CN215870782U

CN215870782U - Auxiliary power supply module for bidirectional direct current charger

Info

Publication number: CN215870782U
Application number: CN202023318258.6U
Authority: CN
Inventors: 杨传超; 邵丹薇; 杨志; 杨立军
Original assignee: Guochuang Mobile Energy Innovation Center Jiangsu Co Ltd; Wanbang Digital Energy Co Ltd; Wanbang Star Charge Technology Co Ltd
Current assignee: Guochuang Mobile Energy Innovation Center Jiangsu Co Ltd; Wanbang Digital Energy Co Ltd; Wanbang Star Charge Technology Co Ltd
Priority date: 2020-12-31
Filing date: 2020-12-31
Publication date: 2022-02-18
Anticipated expiration: 2030-12-31

Abstract

The utility model relates to the field of chargers, and particularly discloses an auxiliary power supply module for a bidirectional direct current charger, which comprises an input end, a first output end and a second output end, wherein the input end is connected with an external power supply, the first output end is connected with a DC/DC circuit to provide insulation detection voltage for the bidirectional direct current charger, the second output end is connected with the anode of a diode D2, and the cathode of a diode D2 is connected with the DC/DC circuit to provide auxiliary power supply for the DC/DC circuit during reverse work. When the auxiliary power supply module is in a reverse off-grid mode, the power level DC/DC circuit is not required to output the insulation detection voltage required by the electric automobile, but the insulation detection voltage is directly provided by the auxiliary power supply module, after the auxiliary power supply module scheme is fixed, the no-load loss is basically fixed, the auxiliary power supply power of the system control circuit and the power supply module of the DC/DC circuit is relatively fixed, and the requirement on the external power supply power is obviously reduced, so that the auxiliary power supply module scheme provided by the utility model has more universal applicability.

Description

Auxiliary power supply module for bidirectional direct current charger

Technical Field

The utility model relates to the field of direct current chargers, in particular to an auxiliary power supply module for a bidirectional direct current charger.

Background

Along with the rise of pure electric vehicle market, the electric vehicle charger trade has also met the rapid development, and simultaneously, the two-way machine that charges can satisfy more application scenarios, for example: the peak clipping and valley filling functions are realized by matching with a national power grid, and the power supply is used for supplying power to household electric equipment and providing illumination for field camping when the power grid is powered off. The auxiliary power supply scheme is an important link, namely the requirement of the charger on the auxiliary power supply in a forward charging mode needs to be met, and meanwhile, the system also needs to be ensured to work normally in a reverse grid-connected mode and a reverse off-grid mode.

The scheme of the traditional auxiliary power supply is shown in fig. 1, the auxiliary power supply of the bidirectional charger is mainly divided into three parts, namely: the system comprises a power module auxiliary power supply, a system power supply auxiliary power supply and a boosting isolation power supply. The auxiliary power supply of the power supply module gets power from a bus voltage output end VBUS, respectively generates VCC1 to supply power for an AC/DC and DC/DC primary side circuit and VCC2 to supply power for a DCDC secondary side circuit after passing through the auxiliary power supply circuit, and VCC1 and VCC2 can supply power for the power supply module control circuit in a single way or at the same time according to the requirements of the power supply module control circuit on the power supply; the system auxiliary power supply obtains power from the AC side of the power grid and mainly supplies power to the system control circuit; the boost isolation power supply takes electricity from an external power supply, outputs the electricity to the bus voltage after passing through the boost isolation power supply, and simultaneously supplies power to the system control circuit after passing through the diode D1.

When the charger is in a forward charging mode and a reverse grid-connected mode, because the power grid side is electrified, both the power module auxiliary power supply and the system power supply auxiliary power supply can work normally without energy supplied by an external power supply;

when the electric automobile is in the reverse off-grid mode, the battery of the electric automobile needs to discharge, but before the high-voltage direct-current contactor at the automobile end is closed, the charger needs to execute insulation detection firstly according to a given output voltage command of the electric automobile, and the high-voltage direct-current contactor at the automobile end is closed and the electric automobile starts to discharge only when the insulation detection meets the requirement. And when the system is in a reverse off-grid mode, the power grid side is disconnected, so that an external power supply is required to supply power to the system control circuit, and the communication between the charger and the electric automobile can be ensured. Meanwhile, the external power supply needs to be boosted to the bus voltage through the boosting isolation power supply to supply power for the auxiliary power supply of the power module, only when the control power of the DC/DC circuit exists, the DC/DC circuit can output the output voltage VO required by the electric automobile under the control of the control circuit of the power module, and the insulation detection is completed by the system control circuit.

