DC boost converter and charging system

Abstract

The invention relates to a DC boost converter and a charging system. The DC boost converter comprises an input power supply, two power switch tubes, two inductors, two energy storage capacitors, an output capacitor and three diodes. The intrinsic characteristics of an inductor-capacitor-diode network are utilized, the original characteristics of a traditional direct-current converter are combined, the output voltage gain of the direct-current converter and the working efficiency are improved, meanwhile, the circuit structure of the direct-current converter is simple, and the requirement for low cost is met.

Description

Technical Field

[0001] The present application relates to the field of power electronics technology, and in particular to a direct current boost converter and a charging system. Background Art

[0002] The existing energy storage charging pile boosts the voltage of the energy storage battery through a DC boost converter, and then sends the boosted voltage to the charging end of the charging pile for use. However, the current DC boost converter requires a high duty cycle to have a high gain, which results in high voltage stress on the DC boost converter. When working at a high duty cycle, the working efficiency of the DC boost converter is significantly reduced.

[0003] Currently, converter topology is often used to solve the problems of high voltage stress and reduced efficiency as the duty cycle increases. However, the converter topology is relatively complex in structure and control strategy, and cannot simultaneously meet the requirements of high gain, high efficiency and low cost of DC boost converters. Summary of the invention

[0004] Based on this, it is necessary to provide a DC boost converter and charging system that can simultaneously meet the high gain, high efficiency and low cost requirements of the DC boost converter in order to address the above technical problems.

[0005] In a first aspect, the present application provides a DC boost converter, comprising:

[0006] Input power V i ;

[0007] The first inductor L1 has one end connected to the input power supply V i The positive electrode is connected;

[0008] A first power switch tube S1, wherein a drain of the first power switch tube S1 is connected to the other end of the first inductor L1;

[0009] A first diode D1, wherein an anode of the first diode D1 is connected to the other end of the first inductor L1 and a drain of the first power switch tube S1 respectively;

[0010] The second diode D2, the anode of the second diode D2 is connected to the source of the first power switch tube S1, and the cathode of the second diode D2 is connected to the input power supply V i The negative electrode;

[0011] A first capacitor C1, one end of the first capacitor C1 is connected to the source of the first power switch tube S1 and the anode of the second diode D2 respectively, and the other end of the first capacitor C1 is connected to the cathode of the first diode D1;

[0012] A second capacitor C2, one end of which is respectively connected to the other end of the first inductor L1, the drain of the first power switch tube S1 and the anode of the first diode D1;

[0013] A second inductor L2, one end of the second inductor L2 is connected to the cathode of the first diode D1 and the other end of the first capacitor C1 respectively, and the other end of the second inductor L2 is connected to the other end of the second capacitor C2;

[0014] The second power switch tube S2, the drain of the second power switch tube S2 is respectively connected to the cathode of the first diode D1, the other end of the first capacitor C1 and one end of the second inductor L2, and the source of the second power switch tube S2 is respectively connected to the cathode of the second diode D2 and the input power supply V i The negative electrode;

[0015] a third diode D3, wherein an anode of the third diode D3 is connected to the other end of the second capacitor C2 and the other end of the second inductor L2 respectively, and a cathode of the third diode D3 is used to connect to the charging end of the charging pile;

[0016] The output capacitor C0 has one end connected to the source of the second power switch tube S2, the cathode of the second diode D2 and the input power supply V i The other end of the output capacitor C0 is connected between the cathode of the third diode D3 and the charging end of the charging pile.

[0017] In one embodiment, the DC boost converter is in a first working mode, a second working mode and a third working mode in sequence within one switching cycle.

[0018] In one embodiment, when the DC boost converter is in the first working mode, the first power switch tube S1 and the second power switch tube S2 are turned on, and the first diode D, the second diode D2 and the third diode D3 are all turned off.

