR₁And a second secondary side switching tube SR₂。

First secondary inductor L₁One terminal of which is connected to the positive terminal of one terminal of the third circuit 160 and the other terminal is connected to the negative terminal of the secondary winding of the main transformer 130. Second secondary side inductor L₂One end of which is connected to the positive terminal of one end of the third circuit 160 and the other end of which is connected to the positive terminal of the secondary winding of the main transformer 130. First secondary side switch tube SR₁One end of which is connected with a first secondary inductor L₁The other end of the first secondary side switching tube SR₁And the other end thereof is connected to the negative electrode of the low-voltage battery 140. Second secondary side switch tube SR₂One end of the second primary side switching tube SR is connected with the positive end of the secondary side winding of the main transformer 130₂And the other end thereof is connected to the negative electrode of the low-voltage battery 140.

The primary side switching tube and the secondary side switching tube may be Metal Oxide Semiconductor (MOS) field effect transistors, and of course, may also be other types of switching tubes, which is not limited in this application.

The third circuit 160 includes a filter capacitor C₃Filter inductor L₃Anti-backflow switch tube S₃And a freewheeling diode D₃。

Filter capacitor C₃Connected in parallel with the second circuit 110. Filter inductance L₃One end is connected with a filter capacitor C₃The positive electrode of (1). Anti-backflow switch tube S₃One end of is connected with a filter inductor L₃And the other end thereof is connected to the positive electrode of the low-voltage battery 140. Freewheeling diode D₃Is connected to the negative pole of the low-voltage battery 140, and a freewheeling diode D₃Negative electrode of the switch tube S is connected with a backflow prevention switch tube S₃And a filter inductor L₃The connecting end of (1). Anti-backflow switch tube S₃When closed, the low-voltage battery 140 is used as a filter inductor L₃And a filter capacitor C₃Charging and backflow preventing switch tube S₃When disconnected, the filter inductor L₃Through a freewheeling diode D₃Follow current as filter capacitor C₃And (6) charging.

The coil ratio of the primary winding and the secondary winding of the main transformer 130 may be n: 1. the inductance of the secondary side resistor may comprise at least one inductance. The number of coils of the inductor, no matter how many inductors are, may be nt 1. Filter inductance L₃At least one inductor may be included. The number of coils of the inductor may be nt 2. Wherein n, nt1 and nt2 may be the same or different.

In the vehicle-mounted DC/DC converter with the reverse pre-charging function provided in this embodiment, during the forward charging, the first primary capacitor C can be used for charging₁A second primary side capacitor C₂A first primary side switch tube P₁And a second primary side switching tube P₂A first circuit 120 is formed as a primary half bridge of the main transformer. First secondary side switch tube SR₁And a second secondary side switch tube SR₂A first secondary inductor L₁And a second secondary side inductor L₂Form a second circuit 110 as the secondary side current-doubling of the main transformerA rectifier circuit. Filter inductance L₃Filter capacitor C₃Freewheel diode D₃Anti-backflow diode S₃The third circuit 160 is configured as a secondary side filter circuit.

During forward charging, the vehicle-mounted DC/DC converter with the reverse pre-charging function is connected to the high-voltage battery 150 through one end and to the low-voltage battery through the other end, so that the high-voltage battery 150 charges the low-voltage battery 140 in a forward direction.

Meanwhile, the vehicle-mounted DC/DC converter with the reverse pre-charging function can be charged reversely by the filter inductor L₃Freewheel diode D₃Anti-backflow switch tube S₃Filter capacitor C₃Forming a buck circuit. First secondary side switch tube SR₁And a second secondary side switch tube SR₂A first secondary inductor L₁And a second secondary side inductor L₂A main transformer 130, a first primary side capacitor C₁A second primary side capacitor C₂A first primary side switch tube P₁A second primary side switch tube P₂An isolated DC/DC circuit is constructed.

When reversely charging, the buck circuit is utilized to prevent the backflow switching tube S₃And (5) controlling. So that the backflow prevention switch tube S₃When closed, the low-voltage battery is connected to the reverse flow prevention switch tube S₃Is a filter inductor L₃And a filter capacitor C₃And (6) charging energy. When the backflow prevention switch tube S₃When disconnected, the filter inductor L₃Through a freewheeling diode D₃Follow current as filter capacitor C₃And (6) charging energy. This process causes the filter capacitor C to be₃Is controlled by the buck circuit.

