Non-isolated DC converter, charging method, device and computer equipment

Abstract

The present invention discloses a non-isolated DC converter, a charging method, a device and a computer device. Among them, the converter includes: a first port, a second port, a third port, a first switch, a second switch, a third switch, a fourth switch, a pre-charge capacitor, an energy storage capacitor, a boost inductor, a freewheeling inductor, a first winding of a coupled inductor and a second winding of the coupled inductor. The present invention realizes the combined energy storage of a low-voltage battery and an energy storage device through the circuit structure of the converter, supports the reverse charging of the pre-charge capacitor at the power battery end by the energy storage device, achieves the purpose of reducing the number of reverse pre-charges of the low-voltage battery to improve the life of the low-voltage battery, and solves the technical problem that the life of the low-voltage battery decreases due to the need for reverse pre-charging of the low-voltage battery before charging the power battery.

Description

Technical Field

[0001] The present invention relates to the field of new energy vehicles, and in particular, to a non-isolated DC converter, a charging method, a device, and a computer device. Background Art

[0002] In the aspect of passenger vehicles, the development of new energy hydrogen fuel cells, pure electric, and hybrid vehicles has been greatly promoted. New energy vehicles generally have characteristics such as high and low voltage power consumption, large acceleration, and rapid speed increase. With the development of electric vehicles, there are more technical requirements for improving the charging and discharging and reverse pre-charging performance of DC converters, especially the response speed of DC converters is greatly tested under harsh working conditions.

[0003] At present, most of the DC converters of new energy vehicles adopt isolated converters in the full-bridge form, which have a large volume, mass, and number of switching tubes of the transformer. Using the transformer increases the volume, the drive circuit is complex, and the energy storage device is only a low-voltage battery, which is relatively single and cannot solve the impact of the rapid change of the terminal voltage of the power battery on the low-voltage battery; and when the battery is severely discharged, the starting function of the whole vehicle cannot be realized.

[0004] For the above problems, no effective solution has been proposed yet. Summary of the Invention

[0005] Embodiments of the present invention provide a non-isolated DC converter, a charging method, a device, and a computer device, so as to at least solve the technical problem that the service life of the low-voltage battery is reduced due to the need for reverse pre-charging by the low-voltage battery before charging the power battery.

[0006] According to one aspect of an embodiment of the present invention, a non-isolated DC converter is provided, including: a non-isolated DC / DC converter, characterized by including: a first port, a second port, a third port, a first switch, a second switch, a third switch, a fourth switch, a pre-charge capacitor, an energy storage capacitor, a boost inductor, a freewheeling inductor, a first winding of a coupled inductor, and a second winding of the coupled inductor; wherein, the positive electrode of the first port is respectively connected to the positive electrode of the energy storage device, the first switch, and the second switch, and the negative electrode is respectively connected to the negative electrode of the energy storage device, the first end of the first winding of the coupled inductor, and the negative electrode of the second port; the positive electrode of the second port is respectively connected to the positive electrode of the low-voltage battery and the first end of the freewheeling inductor, and the negative electrode is respectively connected to the negative electrode of the low-voltage battery, the negative electrode of the first port, and the first end of the first winding of the coupled inductor; the positive electrode of the third port is respectively connected to the positive electrode of the power battery, the first end of the pre-charge capacitor, and the first end of the boost inductor, and the negative electrode is respectively connected to the negative electrode of the power battery and the second end of the pre-charge capacitor; one end of the first switch is connected to the second switch and the positive electrode of the first port, and the other end is connected to the second end of the boost inductor, the first end of the energy storage capacitor, and the third switch; one end of the second switch is connected to the first switch and the positive electrode of the first port, and the other end is connected to the second end of the first winding of the coupled inductor, the second end of the energy storage capacitor, and the first end of the second winding of the coupled inductor; one end of the third switch is connected to the second end of the freewheeling inductor and the fourth switch, and the other end is connected to the second end of the boost inductor, the first switch, and the first end of the energy storage capacitor; one end of the fourth switch is connected to the third switch and the second end of the freewheeling inductor, and the other end is connected to the second end of the second winding of the coupled inductor.

[0007] Optionally, the first switch includes a first MOSFET, the second switch includes a second MOSFET, the third switch includes a third MOSFET, and the fourth switch includes a fourth MOSFET; wherein, the source of the first MOSFET is connected to the positive electrode of the first port and the drain of the second MOSFET, and the drain of the first MOSFET is connected to the second end of the boost inductor, the first end of the energy storage capacitor, and the drain of the third MOSFET; the source of the third MOSFET is connected to the drain of the fourth MOSFET and the second end of the freewheeling inductor; the source of the fourth MOSFET is connected to the first end of the second winding of the coupled inductor.

[0008] Optionally, the converter further includes: a filter capacitor, wherein a first end of the filter capacitor is connected to a positive electrode of the second port and a first end of the freewheeling inductor, and a second end of the filter capacitor is connected to a negative electrode of the first port and a first end of a first winding of the coupled inductor.