[0019] In one embodiment, in the first working mode, the electrical parameter relationship is as follows:

[0020] V L1 =V i +V C1

[0021] V L2 =V C1 -V C2

[0022] Among them, V i Indicates the voltage of the input power supply; V L1 represents the voltage across the first inductor L1 in the first working mode; V L2 represents the voltage across the second inductor L2 in the first working mode; VC1 represents the voltage across the first capacitor C1 in the first working mode; V C2 represents the voltage across the second capacitor C2 in the first working mode.

[0023] In one embodiment, when the DC boost converter is in the second working mode, the first power switch tube S1 and the second power switch tube S2 are turned off, the first diode D1 and the second diode D2 are both turned on, and the third diode D3 is turned off.

[0024] In one embodiment, in the second working mode, the electrical parameter relationship is as follows:

[0025] V L1 =V i -V C1

[0026] V L2 = -V C2

[0027] Among them, V i Indicates the voltage of the input power supply; V L1 represents the voltage across the first inductor L1 in the second working mode; V L2 represents the voltage across the second inductor L2 in the second working mode; V C1 represents the voltage across the first capacitor C1 in the second working mode; V C2 represents the voltage across the second capacitor C2 in the second working mode.

[0028] In one embodiment, when the DC boost converter is in the third working mode, the first power switch tube S1 and the second power switch tube S2 are turned off, and the first diode D1, the second diode D2 and the third diode D3 are all turned on.

[0029] In one embodiment, in the third working mode, the electrical parameter relationship is as follows:

[0030] V L1 =V i -V C1

[0031] V L2 =V C1 –V0

[0032] Among them, V i Indicates the voltage of the input power supply; V L1 represents the voltage across the first inductor L1 in the third working mode; V L2 represents the voltage across the second inductor L2 in the third working mode; V C1represents the voltage across the first capacitor C1 in the third working mode; V0 represents the voltage across the charging pile.

[0033] In one embodiment, the voltage gain G of the DC boost converter is calculated as follows:

[0034]

[0035] Among them, V i Represents the voltage of the input power supply; V0 represents the voltage across the charging pile; D is the duty cycle of the first power switch tube S1 and the second power switch tube S2.

[0036] In a second aspect, the present application further provides a charging system, comprising a control module, a drive module connected to the control module, and a DC boost converter as described above connected to the drive module; wherein:

[0037] The driving module is connected to the gate of the first power switch tube S1 and the gate of the second power switch tube S2 respectively, and the control module is used to connect to the charging pile.

[0038] The above-mentioned DC boost converter and charging system are configured with an input power supply, two power switch tubes, two inductors, two energy storage capacitors, an output capacitor and three diodes in the DC boost converter. Compared with traditional converters, the DC boost converter provided by the present application can achieve improved voltage gain and working efficiency by adopting a simpler circuit topology, while meeting the low-cost requirement. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application or related technologies, the drawings required for use in the embodiments of the present application or related technical descriptions will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0040] FIG1 is a schematic structural diagram of a DC boost converter in one embodiment;

[0041] FIG2 is a schematic diagram of a current of a DC boost converter in a first working mode in one embodiment;

[0042] FIG3 is a current diagram of a DC boost converter in a second working mode in one embodiment;

[0043] FIG4 is a current diagram of a DC boost converter in a third working mode in one embodiment;

[0044] FIG5 is a schematic diagram of the structure of a charging system in one embodiment;

[0045] FIG. 6 is a schematic diagram of current / voltage waveforms of some components in a charging system according to an embodiment. DETAILED DESCRIPTION

[0046] In order to facilitate understanding of the present application, the present application will be described more fully below with reference to the relevant drawings. Embodiments of the present application are provided in the drawings. However, the present application can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present application more thorough and comprehensive.

[0047] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application.

[0048] It is understood that the terms "first", "second", etc. used in this application can be used to describe various elements in this article, but these elements are not limited by these terms. These terms are only used to distinguish a first element from another element. For example, without departing from the scope of this application, a first capacitor can be referred to as a second capacitor, and similarly, a second capacitor can be referred to as a first capacitor. Both the first capacitor and the second capacitor are capacitors, but they are not the same capacitor.