After insulation detection is finished, a high-voltage direct-current contactor in the electric automobile is closed, the power module control circuit controls the output high-voltage direct-current contactor K1 to be closed, the voltage of a battery of the electric automobile is connected to the DC/DC output VO, the battery of the electric automobile supplies energy for a bus when the DC/DC circuit works reversely, then AC/DC reverse work finishes building of voltage on an alternating current side, the boosting isolation power supply can be controlled to be closed by the power module control circuit at the moment, and an external power supply does not need to supply energy any more.

The scheme is a commonly used solution in the conventional bidirectional charger, and is mainly limited by the influence of no-load loss of a reverse off-grid mode DC/DC circuit according to the working process, and if the external power supply is an automobile cigarette lighter, the maximum current capacity of the automobile cigarette lighter is usually 10A, namely the rated maximum power is 120W. The total required power of the power module control circuit and the auxiliary power supply of the power module is unequal to 15W-35W, and then the maximum no-load loss of the DC/DC circuit should not exceed 50W by considering the influence of the actual power supply conversion efficiency (85%) and the requirement of reserving a certain allowance (according to 80% derating) to prevent the cigarette lighter from being damaged when the cigarette lighter is used. However, the difference of the no-load loss of the DC/DC circuit is very large for different application conditions, for example, the ac side is a single-phase system or a three-phase system, the bus voltage in the three-phase system is higher, and the no-load loss is larger; the DC/DC circuit is influenced by different topological structures, other topologies such as CLLC, DAB or phase-shifted full bridge and the like can be selected for the bidirectional topology, and because the topological structures and the control modes are different, the no-load loss difference is large, and if the no-load loss of the DAB topology is difficult to reduce below 100W; the DC/DC circuit adopts single-path output or multi-path parallel output, the larger the power of the charger is, the more the number of parallel circuits is needed, the more the number of parallel circuits is, the no-load is multiplied, and the like, the existing scheme has no universal applicability due to the reasons, and meanwhile, if the using power of the cigarette lighter is too high, the fuse in the cigarette lighter can be burnt out, and certain potential safety hazards exist. Similarly, if the external power source is powered by an external battery, the same problem may also exist because the no-load loss of the DC/DC circuit is not fixed under different application conditions, for example, different application conditions may require batteries with different capacities.

In summary, the auxiliary power supply scheme of the existing bidirectional charger in the off-grid mode has no general applicability to large difference of no-load loss of the DC/DC circuit, and has certain potential safety hazard.

SUMMERY OF THE UTILITY MODEL

The utility model provides a novel auxiliary power supply module for a bidirectional direct current charger, which aims to solve the problem that an auxiliary power supply scheme of the bidirectional charger in an off-grid mode in the prior art has no universal applicability to large difference of no-load loss of a DC/DC circuit.

The technical scheme adopted by the utility model is as follows:

an auxiliary power module for a bi-directional dc charger, comprising:

the input end is connected with an external power supply;

the first output end is connected with the output end of the DC/DC circuit and provides insulation detection voltage for the bidirectional direct current charger;

and the second output end is connected with the anode of the diode D2, and the cathode of the diode D2 is connected with the DC/DC circuit auxiliary power supply VCC2 to provide auxiliary power supply for the reverse operation of the DC/DC circuit.

Furthermore, the auxiliary power module is configured as a boost isolation power supply, the boost isolation power supply includes two flyback circuits, the two flyback circuits are configured as a first flyback circuit and a second flyback circuit, an output terminal of the first flyback circuit is configured as a first output terminal, and an output terminal of the second flyback circuit is configured as a second output terminal.

Furthermore, one end of a primary coil of the first flyback circuit is connected with the anode of an external power supply, the other end of the primary coil of the first flyback circuit is connected with the drain electrode of a switching tube Q2, the source electrode of the switching tube Q2 is grounded, the gate electrode of the switching tube Q2 is connected with the output end of the first PWM controller, and a secondary coil of the first flyback circuit outputs a voltage value required for insulation detection through a rectifying circuit.

Furthermore, one end of a primary coil of the second flyback circuit is connected with the anode of an external power supply, the other end of the primary coil of the second flyback circuit is connected with the drain of a switching tube Q3, the source of the switching tube Q3 is grounded, the gate of the switching tube Q3 is connected with the output end of the second PWM controller, and a secondary coil of the second flyback circuit outputs auxiliary power supply VCC2 required for the reverse operation of the DC/DC circuit through a diode D2.