Utilize and keep apart DC/DC circuit to first secondary switch tube SR₁And a second secondary side switching tube SR₂And (5) controlling.

First secondary side switch tube SR₁When closed, the filter capacitor C₃Is a first secondary inductor L₁And (6) charging energy.

First secondary side switch tube SR₁Off, second secondary side switch tube SR₂When closed, the first secondary inductor L₁Energy of the first secondary side switching tube SR₂And a main transformer 130 for transmitting to the first primary capacitor C₁And a second primary capacitor C₂So that the second secondary side switch tube SR₂When closed, the filter capacitor C is enabled₃A second secondary side inductor L₂And (6) charging energy.

Second secondary side switch tube SR₂Off, first secondary switching tube SR₁When closed, the second secondary inductor L₂Energy of (2) passes through the first secondary side switch tube SR₁And a main transformer 130 for transmitting to the first primary capacitor C₁And a second primary capacitor C₂The low-voltage battery pre-charging device has the advantages that the reverse flow of energy is realized, namely, the reverse charging from the low-voltage battery to the bus capacitor is realized, so that the pre-charging function of the low-voltage battery to an OBC bus and the high-voltage battery side of the whole vehicle is realized, the pre-charging circuit on the OBC and the high-voltage battery side is omitted, the power density and the safety of the OBC are improved, and the cost of the OBC and the whole vehicle is reduced.

Fig. 2 is a schematic structural diagram of another vehicle-mounted DC/DC converter with a reverse precharge function according to an embodiment of the present application.

In this embodiment, the second circuit 110 is changed based on the embodiment shown in fig. 1. The second circuit 110 includes a secondary inductor L₄A first secondary switch tube SR₃And a second secondary side switching transistor SR 4.

Secondary side inductor L₄One end of which is connected to the positive pole of one end of the third circuit 160. First secondary side switch tube SR₃One end of the secondary inductor L is connected with₄And the other end of the primary winding is connected to the positive terminal of the secondary winding of the main transformer 130. Second secondary side switch tube SR₄One end of the secondary inductor L is connected with₄The other end of the primary winding of the primary transformer 130 is connected to the negative terminal of the secondary winding of the primary transformer 130, and the midpoint of the secondary winding of the primary transformer 130 is connected to the negative terminal of the low-voltage battery 140.

During forward charging, the first primary capacitor C₁A second primary side capacitor C₂A first primary side switch tube P₁And a second primary side switching tube P₂A first circuit 120 is formed as a primary half bridge of the main transformer. Third secondary side switch tube SR₃And a fourth secondary side switch tube SR₄Secondary side inductor L₄The second circuit 110 is configured as a secondary side current-doubling rectifying circuit of the main transformer. Filter capacitor C₃Filter inductor L₃Anti-backflow switch tube S₃And the capacitors connected in parallel with the two ends of the low-voltage battery 140 form a second-stage filter circuit. The high-voltage battery 150 is positively charged to the low-voltage battery 140.

During reverse charging, the secondary inductor L₄And a third secondary side switch tube SR₃And a fourth secondary side switch tube SR₄A main transformer T1, a first primary side switch tube P₁A second primary side switch tube P₂A first primary side capacitor C₁A second primary side capacitor C₂An isolated DC/DC circuit is constructed. The isolated DC/DC circuit is used for switching the SR of the third secondary side switch tube₃And a fourth secondary side switching tube SR₄And (5) controlling.

Third secondary side switch tube SR₃And a fourth secondary side switching tube SR₄When closed, the filter capacitor C₃Is a secondary side inductor L₄And (6) charging energy.

Third secondary side switch tube SR₃Secondary side inductance L when disconnected₄Can pass through the fourth secondary side switch tube SR₄Main transformer T₁A first primary side switch tube P₁A second primary side switch tube P₂Is transmitted to the first primary side capacitor C₁And a second primary capacitor C₂。

Fourth secondary side switch tube SR₄Secondary side inductance L when disconnected₄Can pass through the third secondary side switch tube SR₃Main transformer T₁A first primary side switch tube P₁A second primary side switch tube P₂Is transmitted to the primary side capacitor C₁、C₂Realizing the reverse flow of energy and realizing the low-voltage battery 140 to the bus capacitor C₄Is charged in reverse. Therefore, the pre-charging function of the low-voltage battery to the OBC bus and the whole vehicle high-voltage battery side is realized, the pre-charging circuit of the OBC and the high-voltage battery side is omitted, the power density and the safety of the OBC are improved, and meanwhile, the cost of the OBC and the whole vehicle is reduced.