[0049] It can be understood that the “connection” in the following embodiments should be understood as “electrical connection”, “communication connection”, etc. if the connected circuits, modules, units, etc. have electrical signals or data transmission between each other.

[0050] It can be understood that “at least one” means one or more, “plurality” means two or more, and “at least a portion of an element” means a part or all of an element.

[0051] When used herein, the singular forms "a", "an", and "said / the" may also include plural forms, unless the context clearly indicates otherwise. It should also be understood that the terms "include / comprise" or "have" and the like specify the presence of stated features, wholes, steps, operations, components, parts, or combinations thereof, but do not exclude the possibility of the presence or addition of one or more other features, wholes, steps, operations, components, parts, or combinations thereof. At the same time, the term "and / or" used in this specification includes any and all combinations of the relevant listed items.

[0052] The DC boost converter provided in the embodiment of the present application, while meeting the requirements of high voltage gain and high working efficiency, also minimizes the complexity of the converter circuit topology and reduces the difficulty of controlling and adjusting the DC boost converter; compared with the prior art, the DC boost converter provided in the embodiment of the present application has the following advantages: simple structure, convenient control, high working efficiency and large voltage gain.

[0053] In an exemplary embodiment, as shown in FIG1 , a DC boost converter is provided, comprising:

[0054] Input power V i ;

[0055] The first inductor L1 has one end connected to the input power supply V i The positive electrode is connected;

[0056] A first power switch tube S1, wherein a drain of the first power switch tube S1 is connected to the other end of the first inductor L1;

[0057] A first diode D1, wherein an anode of the first diode D1 is connected to the other end of the first inductor L1 and a drain of the first power switch tube S1 respectively;

[0058] The second diode D2, the anode of the second diode D2 is connected to the source of the first power switch tube S1, and the cathode of the second diode D2 is connected to the input power supply V i The negative electrode;

[0059] A first capacitor C1, one end of the first capacitor C1 is connected to the source of the first power switch tube S1 and the anode of the second diode D2 respectively, and the other end of the first capacitor C1 is connected to the cathode of the first diode D1;

[0060] A second capacitor C2, one end of which is respectively connected to the other end of the first inductor L1, the drain of the first power switch tube S1 and the anode of the first diode D1;

[0061] A second inductor L2, one end of the second inductor L2 is connected to the cathode of the first diode D1 and the other end of the first capacitor C1 respectively, and the other end of the second inductor L2 is connected to the other end of the second capacitor C2;

[0062] The second power switch tube S2, the drain of the second power switch tube S2 is respectively connected to the cathode of the first diode D1, the other end of the first capacitor C1 and one end of the second inductor L2, and the source of the second power switch tube S2 is respectively connected to the cathode of the second diode D2 and the input power supply V i The negative electrode;

[0063] a third diode D3, wherein an anode of the third diode D3 is connected to the other end of the second capacitor C2 and the other end of the second inductor L2 respectively, and a cathode of the third diode D3 is used to connect to the charging end of the charging pile;

[0064] The output capacitor C0 has one end connected to the source of the second power switch tube S2, the cathode of the second diode D2 and the input power supply V i The other end of the output capacitor C0 is connected between the cathode of the third diode D3 and the charging end of the charging pile.

[0065] Among them, the input power supply V i Indicates a device used to provide electrical energy, such as a storage battery, input power V i The amount of electric energy provided can be set according to actual conditions and is not limited in the embodiments of the present application; the first capacitor C1 and the second capacitor C2 can be used to store electric energy.

