Three-level direct-current converter, pre-charging method of converter and electronic equipment

Abstract

The invention discloses a three-level direct-current converter, a pre-charging method of the converter and electronic equipment, and relates to the technical field of direct-current conversion, and the three-level direct-current converter comprises an input power supply, at least one flying capacitor and at least one controlled switch tube connected with the flying capacitor; the flying capacitor and the controlled switch tube form a pre-charging circuit, and the input power supply is connected with the pre-charging circuit; wherein the input power supply is used for generating a preset input voltage; the controlled switching tube is used for switching under the control of a preset change pulse signal; and the flying capacitor is used for pre-charging according to the switching of the controlled switching tube. According to the invention, the accurately-controlled preset change pulse signal is adopted to perform on-off control on the controlled switch tube, and the pre-charging process can be dynamically adjusted according to parameters such as flying capacitor voltage and input power supply voltage which are monitored in real time, so that stable pre-charging of the flying capacitor is realized, and the stability of the pre-charging process is improved.

Description

Technical Field

[0001] The present application relates to the technical field of DC conversion, and more specifically, to a three-level DC converter, a pre-charging method for the converter, and an electronic device. Background Art

[0002] A three-level DC converter is a device widely used in the field of DC power conversion. Its characteristics are that the voltage stress of the switching tubes is relatively low, and at the same time, the size of the required filter is also relatively small. These characteristics make the three-level DC converter particularly suitable for application scenarios with relatively high input / output voltages and requiring medium to high power conversion.

[0003] In the existing three-level DC converter technology, the flying capacitor plays a key role. Generally, the pre-charging method of the flying capacitor usually requires additional circuits to implement. These additional circuits may include additional switching tubes, resistors, inductors and other components. The pre-charging process is usually after the converter is powered on, and by controlling these additional circuits, the flying capacitor is gradually charged to the required operating voltage.

[0004] The existing flying capacitor pre-charging circuits are usually relatively complex and require the design and installation of additional circuit components. This not only increases the complexity and cost, but may also introduce additional failure points. And due to the existence of the additional circuit, any component failure in the additional circuit may lead to pre-charging failure or the converter cannot work properly, and its reliability may be affected. At the same time, during the pre-charging process, if the control is improper, a relatively large inrush current may be generated, which will not only damage the bus and the switching tubes, but may also affect the stability of the whole. Summary of the Invention

[0005] In view of at least one defect or improvement requirement of the prior art, the present invention provides a three-level DC converter, a pre-charging method for the converter, and an electronic device, which are used to solve the problems that the existing flying capacitor pre-charging circuit is usually relatively complex, requires the design and installation of additional circuit components, increases the complexity and cost, may introduce additional failure points, its reliability may be affected, and if the control is improper, a relatively large inrush current may be generated, damaging the bus and the switching tubes.

[0006] To achieve the above object, according to the first aspect of the present invention, there is provided a three-level DC converter, including an input power supply, at least one flying capacitor, and at least one controlled switching tube connected to the flying capacitor; the flying capacitor and the controlled switching tube form a pre-charging circuit, and the input power supply is connected to the pre-charging circuit;

[0007] wherein, the input power supply is used to generate a preset input voltage;

[0008] The controlled switch tube is used to switch under the control of a preset variable pulse signal;

[0009] The flying capacitor is used to perform pre - charging according to the switching of the controlled switch tube.

[0010] In a possible implementation, the three - level DC converter is a Buck three - level converter, including: a first controlled switch tube, a first flying capacitor, a first diode, a first inductor, and a first capacitor to form a first pre - charging loop;

[0011] The positive pole of the input power supply is connected to the collector of the first controlled switch tube, the emitter of the first controlled switch tube is connected to one end of the first flying capacitor, the other end of the first flying capacitor is connected to the positive pole of the first diode, the negative pole of the first diode is connected to one end of the first inductor, the other end of the first inductor is connected to one end of the first capacitor, and the other end of the first capacitor is connected to the negative pole of the input power supply.