Further, the system control board power supply circuit is connected with the cathode of the diode D1, and the anode of the diode D1 is connected with the external power supply.

Furthermore, the boost isolation power supply further comprises a boost circuit, and the two flyback circuits are connected with the external power supply through the boost circuit.

An auxiliary power module for a bi-directional dc charger, comprising:

the input end of the first auxiliary power supply is connected with an external power supply, and the output end of the first auxiliary power supply is connected with the output end of the DC/DC circuit to provide insulation detection voltage for the bidirectional direct current charger;

the input end of the second auxiliary power supply is connected with a battery of the electric automobile, and the output end of the second auxiliary power supply is connected with a DC/DC circuit auxiliary power supply VCC2 or a bus voltage output end VBUS to provide auxiliary power supply for the DC/DC circuit during reverse work.

Compared with the prior art, the utility model has the beneficial effects that:

1. according to the utility model, an external power supply can be connected with a boosting isolation power supply, and the insulation detection voltage required by the electric automobile is output according to the output voltage command sent by the system control circuit, so that the no-load loss generated by the power level DCDC is reduced compared with the existing scheme;

2. according to the utility model, the input end of the first auxiliary power supply is connected with an external power supply, the output end of the first auxiliary power supply is connected with the output end of the DC/DC circuit, so that insulation monitoring voltage is provided for the bidirectional direct current charger, the input end of the second auxiliary power supply is connected with the battery of the electric automobile, the output end of the second auxiliary power supply is connected with the auxiliary power supply VCC2 of the DC/DC circuit or the voltage output end VBUS of the bus, so that auxiliary power supply is provided for the DC/DC circuit when the DC/DC circuit works reversely, namely, the reverse working voltage is provided by the battery of the electric automobile, so that the dependence on the external power supply can be reduced.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, 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 invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1: the method is a functional block diagram of a boosting isolation power supply of the existing bidirectional direct current charger;

FIG. 2: the embodiment of the utility model provides a functional block diagram of an auxiliary power module for a bidirectional direct current charger;

FIG. 3: the embodiment of the utility model provides a circuit diagram of a boosting isolation power supply.

Detailed Description

Exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be embodied in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

The first embodiment is as follows:

fig. 2 shows a schematic block diagram of an auxiliary power module for a bidirectional DC charger according to an embodiment of the present invention, where the auxiliary power module for the bidirectional DC charger includes an input terminal, a first output terminal and a second output terminal, where the input terminal is connected to an external power supply, the first output terminal is connected to an output terminal of a DC/DC circuit to provide an insulation detection voltage for the bidirectional DC charger, the second output terminal is connected to an anode of a diode D2, and a cathode of the diode D2 is connected to an auxiliary power VCC2 of the DC/DC circuit to provide auxiliary power for reverse operation of the DC/DC circuit.

It should be noted that, in the reverse off-grid mode, the power-level DC/DC circuit is not required to output the insulation detection voltage required by the electric vehicle, but the auxiliary power module directly provides the insulation detection voltage, after the scheme of the auxiliary power module is fixed, the no-load loss is also basically fixed, the auxiliary power module of the system control circuit and the DC/DC circuit is relatively fixed in power, and the requirement on the external power is significantly reduced.

Furthermore, the selection of the auxiliary power supply control chip is more and more flexible, and the no-load loss of the control chip is lower if a frequency hopping working mode is adopted.

Further, as shown in fig. 3, in this embodiment, the auxiliary power module is configured as a boost isolation power supply, the boost isolation power supply includes two flyback circuits, the two flyback circuits are configured as a first flyback circuit and a second flyback circuit, an output terminal of the first flyback circuit is configured as a first output terminal, and an output terminal of the second flyback circuit is configured as a second output terminal.

Furthermore, the boost isolation power supply comprises a first flyback circuit, the first output end is connected with the first flyback circuit, and the second output end is connected with a battery of the electric automobile.

Specifically, the external power supply voltage employed in the present embodiment is 12V.

Specifically, in this embodiment, the first PWM controller, the second PWM controller, and the third PWM controller may be implemented by a controller in the power module control circuit, or implemented by a controller in the system control circuit, or implemented by a common auxiliary power supply analog control chip, which is not limited to this.

