A power circuit management system and method for a new energy vehicle charging pile

Abstract

The present invention relates to a power circuit management system and method for a new energy vehicle charging pile, comprising: a first DC converter (1), a second DC converter (2), a third DC converter (3), an Nth DC converter (4), an input DC power supply (5), a power distributor (6), a power controller (7), a power control signal line (8), a power distribution control bus (9), a first output end (10), a second output end (11), a third output end (12), and a fourth output end (13). The system solves the problems existing in the existing charging pile power circuit management system in terms of output parameter flexibility, stability, power distribution and control, and realizes efficient, stable and accurate charging of new energy vehicles.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicle charging, and in particular to a power circuit management system and method for a new energy vehicle charging pile. Background Art

[0002] With the vigorous development of the new energy vehicle industry, charging piles, as key infrastructure for providing power supply for new energy vehicles, have attracted much attention for their performance and reliability. New energy vehicles have diverse and strict requirements for parameters such as charging voltage, current, and charging power, and the charging requirements of different models and different battery states vary greatly. However, the existing charging pile power circuit management system has many shortcomings, such as the lack of flexibility in power output parameters, which makes it difficult to accurately match the charging needs of various new energy vehicles; insufficient stability and adaptability when dealing with complex charging scenarios and changing grid input conditions; and the lack of efficient power distribution and control mechanisms, which easily lead to problems such as low charging efficiency and energy waste. Therefore, it is of great practical significance to develop a system and method that can flexibly adapt to the diverse charging needs of new energy vehicles and has efficient power circuit management capabilities. Summary of the Invention

[0003] The purpose of the present invention is to provide a power circuit management system and method for a new energy vehicle charging pile, so as to solve the problems existing in the existing charging pile power circuit management system in terms of output parameter flexibility, stability, power distribution and control, and realize efficient, stable and accurate charging of new energy vehicles.

[0004] The present invention provides a power circuit management system and method for a new energy vehicle charging pile, the system comprising:

[0005] A first DC converter (1), a second DC converter (2), a third DC converter (3), an Nth DC converter (4), an input DC power supply (5), a power distributor (6), a power controller (7), a power control signal line (8), a power distribution control bus (9), a first output end (10), a second output end (11), a third output end (12), and a fourth output end (13);

[0006] The input DC power supply (5) is connected in parallel to the input ends of the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4);

[0007] The output ends of the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) are respectively connected to a power distributor (6), and output four terminals through the power distributor (6): a first output end (10), a second output end (11), a third output end (12), and a fourth output end (13);

[0008] The power controller (7) controls the output current and output voltage of the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) respectively through a power control signal line (8), so as to meet the charging requirements of the new energy vehicle;

[0009] The power controller (7) controls the on and off of the contactor in the power distributor (6) via the power distribution control bus (9), so that the power output meets the power supply system requirements for charging new energy vehicles.

[0010] Furthermore, the power distributor (6) comprises: a first series switch (601), a second series switch (602), a third series switch (603), a first positive switch (604), a second positive switch (605), a third positive switch (606), a first negative switch (607), a second negative switch (608), a third negative switch (609), a first output switch (610), and a second output switch (611); the first series switch (601) is connected to the negative output terminal of the first DC converter (1) and the positive output terminal of the second DC converter (2); the second series switch (602) is connected to the negative output terminal of the second DC converter (2) and the positive output terminal of the third DC converter (3); the third series switch (603) is connected to the negative output terminal of the third DC converter (3) and the positive output terminal of the Nth DC converter (4); the output voltages of the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) are connected in series and then output;

[0011] The first positive switch (604) is connected to the positive output terminal of the first DC converter (1) and the positive output terminal of the second DC converter (2); the second positive switch (605) is connected to the positive output terminal of the first DC converter (1) and the positive output terminal of the third DC converter (3); and the third positive switch (606) is connected to the positive output terminal of the first DC converter (1) and the positive output terminal of the Nth DC converter (4);

[0012] The first negative switch (607) is connected to the negative output terminal of the first DC converter (1) and the negative output terminal of the Nth DC converter (4); the second negative switch (608) is connected to the negative output terminal of the second DC converter (2) and the negative output terminal of the Nth DC converter (4); the third negative switch (609) is connected to the negative output terminal of the third DC converter (3) and the negative output terminal of the Nth DC converter (4); the output voltages of the first DC converter (1), the second DC converter (2), the third DC converter (3) and the Nth DC converter (4) are connected in parallel and then output;

[0013] The first output terminal (10) is directly connected to the positive output terminal of the first DC converter (1) through a power distributor (6); the second output terminal (11) is connected to the negative output terminal of the second DC converter (2) through a first output switch (610); the third output terminal (12) is connected to the positive output terminal of the third DC converter (3) through a second output switch (611); and the fourth output terminal (13) is directly connected to the positive output terminal of the Nth DC converter (4) through a power distributor (6).

