DCDC converter and control method

Abstract

Provided are a DCDC converter and a control method. The DCDC converter comprises one or more DCDC conversion modules (10), which are connected in parallel between a battery pack having a rated voltage of a first value and a direct-current charging pile having an output voltage of a second value, wherein the first value is greater than the second value, and the DCDC converter is further connected to a main control chip (20). The direct-current charging pile is used for charging the battery pack, a first transceiving end of each DCDC conversion module is connected to the direct-current charging pile, and a second transceiving end thereof is connected to the battery pack. The DCDC conversion module is used for bucking a voltage signal that flows to the direct-current charging pile and boosting a voltage that flows to the battery pack, and in this way, a direct-current output of the direct-current charging pile can be converted by means of the DCDC converter, and then the battery pack is charged.

Description

A DCDC converter and control method Technical Field

[0001] The present invention relates to the field of electrical technology, and in particular to a DCDC converter and a control method thereof. Background Art

[0002] Supported by relevant policies, new energy electric vehicles have experienced rapid development in recent years. In particular, electric vehicles offer significant advantages over traditional fuel vehicles in terms of intelligence, power performance, and operating costs. However, slow charging and insufficient long-distance range remain two of the biggest pain points for new energy electric vehicles. To improve range and shorten charging times, various automakers are gradually introducing 800V systems, also known as high-voltage platforms. Using a high-voltage platform is the most direct and effective way to address charging anxiety. By increasing voltage, power is increased at the same charging current, which in turn speeds up charging and alleviates users' charging anxiety.

[0003] However, the existing high-voltage platform has problems with DC charging piles. Currently, the vast majority of DC charging piles on the market use 400V high-voltage DC output to connect directly to the battery pack in the car through a charging gun. In this way, the charging pile can directly output energy to charge the battery pack. When it detects that the battery pack is full, the relay is disconnected to stop charging. The entire charging process is controlled by the BMS (battery management system); only a very small number of DC charging piles can support 800V high-voltage DC output.

[0004] In order to solve the above problems, the general approach is to increase the construction of 800V charging piles, but this solution requires a lot of money and time. The large-scale deployment and installation of charging piles will take several years, consume a lot of manpower and material resources, and the cost is extremely high.

[0005] Therefore, the present invention proposes a DCDC converter, so that the DC output of a traditional 400V charging pile can be converted by the DCDC converter and then directly charged to the 800V on-board battery pack of the car. Summary of the Invention

[0006] In view of this, the present invention provides a DCDC converter and a control method for solving the problem in the prior art that the DC output of a traditional 400V charging pile cannot directly charge the 800V battery pack of a car.

[0007] To achieve one, some, or all of the above objectives, or other objectives, the technical solution of the present invention is a DC-DC converter, comprising: one or more DC-DC conversion modules connected in parallel between a battery pack having a rated voltage of a first value and a DC charging pile having an output voltage of a second value; the DC-CDC converter is further connected to a main control chip; wherein the first value is greater than the second value; and the DC charging pile is used to charge the battery pack;

[0008] The first transceiver end of the DCDC conversion module is used to connect to a DC charging pile, and the second transceiver end of the DCDC conversion module is used to connect to a battery pack; wherein, the DCDC conversion module is used to step down the voltage flowing to the DC charging pile and step up the voltage flowing to the battery pack.

[0009] Furthermore, the DCDC converter is a plurality of DCDC conversion modules arranged in parallel;

[0010] The first transceiver end of each DCDC conversion module is simultaneously connected to a first wiring terminal, which is used to connect to a DC charging pile;

[0011] The second transceiver end of each DCDC conversion module is also connected to a second wiring terminal, which is used to connect to the battery management system of the battery pack;

[0012] The control end of each DCDC conversion module is simultaneously connected to a main control chip.

