Fully-immersed power module and charging system

Abstract

The utility model discloses a fully-immersed power module and a charging system, and relates to the technical field of charging. The power module comprises a PCBA (Printed Circuit Board Assembly), the PCBA is fully immersed in insulating cooling liquid, and the PCBA comprises an AC / DC (Alternating Current / Direct Current) conversion circuit and a heating circuit; the heating circuit is arranged between the AC / DC conversion circuit and the AC power supply, the heating circuit comprises a heating unit and a switch unit, the heating unit and the switch unit are connected in parallel or in series, and the switch unit is used for conducting the heating unit in a closed or closed state so that the heating unit can heat the insulating cooling liquid. Therefore, the insulation cooling liquid is heated through the power module, and the problem that the reliability of the charging system is reduced due to the low temperature of the insulation cooling liquid is solved.

Description

Technical Field

[0001] This application relates to the field of charging technology, and in particular to a fully immersion power module and charging system. Background Technology

[0002] With the increasing popularity of electric vehicles, the performance and reliability requirements of high-power modules are becoming increasingly stringent. In the design of oil-based immersion liquid-cooled power modules, mineral oil and other highly insulating coolants are typically used. Their specific heat capacity is much higher than that of air, which can effectively dissipate heat. However, in low-temperature or ultra-low-temperature environments, the insulating coolant may cause new problems.

[0003] First, low temperatures increase the viscosity of the insulating coolant, increasing system circulation resistance and potentially causing excessively high local pressure, thus affecting the normal operation of the liquid cooling system. Second, when electronic components (such as electrolytic capacitors) operate for extended periods in low-temperature insulating coolant, their performance indicators (such as equivalent series resistance and capacitance) will significantly degrade. Directly initiating charging in such conditions may lead to a deterioration in output characteristics, affecting charging efficiency and even damaging the equipment. Furthermore, uneven heat dissipation within the module may cause localized overheating in low-temperature environments, further threatening system reliability. Utility Model Content

[0004] The main objective of this application is to provide a fully immersion power module and charging system that heats the insulating coolant by the power module itself, thereby solving the problem of reduced charging system reliability caused by low temperature of the insulating coolant.

[0005] To achieve the above objectives, this application provides a fully submerged power module, the power module including a PCBA assembly, the PCBA assembly being fully submerged in an insulating coolant, the PCBA assembly including an AC / DC conversion circuit and a heating circuit; the heating circuit is disposed between the AC / DC conversion circuit and the AC power supply, the heating circuit including a heating unit and a switching unit, the heating unit and the switching unit being connected in parallel or in series, the switching unit being used to turn on the heating unit in a closed or closed state, so that the heating unit heats the insulating coolant.

[0006] Optionally, the heating unit includes at least one heating subunit, and the switching unit includes at least one switching subunit. Each heating subunit is connected in parallel or in series with a corresponding switching subunit. When the heating subunit is connected in parallel with the corresponding switching subunit, the switching subunit is used to turn on the heating subunit in the off state. When the heating subunit is connected in series with the corresponding switching subunit, the switching subunit is used to turn on the heating subunit in the closed state.

[0007] Optionally, the AC power supply is connected to the AC / DC conversion circuit via three input lines; when the heating subunit is connected in series with the corresponding switching subunit, one end of the heating circuit is connected to at least one of the input lines, and the other end of the heating circuit is connected to the N line.

[0008] Optionally, the heating circuit includes three heating sub-units, with the first end of each heating sub-unit connected to one of the three input lines respectively, and the second end of each heating sub-unit connected to the corresponding switch sub-unit; when the number of switch sub-units is one, the second end of each heating sub-unit is connected to the switch sub-unit; when the number of switch sub-units is two, the second ends of any two heating sub-units are connected to one switch sub-unit, and the second ends of the remaining heating sub-units are connected to another switch sub-unit; when the number of switch sub-units is three, each heating sub-unit is connected to each of the switch sub-units respectively.

[0009] Optionally, the AC power supply includes three output terminals; one end of each heating subunit is connected to the corresponding output terminal of the AC power supply, the other end of each heating subunit is connected to the AC / DC conversion circuit, and each switching subunit is connected in parallel with the corresponding heating subunit.

[0010] Optionally, the heating subunit includes at least one heating device, and the switching subunit includes a switching tube; the heating devices are connected in series and / or in parallel.

[0011] Optionally, the power module further includes a temperature detection device; the temperature detection device is disposed in the insulating coolant, the temperature detection device is connected to the controller, and the temperature detection device is used to detect the current temperature of the insulating coolant and transmit the current temperature of the insulating coolant to the controller.

[0012] Optionally, the PCBA assembly further includes an input EMC module; one end of the input EMC module is connected to the AC power supply, and the other end of the input EMC module is connected to the AC / DC conversion circuit; one end of the heating unit is connected between the AC power supply and the input EMC module; or, one end of the heating unit is connected between the input EMC module and the AC / DC conversion circuit.

[0013] Optionally, the PCBA assembly further includes a DC / DC converter circuit, which includes a transformer-rectifier module, an output switch module, an output electrolysis module, and a reverse polarity protection module. One end of the transformer-rectifier module is connected to the AC / DC converter circuit, and the other end of the transformer-rectifier module is connected to one end of the output switch module. The output switch module is connected to the first input terminal and the second output terminal of the output electrolysis module. The first output terminal of the output electrolysis module is connected to one end of the reverse polarity protection module, the second output terminal of the output electrolysis module is connected to the negative terminal of the load, and the other end of the reverse polarity protection module is connected to the positive terminal of the load.

[0014] Furthermore, to achieve the above objectives, this application also provides a charging system, including at least two power modules as described above, a controller, a power distribution device, and at least one charging interface; the power distribution device is connected to the controller, each of the power modules, and each of the charging interfaces respectively; the controller is connected to each of the power modules respectively; for any power module, the controller is used to receive the current temperature of the insulating coolant output by the temperature detection device in the power module, and when the current temperature of the insulating coolant is less than a first temperature value, outputs a control signal to the switching unit of the heating circuit in the power module; the control signal is used to control the heating circuit to be turned on, so that the heating unit of the heating circuit heats the insulating coolant.

[0015] This application introduces a heating circuit into the fully immersed power module. When the current temperature of the insulating coolant is low, the heating unit can be turned on by controlling the closing or closing of the switching unit in the heating circuit. The heating unit in the heating circuit can heat the insulating coolant, thereby solving the problem of reduced reliability of the charging system caused by the low temperature of the insulating coolant. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of the fully immersed power module according to an embodiment of this application;

[0017] Figure 2 This is one of the circuit diagrams of the fully immersed power module according to an embodiment of this application;

[0018] Figure 3 This is a second circuit diagram of the fully immersed power module according to an embodiment of this application;

[0019] Figure 4 This is the third circuit diagram of the fully immersed power module according to an embodiment of this application;

[0020] Figure 5 This is a circuit diagram of an example fully immersed power module of this application;

[0021] Figure 6 This is a circuit diagram of another example of a fully immersed power module in this application;

[0022] Figure 7 This is the fourth circuit diagram of the fully immersed power module according to an embodiment of this application;

[0023] Figure 8 This is a schematic diagram of the charging system according to an embodiment of this application;

[0024] In the figure, 110 is an AC / DC conversion circuit; 120 is a DC / DC conversion circuit; 130 is a heating circuit; 131 is a heating unit; 132 is a switching unit; 140 is a temperature detection device; 150 is an input EMC module; 210 is a power module; 220 is a controller; 230 is a power distribution device; and 240 is a charging interface. The realization of the purpose, functional characteristics, and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. Detailed Implementation

[0025] To make the objectives, technical solutions, and advantages of this application clearer, the technical solutions of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0026] With the rapid development of fast charging technology for electric vehicles, the heat dissipation problem of high-power modules has become increasingly prominent. Oil-based immersion liquid cooling technology, due to its excellent insulation and heat dissipation capabilities, is gradually becoming an ideal solution for high-power-density charging systems. In this design, key electronic components of the power module (such as power semiconductors, magnetic components, and electrolytic capacitors) are directly immersed in insulating coolants such as mineral oil, utilizing the high specific heat capacity of the liquid to achieve efficient thermal management.

[0027] However, because immersion liquid-cooled power modules use a special insulating coolant with high insulation and high specific heat as the heat dissipation medium, its specific heat capacity is typically more than 10 times that of air. At normal operating temperatures, this insulating coolant can efficiently absorb the heat generated by the electronic components inside the module and transfer the heat to the outside through a circulation system for heat exchange, thus ensuring the stable operation of the module. Therefore, in low-temperature or ultra-low-temperature environments, this cooling system faces significant challenges:

[0028] First, electronic devices operate continuously in low-temperature insulating coolant for a much longer time than they are exposed to air. This can cause serious degradation in the performance parameters of key components such as electrolytic capacitors (e.g., equivalent series resistance, capacitance). If the charging process is started directly at this time, the output characteristics will be significantly degraded, affecting the charging performance and even damaging the equipment.

[0029] Secondly, the viscosity of the insulating coolant increases dramatically at low temperatures, which not only significantly increases the operating pressure of the circulation system but may also reduce the fluidity of the insulating coolant, leading to poor local heat dissipation and overheating within the module. This necessitates that electronic components have more reliable low-temperature resistance, or that the insulating coolant be preheated to the appropriate operating temperature for the electronic components, thereby improving the adaptability and safety of immersion liquid-cooled power modules in low-temperature environments.

[0030] Currently, power modules employing efficient circuit architectures such as the Vienna topology or single-level power supply topology, while optimizing energy efficiency, are limited by their circuit characteristics in their ability to generate sufficient heat through their own losses. They can only rely on the inherent characteristics of the devices to withstand various low-temperature operating conditions, making effective preheating during the low-temperature startup phase difficult. Therefore, the requirements for the devices are relatively high, and cost and size cannot be controlled. Thus, there is an urgent need for a solution that can actively regulate the temperature of the insulating coolant in low-temperature environments to ensure the reliability and performance stability of the power module across the entire operating range.

[0031] Based on this, this application provides a fully immersion power module and charging system. By setting a heating circuit in the power module and having the controller output a control signal to the switching unit in the heating circuit when the current temperature of the insulating coolant is lower than a first temperature value, the heating unit in the heating circuit is turned on when the switching unit is closed or turned off, thereby enabling the heating unit to heat the insulating coolant. This solves the problem of reduced reliability of the charging system caused by the low temperature of the insulating coolant.

[0032] To facilitate understanding, the overall hardware structure of the power module will be described in detail below.

[0033] Figure 1 This is a schematic diagram of the structure of the fully immersed power module according to an embodiment of this application, as shown below. Figure 1 As shown, the fully submersible power module mainly consists of a sealed housing, a complete PCBA assembly, a high-insulation coolant, and inlet / outlet ports.

[0034] The sealed housing forms a completely airtight cavity, ensuring no leakage of the insulating coolant. The PCBA assembly contains all power electronic devices and control circuits, all of which are immersed in high-insulation coolant for direct heat dissipation. Temperature detection devices are installed at both the inlet and outlet ports. These devices can interact in real time with the external cold source control system via communication protocols such as CAN, 485, or 232 to control the circulation of the insulating coolant. The inlet and outlet ports employ a specially designed check valve structure to effectively prevent backflow of the insulating coolant, ensuring unidirectional circulation.

[0035] The working principle of this fully submersible power module is as follows: When the power module is in operation, the heat generated by the power devices is directly absorbed by the surrounding insulating coolant, causing the temperature of the insulating coolant to gradually rise. A built-in temperature detection device collects the temperature data of the insulating coolant in real time. When the temperature reaches a certain threshold, the charging system controller activates the external cold source circulation device. At this time, the high-temperature insulating coolant is pumped out of the power module's cavity, while the low-temperature insulating coolant, after being processed by the external cooling system, is injected into the cavity, forming a closed-loop heat exchange. The discharged high-temperature insulating coolant is cooled by the external heat dissipation device and then re-enters the circulation system, continuously providing cooling for the power module.

[0036] This dynamic temperature control mechanism ensures that power devices always operate within their optimal temperature range and enables efficient recycling of the insulating coolant, significantly improving the heat dissipation efficiency and operational reliability of the charging system. The entire process is automated through the charging system's controller, which can dynamically adjust the flow rate and circulation frequency of the insulating coolant according to actual operating conditions to achieve optimal thermal balance.

[0037] Referring to the overall structure of the fully immersed power module described above, the internal circuit structure and control strategy of the fully immersed power module in this application embodiment (i.e., the PCBA assembly part described above) will be described in detail below.

[0038] Figure 2 This is one of the circuit diagrams of the fully immersed power module according to an embodiment of this application, such as... Figure 2 As shown, the power module includes a PCBA assembly, which is fully immersed in an insulating coolant. The PCBA assembly may include an AC / DC conversion circuit 110 and a heating circuit 130.

[0039] The heating circuit 130 is located between the AC / DC conversion circuit 110 and the AC power supply. The heating circuit 130 includes a heating unit 131 and a switching unit 132. The heating unit 131 and the switching unit 132 are connected in parallel or in series. The switching unit 132 is used to turn on the heating unit 131 in a closed or closed state so that the heating unit 131 heats the insulating coolant.

[0040] First, it should be noted that the insulating coolant can be any highly insulating, high-specific-heat liquid, such as mineral oil, that can be used for cooling. Furthermore, the power module in this embodiment can be a power module used for charging and discharging new energy vehicles, or an AC / DC power conversion module in an energy storage system.

[0041] The circuit structure of a power module typically consists of a front-end AC / DC converter circuit 110 and a DC / DC converter circuit 120. The AC / DC converter circuit 110 rectifies the input three-phase AC into approximately ±420V DC, with a total voltage of 840V. It further uses a large-capacity electrolytic capacitor for voltage regulation and filtering before output. The DC / DC converter circuit 120 converts the output through two or more LLC resonant cavities. At the output end, a series and parallel combination of switches is used to achieve a wide range of output voltage from 50V to 1000V.

[0042] In this embodiment, the AC / DC conversion circuit 110 can adopt existing Vienna topologies, single-level power supply topologies, etc., and the circuit structure of the AC / DC conversion circuit 110 is not specifically limited here. One end of the AC / DC conversion circuit 110 can be connected to an AC power source, and the other end can be connected to the DC / DC conversion circuit 120. It should be noted that the two ends of the DC bus of the AC / DC conversion circuit 110 can also be connected to an auxiliary power module (not shown in the figure). The auxiliary power module can draw power from the DC bus to power the power module or other devices in the charging system.

[0043] Furthermore, the heating circuit 130 may include a heating unit 131 and a switching unit 132. The heating unit 131 and the switching unit 132 can be connected in parallel or in series. After the heating unit 131 and the switching unit 132 are connected, they can be placed between the AC power supply and the AC / DC conversion circuit 110. In addition, the switching unit 132 is also connected to the controller of the charging system. The switching unit 132 is controlled by the controller to realize the switching on and off.

[0044] In this embodiment, existing power devices can be used to form the heating unit 131, such as resistance wires, MOSFETs (Metal-Oxide-Semiconductor Field-Effect Transistors), IGBTs (Insulated Gate Bipolar Transistors), power diodes, etc. These power devices, after being energized, can generate heat through self-dissipation, thus achieving the purpose of heating the insulating coolant. Furthermore, existing switching devices can be used to form the switching unit 132, such as relays, transistors, thyristors, etc.

[0045] In this embodiment, the controller can obtain the current temperature of the insulating coolant where the power module is located. Specifically, a temperature sensor can be installed in the insulating coolant of the power module to detect the current temperature of the insulating coolant, and then the temperature sensor transmits the current temperature of the insulating coolant to the controller.

[0046] After receiving the current temperature of the insulating coolant, the controller can first determine whether the current temperature of the insulating coolant is lower than a first temperature value. It should be noted that the first temperature value can be set manually by the operator, and the first temperature value can be set according to the lowest temperature at which each device can operate normally; no specific limitation is made here.

[0047] Before the power module enters the charging process, if the controller determines that the current temperature of the insulating coolant is higher than or equal to the first temperature value, the controller can control the power module to enter the charging process normally without heating the insulating coolant.

[0048] Before the power module enters the charging process, if the controller determines that the current temperature of the insulating coolant is lower than a first temperature value, the controller controls the power module to first enter the heating process of the insulating coolant. When the current temperature of the insulating coolant is heated to equal to or higher than the first temperature value, the controller then controls the power module to enter the normal charging process. During the heating process of the power module, the controller outputs a control signal to the switching unit 132 in the heating circuit 130. The switching unit 132 receives and responds to the control signal to close or close, thereby turning on the circuit where the heating unit 131 is located.

[0049] Therefore, when current flows through the heating unit 131, the heating unit 131 generates heat through its own losses, thereby achieving the purpose of heating the insulating coolant in which it is located.

[0050] In some embodiments, the heating unit 131 includes at least one heating subunit, and the switching unit 132 includes at least one switching subunit. Each heating subunit is connected in parallel or in series with a corresponding switching subunit. When the heating subunit is connected in parallel with the corresponding switching subunit, the switching subunit is used to turn on the heating subunit in the off state. When the heating subunit is connected in series with the corresponding switching subunit, the switching subunit is used to turn on the heating subunit in the closed state.

[0051] In this embodiment, the heating subunit and the switching subunit can be connected in parallel or in series. It is understood that when the heating subunit and the switching subunit are connected in series, they are on the same circuit, so the heating subunit is conductive when the switching subunit is closed. Conversely, when the heating subunit and the switching subunit are connected in parallel, they are on different branches, so the heating subunit is conductive only when the switching subunit is off.

[0052] The following sections will introduce the heating circuits in series and parallel modes respectively.

[0053] In some implementations, the AC power supply is connected to the AC / DC conversion circuit 110 via three input lines; when the heating subunit is connected in series with the corresponding switching subunit, one end of the heating circuit is connected to at least one input line, and the other end of the heating circuit is connected to the N line.

[0054] In this embodiment, there can be multiple heating sub-units and multiple switching sub-units. The more heating sub-units there are, the higher the heating efficiency. One end of each heating sub-unit can be connected to any one of the three input lines. For example, if there are 3 heating sub-units, they can be connected to the three input lines respectively. If there are 5 heating sub-units, two heating sub-units can be connected to any two of the three input lines, and the remaining heating sub-unit can be connected to the other input line.

[0055] The other end of each heating subunit is connected to the corresponding switching subunit. One switching subunit can be connected to multiple heating subunits. The other end of the switching subunit is connected to the N line.

[0056] Figure 3 This is a second circuit diagram of the fully immersive power module according to an embodiment of this application. Figure 3 As shown, in some embodiments, the heating unit 131 includes three heating sub-units. The first end of each heating sub-unit is connected to one of the three input lines respectively, and the second end of each heating sub-unit is connected to a corresponding switch sub-unit. When the number of switch sub-units is 1, the second end of each heating sub-unit is connected to the switch sub-unit. When the number of switch sub-units is 2, the second ends of any two heating sub-units are connected to one switch sub-unit, and the second ends of the remaining heating sub-units are connected to another switch sub-unit. When the number of switch sub-units is 3, each heating sub-unit is connected to each switch sub-unit respectively.

[0057] It should be noted that, Figure 3 The structure of the heating circuit 130 shown is a specific example of a series configuration, and it can also be configured as follows:Figure 3 Using the circuit structure in the example as a reference, the number and combination connection of the heating sub-unit and the switching sub-unit are changed to obtain more heating circuit topologies.

[0058] In this embodiment, the AC power supply may include three input terminals, namely the input terminal of phase A, the input terminal of phase B, and the input terminal of phase C; the AC / DC conversion circuit 110 can be connected to the three input terminals respectively through three input lines.

[0059] Furthermore, the heating unit 131 may include three heating sub-units, and the switching unit 132 may include at least one switching sub-unit. One end of each heating sub-unit is connected to one of the three input lines, with a one-to-one correspondence between the heating sub-unit and the three input lines. The connection method of the other end of the heating sub-unit can be divided into the following three cases:

[0060] In the first scenario, when there are three switching subunits, the other end of each heating subunit is connected to one of the three corresponding switching subunits, with a one-to-one correspondence between the heating subunits and the switching subunits. For example, if heating unit 131 includes heating subunit 1, heating subunit 2, and heating subunit 3, and switching unit 132 includes switching subunit 1, switching subunit 2, and switching subunit 3, with three input lines representing phase A, phase B, and phase C respectively, then one end of heating subunit 1 can be connected to the phase A input line, and the other end to switching subunit 1; one end of heating subunit 2 can be connected to the phase B input line, and the other end to switching subunit 2; one end of heating subunit 3 can be connected to the phase C input line, and the other end to switching subunit 3.

[0061] The second method involves having two switching subunits. The other ends of any two heating subunits are connected to one switching subunit, and the other end of the remaining heating subunit is connected to the other switching subunit. For example, if heating unit 131 includes heating subunit 1, heating subunit 2, and heating subunit 3, and switching unit 132 includes switching subunit 1 and switching subunit 2, with three input lines representing phase A, phase B, and phase C respectively, then one end of heating subunit 1 can be connected to the phase A input line, one end of heating subunit 2 can be connected to the phase B input line, and the other ends of both heating subunit 1 and heating subunit 2 are connected to switching subunit 1; one end of heating subunit 3 can be connected to the phase C input line, and the other end of heating subunit 3 is connected to switching subunit 2. Other combinations can also be used in this example, which will not be elaborated here.

[0062] The third method involves using a single switching subunit, where the other ends of all three heating subunits are connected to this single switching subunit. For example, heating unit 131 includes heating subunit 1, heating subunit 2, and heating subunit 3; switching unit 132 includes switching subunit 1; and the three input lines are the input lines for phase A, phase B, and phase C, respectively. One end of heating subunit 1, heating subunit 2, and heating subunit 3 can be connected to the input lines for phase A, phase B, and phase C, respectively, while the other end of heating subunit 1, heating subunit 2, and heating subunit 3 is connected to switching subunit 1.

[0063] In some implementations, the AC power supply includes three output terminals; one end of each heating subunit is connected to the corresponding output terminal of the AC power supply, the other end of each heating subunit is connected to the AC / DC conversion circuit 110, and each switching subunit is connected in parallel with the corresponding heating subunit.

[0064] In this embodiment, each heating subunit can be set on any input line, that is, one end of each heating subunit can be connected to the output terminal of any AC power supply, and the other end of each heating subunit is connected to the AC / DC conversion circuit.

[0065] Figure 4 This is the third circuit diagram of the fully immersive power module according to an embodiment of this application. Figure 4 As shown in the example, there can be three heating sub-units and three switching sub-units. One end of each heating sub-unit can be connected to one of the three output terminals of the AC power supply, with each heating sub-unit corresponding to one of the three output terminals. Three switching sub-units are connected in parallel across each heating sub-unit, with each switching sub-unit corresponding to one heating sub-unit. When heating is required, simply disconnect each switching sub-unit, and the current input from the AC power supply will flow through each heating sub-unit, causing it to generate heat and thus heating the insulating coolant.

[0066] As another example, there can be four heating sub-units and two switching sub-units. Two of the heating sub-units can be connected to one output terminal of the AC power supply, and a switching sub-unit is connected in parallel across the two heating sub-units. The other two heating sub-units can be connected to the other output terminal of the AC power supply, and another switching sub-unit is connected in parallel across the remaining two heating sub-units.

[0067] It should be noted that when the switch subunit and the heating subunit are connected in parallel, the number of switch subunits and heating subunits can be set by the staff according to actual needs, and there can be several ways to connect the switch subunits and heating subunits in parallel, which will not be listed here.

[0068] In some embodiments, the heating subunit includes at least one heating element, and the switching subunit includes a switching transistor Dx. The heating elements are connected in series and / or in parallel; the first terminal of the switching transistor Dx is connected to the corresponding heating subunit, the second terminal of the switching transistor Dx is grounded, and the third terminal of the switching transistor Dx is connected to the controller.

[0069] It should be noted that the heating device can be a resistor, heating wire, or other device that generates heat through self-dissipation. If the heating device is a resistor, a resistor with a larger resistance value can be selected. The larger the resistance value of the heating resistor, the more heat is generated during self-dissipation, and therefore the higher the heating efficiency. Furthermore, the switching transistor Dx can be a MOSFET (Metal-Oxide-Semiconductor Field-Effect Transistor), IGBT (Insulated Gate Bipolar Transistor), transistor, mechanical relay, silicon controlled thyristor, etc. No specific limitations are imposed on the switching transistor Dx here.

[0070] In this embodiment, each heating subunit may include multiple heating devices, which can be arranged in series and parallel, and then connected in the circuit.

[0071] Figure 5 This is one of the circuit diagrams of an example fully immersed power module of this application. Figure 5 As shown in the illustration, as an example, heating unit 131 includes three heating sub-units, each of which includes a heating resistor Rx. Switching unit 132 also includes three switching sub-units, each of which includes an NMOS switch Dx. One end of each of the three heating resistors Rx is connected to the input lines of phase A, phase B, and phase C, respectively. The other end of each heating resistor Rx is connected to the first terminal (i.e., source or drain) of the three NMOS switches Dx, respectively. The second terminal (i.e., source or drain) of the three NMOS switches Dx is grounded, and the third terminal (i.e., gate) of the three NMOS switches Dx is connected to the controller.

[0072] Continue to refer to Figure 3 In some embodiments, the power module further includes a temperature detection device 140. The temperature detection device 140 is connected to the controller and is used to detect the current temperature of the insulating coolant and transmit the current temperature of the insulating coolant to the controller.

[0073] It should be noted that the temperature detection device 140 can be a temperature sensor, an infrared temperature measurement module, etc.

[0074] In this embodiment, the temperature detection device 140 can be placed in the insulating coolant, and can be placed at any position in the insulating coolant. The temperature detection device 140 can be connected to the controller. The temperature detection device 140 detects the current temperature of the insulating coolant it is in, and feeds back the current temperature of the insulating coolant to the controller, so that the controller can determine whether to heat the insulating coolant based on the current temperature of the insulating coolant.

[0075] In some embodiments, the PCBA assembly further includes an input EMC module 150; one end of the input EMC module 150 is connected to an AC power supply, and the other end of the input EMC module 150 is connected to an AC / DC conversion circuit 110; one end of the heating unit 131 is connected between the AC power supply and the input EMC module 150; or, one end of the heating unit 131 is connected between the input EMC module 150 and the AC / DC conversion circuit 110.

[0076] It should be noted that the input EMC module 150 (electromagnetic compatibility module) of the power module is used to ensure the stable operation of the charging system in an electromagnetic environment, while reducing its interference to the power grid and other equipment.

[0077] The power module typically includes an input EMC module 150, which is positioned between the AC power supply and the AC / DC conversion circuit 110 to prevent electromagnetic noise from the power grid from entering the power module. In this embodiment, the heating circuit 130 can be positioned between the AC power supply and the input EMC module 150, or between the input EMC module 150 and the AC / DC conversion circuit 110.

[0078] Specifically, if the heating circuit 130 can be located between the AC power supply and the input EMC module 150, then one end of the heating unit 131 is connected to the input line between the AC power supply and the input EMC module 150. The specific connection method can be referred to the connection method described above, and will not be repeated here. If the heating circuit 130 can be located between the input EMC module 150 and the AC / DC conversion circuit 110, then one end of the heating unit 131 is connected to the input line between the input EMC module 150 and the AC / DC conversion circuit 110. The specific connection method can be referred to the connection method described above, and will not be repeated here.

[0079] Figure 6 This is a circuit diagram of another example of a fully immersed power module in this application. Figure 6 As shown, the heating circuit 130 is located between the input EMC module 150 and the AC power supply.

[0080] Figure 7 This is the fourth circuit diagram of the fully immersive power module according to an embodiment of this application. Figure 7As shown, in some embodiments, the series heating circuit 130 and the parallel heating circuit 130 can be jointly arranged in the circuit of the power module.

[0081] In addition, continue to refer to Figure 7 The AC / DC conversion circuit 110 may include a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first inductor L1, a second inductor L2, a third inductor L3, a fourth switch Q4, a fifth switch Q5, a sixth switch Q6, a seventh switch Q7, an eighth switch Q8, and a ninth switch Q9.

[0082] The other end of the first switch Q1 is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to one end of the first inductor L1, the other end of the first inductor L1 is connected to the first end of the fourth switch Q4 to form the first node N1, the second end of the fourth switch Q4 is connected to the second end of the fifth switch Q5, and the first end of the fifth switch Q5 is connected to the midpoint of the output bus in the AC / DC conversion circuit 110. The fourth switch Q4 and the fifth switch Q5 are connected in reverse series.

[0083] The other end of the second switch Q2 is connected to one end of the fifth resistor R5, the other end of the fifth resistor R5 is connected to one end of the second inductor L2, the other end of the second inductor L2 is connected to the first end of the sixth switch Q6 to form the second node N2, the second end of the sixth switch Q6 is connected to the second end of the seventh switch Q7, and the first end of the seventh switch Q7 is connected to the midpoint of the output bus in the AC / DC converter circuit 110. The sixth switch Q6 and the seventh switch Q7 are connected in reverse series.

[0084] The other end of the third switch Q3 is connected to one end of the sixth resistor R6, the other end of the sixth resistor R6 is connected to one end of the third inductor L3, the other end of the third inductor L3 is connected to the first end of the eighth switch Q8, forming the third node N3, the second end of the eighth switch Q8 is connected to the second end of the ninth switch Q9, and the first end of the ninth switch Q9 is connected to the midpoint of the output bus in the AC / DC converter circuit 110. The eighth switch Q8 and the ninth switch Q9 are connected in reverse series.

[0085] In addition, the AC / DC conversion circuit 110 may also include a first electrolytic capacitor C1 and a second electrolytic capacitor C2, the first electrolytic capacitor C1 and the second electrolytic capacitor C2 are connected in series, and the first electrolytic capacitor C1 and the second electrolytic capacitor C2 are disposed on the output bus, with the midpoint of the output bus between the first electrolytic capacitor C1 and the second electrolytic capacitor C2.

[0086] In some embodiments, the AC / DC conversion circuit 110 may further include a first diode D1, a second diode D2, a third diode D3, a fourth diode D4, a fifth diode D5, and a sixth diode D6.

[0087] In this configuration, the anode of the first diode D1 is connected to the first node N1, and the cathode of the first diode D1 is connected to one end of the first electrolytic capacitor C1. The cathode of the second diode D2 is connected to the first node N1, and the anode of the second diode D2 is connected to one end of the second electrolytic capacitor C2. The anode of the third diode D3 is connected to the second node N2, and the cathode of the third diode D3 is connected to one end of the first electrolytic capacitor C1. The cathode of the fourth diode D4 is connected to the second node N2, and the anode of the fourth diode D4 is connected to one end of the second electrolytic capacitor C2. The anode of the fifth diode D5 is connected to the third node N3, and the cathode of the fifth diode D5 is connected to one end of the first electrolytic capacitor C1. The cathode of the sixth diode D6 is connected to the third node N3, and the anode of the sixth diode D6 is connected to one end of the third electrolytic capacitor.

[0088] Continue to refer to Figure 7 In some embodiments, the DC / DC converter circuit 120 includes a transformer rectifier module, an output switch module, an output electrolysis module, and a reverse protection module.

[0089] One end of the transformer rectifier module is connected to the AC / DC conversion circuit 110, and the other end of the transformer rectifier module is connected to one end of the output switch module. The output switch module is connected to the first input terminal and the second output terminal of the output electrolysis module. The first output terminal of the output electrolysis module is connected to one end of the reverse protection module, the second output terminal of the output electrolysis module is connected to the negative terminal of the load, and the other end of the reverse protection module is connected to the positive terminal of the load.

[0090] In this embodiment, the transformer-rectifier module may include two transformers and two sets of rectifier bridges; the output switch module may be a combination of multiple relays; the output electrolytic module may include an output bus with two electrolytic capacitors; and the reverse protection module may include a reverse protection diode. For a detailed structure, please refer to [reference needed]. Figure 7 This will not be elaborated upon here.

[0091] Referring to the circuit diagram of the fully immersive power module above, the control strategy of the fully immersive power module will be described in detail below.

[0092] In some embodiments, when the current temperature of the insulating coolant is less than the second temperature value, the controller continuously outputs a first control signal to the switching unit 132. The first control signal can be a high-level signal, used to control the switching unit 132 to close. When the current temperature of the insulating coolant is greater than the second temperature value and less than the third temperature value, the controller outputs a first control signal to the switching unit 132 according to a target duty cycle. The target duty cycle is dynamically adjusted based on the current temperature and the third temperature value of the insulating coolant, wherein the first temperature value is greater than the second temperature value and less than the third temperature value.

[0093] It should be noted that the second temperature value can be less than the first temperature value; for example, the second temperature value can be equal to the first temperature value -10℃. The third temperature value can be set to the temperature at which each component in the power module can operate normally, i.e., the temperature value required for the heating process. This can be set manually by the operator; for example, the third temperature value can be equal to the first temperature value +5℃.

[0094] In some implementations, the switching unit 132 is in the off state when the power module enters the charging operation mode.

[0095] Specifically, before the power module is put into use, the controller first receives the current temperature of the insulating coolant output by the temperature detection device 140 and determines whether the current temperature of the insulating coolant is lower than a first temperature value. If the current temperature of the insulating coolant is lower than the first temperature value, the heating function of the power module is activated. After the heating function of the power module is activated, the controller can determine again whether the current temperature of the insulating coolant is lower than a second temperature value. If the current temperature of the insulating coolant is lower than the second temperature value, the controller can output a continuous first control signal to all three switching subunits, causing all three switching subunits to close, and the corresponding three heating subunits to continuously heat the insulating coolant.

[0096] If, before the power module is put into use, or during the heating process, the controller determines that the current temperature of the insulating coolant is higher than the second temperature value but lower than the third temperature value, the controller can choose to output a pulsed first control signal to all three switching subunits, or it can choose to output a pulsed first control signal to some of the switching subunits. Furthermore, the controller can output the pulsed first control signal according to a target duty cycle. It should be noted that the target duty cycle refers to the ratio of the first control signal to the total time, and the target duty cycle can be dynamically adjusted based on the current temperature of the insulating coolant and the third temperature value. Specifically, a PI control method can be used to gradually bring the current temperature of the insulating coolant closer to the third temperature value.

[0097] It should be noted that the above control method is for the heating circuit 130 in the first series mode. If the heating circuit 130 in the parallel mode is used, it is only necessary to change the first control signal to the second control signal. The second control signal can be a low-level control signal used to control the switching unit 132 to open.

[0098] Therefore, by simply modifying the circuit of the power module and heating the insulating coolant inside it using a heating device, the temperature of the insulating coolant inside the power module can be rapidly raised to the predetermined temperature. This allows the electronic components in the power module to operate in an optimal temperature environment, thereby improving the reliability of the entire module and solving the problem of reduced reliability of the charging system caused by the low temperature of the insulating coolant.

[0099] Based on the above embodiments, this application also provides a charging system. Figure 8 This is a schematic diagram of the charging system according to an embodiment of this application. Figure 8 As shown, the charging system may include at least two power modules 210, controller 220, power distribution device 230 as described above, and at least one charging interface 240;

[0100] The power distribution device 230 is connected to the controller 220, each power module 210, and each charging interface 240. The controller 220 is connected to each power module 210. For any power module 210, the controller 220 receives the current temperature of the insulating coolant output by the temperature detection device 140 in the power module 210. If the current temperature of the insulating coolant is less than a first temperature value, the controller outputs a control signal to the switching unit 132 of the heating circuit 130 in the power module 210 to turn on the circuit where the heating unit 131 of the heating circuit 130 is located.

[0101] In addition, the power module is used to convert the AC power of the power grid into DC power and supply it to the charging interface 240. The controller 220 is used to obtain the power demand of each charging interface 240 and generate scheduling instructions according to the connection relationship of the controllable switches in the power distribution device 230 and the power demand. The power distribution device 230 is used to control the opening or closing of the controllable switches according to the scheduling instructions to distribute the output power of each power module to each charging interface 240.

[0102] In one optional implementation, the charging system provided in this application is an integrated DC charging pile, with the charging interface 240 used to connect the charging gun, and the charging gun being hung on the host of the charging system via the gun holder on the main body of the charging system.

[0103] In one optional implementation, the charging system provided in this application embodiment is a split-type DC charging pile. The charging system also includes multiple charging terminals. The charging interface 240 is used to connect the charging terminals. The charging terminals are set separately from the main body of the charging system. The charging terminals are equipped with a single charging gun or dual charging guns for outputting power to electric vehicles.

[0104] It should be noted that for details not disclosed in the charging system of this embodiment, please refer to the details disclosed in the embodiment of the power module in this specification, which will not be repeated here.

[0105] The device embodiments described above are merely illustrative. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units; that is, they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs. Those skilled in the art can understand and implement this without any creative effort.

[0106] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A fully immersion power module, characterized in that, The power module includes a PCBA assembly, which is fully immersed in an insulating coolant. The PCBA assembly includes an AC / DC conversion circuit and a heating circuit. The heating circuit is disposed between the AC / DC conversion circuit and the AC power supply. The heating circuit includes a heating unit and a switching unit. The heating unit and the switching unit are connected in parallel or in series. The switching unit is used to turn on the heating unit in a closed or closed state so that the heating unit heats the insulating coolant.

2. The fully immersion power module according to claim 1, characterized in that, The heating unit includes at least one heating subunit, and the switching unit includes at least one switching subunit. Each heating subunit is connected in parallel or in series with the corresponding switching subunit. When the heating subunit is connected in parallel with the corresponding switching subunit, the switching subunit is used to turn on the heating subunit in the off state; When the heating subunit is connected in series with the corresponding switching subunit, the switching subunit is used to turn on the heating subunit when it is closed.

3. The fully immersion power module according to claim 2, characterized in that, The AC power supply is connected to the AC / DC conversion circuit via three input lines; When the heating subunit is connected in series with the corresponding switching subunit, one end of the heating circuit is connected to at least one of the input lines, and the other end of the heating circuit is connected to the N line.

4. The fully immersion power module according to claim 3, characterized in that, The heating unit includes three heating sub-units. The first end of each heating sub-unit is connected to one of the three input lines respectively, and the second end of each heating sub-unit is connected to the corresponding switch sub-unit. When the number of the switching subunits is 1, the second end of each of the heating subunits is connected to the switching subunit; When the number of the switching subunits is 2, the second ends of any two of the heating subunits are connected to one of the switching subunits, and the second ends of the remaining heating subunits are connected to the other switching unit. When the number of the switch subunits is 3, each heating subunit is connected to each switch subunit in a one-to-one correspondence.

5. The fully immersion power module according to claim 2, characterized in that, The AC power supply includes three output terminals; One end of each heating subunit is connected to the corresponding output terminal of the AC power supply, and the other end of each heating subunit is connected to the AC / DC conversion circuit. Each switching subunit is connected in parallel with the corresponding heating subunit.

6. The fully immersion power module according to any one of claims 2 to 4, characterized in that, The heating subunit includes at least one heating device, and the switching subunit includes a switching tube; The heating devices are connected in series and / or in parallel.

7. The fully immersion power module according to claim 1, characterized in that, The power module also includes a temperature detection device; The temperature detection device is installed in the insulating coolant and is connected to the controller. The temperature detection device is used to detect the current temperature of the insulating coolant and transmit the current temperature of the insulating coolant to the controller.

8. The fully immersion power module according to claim 3 or 4, characterized in that, The PCBA assembly also includes an input EMC module; One end of the input EMC module is connected to the AC power supply, and the other end of the input EMC module is connected to the AC / DC conversion circuit. One end of the heating unit is connected between the AC power supply and the input EMC module; or, one end of the heating unit is connected between the input EMC module and the AC / DC conversion circuit.

9. The fully immersion power module according to claim 1, characterized in that, The PCBA assembly also includes a DC / DC converter circuit, which includes a transformer rectifier module, an output switch module, an output electrolysis module, and a reverse protection module. One end of the transformer-rectifier module is connected to the AC / DC conversion circuit, and the other end of the transformer-rectifier module is connected to one end of the output switch module. The output switch module is connected to the first input terminal and the second output terminal of the output electrolysis module. The first output terminal of the output electrolysis module is connected to one end of the anti-reverse module, the second output terminal of the output electrolysis module is connected to the negative terminal of the load, and the other end of the anti-reverse module is connected to the positive terminal of the load.

10. A charging system, characterized in that, It includes at least two power modules, a controller, a power distribution device, and at least one charging interface as described in any one of claims 1 to 9; The power distribution device is connected to the controller, each of the power modules, and each of the charging interfaces respectively; The controller is connected to each of the power modules respectively; For any power module, the controller is used to receive the current temperature of the insulating coolant output by the temperature detection device in the power module, and when the current temperature of the insulating coolant is less than a first temperature value, output a control signal to the switching unit of the heating circuit in the power module; the control signal is used to control the heating circuit to be turned on, so that the heating unit of the heating circuit heats the insulating coolant.

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