[0012] In a possible implementation, the three - level DC converter is a Boost three - level converter, including: a second controlled switch tube, a second flying capacitor, a second diode, and a second inductor to form a second pre - charging loop;

[0013] The positive pole of the input power supply is connected to one end of the second inductor, the other end of the second inductor is connected to the positive pole of the second diode, the negative pole of the second diode is connected to one end of the second flying capacitor, the other end of the second flying capacitor is connected to the collector of the second controlled switch tube, and the emitter of the second controlled switch tube is connected to the negative pole of the input power supply.

[0014] In a possible implementation, the three - level DC converter is a half - bridge three - level converter, including: a third controlled switch tube, a third flying capacitor, and a third diode to form a pre - charging loop;

[0015] The positive pole of the input power supply is connected to the collector of the third controlled switch tube, the emitter of the third controlled switch tube is connected to one end of the third flying capacitor, the other end of the third flying capacitor is connected to the positive pole of the third diode, and the negative pole of the third diode is connected to the negative pole of the input power supply.

[0016] In a possible implementation, the three - level DC converter is a full - bridge three - level converter, including: a fourth switch tube, a fourth flying capacitor, and a fourth diode to form a fourth pre - charging loop, and a fifth switch tube, a fifth flying capacitor, and a fifth diode to form a fifth pre - charging loop;

[0017] The positive pole of the input power supply is connected to the collector of the fourth controlled switch tube, the emitter of the fourth controlled switch tube is connected to one end of the fourth flying capacitor, the other end of the fourth flying capacitor is connected to the positive pole of the fourth diode, and the negative pole of the fourth diode is connected to the negative pole of the input power supply;

[0018] The positive electrode of the input power supply is connected to the collector of the fifth controlled switch tube. The emitter of the fifth controlled switch tube is connected to one end of the fifth flying capacitor. The other end of the fifth flying capacitor is connected to the positive electrode of the fifth diode. The negative electrode of the fifth diode is connected to the negative electrode of the input power supply.

[0019] In a possible implementation, an output filter is further included. The output filter is connected to the output end of the three-level DC converter and is used for filtering the output voltage.

[0020] In a possible implementation, a control unit is further included, which is used to apply a preset variable pulse signal to the controlled switch tube for pre-charging, and stop applying the preset variable pulse signal when the flying capacitor reaches a preset voltage value.

[0021] According to the second aspect of the present invention, a pre-charging method for a three-level DC converter is further provided. Based on the three-level DC converter in any one of the above implementation manners, it specifically includes:

[0022] Power on the three-level DC converter, and apply a preset variable pulse signal to form a pre-charging loop with the flying capacitor;

[0023] Based on the pre-charging loop, pre-charge the flying capacitor with a preset input voltage;

[0024] When the voltage of the flying capacitor reaches the preset voltage value, stop pre-charging the flying capacitor, and the pre-charging ends.

[0025] In a possible implementation, the preset variable pulse signal starts from a preset duty cycle and gradually increases according to a preset rule until the pre-charging of the flying capacitor ends.

[0026] According to the third aspect of the present invention, an electronic device including the three-level DC converter in any one of the above implementation manners is further provided, including:

[0027] An input interface for connecting to an external power supply;

[0028] An output interface for connecting to a load;

[0029] Wherein, the three-level DC converter is located between the input interface and the output interface and is used for converting the voltage of the input power supply into a preset load input voltage.

[0030] Generally speaking, compared with the prior art through the above technical solutions conceived by the present invention, the following beneficial effects can be achieved:

[0031] A three-level DC converter provided by the present invention introduces a controlled switch tube and a preset pulse signal control. By using the accurately controlled preset pulse signal to control the switching of the controlled switch tube, the controlled switch tube performs switching actions under the control of the preset pulse signal, which can ensure that the flying capacitor is gradually charged to the preset voltage value under safe conditions, avoiding abnormal situations such as overvoltage or overcurrent, realizing the stable pre-charging of the flying capacitor, effectively reducing the influence of input power supply fluctuations and inconsistent switch tube characteristics on the pre-charging process, and thus improving the stability of the pre-charging process. The pre-charging strategy can be optimized according to the actual situation, enabling fast and efficient charging of the flying capacitor, not only shortening the pre-charging time but also reducing the energy efficiency loss. According to the parameters such as the voltage of the flying capacitor and the input power supply voltage monitored in real time, the pre-charging process can be dynamically adjusted to ensure that the pre-charging process is always in the best state, thereby achieving the best pre-charging effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0033] Figure 1 It is a schematic flowchart of an embodiment of a pre-charging method for a three-level DC converter provided by the present invention;