[0013] Furthermore, each of the DCDC conversion modules includes a first switching tube, a second switching tube, an inductor, a first capacitor and a second capacitor;

[0014] The positive electrode of the first capacitor and the first end of the inductor are connected to the first wiring terminal at the same time, the second end of the inductor is connected to the source of the first switching transistor and the drain of the second switching transistor at the same time, and the source of the second switching transistor and the positive electrode of the second capacitor are connected to the second wiring terminal at the same time;

[0015] The gate of the first switching tube and the gate of the second switching tube are simultaneously connected to the output end of the main control chip;

[0016] The drain of the first switch tube, the negative electrode of the first capacitor and the negative electrode of the second capacitor are all grounded.

[0017] Furthermore, the DCDC converter includes a first DCDC conversion module, a second DCDC conversion module and a third DCDC conversion module arranged in parallel;

[0018] The first DCDC conversion module includes a switch tube Q1, a switch tube Q2, an inductor L1, a capacitor C1 and a capacitor C2; the second DCDC conversion module includes a switch tube Q3, a switch tube Q4, an inductor L2, a capacitor C3 and a capacitor C4; the third DCDC conversion module includes a switch tube Q5, a switch tube Q6, an inductor L3, a capacitor C5 and a capacitor C6;

[0019] The first end of the inductor L1, the positive electrode of the capacitor C1, the first end of the inductor L2, the positive electrode of the capacitor C3, the first end of the inductor L3, and the positive electrode of the capacitor C5 are all connected to a first terminal, which is used to connect to a DC charging pile; the second end of the inductor L1 is simultaneously connected to the source of the switch tube Q1 and the drain of the second switch tube Q2; the second end of the inductor L2 is simultaneously connected to the source of the switch tube Q3 and the drain of the second switch tube Q4; the second end of the inductor L3 is simultaneously connected to the source of the switch tube Q5 and the drain of the second switch tube Q6;

[0020] The source of the switch tube Q2, the positive electrode of the capacitor C2, the source of the switch tube Q4, the positive electrode of the capacitor C4, the source of the switch tube Q6 and the positive electrode of the capacitor C6 are all connected to a second terminal, which is used to connect to the battery management system of the battery pack; the drain of the switch tube Q1, the negative electrode of the capacitor C1, the negative electrode of the capacitor C2, the drain of the switch tube Q3, the negative electrode of the capacitor C3, the negative electrode of the capacitor C4, the drain of the switch tube Q5, the negative electrode of the capacitor C5 and the negative electrode of the capacitor C6 are all grounded; the gate of the switch tube Q1, the gate of the switch tube Q2, the gate of the switch tube Q3, the gate of the switch tube Q4, the gate of the switch tube Q5 and the gate of the switch tube Q6 are all connected to the output end of the main control chip.

[0021] A control method applied to the DCDC converter as described above, comprising:

[0022] Step S1: the DCDC converter receives or detects a request voltage signal from a battery management system in the battery pack requesting a first output voltage;

[0023] Step S2: In response to receiving or detecting a request voltage signal from a battery management system in the battery pack requesting a first output voltage, the DCDC converter converts the first output voltage into a second output voltage through a step-down operation mode, and outputs the second output voltage to a DC charging station;

[0024] Step S3: After the DCDC converter performs a periodic disturbance operation on the second output voltage, a first disturbance voltage is obtained. If the first disturbance voltage is equal to the second output voltage, it is determined that the DC charging pile is supplying power to the DCDC converter, and the buck working mode is stopped and the boost working mode is executed to boost the third output voltage output by the DC charging pile to a fourth output voltage to charge the battery pack.

[0025] Furthermore, when the DCDC converter performs a step-down operation mode, at least one of all the DCDC conversion modules performs a step-down operation mode, and all the remaining DCDC conversion modules stop working.

[0026] Furthermore, when the DCDC converter performs a boost operation mode, all the DCDC conversion modules perform a boost operation.

[0027] Furthermore, the first output voltage is equal to the fourth output voltage.