Fig. 3 is a schematic structural diagram of an in-vehicle charging device according to an embodiment of the present application.

As shown in fig. 3, the vehicle-mounted charging device includes a vehicle-mounted DC/DC converter 100 having a reverse precharge function, a low-voltage battery 140, a vehicle-mounted charger 220, and a high-voltage battery 150.

One end of the vehicle-mounted charger 220 is connected to the ac input end 210 and the vehicle-mounted DC/DC converter 100 having the reverse precharge function, and the other end is connected to the high-voltage battery 150.

Alternatively, the first DCDC converter 100 may be any one of the DCDC converters 100 in fig. 1 or 2, without any limitation.

Fig. 4 is a second schematic structural diagram of an in-vehicle charging device according to an embodiment of the present application.

As shown in fig. 4, the vehicle-mounted charging device includes a vehicle-mounted DC/DC converter 100 having a reverse precharge function, a low-voltage battery 140, a vehicle-mounted charger 220, and a high-voltage battery 150.

One end of the vehicle-mounted charger 220 is connected to the ac input end 210 and the vehicle-mounted DC/DC converter 100 having the reverse precharge function, and the other end is connected to the high-voltage battery 150.

Alternatively, the on-vehicle DC/DC converter 100 with the reverse precharge function may be the on-vehicle DC/DC converter 100 with the reverse precharge function in any one of fig. 1 or fig. 2, without any limitation.

The vehicle-mounted charger 220 includes a circuit module 221 and a second DC/DC converter 222. One end of the circuit module 221 is connected to the ac input terminal, one end of the second DC/DC converter 222 is connected to the other end of the circuit module 221, and the other end is connected to the high-voltage battery 150.

The circuit module 221 is a rectifying circuit or a correcting circuit, and the second DC/DC converter 222 is a bidirectional isolation DC/DC converter or a unidirectional isolation DC/DC converter.

The rectifying circuit 221b may be a bidirectional rectifying circuit; the Correction circuit 221a may be a Power Factor Correction (PFC) circuit.

Alternatively, the rectifying circuit 221b or the rectifying circuit 221a and the bidirectional isolation DCDC converter 222a or the unidirectional isolation DCDC converter 222b may be arbitrarily matched with each other.

Fig. 5 is a third schematic structural diagram of a vehicle-mounted charging device according to an embodiment of the present application.

As shown in fig. 5, the in-vehicle charging apparatus may include a rectification circuit 221a, a unidirectional isolation DCDC converter 222b, a high-voltage battery 150, an in-vehicle DC/DC converter 100 having a reverse precharge function, and a low-voltage battery 140.

One end of the rectifying circuit 221a is connected to the ac input terminal 210, the other end of the rectifying circuit 221a is connected to the unidirectional isolation DC/DC converter 222b, and the other end of the unidirectional isolation DC/DC converter 222b is connected to the high-voltage battery 150.

In the vehicle-mounted charging device shown in fig. 5, the vehicle-mounted charger 220 may be composed of a rectification circuit 221a and a unidirectional isolation DC/DC converter 222 b. One end of the on-vehicle DC/DC converter 100 having the reverse precharge function may be connected to the low-voltage battery 140, and the other end of the on-vehicle DC/DC converter 100 having the reverse precharge function may be hung on a bus side of the on-vehicle charger 220, i.e., on a bus of the unidirectional isolation DC/DC converter 222b in the on-vehicle charger 220.

In this case, the reverse charging function of the vehicle-mounted DC/DC converter 100 with the reverse pre-charging function may be utilized, the bus of the vehicle-mounted charger 220 is charged to the target voltage, the unidirectional isolation DC/DC converter 222b of the vehicle-mounted charger 220 is then turned on to charge the output capacitor, and after the output voltage reaches a required value, the operating states of the unidirectional isolation DC/DC converter 222b and the vehicle-mounted DC/DC converter 100 with the reverse pre-charging function of the vehicle-mounted charger 220 are controlled, so that the voltage is maintained at the target voltage.