[0066] Specifically, the DC boost converter includes an input power supply V i , a first power switch tube S1, a second power switch tube S2, a first inductor L1, a second inductor L2, a first capacitor C1, a second capacitor C2, an output capacitor C0, a first diode D1, a second diode D2 and a third diode D3. By adjusting the working states of the first power switch tube S1 and the second power switch tube S2, the DC boost converter provided in the present application can achieve improved voltage gain and working efficiency by adopting a relatively simple circuit topology, while meeting the low cost requirement. Compared with traditional converters, it can simultaneously meet the requirements of high gain, high efficiency and low cost.

[0067] In one embodiment, the DC boost converter is in a first working mode, a second working mode and a third working mode in sequence within one switching cycle.

[0068] Specifically, by setting the switching period T of the first power switch tube S1 and the second power switch tube S2 s And the duty cycle D, we can get the duration corresponding to each of the three working modes, where the duration of the first working mode is DT s , the duration of the second working mode is DT s , the duration of the third working mode (1-2D) T s .

[0069] Exemplarily, the start time of a switching cycle can be defined as time t0, the time period between time t0 and time t1 is used as the time period for the first working mode, the time period between time t1 and time t2 is used as the time period for the second working mode, and the time period between time t2 and time t3 is used as the time period for the third working mode. Time t3 is both the end time of a switching cycle and the start time of the next switching cycle.

[0070] It should be noted that the switching period T of the first power switch tube S1 and the second power switch tube S2 is s And the duty cycle D can be set according to actual conditions and is not limited in the embodiments of the present application.

[0071] In one embodiment, as shown in FIG. 2 , when the DC boost converter is in the first working mode, the first power switch tube S1 and the second power switch tube S2 are turned on, and the first diode D, the second diode D2 and the third diode D3 are all turned off.

[0072] Specifically, when the DC boost converter is in the first working mode, that is, between time t0 and time t1, as shown in FIG2 , the first power switch tube S1 and the second power switch tube S2 are turned on, and the first diode D, the second diode D2 and the third diode D3 are all turned off. At this time, the input power supply V i The first capacitor C1 and the first inductor L1 are charged, the first capacitor C1 also charges the second capacitor C2 and the second inductor L2, and the output capacitor C0 supplies power to the charging end of the charging pile.

[0073] It should be noted that, as shown in FIG. 2 , the dotted line represents disconnection, the solid line represents flow, and the direction of the arrow is the actual current direction.

[0074] In one embodiment, in the first working mode, the electrical parameter relationship is as follows:

[0075] V L1 =V i +V C1

[0076] V L2 =V C1 -V C2

[0077] Among them, V i Indicates the voltage of the input power supply; V L1 represents the voltage across the first inductor L1 in the first working mode; V L2 represents the voltage across the second inductor L2 in the first working mode; V C1 represents the voltage across the first capacitor C1 in the first working mode; V C2represents the voltage across the second capacitor C2 in the first working mode.

[0078] In one embodiment, as shown in FIG3 , when the DC boost converter is in the second working mode, the first power switch tube S1 and the second power switch tube S2 are turned off, the first diode D1 and the second diode D2 are both turned on, and the third diode D3 is turned off.

[0079] Specifically, when the DC boost converter is in the second working mode, that is, between time t1 and time t2, as shown in FIG3 , the first power switch tube S1 and the second power switch tube S2 are turned off, the first diode D1 and the second diode D2 are both turned on, and the third diode D3 is turned off. At this time, the input power supply V i The first inductor L1 charges the first capacitor C1, the second inductor L2 charges the second capacitor C2, and the output capacitor C0 supplies power to the charging end of the charging pile.

[0080] It should be noted that, as shown in FIG3 , the dotted line represents disconnection, the solid line represents flow, and the direction of the arrow is the actual current direction.

[0081] In one embodiment, in the second working mode, the electrical parameter relationship is as follows:

[0082] V L1 =V i -V C1

[0083] V L2 = -V C2

[0084] Among them, V i Indicates the voltage of the input power supply; V L1 represents the voltage across the first inductor L1 in the second working mode; V L2 represents the voltage across the second inductor L2 in the second working mode; V C1 represents the voltage across the first capacitor C1 in the second working mode; V C2 represents the voltage across the second capacitor C2 in the second working mode.