[0028] Furthermore, the second output voltage is equal to the third output voltage.

[0029] Furthermore, the step-down working mode is a Buck working mode, which is used to step down the voltage of the battery pack flowing to the DC charging pile;

[0030] The boost working mode is a Boost working mode, which is used to boost the voltage of the DC charging pile flowing to the battery pack.

[0031] Compared with the prior art, the present invention has at least the following beneficial effects:

[0032] The present invention uses a DCDC converter to first step down a request voltage signal of a first output voltage flowing from a battery pack to a DC charging pile, obtain a second output voltage, and transmit it to the DC charging pile. The DC charging pile then starts to output a third output voltage. The DCDC converter then steps up the third output voltage to obtain a fourth output voltage, so that the fourth output voltage matches the charging voltage of the battery pack and charging begins. Therefore, the DC output of the DC charging pile can be converted by the DCDC converter to charge the battery pack of the vehicle. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as commonly understood by those skilled in the art to which this invention belongs. The terms used in the specification of the application are for the purpose of describing specific embodiments only and are not intended to limit the present invention. The terms "including" and "having" and any variations thereof in the specification and claims of the present invention and the accompanying drawings are intended to cover non-exclusive inclusions. The terms "first" and "second" in the specification and claims of the present invention and the accompanying drawings are used to distinguish different objects, not to describe a specific order.

[0034] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0035] FIG1 is a circuit diagram of a DCDC converter of the present invention;

[0036] FIG2 is another circuit diagram of a DCDC converter of the present invention;

[0037] FIG3 is a flow chart of a control method of a DCDC converter according to the present invention;

[0038] FIG4 is a control block diagram of the step-down operation of the DCDC conversion module of the present invention;

[0039] FIG5 is a control block diagram of the boost operation of the DCDC conversion module of the present invention;

[0040] FIG6 is a schematic diagram of the present invention for determining whether a DC charging pile supplies power to a DCDC converter, wherein V2 is the second output voltage.

[0041] Reference numerals:

[0042] 10. DCDC conversion module;

[0043] 11. The first DCDC conversion module;

[0044] 12. The second DCDC conversion module;

[0045] 13. The third DCDC conversion module;

[0046] 101, first switch tube; 102, second switch tube; 103, inductor; 104, first capacitor; 105, second capacitor;

[0047] 20. Main control chip. DETAILED DESCRIPTION

[0048] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention clearer, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely used to explain the present invention and are not intended to limit the present invention. Thus, a feature indicated in this specification will be used to illustrate one of the features of an embodiment of the present invention, rather than implying that each embodiment of the present invention must have the described features. In addition, it should be noted that this specification describes many features. Although certain features can be combined together to illustrate possible system designs, these features can also be used in other combinations that are not explicitly stated. Thus, unless otherwise stated, the described combinations are not intended to be limiting.

[0049] The principle and structure of the present invention are described in detail below with reference to the accompanying drawings and embodiments.

[0050] The output voltage of the DC charging pile in this article is 400V, and the battery pack in this article is an on-board battery pack, and the charging voltage of the on-board battery pack is 800V.

[0051] As an embodiment, referring to Figures 1-6, the present invention proposes a DCDC converter, comprising: one or more DCDC conversion modules 10 arranged in parallel between a battery pack having a rated voltage of a first value and a DC charging pile having an output voltage of a second value; the DCDC converter is also connected to a main control chip 20; wherein the first value is greater than the second value; and the DC charging pile is used to charge the battery pack.

[0052] The first transceiver end of the DCDC conversion module 10 is used to connect to a DC charging pile, and the second transceiver end of the DCDC conversion module 10 is used to connect to a battery pack; wherein, the DCDC conversion module 10 is used to step down the voltage flowing to the DC charging pile and step up the voltage flowing to the battery pack.