Fig. 6 is a fourth schematic structural diagram of an in-vehicle charging device according to an embodiment of the present application.

As shown in fig. 6, the vehicle-mounted charging device may include a rectification circuit 221b, a bidirectional isolation DC/DC converter 222a, a high-voltage battery 150, a vehicle-mounted DC/DC converter 100 having a reverse precharge function, and a low-voltage battery 140.

One end of the rectifying circuit 221b is connected to the ac input terminal 210, the other end of the rectifying circuit 221b is connected to the bidirectional isolation DC/DC converter 222a, and the other end of the bidirectional isolation DC/DC converter 222a is connected to the high-voltage battery 150.

In the vehicle charging apparatus shown in fig. 6, the vehicle charger 220 may be composed of a rectifying circuit 221b and a bidirectional isolation DCDC converter 222a, one end of the vehicle DC/DC converter 100 having the reverse precharge function may be connected to the low-voltage battery 140, and the other end of the vehicle DC/DC converter 100 having the reverse precharge function may be hung on a bus side of the vehicle charger 220, that is, on a bus of the unidirectional isolation DC/DC converter 222b in the vehicle charger. In this case, the reverse charging function of the vehicle-mounted DC/DC converter 100 with the reverse pre-charging function may be utilized, the bus of the vehicle-mounted charger 220 is charged to the target voltage, the bidirectional isolation DC/DC converter 222a of the vehicle-mounted charger 220 is then turned on to charge the output capacitor, and after the output voltage reaches a required value, the operating states of the bidirectional isolation DC/DC converter 222a in the vehicle-mounted charger 220 and the vehicle-mounted DC/DC converter 100 with the reverse pre-charging function are controlled, so that the voltage is maintained at the target voltage.

Fig. 7 is a fifth schematic structural diagram of an in-vehicle charging device according to an embodiment of the present application.

As shown in fig. 7, the in-vehicle charging device includes a rectifying circuit 221a, a bidirectional isolation DC/DC converter 222a, a high-voltage battery 150, an in-vehicle DC/DC converter 100 having a reverse precharge function, and a low-voltage battery 140.

One end of the rectifying circuit 221a is connected to the ac input terminal 210, the other end of the rectifying circuit 221a is connected to the bidirectional isolation DC/DC converter 222a, and the other end of the bidirectional isolation DC/DC converter 222a is connected to the high-voltage battery 150.

In the vehicle charging apparatus shown in fig. 7, the vehicle charger 220 may be composed of a rectification circuit 221a and a bidirectional isolation DC/DC converter 222a, one end of the vehicle DC/DC converter 100 with the reverse precharge function may be connected to the low-voltage battery 140, and the other end of the vehicle DC/DC converter 100 with the reverse precharge function may be hung on a bus side of the vehicle charger, that is, on a bus of the unidirectional isolation DC/DC converter 222b in the vehicle charger.

In this case, the reverse charging function of the vehicle-mounted DC/DC converter 100 with the reverse pre-charging function may be utilized, the bus of the vehicle-mounted charger 220 is charged to the target voltage, the bidirectional isolation DC/DC converter 222a of the vehicle-mounted charger 220 is then turned on to charge the output capacitor, and after the output voltage reaches a required value, the operating states of the bidirectional isolation DC/DC converter 222a in the vehicle-mounted charger 220 and the vehicle-mounted DC/DC converter 100 with the reverse pre-charging function are controlled, so that the voltage is maintained at the required voltage.

Fig. 8 is a sixth schematic structural view of an in-vehicle charging device according to an embodiment of the present application.

As shown in fig. 8, the vehicle-mounted charging device includes a rectifying circuit 221a, a unidirectional isolation DC/DC converter 222b, a high-voltage battery 150, a vehicle-mounted DC/DC converter 100 having a reverse precharge function, and a low-voltage battery 140.

One end of the rectifying circuit 221a is connected to the ac input terminal 210, the other end of the rectifying circuit 221a is connected to the unidirectional isolation DC/DC converter 222b, and the other end of the unidirectional isolation DC/DC converter 222b is connected to the high-voltage battery 150.