Specifically, as shown in fig. 3, the PWM controller 1 is configured as a first PWM controller, the PWM controller 2 is configured as a second PWM controller, and the PWM controller 3 is configured as a third PWM controller.

The working principle of the embodiment is as follows:

in the forward charging and reverse grid-connected modes, the auxiliary power supply of the power supply module can take electricity from the bus voltage output end VBUS and provides the required auxiliary power supply for the power supply module after isolated output; the auxiliary power supply of the system control circuit is provided by a system power supply auxiliary power supply, the power supply gets power from an alternating current side power grid and provides a required auxiliary power supply for the system control circuit after isolated output, and under the two working modes, an external power supply does not need to provide energy, and the boosting isolation power supply is controlled by the system control circuit to be in an inoperative state;

in the reverse off-grid mode, because the voltage of the power grid at the alternating current side is disconnected, the battery of the electric automobile is also in a disconnected state before the bidirectional direct current charger completes insulation detection, and therefore, before the bidirectional direct current charger obtains energy from the battery of the electric automobile, the energy is provided by an external power supply;

an external power supply is directly connected to the system control circuit through a diode D1 and provides energy for the system control circuit, so that the bidirectional direct current charger can realize communication transmission with the electric automobile, and an output voltage value required by the electric automobile for insulation detection of the bidirectional direct current charger and other relevant information of the automobile end or the battery of the electric automobile are obtained;

after the system control circuit obtains the normal work of an external power supply, the PWM controller 3 can firstly output a signal to the booster circuit through a control signal to enable the booster circuit to start working, the booster circuit starts working according to the output voltage V1 set in a hardware circuit to complete the establishment of the output voltage V1, and the set value of the output voltage V1 can be designed according to actual needs, such as 48V, 60V and the like;

further, the system control circuit enables the PWM controller 1 to output signals to the first flyback circuit through the control signals to enable the first flyback circuit to start working, the output voltage of the first flyback circuit is a voltage value Vo required by the electric automobile, insulation detection voltages required by different electric automobiles due to different battery voltages are different, an output voltage command can be set by the system control circuit, after the Vo voltage is built, the system control circuit starts insulation detection, if the insulation detection is passed, the system control circuit enables the PWM controller 1 to stop outputting signals through the control signals, the Vo output is closed, the electric automobile is informed that the insulation detection is completed, and the electric automobile is required to close the high-voltage direct current contactor K1 at the automobile end.

Further, the system control circuit makes the PWM controller 2 output a signal to the second flyback circuit through a control signal to start its operation, and its output voltage is an auxiliary power supply voltage required by the DC/DC circuit in reverse operation, and is connected to VCC2 through a bypass diode D2 to prepare conditions for the DC/DC circuit in reverse operation.

The system control circuit communicates with the power module control circuit and requires closing of the output terminal high voltage direct current contactor K1, at which time the battery voltage of the electric vehicle is connected to the output terminal Vo of the DC/DC circuit, the DC/DC circuit starts to work in reverse to complete the establishment of the bus voltage output terminal VBUS, when the VBUS outputs according to the target voltage, the auxiliary power supply of the power supply module works, the auxiliary power supply of the AC/DC circuit and the DC/DC circuit of the power supply module is provided by the auxiliary power supply of the power supply module, then the AC/DC circuit starts to work reversely to complete the establishment of the AC side voltage, after the AC side voltage is established, the system controls the auxiliary power supply to start working, and the system control circuit can make the PWM controller 2 and the PWM controller 3 stop outputting signals through the control signals, and the external power supply does not need to provide energy for the bidirectional charger any more.

Example two:

the embodiment provides an auxiliary power supply module for a bidirectional direct-current charger, which comprises a first auxiliary power supply and a second auxiliary power supply, wherein the input end of the first auxiliary power supply is connected with an external power supply, the output end of the first auxiliary power supply is connected with the output end of a DC/DC circuit to provide insulation detection voltage for the bidirectional direct-current charger, the input end of the second auxiliary power supply is connected with a battery of an electric automobile, and the output end of the second auxiliary power supply is connected with a DC/DC circuit for auxiliary power supply VCC2 or a bus voltage output end VBUS to provide auxiliary power supply for the DC/DC circuit during reverse work.