[0053] In this embodiment, when a 400V DC charging pile is required to charge an 800V battery pack, since the 400V DC charging pile cannot directly charge the 800V battery pack, a DCDC converter needs to be installed on the 800V battery pack for conversion, thereby reducing the 800V request voltage signal requested by the 800V battery pack to 400V and boosting the 400V output of the 400V DC charging pile to 800V.

[0054] When a car's 800V battery pack needs to be charged, the charging plug of a 400V DC charging station is plugged into the DCDC converter. At this point, the DCDC converter is connected to the 800V battery pack's battery management system. The 800V battery pack's battery management system then sends an 800V request voltage signal to the 400V DC charging station. If the 400V DC charging station directly receives the 800V request voltage signal, it will refuse charging due to the voltage mismatch.

[0055] Therefore, the 800V request voltage signal must first be received by the main control chip 20. The main control chip 20 then uses the DCDC conversion module 10 to step down the 800V request voltage signal to a 400V request voltage signal, which is then transmitted to the 400V DC charging station. This "tricks" the 400V DC charging station, causing it to match the stepped-down request voltage signal and output a 400V voltage to the 800V battery pack. The DCDC conversion module 10 then steps up the 400V voltage to 800V, which is then transmitted to the 800V battery pack to complete the matching process. The 400V DC charging station then charges the 800V battery pack.

[0056] In this way, the DCDC conversion module 10 of the present invention will first reduce the 800V request voltage signal sent by the battery management system of the 800V battery pack to the 400V DC charging pile. This is equivalent to the DCDC conversion module 10 simulating a 400V request voltage signal to "cheat" the 400V DC charging pile, so that the 400V request voltage signal matches and successfully identifies the 400V DC charging pile, and the 400V DC charging pile begins to output a 400V voltage. The DCDC conversion module 10 then increases the 400V output voltage transmitted by the 400V DC charging pile to the battery management system to 800V, so that the increased output voltage matches the charging voltage of the 800V battery pack, and the battery pack begins charging. As a result, the 400V DC output of the DC charging pile can be directly used to charge the 800V battery pack of the vehicle through conversion by the DCDC conversion module 10 of the present invention.

[0057] Compared with the solution of increasing the construction of 800V charging piles, the present invention has lower investment costs, is time-saving, and does not consume a lot of manpower and material resources.

[0058] In a specific embodiment, the DCDC converter is a plurality of DCDC conversion modules 10 arranged in parallel.

[0059] The first transceiver end of each DCDC conversion module 10 is also connected to a first wiring terminal, which is used to connect to a DC charging pile; the DC charging pile is preferably a 400V DC charging pile.

[0060] The second transceiver end of each DCDC conversion module 10 is also connected to a second wiring terminal, which is used to connect to the battery management system of the battery pack; the battery pack is preferably an 800V battery pack.

[0061] The control end of each DCDC conversion module 10 is also connected to the main control chip 20 .

[0062] In this way, when the request voltage signal output by the 800V battery pack flows into the DCDC conversion module 10 through the second transceiver end, the DCDC conversion module 10 then enters the step-down working mode (step-down working mode is also known as Buck working mode) and steps down the request voltage signal output by the 800V battery pack.

[0063] Similarly, when the output voltage of the 400V DC charging pile flows into the DCDC conversion module 10 through the first transceiver end, the DCDC conversion module 10 enters the boost working mode (the boost working mode is the Boost working mode) to step down the output voltage of the 400V DC charging pile.

[0064] Specifically, referring to FIG. 1-2 , each of the DCDC conversion modules 10 includes a first switching transistor 101 , a second switching transistor 102 , an inductor 103 , a first capacitor 104 , and a second capacitor 105 .