[0085] In one embodiment, as shown in FIG. 4 , when the DC boost converter is in the third operating mode, the first power switch tube S1 and the second power switch tube S2 are turned off, and the first diode D1 , the second diode D2 and the third diode D3 are all turned on.

[0086] Specifically, when the DC boost converter is in the third working mode, that is, between time t2 and time t3, as shown in FIG4 , the first power switch tube S1 and the second power switch tube S2 are turned off, and the first diode D1, the second diode D2 and the third diode D3 are all turned on. At this time, the input power supply V i The first inductor L1 and the first capacitor C1 are charged, and the second inductor L2 and the second capacitor C2 are charged to supply power to the output capacitor C0 and the charging pile.

[0087] It should be noted that at time t1, the first power switch tube S1 and the second power switch tube S2 are turned off, at which time the current on the first inductor L1 and the second inductor L2 will not change suddenly, the first diode D1 is turned on, and at the same time, the voltage on the first capacitor C1 and the second capacitor C2 is not enough to turn on the third diode D3, so the current on the first capacitor C1 forms a loop through the second diode D2. At time t2, the voltage on the first capacitor C1 and the second capacitor C2 is enough to turn on the third diode D3, so at time t3, the first diode D1, the second diode D2 and the third diode D3 are all turned on.

[0088] As shown in FIG4 , the dotted line represents disconnection, the solid line represents flow, and the direction of the arrow is the actual current direction.

[0089] In one embodiment, in the third working mode, the electrical parameter relationship is as follows:

[0090] V L1 =V i -V C1

[0091] V L2 =V C1 –V0

[0092] Among them, V i Indicates the voltage of the input power supply; V L1 represents the voltage across the first inductor L1 in the third working mode; V L2 represents the voltage across the second inductor L2 in the third working mode; V C1 represents the voltage across the first capacitor C1 in the third working mode; V0 represents the voltage across the charging pile.

[0093] In one embodiment, the voltage gain G of the DC boost converter is calculated as follows:

[0094]

[0095] Among them, V i Represents the voltage of the input power supply; V0 represents the voltage across the charging pile; D is the duty cycle of the first power switch tube S1 and the second power switch tube S2.

[0096] Specifically, the switching period of the first power switch tube S1 and the second power switch tube S2 is set to T s , the duty cycle is D, that is, the duration of the first working mode is DT s , the duration of the second working mode is DT s , the duration of the third working mode (1-2D) T s ; According to the volt-second balance characteristics of inductance, we can get:

[0097]

[0098]

[0099]

[0100] Wherein, VC1 represents the voltage across the first capacitor C1; VC2 represents the voltage across the second capacitor C2; V i Indicates the voltage of the input power supply; V0 indicates the voltage across the charging pile (output voltage).

[0101] Combining the above formulas, we can get the calculation formula for the voltage gain. By comparison, it can be seen that when the duty cycle D varies in the range of 0 to 0.49, the voltage gain of the traditional DC converter can only vary in the range of 0 to 2, that is, the output voltage (the voltage at both ends of the charging pile) can only be 0 to 2 times the input voltage (the voltage of the input power supply), while the voltage gain of the DC boost converter provided in the present application can vary in the range of 0 to 74.5, and the output voltage can be up to 37.25 times the input voltage, which greatly expands the gain of the traditional DC converter.