[0034] Figure 2 It is a schematic circuit structure diagram of an embodiment of a Buck three-level converter provided by the present invention;

[0035] Figure 3 It is a schematic circuit structure diagram of an embodiment of a Boost three-level converter provided by the present invention;

[0036] Figure 4 It is a schematic circuit structure diagram of an embodiment of a half-bridge three-level converter provided by the present invention;

[0037] Figure 5 It is a schematic circuit structure diagram of an embodiment of a full-bridge three-level converter provided by the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0038] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0039] The terms "first", "second", "third", etc. in the description, claims and the above-mentioned drawings of this application are used to distinguish different objects, rather than to describe a specific order. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, product or device that includes a series of steps or units is not limited to the listed steps or units, but optionally further includes steps or units not listed, or optionally further includes other steps or units inherent to these processes, methods, products or devices.

[0040] The present invention provides a three-level DC converter, a pre-charging method for the converter and an electronic device, which will be described separately below.

[0041] Please refer to Figure 1 , Figure 1 is a schematic flow chart of an embodiment of a pre-charging method for a three-level DC converter provided by the present invention. In a specific embodiment of the present invention, a pre-charging method for a three-level DC converter is disclosed, including:

[0042] S101. Power on the three-level DC converter, and apply a preset variable pulse signal to the controlled switch tube to form a pre-charging loop with the flying capacitor;

[0043] S102. Based on the pre-charging loop, pre-charge the flying capacitor with a preset input voltage;

[0044] S103. When the voltage of the flying capacitor reaches a preset voltage value, stop pre-charging the flying capacitor, and the pre-charging ends.

[0045] In the above embodiment, the three-level DC converter is powered on, and a preset variable pulse signal is applied to the controlled switch tube connected to the flying capacitor. The role of the preset variable pulse signal is to jointly form an effective pre-charging loop with the flying capacitor. The pre-charging loop ensures that the current can flow along a predetermined path, thereby charging the flying capacitor.

[0046] Based on the pre-charging loop constructed above, start pre-charging the flying capacitor with a preset charging input voltage. The preset input voltage is selected according to the design specifications of the converter and the actual application requirements to ensure that the flying capacitor can be safely and effectively charged to the required voltage level.

[0047] During the pre - charging process, continuously monitor the voltage of the flying capacitor. When the voltage of the flying capacitor gradually rises to the preset voltage value, immediately stop the pre - charging operation of the flying capacitor. This preset voltage value is determined according to the normal operating conditions and performance requirements of the converter to ensure that the converter can operate stably after startup. As a preferred embodiment, the preset voltage value in the present invention is half of the input voltage.

[0048] Compared with the prior art, a three - level DC converter provided in this embodiment introduces a controlled switch tube and a preset pulse signal control. By using a precisely controlled preset pulse signal to control the switching of the controlled switch tube, the controlled switch tube performs switching actions under the control of the preset pulse signal, which can ensure that the flying capacitor is gradually charged to the preset voltage value under safe conditions, avoiding abnormal situations such as over - voltage or over - current, realizing the smooth pre - charging of the flying capacitor, effectively reducing the influence of input power supply fluctuations and inconsistent switch tube characteristics on the pre - charging process, and thus improving the stability of the pre - charging process. The pre - charging strategy can be optimized according to actual situations, enabling fast and efficient charging of the flying capacitor, not only shortening the pre - charging time but also reducing energy efficiency losses. According to parameters such as the voltage of the flying capacitor and the input power supply voltage monitored in real - time, the pre - charging process can be dynamically adjusted to ensure that the pre - charging process is always in the best state, thereby achieving the best pre - charging effect.

[0049] In some embodiments of the present invention, the preset variable pulse signal starts from a preset duty cycle and gradually increases according to a preset rule until the pre - charging of the flying capacitor ends.