[0065] The positive electrode of the first capacitor 104 and the first end of the inductor 103 are simultaneously connected to the first wiring terminal; the second end of the inductor 103 is simultaneously connected to the source of the first switching tube 101 and the drain of the second switching tube 102, and the source of the second switching tube 102 and the positive electrode of the second capacitor 105 are simultaneously connected to the second wiring terminal; the gate of the first switching tube 101 and the gate of the second switching tube 102 are simultaneously connected to the output end of the main control chip 20; the drain of the first switching tube 101, the negative electrode of the first capacitor 104, and the negative electrode of the second capacitor 105 are all grounded.

[0066] Among them, the voltage at the battery management system end is VH, and the voltage at the DC charging pile end is VL.

[0067] In this way, the DCDC conversion module 10 steps down the voltage request signal sent by the battery management system of the 800V charging pack to the 400V DC charging pile as follows:

[0068] When the second switch 102 is on, the inductor 103 is excited by the voltage VH, and the magnetic flux of the inductor 103 increases by VH*Ton. When the second switch 102 is off, the output current continues, and the first switch 101 is on, reducing the magnetic flux of the inductor 103. At this time, the magnetic flux of the inductor 103 decreases by VL*Toff (when the on state and the off state of the second switch 102 reach equilibrium, VH*Ton=VL*Toff). Since Ton / Toff < 1 at this time, VH>VL, achieving voltage reduction.

[0069] The process of the DCDC conversion module 10 boosting the charging voltage output from the 400V DC charging pile to the battery management system of the 800V charging pack is as follows:

[0070] When the first switch 101 is on, the voltage VL excites the inductor 103, and the magnetic flux of the inductor 103 increases by VL*Ton. When the first switch 101 is off, the output current continues, and the second switch 102 is on, cutting the magnetic flux of the inductor 103. At this time, the magnetic flux of the inductor 103 decreases by VH*Toff (when the on and off states of the first switch 101 reach equilibrium, VL*Ton'=VH*Toff'). Since Ton' / Toff'>1 at this time, VH>VL, achieving a voltage boost.

[0071] The DCDC converter comprises three DCDC conversion modules 10 connected in parallel. Of course, four, five, or even more DCDC conversion modules 10 can be connected in parallel. However, this embodiment uses three parallel DCDC conversion modules 10 as an example, and the three parallel DCDC conversion modules 10 are a first DCDC conversion module 11, a second DCDC conversion module 12, and a third DCDC conversion module 13.

[0072] The first DCDC conversion module 11 includes a switch tube Q1, a switch tube Q2, an inductor L1, a capacitor C1 and a capacitor C2; the second DCDC conversion module 12 includes a switch tube Q3, a switch tube Q4, an inductor L2, a capacitor C3 and a capacitor C4; and the third DCDC conversion module 13 includes a switch tube Q5, a switch tube Q6, an inductor L3, a capacitor C5 and a capacitor C6.

[0073] Among them, the switch tube Q1, the switch tube Q3 and the switch tube Q5 can all be called the first switch tube 101, the switch tube Q2, the switch tube Q4 and the switch tube Q6 can all be called the second switch tube 102, the inductor L1, the inductor L2 and the inductor L3 can all be called the inductor 103, the capacitor C1, the capacitor C3 and the capacitor C5 can all be called the first capacitor 104, and the capacitor C2, the capacitor C4 and the capacitor C6 can all be called the second capacitor 105.

[0074] Specifically, the first end of the inductor L1, the positive electrode of the capacitor C1, the first end of the inductor L2, the positive electrode of the capacitor C3, the first end of the inductor L3 and the positive electrode of the capacitor C5 are all connected to a first wiring terminal, which is used to connect to a 400V DC charging pile; the second end of the inductor L1 is simultaneously connected to the source of the switch tube Q1 and the drain of the second switch tube Q2; the second end of the inductor L2 is simultaneously connected to the source of the switch tube Q3 and the drain of the second switch tube Q4; the second end of the inductor L3 is simultaneously connected to the source of the switch tube Q5 and the drain of the second switch tube Q6.