[0102] In the above DC boost converter, an input power supply, two power switch tubes, two inductors, three capacitors and three diodes are configured in the DC boost converter, and the inherent characteristics of the inductor-capacitor-diode network are utilized. When the first power switch tube S1 and the second power switch tube S2 are turned on, the input power supply V i The first capacitor C1 charges the first inductor L1, the first capacitor C1 also charges the second capacitor C2 and the second inductor L2, and the output capacitor C0 supplies power to the charging pile; when the first power switch tube S1 and the second power switch tube S2 are disconnected, the input power supply V i The first inductor L1 charges the first capacitor C1, the second inductor L2 charges the second capacitor C2, and the output capacitor C0 supplies power to the charging pile. When the voltage on the first capacitor C1 and the second capacitor C2 is sufficient to turn on the third diode D3, the input power supply V iThe first capacitor C1 is charged by the first inductor L1, and the second inductor L2 and the second capacitor C2 are charged to supply power to the output capacitor C0 and the charging pile, thereby increasing the output voltage. The original characteristics of the traditional DC converter are combined to achieve the expansion of the converter output voltage gain, while improving the work efficiency. The voltage gain and work efficiency can be improved by adopting a relatively simple circuit topology, meeting the low-cost requirement.

[0103] In an exemplary embodiment, as shown in FIG5 , a charging system is provided, including a control module, a driving module connected to the control module, and a DC boost converter as described above connected to the driving module; wherein:

[0104] The driving module is connected to the gate of the first power switch tube S1 and the gate of the second power switch tube S2 respectively, and the control module is used to connect to the charging pile.

[0105] Specifically, the control module can control the driving module to adjust the working states of the first power switch tube S1 and the second power switch tube S2 at the corresponding time, and the feedback amounts received by the current feedback and the voltage feedback are respectively the current I0 (output current) flowing into the charging end of the charging pile and the voltage V0 (output voltage) flowing into the charging end of the charging pile in Figure 5.

[0106] It should be noted that the circuit structure of the DC boost converter is relatively simple and occupies a relatively small space in the charging system, that is, the total volume of the charging system is relatively small and has the characteristic of portability.

[0107] By way of example, in order to facilitate the understanding of those skilled in the art, the voltage / current inside the charging system is explained below with reference to a specific example, as shown in FIG6 , which exemplarily shows a schematic diagram of the voltage / current waveforms corresponding to each device in the charging system during a switching cycle.

[0108] As shown in Figure 6, V G represents the driving signal of the first power switch tube S1 and the second power switch tube S2; V L1 、i L1 They are respectively represented as the voltage and current across the first inductor L1 (the solid line is the voltage, and the dotted line is the current); V L2 、i L2 They are respectively represented as the voltage and current across the second inductor L2 (the solid line is the voltage, and the dotted line is the current); V i Indicates the voltage of the input power supply; V C1 Represents the voltage across the first capacitor C1; V C2 Represents the voltage across the second capacitor C2; V D1 Represented as the voltage across the first diode D1; V D2 Represented as the voltage across the second diode D2; V D3Represented as the voltage across the third diode D3; V S1 It is represented by the voltage between the drain and source of the first power switch tube S1; V S2 It is represented by the voltage between the drain and source of the second power switch tube S2; i C0 It is represented by the current flowing through the output capacitor C0; the switching period T of the first power switch tube S1 and the second power switch tube S2 s and duty cycle D.

[0109] In the description of this specification, the description with reference to the terms "some embodiments", "other embodiments", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic description of the above terms does not necessarily refer to the same embodiment or example.