[0050] In the above - mentioned embodiment, the preset variable pulse signal is a pulse signal with a gradually increasing duty cycle. As a preferred embodiment, the duty cycle of the preset variable pulse signal in the present invention starts from 0% and gradually increases at a specific ratio every other cycle time until the pre - charging of the flying capacitor ends. It can be understood that the cycle time and the specific ratio in the present invention can be adjusted according to actual needs.

[0051] According to the second aspect of the present invention, there is also provided a three - level DC converter, including an input power supply, at least one flying capacitor, and at least one controlled switch tube connected to the flying capacitor; the flying capacitor and the controlled switch tube form a pre - charging circuit, and the input power supply is connected to the pre - charging circuit;

[0052] wherein, the input power supply is used to generate a preset input voltage;

[0053] The controlled switch tube is used to perform switching under the control of the preset variable pulse signal;

[0054] The flying capacitor is used to be pre - charged according to the switching of the controlled switch tube.

[0055] In the above embodiments, as the energy source of the entire converter, the input power supply provides a stable DC voltage or current, laying the foundation for the subsequent voltage conversion process. The input power supply can be a battery, a solar panel, the DC power after rectifying the mains power, etc., depending on the application scenario and design.

[0056] The flying capacitor is used to store and release charges between different operating states of the converter, thereby achieving smooth voltage conversion and stable output. In the present invention, at least one flying capacitor is adopted and connected in parallel to the circuit of the converter, and its charging and discharging process is managed by the opening and closing of a controlled switch.

[0057] Connected to the flying capacitor are at least one controlled switch. These switches (such as MOSFETs, IGBTs, etc.) perform rapid opening and closing actions under the drive of a control signal, thereby precisely controlling the charging and discharging process of the flying capacitor. The performance of the controlled switch directly affects the efficiency and stability of the converter. Therefore, it is crucial to select high-quality switches.

[0058] It should be noted that according to the specific type of three-level DC converter (such as Buck, Boost, half-bridge or full-bridge, etc.), the design of the pre-charge circuit will be different. However, regardless of the type, the pre-charge circuit includes a flying capacitor and a controlled switch, as well as possible other components (such as inductors, diodes, etc.) to form a complete charge transfer path. During the pre-charge process, the control unit sends a preset variable pulse signal to the controlled switch to gradually charge the flying capacitor to a predetermined voltage level.

[0059] Please refer to Figure 2 , Figure 2 FIG. is a schematic circuit structure diagram of an embodiment of the Buck three-level converter provided by the present invention. In some embodiments of the present invention, the three-level DC converter is a Buck three-level converter, including: a first controlled switch, a first flying capacitor, a first diode, a first inductor, and a first capacitor to form a first pre-charge circuit;

[0060] The positive pole of the input power supply is connected to the collector of the first controlled switch, the emitter of the first controlled switch is connected to one end of the first flying capacitor, the other end of the first flying capacitor is connected to the positive pole of the first diode, the negative pole of the first diode is connected to one end of the first inductor, the other end of the first inductor is connected to one end of the first capacitor, and the other end of the first capacitor is connected to the negative pole of the input power supply.

[0061] In the above embodiments, the first controlled switch is responsible for periodically turning on and off under the drive of a control signal to regulate the output voltage; the first flying capacitor provides charge storage between the two output levels of the converter, which helps to achieve a smoother voltage conversion. The first diode is usually used as a freewheeling diode to provide a path for the current in the inductor when the controlled switch is turned off, preventing current mutation. The first inductor is used to smooth the input current, store energy when the switch is turned on, and release energy when the switch is turned off. The first capacitor serves as an output filter capacitor to reduce the ripple of the output voltage and provide a stable DC output.

[0062] After power-on, a preset variable pulse signal is applied to the first controlled switch Q 1 The duty cycle of the preset variable pulse signal increases from small to large, and its duty cycle gradually increases from 0%, and the first flying capacitor C fly1 is pre-charged through the pre-charge circuit until the first flying capacitor C fly1 The pre-charging ends. After the pre-charging ends, the voltage across the first flying capacitor C fly1 is V in1 *C fly1 / (C fly1 +C f1 )). Taking the capacitance values of the first flying capacitor C fly1 and the first capacitor C f1 to be equal, after the pre-charging ends, the voltage across the first flying capacitor C fly1 is V in1 / 2. At this time, all the switches of the three-level DC converter start to work, and the voltage stress of the first controlled switch is V in1 / 2, and the converter stably outputs.