[0075] The source of the switch tube Q2, the positive electrode of the capacitor C2, the source of the switch tube Q4, the positive electrode of the capacitor C4, the source of the switch tube Q6 and the positive electrode of the capacitor C6 are all connected to the second terminal, which is used to connect to the battery management system of the 800V battery pack; the drain of the switch tube Q1, the negative electrode of the capacitor C1, the negative electrode of the capacitor C2, the drain of the switch tube Q3, the negative electrode of the capacitor C3, the negative electrode of the capacitor C4, the drain of the switch tube Q5, the negative electrode of the capacitor C5 and the negative electrode of the capacitor C6 are all grounded; the gate of the switch tube Q1, the gate of the switch tube Q2, the gate of the switch tube Q3, the gate of the switch tube Q4, the gate of the switch tube Q5 and the gate of the switch tube Q6 are all connected to the output terminal OUT of the main control chip 20.

[0076] In this embodiment, the main control chip 20 is a digital signal processor chip, and its model includes but is not limited to any one of the TMS320F240X series, TMS320C2XX series, TMS320C2X / 4X series, TMS320C54X / 55X series, and TMS320C2XX series. Of course, the main control chip 20 also includes other dedicated integrated circuit chips that can quickly process digital signals.

[0077] As an embodiment, referring to Figures 3-6 , the present invention provides a control method for the DCDC converter as described above, comprising:

[0078] Step S1: The DCDC converter receives or detects a request voltage signal from the battery management system in the battery pack requesting a first output voltage; the request voltage signal is an electrical signal from the battery management system of the 800V battery pack requesting the 400V DC charging pile to output 800V DC power.

[0079] Step S2: In response to receiving or detecting a voltage request signal from the battery management system in the battery pack requesting a first output voltage, the DCDC converter converts the first output voltage into a second output voltage through a step-down operation mode, and outputs the second output voltage to the DC charging station. The first output voltage is preferably 800V, and the second output voltage is preferably 400V. When the DCDC converter operates in step-down mode, at least one of the DCDC conversion modules 10 operates in step-down mode, and all remaining DCDC conversion modules 10 cease operation (see FIG. 4 ).

[0080] Step S3: The DCDC converter periodically perturbs the second output voltage to obtain a first perturbation voltage. If the first perturbation voltage is equal to the second output voltage, it is determined that the DC charging pile is supplying power to the DCDC converter. The buck mode is stopped and the boost mode is activated to boost the third output voltage of the DC charging pile to a fourth output voltage for charging the battery pack. The third output voltage is equal to the second output voltage, i.e., the third output voltage is preferably 400V; the fourth output voltage is equal to the first output voltage, i.e., the fourth output voltage is preferably 800V.

[0081] 5 , when the DCDC converter performs a boost operation mode, all the DCDC conversion modules perform a boost operation.

[0082] The step-down working mode is the Buck working mode, which is used to step down the voltage of the 800V battery pack flowing to the 400V DC charging pile;

[0083] The boost working mode is the Boost working mode, which is used to boost the voltage of the 400V DC charging pile flowing to the 800V battery pack.

[0084] The control method of the DCDC converter of the present invention is specifically as follows:

[0085] When a 400V DC charging station starts charging an 800V battery pack, the main control chip 20 will first enter the pre-charging state. That is, the battery management system of the 800V battery pack will first send an 800V request voltage signal to the main control chip 20. After receiving the signal, the main control chip 20 will control one of the DCDC conversion modules 10 to perform step-down operation (i.e., Buck operation mode), and the remaining DCDC conversion modules 10 will be in a stopped state (see Figure 4). Then the step-down DCDC conversion module 10 steps down the 800V request voltage signal to a 400V request voltage signal, and then sends it to the 400V DC charging pile, thereby "deceiving" the 400V DC charging pile into thinking that it is matched with a 400V battery pack instead of an 800V battery pack. The 400V DC charging pile then successfully matches the 800V battery pack, and the 400V DC charging pile attempts to start the charging process. During the startup process, the step-down DCDC conversion module 10 needs to stably output a 400V request voltage signal to ensure that the 400V request voltage signal detected by the 400V DC charging pile is reliable. If the request voltage signal changes periodically between 400V and 800V, the 400V DC charging pile will shut down the charging process.