[0014] Furthermore, the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) have the same module structure, the output rated power of each DC converter is 1 / N of the maximum total output power Pmax, N is greater than or equal to 4, and the output voltage of each DC converter is adjustable from 0 to a maximum output voltage Umax.

[0015] Furthermore, the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) have the same structure and are all DC / DC converters with input and output isolation, including at least one isolation transformer. Specifically, each DC converter includes: a first power switch (101), a second power switch (102), a third power switch (103), a fourth power switch (104), a primary inductor (105), a high-frequency transformer (106), a diode A (107), a diode B (108), an output inductor (109), and an output capacitor (109);

[0016] The first power switch (101), the second power switch (102), the third power switch (103), the fourth power switch (104), the primary inductor (105), and the primary side of the high-frequency transformer (106) form a high-frequency inverter circuit;

[0017] The secondary side of the high-frequency transformer (106), the diode A (107), the diode B (108), the output inductor (109), and the output capacitor (109) form a rectifier and filter circuit;

[0018] By adjusting the duty ratios of the first power switch (101), the second power switch (102), the third power switch (103), and the fourth power switch (104), the output voltage and current can be controlled.

[0019] Furthermore, the switch in the power distributor (6) is a contactor or a power semiconductor field effect MOSFET tube.

[0020] Furthermore, in the power distributor (6), when the first series switch (601), the second series switch (602), and the third series switch (603) are turned on, the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), the third negative switch (609), the first output switch (610), and the second output switch (611) are all turned off.

[0021] Furthermore, when the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) are turned on, the first series switch (601), the second series switch (602), and the third series switch (603) are all turned off.

[0022] Furthermore, when the first output switch (610) and the second output switch (611) are turned on, the first series switch (601) and the third series switch (603) are turned on, the second series switch (602) is not turned on, and the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) are all not turned on.

[0023] Furthermore, the power controller (7) has the following control strategy:

[0024] The first series switch (601), the second series switch (602), and the third series switch (603) of the power distributor (6) are controlled to be turned on; the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), the third negative switch (609), the first output switch (610), and the second output switch (611) are all turned off;

[0025] At the same time, the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) are controlled to output an adjustable voltage U between 0 and Umax, and the output power of each converter is P;

[0026] The output voltage between the first output terminal (10) and the fourth output terminal (13) is 4U, and U≤Umax; the total power output between the first output terminal (10) and the fourth output terminal (13) is 4P≤Pmax.

[0027] Furthermore, the power controller (7) has the following control strategy:

[0028] The first series switch (601), the second series switch (602), and the third series switch (603) of the power distributor (6) are controlled to be non-conductive; the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) are controlled to be conductive, and the first output switch (610) and the second output switch (611) are controlled to be non-conductive;

[0029] At the same time, the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) are controlled to output an adjustable voltage U between 0 and Umax, and the output power of each converter is P;

[0030] The voltage U is output between the first output terminal (10) and the fourth output terminal (13), and U≤Umax; the total power output between the first output terminal (10) and the fourth output terminal (13) is 4P≤Pmax.

[0031] Beneficial Technical Effect: Utilizing multiple DC converter modules with identical structures, their output rated power is proportionally distributed and their voltage is adjustable. This modular design allows for easy addition and subtraction of modules based on charging needs, enabling flexible power adjustment. The modules are highly interchangeable, facilitating maintenance and replacement, effectively improving the availability and reliability of the charging pile system and enabling precise adaptation to the charging power requirements of different new energy vehicles.

[0032] The power divider features a unique architecture and multiple switches. By combining different switch conduction modes, it can achieve various output modes, such as series output for high voltage and parallel output for high current, as well as complex and diverse output configurations. This precisely matches the varying voltage, current, and power requirements of new energy vehicles at different charging stages and for different vehicle models, ensuring charging compatibility.

[0033] Innovative, multi-control strategies leverage a power controller to coordinate the DC converter and power distributor. Output parameters and switch states can be dynamically adjusted based on the real-time charging status and external conditions, enabling precise control of charging voltage, current, and power. This not only meets diverse charging needs but also efficiently utilizes power, avoiding waste and improving charging efficiency.

[0034] The DC converter utilizes a DC / DC converter structure with input and output isolation and an isolation transformer. This provides enhanced electrical safety, preventing input-side faults from damaging the vehicle battery. Furthermore, it reduces the impact of input-side fluctuations and interference on the output, ensuring stable and pure output power, providing a reliable charging environment for the vehicle and extending battery life.

[0035] The power distributor's switches can be either contactors or MOSFETs. Contactors are suitable for high-power, high-reliability applications, while MOSFETs excel in applications requiring high switching speed and precision. Choosing the right component based on different charging requirements optimizes system performance, enhancing both applicability and competitiveness. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 Composed of multi-module universal DC power supply;

[0037] Figure 2 Traditional multi-power supply system DC power supply;

[0038] Figure 3 Internal structure of power distributor;

[0039] Figure 4 DC converter options;

[0040] Figure 5 It is composed of a multi-module universal DC power supply with AC input. DETAILED DESCRIPTION

[0041] Example 1

[0042] (1) Overall architecture

[0043] like Figure 1-5 The power circuit management system of the new energy vehicle charging pile of the present invention comprises: a first DC converter (1), a second DC converter (2), a third DC converter (3), an Nth DC converter (4), an input DC power supply (5), a power distributor (6), a power controller (7), a power control signal line (8), a power distribution control bus (9), a first output end (10), a second output end (11), a third output end (12), and a fourth output end (13).

[0044] (2) Connection relationship between components

[0045] 1. Connection of input DC power supply and DC converters The input DC power supply (5) is connected in parallel to the input terminals of the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4). This connection ensures that each DC converter can obtain electrical energy from the same input source, laying the foundation for subsequent voltage conversion and power distribution to meet the charging requirements of different new energy vehicles.

[0046] 2. Connection between DC converter and power distributor

[0047] The output ends of the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) are respectively connected to a power distributor (6), and output four terminals through the power distributor (6): a first output terminal (10), a second output terminal (11), a third output terminal (12), and a fourth output terminal (13). This connection enables the electric energy output by each DC converter to be reasonably distributed and combined through the power distributor, thereby providing suitable charging voltage, current, and power for the new energy vehicle.

[0048] 3. Connection between power controller and other components

[0049] The power controller (7) controls the output current and output voltage of the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) respectively through the power control signal line (8), so that they meet the charging requirements of the new energy vehicle. At the same time, the power controller (7) controls the on and off of the contactor in the power distributor (6) through the power distribution control bus (9), so that the power output meets the power supply system requirements of the new energy vehicle charging. Through these two connection methods, the power controller can comprehensively and accurately regulate the output parameters of the entire power circuit management system to adapt to the charging conditions of various new energy vehicles.

[0050] (3) Specific structure of power divider

[0051] The power distributor (6) comprises: a first series switch (601), a second series switch (602), a third series switch (603), a first positive switch (604), a second positive switch (605), a third positive switch (606), a first negative switch (607), a second negative switch (608), a third negative switch (609), a first output switch (610), and a second output switch (611).

[0052] 1. Connection and function of series switches

[0053] The first series switch (601) is connected to the output negative terminal of the first DC converter (1) and the output positive terminal of the second DC converter (2), the second series switch (602) is connected to the output negative terminal of the second DC converter (2) and the output positive terminal of the third DC converter (3), and the third series switch (603) is connected to the output negative terminal of the third DC converter (3) and the output positive terminal of the Nth DC converter (4). The output voltages of the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) are connected in series and then output. By connecting these series switches, the series combination of the output voltages of the various DC converters can be achieved, thereby obtaining output voltages of different levels to meet the high-voltage charging requirements of new energy vehicles at different charging stages or different models.

[0054] 2. Connection and function of positive switch and negative switch

[0055] The first positive switch (604) is connected to the positive output terminal of the first DC converter (1) and the positive output terminal of the second DC converter (2); the second positive switch (605) is connected to the positive output terminal of the first DC converter (1) and the positive output terminal of the third DC converter (3); the third positive switch (606) is connected to the positive output terminal of the first DC converter (1) and the positive output terminal of the Nth DC converter (4); the first negative switch (607) is connected to the negative output terminal of the first DC converter (1) and the negative output terminal of the Nth DC converter (4); the second negative switch (608) is connected to the negative output terminal of the second DC converter (2) and the negative output terminal of the Nth DC converter (4); the third negative switch (609) is connected to the negative output terminal of the third DC converter (3) and the negative output terminal of the Nth DC converter (4); the output voltages of the first DC converter (1), the second DC converter (2), the third DC converter (3) and the Nth DC converter (4) are connected in parallel and then output. This connection method of the positive switch and the negative switch enables the output voltages of the various DC converters to be combined in parallel, providing a larger output current to meet the high-current charging needs of new energy vehicles, especially during the fast charging stage.

[0056] 3. Connection and function of output switch

[0057] The first output terminal (10) is directly connected to the positive output terminal of the first DC converter (1) through a power divider (6), the second output terminal (11) is connected to the negative output terminal of the second DC converter (2) through a first output switch (610), the third output terminal (12) is connected to the positive output terminal of the third DC converter (3) through a second output switch (611), and the fourth output terminal (13) is directly connected to the positive output terminal of the Nth DC converter (4) through a power divider (6). The arrangement of these output switches facilitates the transmission of electric energy from the power divider to each output terminal, and can achieve different voltage and current output combinations according to different switch conduction states, so as to meet the specific needs of new energy vehicles in different charging scenarios.

[0058] (4) Modular structure and characteristics of DC converter

[0059] 1. Module structure similarity and rated power

[0060] The first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) have the same module structure, and the output rated power of each DC converter is 1 / N of the total output power maximum value Pmax, where N is greater than or equal to 4. This identical module structure design makes each DC converter consistent and interchangeable, and is convenient for production, maintenance, and expansion. In the application scenario of the charging pile, if a DC converter fails, it can be easily replaced with a spare module to ensure the normal operation of the charging pile, and it is also conducive to flexibly adjusting the configuration of the charging pile according to different charging power requirements.

[0061] 2. Output voltage adjustability

[0062] The output voltage of each DC converter is adjustable from 0 to the maximum output voltage Umax. This feature enables the power circuit management system to flexibly adjust the output voltage of each DC converter according to the specific charging voltage requirements of the new energy vehicle. Then, through the combined output of the power divider, it can meet the charging needs of new energy vehicles with different voltage levels, whether in conventional charging or fast charging scenarios.

[0063] (V) Specific circuit structure of DC converter

[0064] The first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) have the same structure and are all DC / DC converters with input and output isolation, including at least one isolation transformer. Specifically, each DC converter includes: a first power switch (101), a second power switch (102), a third power switch (103), a fourth power switch (104), a primary inductor (105), a high-frequency transformer (106), a diode A (107), a diode B (108), an output inductor (109), and an output capacitor (110).

[0065] 1. High-frequency inverter circuit composition

[0066] The first power switch (101), the second power switch (102), the third power switch (103), the fourth power switch (104), the primary inductor (106), and the primary side of the high-frequency transformer (106) constitute a high-frequency inverter circuit. In the high-frequency inverter circuit, by controlling the on and off states of each power switch, input direct current power can be converted into high-frequency alternating current power, preparing for subsequent voltage conversion and isolation processing. This conversion process helps to improve power conversion efficiency and reduce energy loss, thereby providing more efficient charging services for new energy vehicles.

[0067] 2. Composition of rectifier and filter circuit

[0068] The secondary side of the high-frequency transformer (106), diode A (107), diode B (108), output inductor (109), and output capacitor (110) form a rectifier filter circuit. The function of the rectifier filter circuit is to convert the high-frequency AC power output by the high-frequency inverter circuit into stable DC power, and filter the power through the output inductor and output capacitor to obtain a DC output voltage and current that meet the requirements. By adjusting the duty cycle of the first power switch (101), the second power switch (102), the third power switch (103), and the fourth power switch (104), the output voltage and current can be controlled. This method of controlling the output parameters by adjusting the duty cycle of the power switches enables the DC converter to flexibly adjust the output voltage and current according to the instructions of the power controller to meet the charging requirements of the new energy vehicle.

[0069] (6) Types and characteristics of switches in power dividers

[0070] 1. Contactor type switch

[0071] The switch in the power distributor (6) is a contactor. As a commonly used electrical control component, the contactor has the characteristics of strong switching capability and high reliability. It can work stably under large current and voltage conditions and is suitable for high-power and high-reliability control of the charging pile power output. In scenarios such as fast charging of new energy vehicles that require high current output, the contactor can ensure the stable transmission of electric energy and guarantee the safety and reliability of the charging process.

[0072] 2. Power semiconductor field effect MOSFET tube type switch

[0073] The switch in the power distributor (6) may also be a power semiconductor field effect MOSFET tube. MOSFET tubes have advantages such as fast switching speed, low drive power, and ease of integration. They are advantageous in certain application scenarios that require high switching speed and control accuracy, and can achieve more precise power output control. For example, in the initial low-current charging stage of new energy vehicles, or when fine-tuning the charging voltage and current to meet the charging requirements of a specific vehicle model, MOSFET tubes can more accurately adjust the power output parameters.

[0074] (VII) The conduction logic relationship of the switches in the power divider

[0075] 1. The conduction relationship between the series switch and other switches

[0076] In the power distributor (6), when the first series switch (601), the second series switch (602), and the third series switch (603) are turned on, the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), the third negative switch (609), the first output switch (610), and the second output switch (611) are all turned off. This conduction logic relationship ensures that when the output voltages of the DC converters need to be combined in series, parallel connection or other inappropriate connection modes will not occur at the same time, thereby ensuring the correctness and stability of the voltage series output and meeting the requirements of new energy vehicles for high voltage output in certain charging stages.

[0077] 2. The conduction relationship between the positive switch, negative switch and series switch

[0078] When the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) are turned on, the first series switch (601), the second series switch (602), and the third series switch (603) are all turned off. This logical relationship ensures that when the output voltages of the DC converters need to be combined in parallel, there will be no conflict with the series connection mode, ensuring the effectiveness and reliability of the parallel voltage output, so as to provide high current output for new energy vehicles and meet their fast charging needs.

[0079] 3. The conduction relationship between the output switch and other switches

[0080] When the first output switch (610) and the second output switch (611) are turned on, the first series switch (601) and the third series switch (603) are turned on, the second series switch (602) is not turned on, and the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) are all not turned on. This conduction relationship specifies the coordinated working mode with other types of switches when the output switch is turned on, so as to achieve a specific voltage and current output combination to meet the specific needs of new energy vehicles in different charging scenarios.

[0081] 2. Control method of power circuit management system of new energy vehicle charging pile

[0082] (1) Overview of control strategy

[0083] The present invention is based on the power circuit management system structure of the new energy vehicle charging pile and proposes the following control strategies, which accurately control the output parameters of each switch in the power distributor (6) and each DC converter through a power controller (7) to meet the charging needs of different new energy vehicles.

[0084] (2) Specific control strategies

[0085] The power controller (7) controls the first series switch (601), the second series switch (602), and the third series switch (603) of the power distributor (6) to be turned on; the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), the third negative switch (609), the first output switch (610), and the second output switch (611) are all turned off.

[0086] At the same time, the power controller (7) controls the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) to output an adjustable voltage U between 0 and Umax, and the output power of each converter is P.

[0087] In this case, the output voltage between the first output terminal (10) and the fourth output terminal (13) is 4U, and U≤Umax; the total power output between the first output terminal (10) and the fourth output terminal (13) is 4P≤Pmax. This strategy is applicable to the situation where new energy vehicles require higher voltages and power requirements within a certain range during certain charging stages. By combining the output voltages of the various DC converters in series, a relatively high output voltage can be provided. At the same time, by reasonably controlling the output power of each converter, the total power requirement of the new energy vehicle charging can be met.

[0088] The power controller (7) controls the first series switch (601), the second series switch (602), and the third series switch (603) of the power distributor (6) to be non-conductive; the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) to be conductive, and the first output switch (610) and the second output switch (611) to be non-conductive.

[0089] Furthermore, the power controller (7) controls the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) to output an adjustable voltage U between 0 and Umax, and the output power of each converter is P.

[0090] At this time, a voltage U is output between the first output terminal (10) and the fourth output terminal (13), and U

[0091] ≤Umax; the total power output between the first output terminal (10) and the fourth output terminal (13) is 4P

[0092] ≤Pmax. This strategy is suitable for charging scenarios where new energy vehicles have relatively low voltage requirements but require a large current, such as the initial stage of fast charging. By combining the output voltages of the various DC converters in parallel, a large output current can be provided. At the same time, by controlling the output power of each converter, the total power requirement of the new energy vehicle charging can be met. The power controller (7) controls the first series switch (601), the second series switch (602), and the third series switch (603) of the power distributor (6) to be non-conductive; the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) to be conductive, and the first output switch (610) and the second output switch (611) to be non-conductive.

[0093] In addition, the power controller (7) controls the output voltage U of the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) to change from 0 to Umax, and the output power of each converter is P.

[0094] In this case, the output voltage between the first output terminal (10) and the fourth output terminal (13) changes from 0 to Umax; the total power output between the first output terminal (10) and the fourth output terminal (13) is 4P≤Pmax. This strategy can be used when a new energy vehicle needs to dynamically adjust the voltage within a certain voltage range during the charging process. By flexibly controlling the output voltage changes of each DC converter, the dynamic voltage requirements of the new energy vehicle at different charging stages can be met while ensuring that the total power is within the allowable range.

[0095] A power circuit management system is formed by using multiple DC converter modules (a first DC converter (1), a second DC converter (2), a third DC converter (3), and an Nth DC converter (4)) with the same structure. The output rated power of each module is a fixed proportion of the maximum total output power, and the output voltage can be flexibly adjusted. This modular design has excellent scalability and can easily increase or decrease the number of modules according to the charging power requirements of different new energy vehicles, making it easy to adjust the charging power. At the same time, the consistency and interchangeability of the modules facilitate production, maintenance, and replacement of faulty modules, effectively improving the overall availability and reliability of the charging pile system.

[0096] The unique architecture of the power divider (6) is a major innovation highlight. It is equipped with various types of switches (such as series switches, positive switches, negative switches, output switches, etc.), and can achieve various voltage and current output modes through the conduction combination of different switches. It can not only connect the output voltage of the DC converter in series to meet the high voltage charging requirements, but also output in parallel to meet the high current charging scenario. It can also achieve more complex and diverse output configurations based on specific conduction logic, thereby accurately matching the differentiated voltage, current and power requirements of different new energy vehicles at different charging stages (such as conventional charging, fast charging, etc.) or different models.

[0097] The present invention proposes a variety of innovative control strategies (such as strategies 1-3, etc.), which use a power controller (7) to coordinately control the DC converter and the power distributor. These strategies can dynamically adjust the output parameters of each DC converter and the switching state of the power distributor according to the real-time status of the new energy vehicle during the charging process (such as different charging stages, battery power changes, etc.) and external conditions (such as power grid fluctuations, etc.). In this way, not only can the precise control of charging voltage, current and power be achieved to meet diverse charging needs, but also the power of the power supply can be efficiently utilized, energy waste can be avoided, and charging efficiency can be improved.

[0098] Each DC converter utilizes a DC / DC converter structure with input and output isolation and includes at least one isolation transformer. This design offers multiple advantages: First, the isolation transformer effectively isolates the electrical connections between the input and output sides, significantly improving electrical safety. This effectively prevents damage to new energy vehicle batteries caused by input-side electrical faults (such as short circuits and overvoltages), making it particularly suitable for new energy vehicle charging scenarios with stringent electrical safety requirements. Second, the isolation structure significantly reduces the impact of input-side power supply fluctuations, electromagnetic interference, and other factors on the output voltage and current, ensuring a more stable and pure output DC power. This provides a stable and reliable charging environment for new energy vehicles and helps extend battery life.

[0099] The switch in the power distributor (6) can be a contactor or a power semiconductor field effect MOSFET tube. The contactor has the characteristics of strong switching capability and high reliability, and is suitable for charging scenarios with high power and high reliability control, such as providing stable high current output for large new energy vehicles or in the fast charging stage; while the MOSFET tube has the advantages of fast switching speed, low driving power, and easy integration, and performs well in scenarios with high switching speed and control accuracy requirements (such as fine control in the early stage of charging, meeting the precise charging requirements of specific models, etc.). By providing two switching element options, the system can better adapt to the specific characteristics of different new energy vehicle charging requirements, optimize the overall performance of the power circuit management system, and improve applicability and competitiveness.

[0100] Example 2

[0101] At a public charging station, new energy vehicles of various makes and models come to charge. These vehicles have significantly different battery capacities, charging voltages, and current requirements. For example, the battery charging voltage of a small electric vehicle typically ranges from 200V to 300V, with a charging current requirement of 10A to 20A; while the battery of a large luxury new energy SUV may require a charging voltage range of 350V to 450V, with a charging current of 30A to 50A.

[0102] In response to this diverse charging demand, the power circuit management system of the new energy vehicle charging pile of the present invention is configured. Ten DC converter modules (i.e., N=10) are selected, and the output rated power of each module is 1 / 10 of the total output power maximum value Pmax. The maximum output voltage Umax is set to 500V. Contactors are used as switches in the power distributor (6) to ensure stable transmission of large currents when charging large vehicles.

[0103] Charging of small electric vehicles: When a small electric vehicle is connected to a charging pile, the power controller (7) adopts strategy 2 for control. That is, the first series switch (601), the second series switch (602), and the third series switch (603) of the power distributor (6) are controlled to be non-conductive; the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) are controlled to be conductive, and the first output switch (610) and the second output switch (611) are controlled to be non-conductive. At the same time, the output voltage of each DC converter module is controlled to be between 200V and 250V (within the range of 0-500V), and the output power is a corresponding smaller value, so that through the parallel combination mode, the output voltage between the first output terminal (10) and the fourth output terminal (13) is between 200V and 250V, and the output current is within the range of 10A-20A, meeting the charging requirements of the small electric vehicle, and the total output power is within the allowable range.

[0104] Charging of a large luxury new energy SUV: When the large luxury new energy SUV is connected to the charging pile, the power controller (7) switches to strategy 1 for control. The first series switch (601), the second series switch (602), and the third series switch (603) of the power distributor (6) are controlled to be turned on; the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), the third negative switch (609), the first output switch (610), and the second output switch (611) are all turned off. In addition, the output voltage of each DC converter module is controlled to be between 350V and 400V (within the range of 0-500V), and the output power is the corresponding larger value. At this time, the output voltage between the first output terminal (10) and the fourth output terminal (13) is 4×(350V-400V), which can reach between 1400V-1600V, and the output current is within the range of 30A-50A, meeting the charging needs of large luxury new energy SUVs, while the total power is also within the allowable range.

[0105] Through the power circuit management system and method of the present invention, the charging needs of new energy vehicles of different models can be flexibly adapted on the same charging pile, thereby improving the versatility and utilization efficiency of the charging pile.

[0106] Example 3

[0107] In some areas, grid voltage may fluctuate, especially during peak hours. The DC power voltage fed to charging stations may fluctuate within a certain range. This grid fluctuation can affect the normal charging of new energy vehicles and may even damage the vehicle's battery.

[0108] The power circuit management system for the new energy vehicle charging pile of the present invention uses eight DC converter modules (i.e., N=8), with the output rated power of each module being 1 / 8 of the total maximum output power Pmax. The maximum output voltage Umax is set to 450V. The switches in the power distributor (6) use power semiconductor field-effect MOSFETs to more accurately adjust the power output parameters when the power grid fluctuates.

[0109] During grid voltage fluctuations, the power controller (7) flexibly switches control strategies based on the real-time monitored grid input voltage. For example, when the grid input voltage decreases, if a new energy vehicle is being charged at this time, the power controller (7) may adopt strategy 3 for control. That is, the first series switch (601), the second series switch (602), and the third series switch (603) of the power distributor (6) are controlled to be non-conductive; the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) are controlled to be conductive, and the first output switch (610) and the second output switch (611) are controlled to be non-conductive. At the same time, according to the current charging state of the vehicle and the degree of grid voltage reduction, the output voltage of each DC converter module is controlled to gradually increase from a lower value to an appropriate value (within the range of 0-450V), and the output power is adjusted accordingly, so that the output voltage between the first output terminal (10) and the fourth output terminal (13) can be maintained within the charging voltage range required by the vehicle battery, the output current can also meet the charging requirements, and the total power is within the allowable range.

[0110] When the grid input voltage increases, the power controller (7) can switch to other appropriate control strategies according to the situation, such as strategy 2 (reducing the output voltage and increasing the output current through parallel combination) or strategy 1 (increasing the output voltage and adjusting the output power through series combination), etc., to ensure that in the case of grid fluctuations, stable and appropriate charging voltage, current and power can always be provided to the new energy vehicle, protecting the vehicle battery from damage, and ensuring the normal progress of the charging process.

[0111] Example 4

[0112] New energy vehicles require different charging voltages and currents at different stages of the charging process. Generally, in the initial stages of charging, the battery can handle a higher current. However, as the charge level increases, the current gradually decreases and the voltage may be adjusted to preserve battery life.

[0113] In response to this situation of changing charging demand, the power circuit management system of the new energy vehicle charging pile of the present invention is used, and 6 DC converter modules (i.e., N=6) are selected. The output rated power of each module is 1 / 6 of the total output power maximum value Pmax. The maximum output voltage Umax is set to 400V. The switch in the power distributor (6) is a mixed configuration of contactors and power semiconductor field effect MOSFET tubes. In the early stage of charging, the fast switching characteristics of the MOSFET tube are used for fine control. In the later stage of charging, the switch is switched to the contactor to ensure the stability of high current transmission.

[0114] Initial charging stage: When the new energy vehicle starts charging, the power controller (7) adopts strategy 2 combined with the switching characteristics of some MOSFET tubes for control. That is, the first series switch (601), the second series switch (602), and the third series switch (603) of the power distributor (6) are controlled to be non-conductive; the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) are controlled to be conductive, and the first output switch (610) and the second output switch (611) are controlled to be non-conductive. At the same time, the output voltage of each DC converter module is controlled to be at a lower value (e.g., 200V-250V), and the output power is at a correspondingly higher value. By utilizing the fast switching characteristics of the MOSFET tube, the output current can quickly reach a higher value (e.g., 30A-40A), meeting the battery's demand for high current in the initial charging stage, and the total power is within the allowable range.

[0115] In the middle and late stages of charging: as the charging amount increases, the power controller (7) gradually switches to strategy 3 and performs control in conjunction with the contactor. That is, the first series switch (601), the second series switch (602), and the third series switch (603) of the power distributor (6) are controlled to be non-conductive; the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) are turned on, and the first output switch (610) and the second output switch (611) are turned off. At the same time, according to the charging state of the battery, the output voltage of each DC converter module is controlled to gradually increase from 250V to an appropriate value (such as 300V-350V), and the output power is adjusted accordingly, so that the output current gradually decreases to an appropriate value (such as 10A-20A), meeting the battery's requirements for charging voltage and current in the middle and late stages of charging, and the total power is within the allowable range.

[0116] The power circuit management system and method of the present invention can flexibly adjust charging parameters according to the requirements of different charging stages of new energy vehicles, effectively protect battery life, and improve charging efficiency.

[0117] The present invention has been described in detail above with reference to the embodiments. However, those skilled in the art will appreciate that, without departing from the spirit of the present invention, the specific parameters in the above embodiments may be modified to form multiple specific embodiments, which are all within the common variation range of the present invention and will not be described in detail here.

Claims

1. A power circuit management system for a new energy vehicle charging pile, characterized in that: include: A first DC converter (1), a second DC converter (2), a third DC converter (3), an Nth DC converter (4), an input DC power supply (5), a power distributor (6), a power controller (7), a power control signal line (8), a power distribution control bus (9), a first output end (10), a second output end (11), a third output end (12), and a fourth output end (13); the input DC power supply (5) is connected in parallel with the input ends of the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4); the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) are connected in parallel with the input ends of the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4). The output ends of the DC converter (4) are respectively connected to the power distributor (6), and four terminals are output through the power distributor (6): a first output end (10), a second output end (11), a third output end (12), and a fourth output end (13); the power controller (7) controls the output current and output voltage of the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) respectively through the power control signal line (8), so that they meet the charging requirements of the new energy vehicle; the power controller (7) controls the contactor in the power distributor (6) to be turned on and off through the power distribution control bus (9), so that the power output meets the power supply system requirements of the new energy vehicle charging; The power distributor (6) comprises: a first series switch (601), a second series switch (602), a third series switch (603), a first positive switch (604), a second positive switch (605), a third positive switch (606), a first negative switch (607), a second negative switch (608), a third negative switch (609), a first output switch (610), and a second output switch (611); the first series switch (601) is connected to the negative output terminal of the first DC converter (1) and the positive output terminal of the second DC converter (2); the second series switch (602) is connected to the negative output terminal of the second DC converter (2) and the positive output terminal of the third DC converter (3); the third series switch (603) is connected to the negative output terminal of the third DC converter (3) and the positive output terminal of the Nth DC converter (4); the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) are connected to each other. The output voltage of the DC converter (4) is connected in series and then output; the first positive switch (604) is connected to the output positive end of the first DC converter (1) and the output positive end of the second DC converter (2); the second positive switch (605) is connected to the output positive end of the first DC converter (1) and the output positive end of the third DC converter (3); the third positive switch (606) is connected to the output positive end of the first DC converter (1) and the output positive end of the Nth DC converter (4); the first negative switch (607) is connected to the output negative end of the first DC converter (1) and the output negative end of the Nth DC converter (4); the second negative switch (608) is connected to the output negative end of the second DC converter (2) and the output negative end of the Nth DC converter (4); the third negative switch (609) is connected to the output negative end of the third DC converter (3) and the output negative end of the Nth DC converter (4); the first DC converter (1), the second DC converter (2), the third DC converter (3), the Nth DC converter (4) are connected in series. The output voltages of the DC converters (4) are connected in parallel and then output; the first output terminal (10) is directly connected to the positive output terminal of the first DC converter (1) through the power divider (6); the second output terminal (11) is connected to the negative output terminal of the second DC converter (2) through the first output switch (610); the third output terminal (12) is connected to the positive output terminal of the third DC converter (3) through the second output switch (611); and the fourth output terminal (13) is directly connected to the positive output terminal of the Nth DC converter (4) through the power divider (6); In the power distributor (6), when the first series switch (601), the second series switch (602), and the third series switch (603) are turned on, the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), the third negative switch (609), the first output switch (610), and the second output switch (611) are all turned off; When the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) are turned on, the first series switch (601), the second series switch (602), and the third series switch (603) are all turned off; When the first output switch (610) and the second output switch (611) are turned on, the first series switch (601) and the third series switch (603) are turned on, the second series switch (602) is not turned on, and the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) are all not turned on.

2. The power circuit management system for a new energy vehicle charging pile according to claim 1, characterized in that: The first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) have the same module structure, the output rated power of each DC converter is 1 / N of the maximum total output power Pmax, N is greater than or equal to 4, and the output voltage of each DC converter is adjustable from 0 to the maximum output voltage Umax.

3. The power circuit management system for a new energy vehicle charging pile according to claim 1, characterized in that: The first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) have the same structure and are all DC / DC converters with input and output isolation, including at least one isolation transformer. Specifically, each DC converter includes: A first power switch (101), a second power switch (102), a third power switch (103), a fourth power switch (104), a primary inductor (105), a high-frequency transformer (106), a diode A (107), a diode B (108), an output inductor, and an output capacitor; the first power switch (101), the second power switch (102), the third power switch (103), the fourth power switch (104), the primary inductor (105), and the primary side of the high-frequency transformer (106) constitute a high-frequency inverter circuit; the secondary side of the high-frequency transformer (106), the diode A (107), the diode B (108), the output inductor, and the output capacitor constitute a rectifier filter circuit; and the output voltage and current can be controlled by adjusting the duty ratio of the first power switch (101), the second power switch (102), the third power switch (103), and the fourth power switch (104).

4. The power circuit management system for a new energy vehicle charging pile according to claim 1, characterized in that: The switch in the power distributor (6) is a contactor or a power semiconductor field effect MOSFET tube.

5. The power circuit management system for a new energy vehicle charging pile according to claim 1, characterized in that: The control method of the power controller (7) is as follows: The first series switch (601), the second series switch (602), and the third series switch (603) of the control power distributor (6) are turned on; the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), the third negative switch (609), the first output switch (610), and the second output switch (611) are all turned off; At the same time, the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) are controlled to output an adjustable voltage U between 0 and Umax, and the output power of each converter is P; The output voltage 4U is generated between the first output terminal (10) and the fourth output terminal (13), and U≤Umax; The total power output between the first output terminal (10) and the fourth output terminal (13) is 4P≤Pmax.

6. The power circuit management system for a new energy vehicle charging pile according to claim 1, characterized in that: The control method of the power controller (7) is as follows: The first series switch (601), the second series switch (602), and the third series switch (603) of the control power distributor (6) are not conducting; the first positive switch (604), the second positive switch (605), the third positive switch (606), the first negative switch (607), the second negative switch (608), and the third negative switch (609) are conducting, and the first output switch (610) and the second output switch (611) are not conducting; At the same time, the first DC converter (1), the second DC converter (2), the third DC converter (3), and the Nth DC converter (4) are controlled to output an adjustable voltage U between 0 and Umax, and the output power of each converter is P; A voltage U is output between the first output terminal (10) and the fourth output terminal (13), and U≤Umax; The total power output between the first output terminal (10) and the fourth output terminal (13) is 4P≤Pmax.

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