[0063] Please refer to Figure 3 , Figure 3 which is a schematic diagram of the circuit structure of an embodiment of the Boost three-level converter provided by the present invention. In some embodiments of the present invention, the three-level DC converter is a Boost three-level converter, including: a second controlled switch, a second flying capacitor, a second diode, and a second inductor to form a second pre-charge circuit;

[0064] The positive pole of the input power supply is connected to one end of the second inductor, the other end of the second inductor is connected to the positive pole of the second diode, the negative pole of the second diode is connected to one end of the second flying capacitor, the other end of the second flying capacitor is connected to the collector of the second controlled switch, and the emitter of the second controlled switch is connected to the negative pole of the input power supply.

[0065] In the above embodiments, the second controlled switch is responsible for turning on and off under the drive of the control signal. In this configuration, voltage boost is achieved. The second flying capacitor is similar to the first flying capacitor in the Buck converter and is used to provide charge storage between two output levels. The second diode serves as a rectifying diode and allows the energy released by the inductor to flow to the output terminal through the diode when the switch is turned off. The second inductor stores energy when the switch is turned on and releases energy together with the flying capacitor when the switch is turned off to boost the output voltage.

[0066] After power-on, a preset variable pulse signal is applied to the second controlled switch Q 4 The duty cycle of the preset variable pulse signal increases from small to large. Its duty cycle gradually increases from 0% and cycles. The second flying capacitor C fly2 is pre-charged through the pre-charge circuit. After the pre-charge is completed, the voltage across the second flying capacitor C fly2 is V in2 . At this time, all the switches of the three-level DC converter start to work. The voltage stress of the second controlled switch is V in2 / 2, and the converter stably outputs.

[0067] Please refer to Figure 4 , Figure 4 which is a schematic circuit diagram of an embodiment of the half-bridge three-level converter provided by the present invention. In some embodiments of the present invention, the three-level DC converter is a half-bridge three-level converter, including: a third controlled switch, a third flying capacitor, and a third diode forming a pre-charge circuit;

[0068] The positive pole of the input power supply is connected to the collector of the third controlled switch. The emitter of the third controlled switch is connected to one end of the third flying capacitor. The other end of the third flying capacitor is connected to the positive pole of the third diode. The negative pole of the third diode is connected to the negative pole of the input power supply.

[0069] In the above embodiments, the third controlled switch and another switch (usually called a complementary switch) alternately turn on and off to generate two output levels. The third flying capacitor provides charge storage between the two output levels of the half-bridge circuit, which helps to achieve a smoother voltage conversion. The third diode is usually used as a freewheeling diode to provide a path for the current in the inductor and prevent current mutation.

[0070] After power-on, a preset variable pulse signal is applied to the third controlled switch Q 5 The duty cycle of the preset variable pulse signal increases from small to large. Its duty cycle gradually increases from 0% and the third flying capacitor C fly3 is pre-charged through the pre-charge circuit. After the pre-charge is completed, the voltage across the third flying capacitor C fly3 is the voltage between two points of capacitor C 1 , that is, Vin3 *(C 1 / C 1 +C 2 ), take the capacitor C 1 and C 2 with equal capacitance values. The voltage across the capacitor C 1 is V in3 / 2. Therefore, after the pre-charging is completed, the voltage across the third flying capacitor is V in3 / 2. At this time, all the switching transistors of the three-level DC converter start to operate, and the voltage stress of the switching transistors is V in3 / 2, and the converter outputs stably.