[0110] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0111] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A DC boost converter, characterized in that: include: Input power V i ; A first inductor L1, one end of which is connected to the input power supply V i The positive electrode is connected; A first power switch tube S1, wherein a drain of the first power switch tube S1 is connected to the other end of the first inductor L1; a first diode D1, wherein an anode of the first diode D1 is connected to the other end of the first inductor L1 and a drain of the first power switch tube S1 respectively; A second diode D2, wherein the anode of the second diode D2 is connected to the source of the first power switch tube S1, and the cathode of the second diode D2 is connected to the input power supply V i The negative electrode; A first capacitor C1, one end of the first capacitor C1 is connected to the source of the first power switch tube S1 and the anode of the second diode D2 respectively, and the other end of the first capacitor C1 is connected to the cathode of the first diode D1; A second capacitor C2, one end of which is respectively connected to the other end of the first inductor L1, the drain of the first power switch tube S1 and the anode of the first diode D1; a second inductor L2, one end of the second inductor L2 being connected to the cathode of the first diode D1 and the other end of the first capacitor C1 respectively, and the other end of the second inductor L2 being connected to the other end of the second capacitor C2; The second power switch tube S2, the drain of the second power switch tube S2 is respectively connected to the cathode of the first diode D1, the other end of the first capacitor C1 and one end of the second inductor L2, and the source of the second power switch tube S2 is respectively connected to the cathode of the second diode D2 and the input power supply V i The negative electrode; A third diode D3, wherein an anode of the third diode D3 is connected to the other end of the second capacitor C2 and the other end of the second inductor L2 respectively, and a cathode of the third diode D3 is used to connect to a charging end of a charging pile; The output capacitor C0 has one end connected to the source of the second power switch tube S2, the cathode of the second diode D2 and the input power supply V i The other end of the output capacitor C0 is connected between the cathode of the third diode D3 and the charging end of the charging pile.

2. The DC boost converter according to claim 1, characterized in that: The DC boost converter is in a first working mode, a second working mode and a third working mode in sequence within a switching cycle.

3. The DC boost converter according to claim 2, characterized in that: When the DC boost converter is in the first working mode, the first power switch tube S1 and the second power switch tube S2 are turned on, and the first diode D1, the second diode D2 and the third diode D3 are all turned off.

4. The DC boost converter according to claim 3, characterized in that: In the first working mode, the electrical parameter relationship is as follows: V L1 =V i +V C1 V L2 =V C1 -V C2 Among them, the V i represents the voltage of the input power supply; the V L1 represents the voltage across the first inductor L1 in the first working mode; the V L2 represents the voltage across the second inductor L2 in the first working mode; the V C1 represents the voltage across the first capacitor C1 in the first working mode; the V C2 Represents the voltage across the second capacitor C2 in the first working mode.

5. The DC boost converter according to claim 2, characterized in that: When the DC boost converter is in the second working mode, the first power switch tube S1 and the second power switch tube S2 are turned off, the first diode D1 and the second diode D2 are both turned on, and the third diode D3 is turned off.

6. The DC boost converter according to claim 5, characterized in that: In the second working mode, the electrical parameter relationship is as follows: V L1 = V i -V C1 V L2 = -V C2 Among them, the V i represents the voltage of the input power supply; the V L1 represents the voltage across the first inductor L1 in the second working mode; the V L2 represents the voltage across the second inductor L2 in the second working mode; the V C1 represents the voltage across the first capacitor C1 in the second working mode; the V C2 Represents the voltage across the second capacitor C2 in the second working mode.

7. The DC boost converter according to claim 2, characterized in that: When the DC boost converter is in the third working mode, the first power switch tube S1 and the second power switch tube S2 are turned off, and the first diode D1, the second diode D2 and the third diode D3 are all turned on.

8. The DC boost converter according to claim 7, characterized in that: In the third working mode, the electrical parameter relationship is as follows: V L1 =V i -V C1 V L2 =V C1 –V0 Among them, the V i represents the voltage of the input power supply; the V L1 represents the voltage across the first inductor L1 in the third working mode; the V L2 represents the voltage across the second inductor L2 in the third working mode; the V C1 represents the voltage across the first capacitor C1 in the third working mode; V0 represents the voltage across the charging pile.

9. The DC boost converter according to claim 1, characterized in that: The voltage gain G of the DC boost converter is calculated as follows: Among them, the V i represents the voltage of the input power supply; V0 represents the voltage across the charging pile; D is the duty cycle of the first power switch tube S1 and the second power switch tube S2.

10. A charging system, characterized in that: It comprises a control module, a driving module connected to the control module, and a DC boost converter according to any one of claims 1 to 9 connected to the driving module; wherein: The driving module is respectively connected to the gate of the first power switch tube S1 and the gate of the second power switch tube S2, and the control module is used to connect to the charging pile.

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