[0009] Optionally, the converter further includes: an energy storage device, wherein the energy storage device is configured to store electrical energy, a positive electrode thereof is connected to a positive electrode of the first port, and a negative electrode thereof is connected to a negative electrode of the first port.

[0010] Optionally, the energy storage device includes: an energy storage capacitor.

[0011] According to another aspect of an embodiment of the present invention, there is also provided a charging method, which is applied to the non-isolated DC / DC converter described in any one of the above, and includes: detecting a power state of a low-voltage storage battery and a power state of an energy storage device; when the low-voltage storage battery is out of power and the power of the energy storage device is not less than a first power threshold, controlling the energy storage device to charge the low-voltage storage battery; when the low-voltage storage battery is out of power and the power of the energy storage device is less than the first power threshold, controlling the energy storage device to charge a pre-charge capacitor until the pre-charge capacitor reaches a wake-up voltage; after the pre-charge capacitor reaches the wake-up voltage, controlling a power battery to charge the low-voltage storage battery.

[0012] Optionally, the controlling the energy storage device to charge the pre-charge capacitor until the pre-charge capacitor reaches a wake-up voltage includes: when the power of the energy storage device is less than a second power threshold, controlling the low-voltage storage battery and the energy storage device to jointly charge the pre-charge capacitor until the pre-charge capacitor reaches the wake-up voltage, wherein the second power threshold is less than the first power threshold.

[0013] According to another aspect of an embodiment of the present invention, there is also provided a charging device, including: a detection module, configured to detect a power state of a low-voltage storage battery and a power state of an energy storage device; a first control module, configured to control the energy storage device to charge the low-voltage storage battery when the low-voltage storage battery is out of power and the power of the energy storage device is not less than a first power threshold; a second control module, configured to control the energy storage device to charge a pre-charge capacitor until the pre-charge capacitor reaches a wake-up voltage when the low-voltage storage battery is out of power and the power of the energy storage device is less than the first power threshold; a third control module, configured to control a power battery to charge the low-voltage storage battery after the pre-charge capacitor reaches the wake-up voltage.

[0014] According to another aspect of the embodiments of the present invention, there is also provided a non-volatile storage medium, which includes a stored program. When the program runs, it controls the device where the non-volatile storage medium is located to execute the charging method described in any one of the above.

[0015] According to still another aspect of the embodiments of the present invention, there is also provided a computer device, which includes a processor for running a program. When the program runs, it executes the charging method described in any one of the above.

[0016] In the embodiments of the present invention, a converter circuit is constituted by multiple ports, multiple switches, a pre-charge capacitor, an energy storage capacitor, a boost inductor, a freewheeling inductor, a first winding of a coupling inductor, and a second winding of the coupling inductor. Through the circuit structure of this converter, combined energy storage of a low-voltage battery and an energy storage device is realized, and it supports reverse charging of the pre-charge capacitor at the power battery end by the energy storage device, achieving the purpose of reducing the number of reverse pre-charges of the low-voltage battery to improve the life of the low-voltage battery, thereby realizing the technical effect of improving the life of the low-voltage battery, and further solving the technical problem that the life of the low-voltage battery decreases due to reverse pre-charging by the low-voltage battery before charging the power battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] The drawings described herein are used to provide a further understanding of the present invention, and constitute a part of this application. The schematic embodiments of the present invention and their descriptions are used to explain the present invention, and do not constitute an improper limitation to the present invention. In the drawings:

[0018] Figure 1 is a structural block diagram of a non-isolated DC converter provided according to an embodiment of the present invention;

[0019] Figure 2 shows a hardware structural block diagram of a computer terminal for implementing the charging method;

[0020] Figure 3 is a schematic flowchart of the charging method provided according to an embodiment of the present invention;

[0021] Figure 4 is a schematic flowchart of the reverse pre-charge control method provided according to an optional embodiment of the present invention;

[0022] Figure 5 is a working waveform diagram of a DC converter provided according to an optional embodiment of the present invention;

[0023] Figure 6 is an equivalent circuit diagram of working mode Ⅰ of a DC converter provided according to an optional embodiment of the present invention;

[0024] Figure 7It is the equivalent circuit diagram of the working mode II of the DC converter provided by an alternative embodiment of the present invention;

[0025] Figure 8 It is the equivalent circuit diagram of the working mode III of the DC converter provided by an alternative embodiment of the present invention;

[0026] Figure 9 It is the equivalent circuit diagram of the working mode IV of the DC converter provided by an alternative embodiment of the present invention;

[0027] Figure 10 It is the structural block diagram of the charging device provided by an embodiment of the present invention. Detailed implementation manners

[0028] In order to enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0029] It should be noted that the terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so that the embodiments of the present invention described here can be implemented in an order other than those illustrated or described here. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0030] First, some nouns or terms that appear during the description of the embodiments of the present application are applicable to the following explanations:

[0031] A non-isolated DC converter, that is, a non-isolated DC / DC converter, is used to realize the conversion between high and low voltages of direct current.