[0071] Please refer to Figure 5 , Figure 5 , which is a schematic circuit diagram of an embodiment of the full-bridge three-level converter provided by the present invention. In some embodiments of the present invention, the three-level DC converter is a full-bridge three-level converter, including: a fourth switching transistor, a fourth flying capacitor, and a fourth diode forming a fourth pre-charging circuit, and a fifth switching transistor, a fifth flying capacitor, and a fifth diode forming a fifth pre-charging circuit;

[0072] The positive pole of the input power supply is connected to the collector of the fourth controlled switching transistor, the emitter of the fourth controlled switching transistor is connected to one end of the fourth flying capacitor, the other end of the fourth flying capacitor is connected to the positive pole of the fourth diode, and the negative pole of the fourth diode is connected to the negative pole of the input power supply;

[0073] The positive pole of the input power supply is connected to the collector of the fifth controlled switching transistor, the emitter of the fifth controlled switching transistor is connected to one end of the fifth flying capacitor, the other end of the fifth flying capacitor is connected to the positive pole of the fifth diode, and the negative pole of the fifth diode is connected to the negative pole of the input power supply.

[0074] In the above embodiment, the fourth switching transistor, the fourth flying capacitor, and the fourth diode together constitute the fourth pre-charging circuit, which is similar to the components in the half-bridge converter, but the full-bridge converter has higher voltage conversion efficiency and greater power handling capacity. The fifth switching transistor, the fifth flying capacitor, and the fifth diode together constitute the fifth pre-charging circuit, which works together with the fourth pre-charging circuit to form two half-bridge parts of the full-bridge circuit.

[0075] After power-on, a preset variable pulse signal is applied to the fourth controlled switching transistor Q 9 , the fifth controlled switching transistor Q 13 , the duty cycle of which changes from small to large, and the duty cycle gradually increases from 0%, and the fourth flying capacitor C fly4 is pre-charged through the fourth pre-charging circuit, and the fifth flying capacitor C fly5 is pre-charged through the fifth pre-charging circuit. After the pre-charging is completed, the fourth flying capacitor C fly4 , the fifth flying capacitor C fly5The voltages at both ends are both capacitance C 3 The voltage between two points, that is, V in4 *(C 3 / C 3 +C 4 ), take capacitance C 3 and C 4 with equal capacitance values. The voltage across capacitance C 3 is V in4 / 2. Therefore, after the pre-charging is completed, the voltages at both ends of the fourth flying capacitor C fly4 and the fifth flying capacitor C fly5 are V in4 / 2. At this time, all the switching tubes of the three-level DC converter start to work, and the voltage stress of the switching tubes is V in4 / 2, and the converter stably outputs.

[0076] In some embodiments of the present invention, an output filter is further included. The output filter is connected to the output end of the three-level DC converter and is used to filter the output voltage.

[0077] In the above embodiments, the output filter effectively reduces the high-frequency components and ripples in the output voltage through the combination of its capacitance and inductance (or other filtering elements), making the output voltage smoother and more stable. For sensitive load devices (such as precision electronic devices, communication devices, etc.), the ripples and noises in the output voltage may have an adverse impact on their performance. The output filter protects the load devices from damage by filtering out these harmful components.

[0078] In some embodiments of the present invention, a control unit is further included, which is used to apply a preset variable pulse signal to the controlled switching tubes for pre-charging and stop applying the preset variable pulse signal when the flying capacitor reaches the preset voltage value.

[0079] In the above embodiments, when the converter starts or the load changes, the control unit controls the charging process of the flying capacitor by applying a preset variable pulse signal to the controlled switching tubes. The parameters such as the frequency and duty cycle of these pulse signals need to be determined according to the specific type and design requirements of the converter to achieve the best pre-charging effect.

[0080] The control unit monitors the voltage value of the flying capacitor in real time and compares it with the preset voltage value. When the voltage of the flying capacitor reaches or exceeds the preset voltage value, the control unit will immediately stop applying the pulse signal to the controlled switching tubes to prevent overvoltage from damaging the converter or the load device.

[0081] In addition to voltage monitoring, the control unit is also responsible for detecting other fault conditions in the converter, such as overcurrent, overheating, etc. Once a fault is detected, the control unit will quickly take measures, such as turning off the controlled switching tubes, cutting off the power supply, etc., to protect the safety of the converter and the load device.

[0082] According to the load variation and the fluctuation of the input voltage, the control unit can dynamically adjust the parameters of the pulse signal (such as frequency, duty cycle, etc.) to optimize the performance of the converter, achieving more efficient voltage conversion and lower energy consumption.