[0086] Therefore, when the 400V DC charging pile starts the charging process, the main control chip 20 will perform a periodic disturbance operation on the 400V request voltage signal and obtain a first disturbance voltage to determine that the 400V DC charging pile is supplying power to the DCDC converter:

[0087] If the first disturbance voltage is equal to the second output voltage, it is determined that the 400V DC charging pile is supplying power to the DCDC converter. The main control chip 20 will control the DCDC conversion module 10 in the buck working mode to stop working, and then make all DCDC conversion modules 10 perform the boost working mode (i.e., Boost working mode). That is, all DCDC conversion modules 10 working in the forward direction will boost the output voltage of the 400V DC charging pile to 800V, and then transmit it to the battery pack, so that the 800V output voltage matches the charging voltage of the 800V battery pack. In this way, the 400V DC charging pile can enter the normal charging working state for the 800V battery pack and complete the charging.

[0088] If the first disturbance voltage is not equal to the second output voltage, it is determined that the DC charging pile does not supply power to the DCDC converter, and the DCDC conversion module 10 in the step-down working mode continues to operate until the first disturbance voltage is equal to the second output voltage.

[0089] Obviously, the embodiments described above are only some embodiments of the present invention, rather than all embodiments. The preferred embodiments of the present invention are given in the accompanying drawings, but they do not limit the patent scope of the present invention. The present invention can be implemented in many different forms. On the contrary, the purpose of providing these embodiments is to make the understanding of the disclosure of the present invention more thorough and comprehensive. Although the present invention has been described in detail with reference to the aforementioned embodiments, for those skilled in the art, it is still possible to modify the technical solutions described in the aforementioned specific embodiments, or to make equivalent replacements for some of the technical features therein. Any equivalent structure made using the contents of the present invention specification and drawings, directly or indirectly used in other related technical fields, is also within the scope of patent protection of the present invention.

Claims

1. A DCDC converter, characterized in that: include: One or more parallel-arranged DCDC conversion modules connected between a battery pack having a first rated voltage and a DC charging pile having a second output voltage; the DCDC converter is also connected to a main control chip; wherein the first value is greater than the second value; the DC charging pile is used to charge the battery pack; The first transceiver end of the DCDC conversion module is used to connect to a DC charging pile, and the second transceiver end of the DCDC conversion module is used to connect to a battery pack; wherein the DCDC conversion module is used to step down the voltage flowing to the DC charging pile and step up the voltage flowing to the battery pack.

2. The DCDC converter according to claim 1, characterized in that: The DCDC converter is a plurality of DCDC conversion modules arranged in parallel; Wherein, the first transceiver end of each of the DCDC conversion modules is simultaneously connected to a first wiring terminal, and the first wiring terminal is used to connect to a DC charging pile; The second transceiver end of each of the DCDC conversion modules is simultaneously connected to a second wiring terminal, and the second wiring terminal is used to connect to the battery management system of the battery pack; The control end of each DCDC conversion module is simultaneously connected to a main control chip.

3. The DCDC converter according to claim 2, characterized in that: Each of the DCDC conversion modules includes a first switch tube, a second switch tube, an inductor, a first capacitor and a second capacitor; The positive electrode of the first capacitor and the first end of the inductor are connected to the first wiring terminal at the same time, the second end of the inductor is connected to the source of the first switch tube and the drain of the second switch tube at the same time, and the source of the second switch tube and the positive electrode of the second capacitor are connected to the second wiring terminal at the same time; The gate of the first switch tube and the gate of the second switch tube are simultaneously connected to the output end of the main control chip; The drain of the first switch tube, the negative electrode of the first capacitor and the negative electrode of the second capacitor are all grounded.