[0032] Metal Oxide Semiconductor Field Effect Transistor (abbreviation: MOSFET), a type of field effect transistor widely used in analog circuits and digital circuits.

[0033] Figure 1 It is the structural block diagram of the non-isolated DC converter provided by an embodiment of the present invention, as Figure 1As shown, the non-isolated DC converter includes: a first port P1, a second port P2, a third port P3, a first switch S1, a second switch S2, a third switch S3, a fourth switch S4, a pre-charge capacitor C2, an energy storage capacitor C3, a boost inductor L1, a freewheeling inductor L3, a first winding L2 of a coupled inductor, and a second winding L4 of the coupled inductor. The non-isolated DC converter will be described below.

[0034] For the first port, the positive pole is respectively connected to the positive pole of the energy storage device, the first switch, and the second switch, and the negative pole is respectively connected to the negative pole of the energy storage device, the first end of the first winding of the coupled inductor, and the negative pole of the second port.

[0035] For the second port, the positive pole is respectively connected to the positive pole of the low-voltage battery and the first end of the freewheeling inductor, and the negative pole is respectively connected to the negative pole of the low-voltage battery, the negative pole of the first port, and the first end of the first winding of the coupled inductor.

[0036] For the third port, the positive pole is respectively connected to the positive pole of the power battery, the first end of the pre-charge capacitor, and the first end of the boost inductor, and the negative pole is respectively connected to the negative pole of the power battery and the second end of the pre-charge capacitor.

[0037] One end of the first switch is connected to the second switch and the positive pole of the first port, and the other end is connected to the second end of the boost inductor, the first end of the energy storage capacitor, and the third switch.

[0038] One end of the second switch is connected to the first switch and the positive pole of the first port, and the other end is connected to the second end of the first winding of the coupled inductor, the second end of the energy storage capacitor, and the first end of the second winding of the coupled inductor.

[0039] One end of the third switch is connected to the second end of the freewheeling inductor and the fourth switch, and the other end is connected to the second end of the boost inductor, the first switch, and the first end of the energy storage capacitor.

[0040] One end of the fourth switch is connected to the third switch and the second end of the freewheeling inductor, and the other end is connected to the second end of the second winding of the coupled inductor.

[0041] It should be noted that the working voltage of the power battery of an electric vehicle is usually between 400 and 800V, and the working voltage of the low-voltage battery is usually between 10 and 20V. Therefore, when the low-voltage battery is out of power, the power battery and the low-voltage battery cannot be directly connected to the same circuit, otherwise the low-voltage battery will be damaged. Therefore, in the DC / DC converter provided in this embodiment, when the power battery needs to charge the low-voltage battery with insufficient power, it is necessary to first keep the power battery out of the circuit, and charge the pre-charge capacitor at the power battery end through an electrical energy source other than the power battery. After the pre-charge capacitor reaches the working state, the power battery is then connected to the circuit to charge the low-voltage battery. In the above process, the low-voltage battery usually charges the pre-charge capacitor, and this process is called reverse pre-charging. However, if the low-voltage battery performs the reverse pre-charging operation before each charge, the charge and discharge frequency of the low-voltage battery is relatively high, which will reduce the life of the low-voltage battery.

[0042] Based on the above structure proposed in this embodiment, it is possible to support the reverse charging of the pre-charge capacitor at the power battery end by the energy storage device, achieving the purpose of reducing the number of reverse pre-charges of the low-voltage battery to improve the life of the low-voltage battery, thereby achieving the technical effect of improving the life of the low-voltage battery, and further solving the technical problem that the life of the low-voltage battery decreases due to the need for reverse pre-charging by the low-voltage battery before charging with the power battery.

[0043] As an alternative embodiment, the DC converter may further include an energy storage device, where the energy storage device is used to store electrical energy, the positive electrode is connected to the positive electrode of the first port, and the negative electrode is connected to the negative electrode of the first port. In this alternative embodiment, the energy storage device can be used as a part of the DC converter. The energy storage device stores electrical energy in advance. When reverse charging of the pre-charge capacitor is required, the switch state in the circuit can be changed to control the energy storage device to directly charge the pre-charge capacitor, or control the energy storage device and the low-voltage battery to jointly charge the pre-charge capacitor. Even when the electrical energy in the energy storage device is sufficient, the energy storage device can directly charge the low-voltage battery, greatly reducing the reverse pre-charge frequency of the low-voltage battery and achieving the technical effect of improving the life of the low-voltage battery. As an alternative embodiment, the energy storage device can use an energy storage capacitor.