[0083] According to the third aspect of the present invention, there is also provided an electronic device including the three-level DC converter in any one of the above implementation manners, comprising:

[0084] An input interface for connecting to an external power supply;

[0085] An output interface for connecting to a load;

[0086] Wherein, the three-level DC converter is located between the input interface and the output interface and is used to convert the voltage of the input power supply into a preset load input voltage.

[0087] In the above embodiment, the input interface is used to connect to an external power supply to provide the required electrical energy for the electronic device. It supports power inputs of multiple voltage levels and current specifications to meet the requirements of different application scenarios. The input interface can adopt high-performance power sockets and connectors to ensure a reliable connection with the external power supply. At the same time, overcurrent, overvoltage and other protection circuits are equipped inside the interface to prevent damage to the device caused by abnormal external power supplies.

[0088] The output interface is used to connect to a load device to provide a stable DC power supply for the load, supporting power outputs of multiple voltage levels and current specifications to adapt to the power supply requirements of different load devices. The output interface adopts high-performance power sockets and connectors to ensure a reliable connection with the load device. At the same time, a filter circuit and a protection circuit are equipped inside the interface to reduce the ripple and noise of the output voltage and prevent damage to the electronic device caused by abnormal load devices.

[0089] In summary, the three-level DC converter provided by the present invention introduces a controlled switch tube and a preset pulse signal control. By using the accurately controlled preset pulse signal to control the switching of the controlled switch tube, the controlled switch tube performs switching actions under the control of the preset pulse signal, which can ensure that the flying capacitor is gradually charged to the preset voltage value under safe conditions, avoiding abnormal situations such as overvoltage or overcurrent, realizing the smooth pre-charging of the flying capacitor, effectively reducing the influence of input power supply fluctuations and inconsistent switch tube characteristics on the pre-charging process, thereby improving the stability of the pre-charging process. The pre-charging strategy can be optimized according to actual situations, enabling fast and efficient charging of the flying capacitor, not only shortening the pre-charging time but also reducing energy efficiency losses. According to parameters such as the voltage of the flying capacitor and the input power supply voltage monitored in real time, the pre-charging process can be dynamically adjusted to ensure that the pre-charging process is always in the best state, thereby achieving the best pre-charging effect.

[0090] 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 this application is not limited by the described action sequence, because according to this application, 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 this application.

[0091] In the above embodiments, the descriptions of each embodiment have their own emphases. For the parts not detailed in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0092] In several embodiments provided by this application, it should be understood that the disclosed device can be implemented in other ways. For example, the device embodiments described above are only illustrative. For example, the division of the units is only a logical function division. In actual implementation, there can be other division methods. For example, multiple units or components can be combined or integrated into another one, or some features can be ignored or not executed. Another point is that the displayed or discussed coupling or direct coupling or communication connection to each other can be through some service interfaces. The indirect coupling or communication connection of the device or unit can be in an electrical or other form.

[0093] 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 network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0094] The above are only exemplary embodiments of the present disclosure, and the scope of the present disclosure cannot be limited thereby. That is, all equivalent changes and modifications made according to the teachings of the present disclosure still fall within the scope covered by the present disclosure. After considering the specification and practicing the disclosure herein, those skilled in the art will readily think of other implementations of the present disclosure. This application aims to cover any variations, uses, or adaptive changes of the present disclosure, and these variations, uses, or adaptive changes follow the general principles of the present disclosure and include common general knowledge or conventional technical means in the technical field not recorded in the present disclosure. The specification and embodiments are only regarded as exemplary, and the scope and spirit of the present disclosure are defined by the claims.

[0095] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, it should be considered that it is within the scope described in this specification.

[0096] Those skilled in the art can easily understand that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent replacements, and improvements made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A three-level DC converter, characterized in that: The device comprises an input power supply, at least one flying capacitor and at least one controlled switch tube connected to the flying capacitor; the flying capacitor and the controlled switch tube form a pre-charging circuit, and the input power supply is connected to the pre-charging circuit; Wherein, the input power supply is used to generate a preset input voltage; The controlled switch tube is used to switch under the control of a preset changing pulse signal; The flying capacitor is used for pre-charging according to the switching of the controlled switch tube.