In the vehicle-mounted charging device shown in fig. 8, the vehicle-mounted charger 220 may be composed of a rectification circuit 221a and a unidirectional isolation DCDC converter 222b, one end of the vehicle-mounted DC/DC converter 100 having the reverse precharge function may be connected to the low-voltage battery 140, and the other end of the vehicle-mounted DC/DC converter 100 having the reverse precharge function may be hooked to the output side of the vehicle-mounted charger 220.

In this case, the output terminal of the vehicle-mounted charger 220 can be charged to the target voltage by using the reverse charging function of the vehicle-mounted DC/DC converter 100 having the reverse pre-charging function, and the bus voltage of the vehicle-mounted charger 220 is supplied with power through the ac input terminal 210 to achieve soft start.

Fig. 9 is a seventh schematic structural diagram of an in-vehicle charging device according to an embodiment of the present application.

As shown in fig. 9, the vehicle-mounted charging device includes a rectifying circuit 221b, a bidirectional isolation DC/DC converter 222a, a high-voltage battery 150, a vehicle-mounted DC/DC converter 100 having a reverse precharge function, and a low-voltage battery 140.

One end of the rectifying circuit 221b is connected to the ac input terminal 210, the other end of the rectifying circuit 221b is connected to the bidirectional isolation DC/DC converter 222a, and the other end of the bidirectional isolation DC/DC converter 222a is connected to the high-voltage battery 150.

In the vehicle-mounted charging apparatus shown in fig. 9, the vehicle-mounted charger 220 may be composed of a rectifying circuit 221b and a bidirectional isolation DC/DC converter 222a, one end of the vehicle-mounted DC/DC converter 100 having the reverse precharge function may be connected to the low-voltage battery 140, and the other end of the vehicle-mounted DC/DC converter 100 having the reverse precharge function may be hung on the output side of the vehicle-mounted charger 220.

In this case, the reverse charging function of the vehicle-mounted DC/DC converter 100 with the reverse pre-charging function may be utilized, after the output terminal of the vehicle-mounted charger 220 is charged to the required voltage, the bidirectional isolation DC/DC converter 222a of the vehicle-mounted charger 220 is turned on, and after the bus voltage of the vehicle-mounted charger 220 is charged to the target voltage, the operating states of the bidirectional isolation DC/DC converter 222a in the vehicle-mounted charger 220 and the vehicle-mounted DC/DC converter 100 with the reverse pre-charging function are controlled, so that the voltage is maintained at the required voltage.

Fig. 10 is an eighth schematic structural diagram of an in-vehicle charging device according to an embodiment of the present application.

As shown in fig. 10, the in-vehicle charging device includes a rectifying circuit 221a, a bidirectional isolation DC/DC converter 222a, a high-voltage battery 150, an in-vehicle DC/DC converter 100 having a reverse precharge function, and a low-voltage battery 140.

One end of the rectifying circuit 221a is connected to the ac input terminal 210, the other end of the rectifying circuit 221a is connected to the bidirectional isolation DC/DC converter 222a, and the other end of the bidirectional isolation DC/DC converter 222a is connected to the high-voltage battery 150.

In the vehicle-mounted charging device shown in fig. 10, the vehicle-mounted charger 220 may be composed of a rectification circuit 221a and a bidirectional isolation DC/DC converter 222a, one end of the vehicle-mounted DC/DC converter 100 having the reverse precharge function may be connected to the low-voltage battery 140, and the other end of the vehicle-mounted DC/DC converter 100 having the reverse precharge function may be hooked to the output side of the vehicle-mounted charger 220.

In this case, the reverse charging function of the vehicle-mounted DC/DC converter 100 with the reverse pre-charging function may be utilized, after the output terminal of the vehicle-mounted charger 220 is charged to the target voltage, the bidirectional isolation DC/DC converter 222a of the vehicle-mounted charger 220 is turned on, and after the bus voltage of the vehicle-mounted charger 220 is charged to the target voltage, the operating states of the bidirectional isolation DC/DC converter 222a in the vehicle-mounted charger 220 and the vehicle-mounted DC/DC converter 100 with the reverse pre-charging function are controlled, so that the voltage is maintained at the required voltage.