[0044] As an alternative embodiment, the converter may further include a filter capacitor C1, where the first end of the filter capacitor is connected to the positive electrode of the second port and the first end of the freewheeling inductor, and the second end of the filter capacitor is connected to the negative electrode of the first port and the first end of the first winding of the coupling inductor. As Figure 1 shown, the filter capacitor can be used to reduce the spikes in the voltage when the low-voltage battery reversely charges the pre-charge capacitor, playing a role in smooth filtering.

[0045] As an alternative embodiment, the first switch may include a first MOSFET, the second switch may include a second MOSFET, the third switch may include a third MOSFET, and the fourth switch may include a fourth MOSFET. Among them, the source of the first MOSFET is connected to the positive pole of the first port and the drain of the second MOSFET, and the drain of the first MOSFET is connected to the second end of the boost inductor, the first end of the energy storage capacitor, and the drain of the third MOSFET. The source of the third MOSFET is connected to the drain of the fourth MOSFET and the second end of the freewheeling inductor. The source of the fourth MOSFET is connected to the first end of the second winding of the coupled inductor. Optionally, Figure 1 A specific embodiment showing a connection manner of the first MOSFET to the fourth MOSFET is shown.

[0046] According to an embodiment of the present invention, an embodiment of a charging method is provided. It should be noted that the steps shown in the flowchart of the accompanying drawings can be executed in a computer system such as a set of computer-executable instructions. And although the logical order is shown in the flowchart, in some cases, the steps shown or described can be executed in a different order than here.

[0047] The method embodiment provided in the first embodiment of the present application can be executed in a mobile terminal, a computer terminal, or a similar computing device. Figure 2 A hardware structure block diagram of a computer terminal for implementing a charging method is shown. As Figure 2 shown, the computer terminal 20 may include one or more (shown as 202a, 202b,..., 202n in the figure) processors (the processor may include, but is not limited to, a processing device such as a microprocessor MCU or a programmable logic device FPGA), and a memory 204 for storing data. In addition, it may further include: a display, an input / output interface (I / O interface), a universal serial bus (USB) port (which may be included as one of the ports of the BUS bus), a network interface, a power supply, and / or a camera. Those of ordinary skill in the art can understand that Figure 2 the structure shown is only schematic and does not limit the structure of the above-mentioned electronic device. For example, the computer terminal 20 may further include more or fewer components than Figure 2 shown in the figure, or have a different configuration from Figure 2 shown in the figure.

[0048] It should be noted that one or more of the above-mentioned processors and / or other data processing circuits can generally be referred to as "data processing circuits" herein. The data processing circuit can be embodied in software, hardware, firmware, or any combination thereof, either in whole or in part. In addition, the data processing circuit can be a single independent processing module, or be incorporated in whole or in part into any one of the other elements in the computer terminal 20. As involved in the embodiments of the present application, the data processing circuit is a kind of processor control (such as the selection of a variable resistor terminal path connected to an interface).

[0049] The memory 204 can be used to store software programs and modules of application software, such as the program instructions / data storage devices corresponding to the charging method in the embodiments of the present invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory 204, that is, to implement the charging method of the above-mentioned application program. The memory 204 can include a high-speed random access memory, and can also include a non-volatile memory, such as one or more magnetic storage devices, flash memory, or other non-volatile solid-state memories. In some instances, the memory 204 can further include a memory remotely set relative to the processor, and these remote memories can be connected to the computer terminal 20 through a network. Examples of the above-mentioned network include but are not limited to the Internet, enterprise intranet, local area network, mobile communication network, and combinations thereof.

[0050] The display can be, for example, a touch-screen liquid crystal display (LCD), which enables the user to interact with the user interface of the computer terminal 20.

[0051] Figure 3 is a schematic flowchart of the charging method provided according to the embodiments of the present invention, and this method can be applied to the non-isolated DC converter described in any of the above-mentioned embodiments or alternative embodiments. As Figure 3 shown, the method includes the following steps:

[0052] Step S302, detect the power state of the low-voltage battery and the power state of the energy storage device.

[0053] Step S304, when the low-voltage battery is out of power and the power of the energy storage device is not less than the first power threshold, control the energy storage device to charge the low-voltage battery.

[0054] Step S306, when the low-voltage battery is out of power and the power of the energy storage device is less than the first power threshold, control the energy storage device to charge the pre-charge capacitor until the pre-charge capacitor reaches the wake-up voltage.

[0055] Step S308, after the pre-charge capacitor reaches the wake-up voltage, control the power battery to charge the low-voltage battery.

[0056] It should be noted that in the case where the energy storage device is an energy storage capacitor, the first power threshold can also be referred to as the minimum charging voltage. When the voltage of the energy storage capacitor is greater than the minimum charging voltage, the electric energy stored in the energy storage capacitor is sufficient to first fully charge the low-voltage battery and then supplement the voltage of the pre-charge capacitor to the wake-up voltage. When the power of the energy storage device is less than the first power threshold, or the voltage of the energy storage capacitor is less than the minimum charging voltage, the electric energy of the energy storage capacitor is not sufficient to supplement the electric energy for the low-voltage battery and the pre-charge capacitor entirely by itself. At this time, the energy storage capacitor can fully charge the pre-charge capacitor until the pre-charge capacitor reaches the wake-up voltage, and then the power battery can be connected to the circuit to charge the low-voltage battery and / or the energy storage device.

[0057] Through the above steps, it is possible to support the reverse charging of the pre-charge capacitor at the power battery end by the energy storage device, achieving the purpose of reducing the number of reverse pre-charges of the low-voltage battery to improve the life of the low-voltage battery, thereby achieving the technical effect of improving the life of the low-voltage battery, and further solving the technical problem that the life of the low-voltage battery decreases due to the need for reverse pre-charging by the low-voltage battery before charging the power battery.

[0058] As an optional embodiment, controlling the energy storage device to charge the pre-charge capacitor until the pre-charge capacitor reaches the wake-up voltage may include the following steps: When the power of the energy storage device is less than the second power threshold, control the low-voltage battery and the energy storage device to jointly charge the pre-charge capacitor until the pre-charge capacitor reaches the wake-up voltage, where the second power threshold is less than the first power threshold.

[0059] It should be noted that in the case where the energy storage device is an energy storage capacitor, the second power threshold can also be referred to as the minimum wake-up voltage. When the power of the energy storage device is less than the second power threshold, or the voltage of the energy storage capacitor is less than the minimum wake-up voltage, the energy storage device or the energy storage capacitor can jointly charge the pre-charge capacitor with the low-voltage battery until the pre-charge capacitor is charged to the rated voltage, and then the power battery can be connected to the circuit to jointly charge the energy storage device and the low-voltage battery.

[0060] Figure 4 is a schematic flowchart of the reverse pre-charge control method provided by an optional embodiment of the present invention, where the battery is the above-mentioned low-voltage battery, the super capacitor is the above-mentioned energy storage capacitor, and V bat represents the voltage of the low-voltage battery, and V ca represents the voltage of the energy storage capacitor.

[0061] Such as Figure 4As shown, this energy conversion strategy can achieve the reverse pre-charging function and reduce the frequency of frequently applying high-voltage power to charge the low-voltage battery due to reverse pre-charging, reduce the number of times of repeatedly applying high-voltage power, and charge the pre-charge capacitor through the super capacitor to reduce the working times of the low-voltage battery and improve the service life of the low-voltage battery.

[0062] Specifically, when it is detected that the voltage of the low-voltage battery is within the normal working range, the entire vehicle of the electric vehicle can maintain the normal power-off state; when it is detected that the low-voltage battery is out of power and the voltage of the super capacitor is not less than the minimum charging voltage, by controlling the energy conversion between the first port and the second port in the DC converter, the super capacitor charges the low-voltage battery to 14V to ensure that the voltage of the low-voltage battery is within the normal working range; when it is detected that the low-voltage battery is out of power and the voltage of the super capacitor is greater than the minimum wake-up voltage and less than the minimum charging voltage, for the purpose of charging the low-voltage battery and the super capacitor, the super capacitor can be used to charge the pre-charge capacitor to wake up the entire vehicle, and energy transfer is realized by connecting the third port of the power battery to the first port where the super capacitor is located and the second port corresponding to the low-voltage battery, so that the super capacitor is charged to the rated voltage and the low-voltage battery is charged to 14V; when it is detected that the low-voltage battery is out of power and the voltage of the super capacitor is less than the minimum wake-up voltage, the low-voltage battery and the super capacitor are jointly used to charge the pre-charge capacitor to wake up the entire vehicle, and electrical energy is transferred from the third port connected to the power battery to the first port and the second port, so that the super capacitor is charged to the rated voltage and the low-voltage battery is charged to 14V.

[0063] Figure 5 is the working waveform diagram of the DC converter provided according to an optional embodiment of the present invention, Figure 5 shows the driving waveform and the current of the inductor L1 the current of the first winding L2 of the coupled inductor the current of the freewheeling inductor L3 the current of the second winding L4 of the coupled inductor changing waveforms.

[0064] Figure 6It is the equivalent circuit diagram of the working mode I of the DC converter provided according to an alternative embodiment of the present invention. As shown in Figure 6, when the converter operates in the time period [t0 - t1], the switching transistor S1 turns from off to on, the switching transistor S2 turns from on to off, the switching transistor S3 remains in the on state, and the switching transistor S4 remains in the off state. At this time, the supercapacitor port charges the intermediate energy storage capacitor C3 through the power switching transistor S1 and the first winding L2 of the coupled inductor, the freewheeling inductor L1 charges the power battery port, and at the same time, the low-voltage battery port charges the intermediate energy storage capacitor C3 through the freewheeling inductor L3 and the power switch S3.

[0065] Figure 7 It is the equivalent circuit diagram of the working mode II of the DC converter provided according to an alternative embodiment of the present invention. As Figure 7 shown, when the converter operates in the time period [t1 - t2], the switching transistor S1 remains in the on state, the switching transistor S2 remains in the off state, the switching transistor S3 turns from the on state to the off state, and the switching transistor S4 turns from the off state to the on state. At this time, the supercapacitor port charges the intermediate energy storage capacitor C3 through the power switching transistor S1 and the first winding L2 of the coupled inductor, the freewheeling inductor L1 charges the power battery port, and at the same time, the low-voltage battery port charges the first winding L2 and the second winding L4 of the coupled inductor through the freewheeling inductor L3, the second winding L4 of the coupled inductor, and the power switching transistor S4.

[0066] Figure 8 It is the equivalent circuit diagram of the working mode III of the DC converter provided according to an alternative embodiment of the present invention. As Figure 8 shown, when the converter operates in the time period [t2 - t3], the switching transistor S1 turns from the on state to the off state, the switching transistor S2 turns from the off state to the on state, the switching transistor S3 remains in the off state, and the switching transistor S4 remains in the on state. At this time, the supercapacitor port charges the first winding L2 of the coupled inductor through the power switching transistor S1, the freewheeling inductor L1 and the intermediate energy storage capacitor C3 charge the power battery port, and at the same time, the low-voltage battery port charges the first winding L2 and the second winding L4 of the coupled inductor through the freewheeling inductor L3, the second winding L4 of the coupled inductor, and the power switching transistor S4.

[0067] Figure 9 It is the equivalent circuit diagram of the working mode IV of the DC converter provided according to an alternative embodiment of the present invention. As Figure 9As shown, when the converter operates in the time period [t3 - t4], the switch S1 remains off, the switch S2 remains on, the switch S3 changes from the off state to the on state, and the switch S4 changes from the on state to the off state. At this time, the supercapacitor port charges the first winding L2 of the coupled inductor through the power switch S1, the freewheeling inductor L1 and the intermediate energy storage capacitor C3 charge the power battery port, and at the same time, the low-voltage battery port supplements energy to the intermediate energy storage capacitor through the freewheeling inductor L3, the power switch S3, and the first winding L2 of the coupled inductor.

[0068] Based on the working states of the conduction circuits of the switches in each working mode and the volt-second balance principle, the relationships between the voltages of each device can be listed as follows:

[0069]

[0070] Among them, V in represents the voltage of the power battery, V cap represents the voltage of the energy storage device, V bat represents the voltage of the low-voltage battery.

[0071] Through formula rearrangement, the voltage gain relationships between each port can be obtained as follows:

[0072]

[0073] From the relationships between the voltage gains of each port, it can be seen that the voltage gain from the low-voltage battery port to the power battery port can achieve a change with a high gain by adjusting the coupling coefficient, the turns ratio of the coupled inductor, and the duty cycle control, which can meet the basic functions of the on-vehicle DC / DC converter and provide support for the energy transfer of the multi-port hybrid energy storage system.

[0074] It should be noted that for the foregoing method embodiments, for the sake of simple description, they are all expressed as a series of action combinations. However, those skilled in the art should know that the present invention is not limited by the described action sequence, because according to the present invention, certain steps can be performed in other sequences or simultaneously. Secondly, those skilled in the art should also know that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily essential to the present invention.

[0075] Through the description of the above embodiments, those skilled in the art can clearly understand that the charging method according to the above embodiments can be implemented by means of software plus a necessary general hardware platform. Of course, it can also be implemented by hardware. However, in many cases, the former is a better implementation method. Based on such an understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art can be embodied in the form of a software product. The computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions for causing a terminal device (which can be a mobile phone, computer, server, or network device, etc.) to execute the methods of the various embodiments of the present invention.

[0076] According to an embodiment of the present invention, there is also provided a charging device for implementing the above charging method. Figure 10 It is a structural block diagram of the charging device provided according to an embodiment of the present invention, as Figure 10 shown. The charging device includes: a detection module 1002, a first control module 1004, a second control module 1006, and a third control module 1008. The charging device will be described below.

[0077] The detection module 1002 is used to detect the power state of the low-voltage battery and the power state of the energy storage device.

[0078] The first control module 1004 is used to control the energy storage device to charge the low-voltage battery when the low-voltage battery is out of power and the power of the energy storage device is not less than the first power threshold.

[0079] The second control module 1006 is used to control the energy storage device to charge the pre-charge capacitor until the pre-charge capacitor reaches the wake-up voltage when the low-voltage battery is out of power and the power of the energy storage device is less than the first power threshold.

[0080] The third control module 1008 is used to control the power battery to charge the low-voltage battery after the pre-charge capacitor reaches the wake-up voltage.

[0081] It should be noted here that the above detection module 1002, first control module 1004, second control module 1006, and third control module 1008 correspond to steps S302 to S308 in the embodiment. The instances and application scenarios implemented by the multiple modules and the corresponding steps are the same, but are not limited to the content disclosed in the above embodiments. It should be noted that the above modules, as part of the device, can run in the computer terminal 10 provided in the embodiment.

[0082] An embodiment of the present invention can provide a computer device. Optionally, in this embodiment, the above computer device can be at least one network device among multiple network devices in a computer network. The computer device includes a memory and a processor.

[0083] Among them, the memory can be used to store software programs and modules, such as the program instructions / modules corresponding to the charging method and device in the embodiments of the present invention. The processor executes various functional applications and data processing by running the software programs and modules stored in the memory, that is, the above-mentioned charging method is implemented. The memory may include a high-speed random access memory, and may also include a non-volatile memory, such as one or more magnetic storage devices, flash memories, or other non-volatile solid-state memories. In some instances, the memory may further include a memory remotely set relative to the processor, and these remote memories can be connected to the computer terminal through a network. Examples of the above network include but are not limited to the Internet, enterprise intranet, local area network, mobile communication network, and combinations thereof.

[0084] The processor can call the information and application programs stored in the memory through the transmission device to perform the following steps: detecting the power state of the low-voltage battery and the power state of the energy storage device; controlling the energy storage device to charge the low-voltage battery when the low-voltage battery is out of power and the power of the energy storage device is not less than the first power threshold; controlling the energy storage device to charge the pre-charge capacitor until the pre-charge capacitor reaches the wake-up voltage when the low-voltage battery is out of power and the power of the energy storage device is less than the first power threshold; and controlling the power battery to charge the low-voltage battery after the pre-charge capacitor reaches the wake-up voltage.

[0085] Those of ordinary skill in the art can understand that all or part of the steps in the various methods of the above embodiments can be completed by instructing the relevant hardware of the terminal device through a program, and this program can be stored in a non-volatile storage medium. The storage medium can include: flash drive, read-only memory (ROM), random access memory (RAM), magnetic disk or optical disk, etc.

[0086] The embodiments of the present invention also provide a non-volatile storage medium. Optionally, in this embodiment, the above non-volatile storage medium can be used to save the program code executed by the charging method provided in the above embodiments.

[0087] Optionally, in this embodiment, the above non-volatile storage medium can be located in any one of the computer terminals in the computer terminal group in the computer network, or in any one of the mobile terminals in the mobile terminal group.

[0088] Optionally, in this embodiment, the non-volatile storage medium is configured to store program code for performing the following steps: detecting the power state of the low-voltage battery and the power state of the energy storage device; controlling the energy storage device to charge the low-voltage battery when the low-voltage battery is out of power and the power of the energy storage device is not less than the first power threshold; controlling the energy storage device to charge the pre-charge capacitor until the pre-charge capacitor reaches the wake-up voltage when the low-voltage battery is out of power and the power of the energy storage device is less than the first power threshold; and controlling the power battery to charge the low-voltage battery after the pre-charge capacitor reaches the wake-up voltage.

[0089] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0090] In the above embodiments of the present invention, the descriptions of the respective embodiments have their own emphases. For the parts not detailed in a certain embodiment, reference may be made to the relevant descriptions of other embodiments.

[0091] In the several embodiments provided by the present application, it should be understood that the disclosed technical content can be implemented in other ways. Among them, the device embodiments described above are only illustrative. For example, the division of the units can be a logical function division. In actual implementation, there may be other division methods. For example, multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the displayed or discussed couplings or direct couplings or communication connections to each other can be through some interfaces. The indirect couplings or communication connections of the units or modules can be in electrical or other forms.

[0092] The units described as separate components may or may not be physically separated. The components displayed as units may or may not be physical units, that is, they can be located in one place or distributed to multiple units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0093] In addition, the functional units in the various embodiments of the present invention can be integrated into one processing unit, or each unit can exist physically alone, or two or more units can be integrated into one unit. The above integrated units can be implemented in the form of hardware or in the form of software functional units.

[0094] When the integrated unit is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a non-volatile storage medium. Based on this understanding, the technical solution of the present invention, in essence, or the part that contributes to the prior art, or all or part of the technical solution, can be embodied in the form of a software product. The computer software product is stored in a storage medium and includes several instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present invention. The aforementioned storage medium includes: various media such as USB flash drives, read-only memories (ROMs), random access memories (RAMs), mobile hard disks, magnetic disks, or optical discs that can store program codes.

[0095] The above are only the preferred embodiments of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements can be made, and these improvements and refinements should also be regarded as the protection scope of the present invention.

Claims

1. A non-isolated DC converter, characterized in that, Comprising: A first port, a second port, a third port, a first switch, a second switch, a third switch, a fourth switch, a pre-charge capacitor, an energy storage capacitor, a boost inductor, a freewheeling inductor, a first winding of a coupled inductor, and a second winding of the coupled inductor; wherein, The positive pole of the first port is respectively connected to the positive pole of the energy storage device, the first switch, and the second switch, and the negative pole is respectively connected to the negative pole of the energy storage device, the first end of the first winding of the coupled inductor, and the negative pole of the second port; The positive pole of the second port is respectively connected to the positive pole of the low-voltage battery and the first end of the freewheeling inductor, and the negative pole is respectively connected to the negative pole of the low-voltage battery, the negative pole of the first port, and the first end of the first winding of the coupled inductor; The positive pole of the third port is respectively connected to the positive pole of the power battery, the first end of the pre-charge capacitor, and the first end of the boost inductor, and the negative pole is respectively connected to the negative pole of the power battery and the second end of the pre-charge capacitor; One end of the first switch is connected to the second switch and the positive pole of the first port, and the other end is connected to the second end of the boost inductor, the first end of the energy storage capacitor, and the third switch; One end of the second switch is connected to the first switch and the positive pole of the first port, and the other end is connected to the second end of the first winding of the coupled inductor, the second end of the energy storage capacitor, and the first end of the second winding of the coupled inductor; One end of the third switch is connected to the second end of the freewheeling inductor and the fourth switch, and the other end is connected to the second end of the boost inductor, the first switch, and the first end of the energy storage capacitor; One end of the fourth switch is connected to the third switch and the second end of the freewheeling inductor, and the other end is connected to the second end of the second winding of the coupled inductor.

2. The converter according to claim 1, characterized in that The first switch includes a first MOSFET, the second switch includes a second MOSFET, the third switch includes a third MOSFET, and the fourth switch includes a fourth MOSFET; wherein, the source of the first MOSFET is connected to the positive pole of the first port and the drain of the second MOSFET, and the drain of the first MOSFET is connected to the second end of the boost inductor, the first end of the energy storage capacitor, and the drain of the third MOSFET; the source of the third MOSFET is connected to the drain of the fourth MOSFET and the second end of the freewheeling inductor; the source of the fourth MOSFET is connected to the first end of the second winding of the coupled inductor.

3. The converter according to claim 1, characterized in that The converter further includes: a filter capacitor, wherein the first end of the filter capacitor is connected to the positive pole of the second port and the first end of the freewheeling inductor, and the second end of the filter capacitor is connected to the negative pole of the first port and the first end of the first winding of the coupled inductor.

4. The converter according to claim 1, characterized in that, The converter further includes: an energy storage device, wherein the energy storage device is used for storing electrical energy, the positive pole is connected to the positive pole of the first port, and the negative pole is connected to the negative pole of the first port.

5. The converter according to claim 4, characterized in that, The energy storage device includes: an energy storage capacitor.

6. A charging method, characterized in that, The method is applied to the non-isolated DC converter described in any one of claims 1 to 5, and includes: Detecting the power state of the low-voltage battery and the power state of the energy storage device; When the low-voltage battery is out of power and the power of the energy storage device is not less than the first power threshold, controlling the energy storage device to charge the low-voltage battery; When the low-voltage battery is out of power and the power of the energy storage device is less than the first power threshold, controlling the energy storage device to charge the pre-charge capacitor until the pre-charge capacitor reaches the wake-up voltage; After the pre-charge capacitor reaches the wake-up voltage, controlling the power battery to charge the low-voltage battery.

7. The method according to claim 6, wherein The controlling the energy storage device to charge the pre-charge capacitor until the pre-charge capacitor reaches the wake-up voltage includes: When the power of the energy storage device is less than the second power threshold, controlling the low-voltage battery and the energy storage device to jointly charge the pre-charge capacitor until the pre-charge capacitor reaches the wake-up voltage, where the second power threshold is less than the first power threshold.

8. A charging device, characterized in that, The device is applied to the non-isolated DC converter described in any one of claims 1 to 5, and includes: A detection module for detecting the power state of the low-voltage battery and the power state of the energy storage device; A first control module for controlling the energy storage device to charge the low-voltage battery when the low-voltage battery is out of power and the power of the energy storage device is not less than the first power threshold; A second control module for controlling the energy storage device to charge the pre-charge capacitor until the pre-charge capacitor reaches the wake-up voltage when the low-voltage battery is out of power and the power of the energy storage device is less than the first power threshold; A third control module for controlling the power battery to charge the low-voltage battery after the pre-charge capacitor reaches the wake-up voltage.

9. A non-volatile storage medium, characterized in that, The non-volatile storage medium includes a stored program, wherein when the program runs, it controls the device where the non-volatile storage medium is located to execute the charging method described in any one of claims 6 to 7.

10. A computer device, characterized in that, The computer device includes a processor, and the processor is used to run a program, wherein when the program runs, it executes the charging method described in any one of claims 6 to 7.

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