2. The three-level DC converter according to claim 1, characterized in that: The three-level DC converter is a Buck three-level converter, comprising: a first controlled switch tube, a first flying capacitor, a first diode, a first inductor, and a first capacitor forming a first pre-charging circuit; The positive electrode of the input power supply is connected to the collector of the first controlled switch tube, the emitter of the first controlled switch tube is connected to one end of the first flying capacitor, the other end of the first flying capacitor is connected to the positive electrode of the first diode, the negative electrode of the first diode is connected to one end of the first inductor, the other end of the first inductor is connected to one end of the first capacitor, and the other end of the first capacitor is connected to the negative electrode of the input power supply.

3. The three-level DC converter according to claim 1, characterized in that: The three-level DC converter is a Boost three-level converter, comprising: a second controlled switch tube, a second flying capacitor, a second diode, and a second inductor forming a second pre-charging circuit; The positive electrode of the input power supply is connected to one end of the second inductor, the other end of the second inductor is connected to the positive electrode of the second diode, the negative electrode of the second diode is connected to one end of the second flying capacitor, the other end of the second flying capacitor is connected to the collector of the second controlled switch tube, and the emitter of the second controlled switch tube is connected to the negative electrode of the input power supply.

4. The three-level DC converter according to claim 1, characterized in that: The three-level DC converter is a half-bridge three-level converter, comprising: a third controlled switch tube, a third flying capacitor, and a third diode forming a pre-charging circuit; The positive electrode of the input power supply is connected to the collector of the third controlled switch tube, the emitter of the third controlled switch tube is connected to one end of the third flying capacitor, the other end of the third flying capacitor is connected to the positive electrode of the third diode, and the cathode of the third diode is connected to the negative electrode of the input power supply.

5. The three-level DC converter according to claim 1, characterized in that: The three-level DC converter is a full-bridge three-level converter, comprising: a fourth switch tube, a fourth flying capacitor, and a fourth diode forming a fourth pre-charging loop, and a fifth switch tube, a fifth flying capacitor, and a fifth diode forming a fifth pre-charging loop; The positive electrode of the input power supply is connected to the collector of the fourth controlled switch tube, the emitter of the fourth controlled switch tube is connected to one end of the fourth flying capacitor, the other end of the fourth flying capacitor is connected to the positive electrode of the fourth diode, and the cathode of the fourth diode is connected to the negative electrode of the input power supply; The positive electrode of the input power supply is connected to the collector of the fifth controlled switch tube, the emitter of the fifth controlled switch tube is connected to one end of the fifth flying capacitor, the other end of the fifth flying capacitor is connected to the positive electrode of the fifth diode, and the cathode of the fifth diode is connected to the negative electrode of the input power supply.

6. The three-level DC converter according to claim 1, characterized in that: It also includes an output filter, which is connected to the output end of the three-level DC converter and is used to filter the output voltage.

7. The three-level DC converter according to claim 1, characterized in that: It also includes a control unit, which is used to apply a preset change pulse signal to the controlled switch tube for pre-charging, and stop applying the preset change pulse signal when the flying capacitor reaches a preset voltage value.

8. A pre-charging method for a three-level DC converter, based on the three-level DC converter as described in any one of claims 1 to 7, characterized in that: Specifically include: Powering on the three-level DC converter, applying a preset change pulse signal to the controlled switch tube and forming a pre-charging circuit with the flying capacitor; Based on the pre-charging circuit, pre-charging the flying capacitor with a preset input voltage; When the voltage of the flying capacitor reaches a preset voltage value, precharging the flying capacitor is stopped, and the precharging ends.

9. The precharging method of a three-level DC converter according to claim 8, characterized in that: The preset change pulse signal gradually increases from a preset duty cycle according to a preset rule until the pre-charging of the flying capacitor is completed.

10. An electronic device comprising the three-level DC converter according to any one of claims 1 to 7, characterized in that: The device also includes: Input interface, used to connect external power supply; Output interface, used to connect the load; Wherein, the three-level DC converter is located between the input interface and the output interface, and is used to convert the voltage of the input power supply into a preset load input voltage.

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