The second direct current power supply terminal is connected to one terminal of the second DC/DC converter 222 or the other terminal of the second DC/DC converter 222.

In this embodiment, a buck circuit and an isolation DC/DC circuit are formed by using a vehicle-mounted DC/DC converter having a reverse precharge function. The buck circuit is utilized to control the voltage of a filter capacitor, and the voltage of the filter capacitor is the input voltage of the isolation DC/DC circuit. The isolation DC/DC circuit is used for controlling the secondary side switch tube, so that when the first secondary side switch tube is closed, the filter capacitor charges energy for the first secondary side inductor; when the first secondary switch tube is disconnected and the second secondary switch tube is closed, the energy of the first secondary inductor passes through the second secondary switch tube and the main transformer and can be transmitted to the primary capacitor, the reverse flow of the energy is realized, namely, the reverse charging from the low-voltage battery to the vehicle-mounted charger is realized, so that the pre-charging function of the low-voltage battery to an OBC bus and the whole vehicle high-voltage battery side is realized, the pre-charging circuit of the OBC and the high-voltage battery side is omitted, the power density and the safety of the OBC are improved, and the cost of the OBC and the whole vehicle is also reduced.

Fig. 11 is a schematic structural diagram of an in-vehicle charging system according to an embodiment of the present application.

As shown in fig. 11, the in-vehicle charging system 300 includes the in-vehicle charging device 200 and the control circuit 310 as described above.

The control circuit 310 is connected to the in-vehicle charging device 200, and is configured to control an operating state of the in-vehicle charging device 200.

The vehicle-mounted charging device 200 realizes reverse charging from the low-voltage battery to the vehicle-mounted charger, so that the low-voltage battery can pre-charge the OBC bus and the high-voltage battery side of the whole vehicle, a pre-charging circuit on the OBC and the high-voltage battery side is omitted, the power density and the safety of the OBC are improved, and the cost of the OBC and the whole vehicle is reduced.

In a specific operation process of the in-vehicle charging system 300, the control circuit 310 communicates with the vehicle control unit through the communication line to receive an operation command, and controls an operation state of the charging device through a connection with a part or the whole of the in-vehicle charging device 200.

When the start instruction is not received, the control circuit 310 controls the charging device to be in the sleep state. Upon receiving the start instruction, the control circuit 310 wakes up the in-vehicle charging device 200 to be in the pre-sleep state. The control circuit 310 then determines whether the high-voltage battery 150 of the entire vehicle is connected, and if the high-voltage battery 150 is not connected, controls the vehicle-mounted charging device 200 to operate in a pre-charging state (i.e., the pre-charging state is that the low-voltage battery 140 charges at least one bus in the vehicle-mounted charger 220 through the second DC/DC converter 222 in the buck circuit and isolated DC/DC circuit mode). If the high-voltage battery 150 is in the connected state, the vehicle-mounted charging device 200 is controlled to operate in the entire vehicle operating state (the entire vehicle operating state is in the charging state, the inversion state or the single DC/DC operating state).

Further, in the pre-charging state, the control circuit 310 further needs to determine whether a reverse pre-charging command is received, and if so, the second DC/DC converter 222 is controlled to operate in the buck circuit mode and the isolated DC/DC circuit mode, and the low-voltage battery 140 is converted to charge at least one bus in the vehicle-mounted charger 220 through the buck circuit and the isolated DC/DC circuit. And when the whole vehicle high-voltage battery 150 is in a connected state, the buck circuit mode and the isolated DC/DC circuit mode are controlled to stop. And if the reverse pre-flushing instruction is not received, entering a pre-sleep state. When the whole vehicle works, the whole vehicle further needs to wait for a whole vehicle working instruction, when the whole vehicle working instruction does not arrive, the whole vehicle is in a standby state, and when the whole vehicle working instruction arrives, the whole vehicle is controlled to be in a charging state, an inversion state or an independent DC/DC working state according to the working instruction.

The foregoing detailed description of the embodiments of the present application has been presented to illustrate the principles and implementations of the present application, and the description of the embodiments is only intended to facilitate the understanding of the methods and their core concepts of the present application. Meanwhile, a person skilled in the art should, according to the idea of the present application, change or modify the embodiments and applications of the present application based on the scope of the present application. In view of the above, the description should not be taken as limiting the application.