4. The DCDC converter according to claim 2, characterized in that: The DCDC converter includes a first DCDC conversion module, a second DCDC conversion module and a third DCDC conversion module which are arranged in parallel; The first DCDC conversion module includes a switch tube Q1, a switch tube Q2, an inductor L1, a capacitor C1 and a capacitor C2; the second DCDC conversion module includes a switch tube Q3, a switch tube Q4, an inductor L2, a capacitor C3 and a capacitor C4; the third DCDC conversion module includes a switch tube Q5, a switch tube Q6, an inductor L3, a capacitor C5 and a capacitor C6; The first end of the inductor L1, the positive electrode of the capacitor C1, the first end of the inductor L2, the positive electrode of the capacitor C3, the first end of the inductor L3 and the positive electrode of the capacitor C5 are simultaneously connected to a first wiring terminal, and the first wiring terminal is used to connect to a DC charging pile; the second end of the inductor L1 is simultaneously connected to the source of the switch tube Q1 and the drain of the second switch tube Q2; the second end of the inductor L2 is simultaneously connected to the source of the switch tube Q3 and the drain of the second switch tube Q4; the second end of the inductor L3 is simultaneously connected to the source of the switch tube Q5 and the drain of the second switch tube Q6; The source of the switch tube Q2, the positive electrode of the capacitor C2, the source of the switch tube Q4, the positive electrode of the capacitor C4, the source of the switch tube Q6 and the positive electrode of the capacitor C6 are all connected to the second terminal, which is used to connect the battery management system of the battery pack; the drain of the switch tube Q1, the negative electrode of the capacitor C1, the negative electrode of the capacitor C2, the drain of the switch tube Q3, the negative electrode of the capacitor C3, the negative electrode of the capacitor C4, the drain of the switch tube Q5, the negative electrode of the capacitor C5 and the negative electrode of the capacitor C6 are all grounded; the gate of the switch tube Q1, the gate of the switch tube Q2, the gate of the switch tube Q3, the gate of the switch tube Q4, the gate of the switch tube Q5 and the gate of the switch tube Q6 are all connected to the output end of the main control chip.

5. A control method for a DCDC converter as claimed in any one of claims 1 to 4, characterized in that: include: Step S1: the DCDC converter receives or detects a request voltage signal from a battery management system in the battery pack requesting a first output voltage; Step S2: in response to receiving or detecting a request voltage signal from a battery management system in the battery pack requesting a first output voltage, the DCDC converter obtains a second output voltage through a step-down operation mode using the first output voltage, and outputs the second output voltage to a DC charging pile; Step S3: After the DCDC converter performs a periodic disturbance operation on the second output voltage, a first disturbance voltage is obtained. If the first disturbance voltage is equal to the second output voltage, it is determined that the DC charging pile is supplying power to the DCDC converter, the buck working mode is stopped, and the boost working mode is executed to boost the third output voltage output by the DC charging pile to a fourth output voltage to charge the battery pack.

6. The control method according to claim 5, characterized in that: When the DCDC converter performs a step-down operation mode, at least one of all the DCDC conversion modules performs a step-down operation mode, and all the remaining DCDC conversion modules stop working.

7. The control method according to claim 5, characterized in that: When the DCDC converter performs a boost operation mode, all the DCDC conversion modules perform a boost operation.

8. The control method according to claim 5, characterized in that: The first output voltage is equal to the fourth output voltage.

9. The control method according to claim 5, characterized in that: The second output voltage is equal to the third output voltage.

10. The control method according to any one of claims 5 to 9, characterized in that: The step-down working mode is a Buck working mode, which is used to step down the voltage flowing from the battery pack to the DC charging pile; The boost working mode is a Boost working mode, which is used to boost the voltage flowing from the DC charging pile to the battery pack.

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