The working principle of the embodiment is as follows:

the working principle of the embodiment is basically the same as that of the first embodiment, except that the second auxiliary power supply input end is connected with a battery of the electric automobile, and after insulation detection is passed, the electric automobile closes the high-voltage direct-current contactor K1 at the automobile end, so that the second auxiliary power supply is powered on;

when the output end of the second auxiliary power supply is connected with a bus voltage output end VBUS of the DC/DC circuit, the establishment of the bus voltage output end VBUS is completed after the second auxiliary power supply is electrified, when the VBUS is output according to a target voltage, the auxiliary power supply of the power module works, so that the auxiliary power supply VCC2 of the DC/DC circuit is electrified, the auxiliary power supplies of the AC/DC circuit and the DC/DC circuit of the power module are both provided by the auxiliary power supply, then the AC/DC circuit starts to work reversely, the establishment of the voltage at the alternating current side is completed, and after the voltage at the alternating current side is established, the system controls the auxiliary power supply to start working and starts to provide energy for the system control circuit, so that the bidirectional power supply is realized;

when the output end of the second auxiliary power supply is connected with the DC/DC circuit auxiliary power supply VCC2, and the second auxiliary power supply is electrified, the DC/DC circuit auxiliary power supply VCC2 is electrified, at the moment, the power supply module auxiliary power supply works, and further, the DC/DC circuit bus voltage output end VBUS is electrified, and further, the AC/DC circuit starts to work reversely, so that the establishment of the voltage of the alternating current side is completed, and after the voltage of the alternating current side is established, the system control auxiliary power supply starts to work, and starts to provide energy for the system control circuit, so that the bidirectional power supply is realized.

In summary, the auxiliary power scheme of the present invention has more general applicability, and the applicable scheme system is more various and is not affected by the system architecture, power class and topology of the DC/DC circuit.

Any process or method descriptions in flow charts or otherwise described herein may be understood as representing modules, segments, or portions of code which include one or more executable instructions for implementing specific logical functions or steps of the process, and alternate implementations are included within the scope of the preferred embodiment of the present invention in which functions may be executed out of order from that shown or discussed, including substantially concurrently or in reverse order, depending on the functionality involved, as would be understood by those reasonably skilled in the art of the present invention.

It will be understood by those skilled in the art that all or part of the steps carried by the method for implementing the above embodiments may be implemented by hardware that is related to instructions of a program, and the program may be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

In the description herein, references to the description of the term "one embodiment," "some embodiments," "an example," "a specific example," or "some examples," etc., mean that a particular feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of the utility model. In this specification, the schematic representations of the terms used above do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

The above examples are only for describing the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention, and various modifications and improvements made to the technical solution of the present invention by those skilled in the art without departing from the spirit of the present invention should fall within the protection scope defined by the claims of the present invention.

Claims

1. An auxiliary power supply module for a bidirectional direct current charger, comprising:

the input end is connected with an external power supply;

2. The auxiliary power module for a bidirectional dc charger according to claim 1, wherein the auxiliary power module is configured as a boost isolated power, the boost isolated power includes two flyback circuits, the two flyback circuits are configured as a first flyback circuit and a second flyback circuit, an output terminal of the first flyback circuit is configured as a first output terminal, and an output terminal of the second flyback circuit is configured as a second output terminal.

3. The auxiliary power supply module for the bidirectional direct current charger according to claim 2, wherein one end of the primary coil of the first flyback circuit is connected to an anode of an external power supply, the other end of the primary coil of the first flyback circuit is connected to a drain of a switching tube Q2, a source of the switching tube Q2 is grounded, a gate of the switching tube Q2 is connected to an output end of the first PWM controller, and a secondary coil of the first flyback circuit outputs a voltage value required for insulation detection through the rectifying circuit.

4. The auxiliary power supply module for the bidirectional direct current charger according to claim 2, wherein one end of the primary coil of the second flyback circuit is connected to an anode of an external power supply, the other end of the primary coil of the second flyback circuit is connected to a drain of a switching tube Q3, a source of the switching tube Q3 is grounded, a gate of the switching tube Q3 is connected to an output end of the second PWM controller, and a secondary coil of the second flyback circuit outputs auxiliary power supply VCC2 required for reverse operation of the DC/DC circuit through a diode D2.

5. An auxiliary power supply module for a bidirectional DC charger according to claim 3 or 4, characterized in that the anode of the diode D1 is connected to the external power supply.

6. The auxiliary power supply module for the bidirectional direct current charger according to claim 2, wherein the boost isolation power supply further comprises a boost circuit, and the two flyback circuits are connected to the external power supply through the boost circuit.

7. An auxiliary power supply module for a bidirectional direct current charger, comprising: