Liquid metal cooling system for port self-powering of high power density converters

Abstract

The application discloses a liquid metal cooling system with port self-power supply for high-power-density converters, comprising a high-power-density converter, a secondary auxiliary conversion circuit, a liquid metal cooling loop and a temperature feedback control module, the high-power-density converter constructs an auxiliary power supply channel through an auxiliary power supply port and outputs an auxiliary power supply voltage; the secondary auxiliary conversion circuit is connected with the auxiliary power supply port and is used for converting the auxiliary power supply voltage into a low-voltage and large-current suitable for driving a direct-current electromagnetic pump; the liquid metal cooling loop drives liquid metal cooling medium to flow in a closed circulation loop by the direct-current electromagnetic pump using the low-voltage and large-current, so as to absorb and dissipate heat generated by power devices in the high-power-density converter; and the temperature feedback control module is used for collecting operation temperature in real time and realizing closed-loop regulation of system temperature. The application does not need an additional independent auxiliary power supply, and improves the integration, heat exchange capacity and operation stability of the heat dissipation system of the high-power-density converter.

Description

Technical Field

[0001] This invention relates to the field of power electronic converters and their thermal management control technology, specifically to a port self-powered liquid metal cooling system for high power density converters. Background Technology

[0002] With the widespread application of high-power-density converters such as Dual Active Bridge (DAB), Phase-Shifted Full Bridge, and LLC Resonant Converters in DC microgrids, energy storage systems, electric vehicles, and data center power supplies, the power density and heat flux density of power semiconductor devices (such as SiC / GaN MOSFETs or IGBTs) are continuously increasing. This has led to increasingly prominent issues of thermal stress concentration and device temperature rise. Traditional air-cooling methods are limited by air heat exchange capacity, resulting in low heat dissipation efficiency, high noise, and difficulty in adapting to high heat flux density scenarios. While traditional water-cooling systems can improve heat dissipation capacity, they still suffer from limited thermal conductivity, large cooling loop volume, easy evaporation of the cooling medium, and high noise from mechanical pump operation, making it difficult to meet the requirements of high-power-density converters for efficient, compact, and low-noise heat dissipation systems.

[0003] Liquid metal cooling media (such as gallium-based alloys) are increasingly becoming an important heat dissipation solution for high heat flux density electronic devices due to their high thermal conductivity, good fluidity, and wide operating temperature range. To drive the liquid metal to circulate in the cooling circuit, a DC electromagnetic pump is typically used as the power source. Because DC electromagnetic pumps have low impedance characteristics, they often require a low-voltage, high-current drive power supply during operation.

[0004] In existing technologies, liquid metal cooling systems typically use an external independent auxiliary power supply to power the DC electromagnetic pump. This approach not only increases the system size and insulation design complexity but also reduces system integration and energy utilization efficiency. Furthermore, existing low-voltage, high-current drive solutions usually require complex current detection and active current sharing control structures, leading to increased control system complexity and hardware costs. Additionally, sensor drift or localized failures may affect system reliability. Summary of the Invention

[0005] The purpose of this invention is to provide a port-self-powered liquid metal cooling system for high power density converters. By constructing an auxiliary power supply channel inside the high power density converter and combining a two-stage auxiliary conversion circuit with a liquid metal circulating heat dissipation loop, the self-powered drive of the DC electromagnetic pump and the dynamic adjustment of its heat dissipation capacity are realized, thereby improving the system's integration, energy utilization efficiency, and thermal stability. This solves the problems of low integration, complex auxiliary power supply structure, and difficulty in driving low-voltage, high-current systems in existing high power density converter heat dissipation systems.

[0006] To achieve the above objectives, the present invention provides the following technical solution: a liquid metal cooling system for port self-powered high power density converters, comprising a high power density converter, a secondary auxiliary conversion circuit, a liquid metal cooling loop, and a temperature feedback control module;

[0007] The high power density converter is equipped with power devices and multi-port magnetic components. The multi-port magnetic components include a main power winding wound with a common magnetic core and an auxiliary power supply winding. The main power winding forms the main power transmission channel, and the output end of the auxiliary power supply winding forms an auxiliary power supply port after passing through a rectifier circuit, which is used to output the auxiliary power supply voltage.

[0008] The input terminal of the secondary auxiliary conversion circuit is connected to the auxiliary power supply port, and is used to convert the auxiliary power supply voltage into a low-voltage, high-current output suitable for driving a DC electromagnetic pump.

[0009] The liquid metal cooling loop includes a DC electromagnetic pump, a delivery pipe, a heat-absorbing cold plate, and a heat sink. The DC electromagnetic pump is connected to the output of the secondary auxiliary conversion circuit and is used to drive the liquid metal cooling medium to flow in a closed loop to dissipate heat from the power devices.

[0010] The temperature feedback control module is used to collect the system operating temperature in real time and dynamically adjust the control signal of the secondary auxiliary conversion circuit according to the temperature change, so as to change the DC electromagnetic pump drive current and the liquid metal circulation flow rate, thereby realizing the closed-loop regulation of the system temperature.

[0011] Furthermore, the high power density converter includes a main power transmission unit and an auxiliary power supply unit. The main power transmission unit consists of a power conversion unit and a main power winding, while the auxiliary power supply unit consists of an auxiliary power supply winding, a rectifier circuit, and an auxiliary power supply channel.

[0012] Furthermore, the secondary auxiliary conversion circuit is an auxiliary power conversion structure suitable for low-voltage, high-current output, including a power conversion unit and an output adjustment unit, used to realize the conversion of auxiliary power supply voltage to low-voltage, high-current output.

[0013] Furthermore, the secondary auxiliary conversion circuit adopts a multi-phase parallel structure to reduce output current ripple and improve the stability of low-voltage, high-current output.

[0014] Furthermore, the heat-absorbing cold plate is attached to the surface of the power device through a highly thermally conductive insulating interface material to achieve thermal coupling and electrical isolation between the electrical domain of the main circuit and the heat dissipation fluid domain.

[0015] Furthermore, the DC electromagnetic pump has no internal mechanical moving parts and uses the Lorentz force generated by electromagnetic fluid dynamics to drive the liquid metal cooling medium to circulate.

[0016] Furthermore, the liquid metal cooling medium is a gallium-based liquid metal alloy or other conductive and highly thermally conductive liquid metal material.

[0017] Furthermore, the temperature feedback control module includes a temperature sensor unit and a system control unit. The system control unit dynamically adjusts the PWM control signal of the secondary auxiliary conversion circuit based on real-time temperature information using a PID algorithm.

[0018] Furthermore, the temperature feedback control module adopts a PID closed-loop control strategy with a temperature control dead zone to reduce the adjustment oscillation of the liquid metal cooling loop near the temperature equilibrium point.

[0019] Compared with the prior art, the beneficial effects of the present invention are:

[0020] 1. The liquid metal cooling system for port self-powered high power density converters of the present invention realizes internal self-powered liquid metal heat dissipation system by constructing an auxiliary power supply channel inside the high power density converter. This avoids the problems of complex system structure, increased size and difficulty in high and low voltage isolation design caused by additional configuration of independent auxiliary power supply in traditional heat dissipation schemes, thereby improving system integration and structural compactness.

[0021] 2. The self-powered liquid metal cooling system for high power density converters of the present invention, through the setting of a two-stage auxiliary conversion circuit, realizes the conversion of auxiliary power supply voltage to low-voltage, high-current output, which can meet the driving requirements of DC electromagnetic pumps in liquid metal circulation systems. Simultaneously, the two-stage auxiliary conversion circuit adopts a multi-branch parallel output structure, which helps to reduce the impact of parasitic parameter differences among branches on current distribution during low-voltage, high-current output, reduces output current fluctuations, improves system output stability, and thus enhances the reliability and robustness of the heat dissipation system during long-term operation.

[0022] 3. The liquid metal cooling system for port self-powered high-power-density converters of the present invention uses liquid metal as the circulating cooling medium. Utilizing its high thermal conductivity and high heat transfer capacity, it can effectively improve the heat dissipation performance of power devices under high heat flux density conditions and reduce localized heat accumulation in the devices. Simultaneously, by combining it with a DC electromagnetic pump without mechanical moving parts to construct a closed-loop circulating heat dissipation structure, it can reduce the mechanical wear, operating noise, and long-term maintenance problems associated with traditional mechanical pumps, thereby improving the system's operational stability and service life.

[0023] 4. The self-powered liquid metal cooling system for high power density converters of the present invention achieves dynamic matching between the liquid metal circulation flow rate and the system thermal load through a temperature feedback closed-loop control mechanism. The system can automatically adjust the DC electromagnetic pump drive capability according to the changes in the operating temperature of the power devices, thereby improving the adaptability of the heat dissipation system to different operating conditions, reducing device temperature fluctuations, and improving the thermal stability and operational safety of the high power density converter during long-term operation.

[0024] 5. The liquid metal cooling system for port self-powered high power density converters of the present invention integrates the high power density converter, electromagnetic pump drive, electrothermal coupling heat dissipation circuit and temperature closed-loop control into one integrated system, realizing the coordinated operation between electrical energy transmission and thermal management system, which is conducive to improving the overall energy utilization efficiency of the system, and provides a new implementation scheme for the miniaturization, high integration and high reliability heat dissipation design of high power density power electronic equipment. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the circuit connection of the liquid metal cooling system of the present invention;

[0026] Figure 2(a) is a schematic diagram of the multi-port high-frequency isolation converter structure in an embodiment of the present invention;

[0027] Figure 2(b) is a schematic diagram of the star-shaped equivalent leakage inductance model circuit established in the embodiment of the present invention;

[0028] Figure 2(c) is a schematic diagram of the circuit for the equivalent conversion of the star model to the triangle model in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the secondary auxiliary conversion circuit structure in an embodiment of the present invention;

[0030] Figure 4 This is a schematic diagram of the liquid metal cooling loop structure in an embodiment of the present invention;

[0031] Figure 5 This is a logic block diagram of the system control strategy based on temperature feedback closed loop in an embodiment of the present invention;

[0032] Figure 6(a) is a simulation distribution diagram of electromagnetic-fluid coupling of DC electromagnetic pump under steady-state working conditions in an embodiment of the present invention;

[0033] Figure 6(b) is a simulation distribution diagram of the basic output capacity of the electromagnetic pump under high flow rate in a low resistance pipeline in an embodiment of the present invention;

[0034] Figure 6(c) is a simulation diagram of the steady-state temperature field distribution of the high-power device in the main circuit when liquid metal is used as the cooling medium in an embodiment of the present invention. Detailed Implementation

[0035] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0036] like Figure 1 As shown, in order to solve the problems of low integration, complex auxiliary power supply structure and difficulty in driving low voltage and high current in the heat dissipation system of high power density converter in the prior art, this invention provides a port self-powered liquid metal cooling system for high power density converter, including high power density converter, secondary auxiliary conversion circuit, liquid metal cooling loop and temperature feedback control module.

[0037] The high-power-density converter includes an internal auxiliary power supply port. This port obtains auxiliary power supply voltage from within the converter and forms an auxiliary power supply channel. The auxiliary power supply port can be powered via high-frequency magnetic coupling, power transmission node connection, or other internal auxiliary power supply methods. To reduce the power coupling effect between the main power transmission channel and the auxiliary power supply channel under asymmetrical load conditions, the high-power-density converter preferably employs a multi-port high-frequency isolation converter structure that includes an auxiliary power supply winding. This structure comprises a main power winding and an auxiliary power supply winding. The main power winding is used for main power transmission, while the auxiliary power supply winding is used to construct the auxiliary power supply channel to provide auxiliary power supply voltage to the secondary auxiliary converter circuit.

[0038] The input terminal of the secondary auxiliary converter circuit is connected to the auxiliary power supply port to convert the auxiliary power supply voltage into a low-voltage, high-current output suitable for driving a DC electromagnetic pump. The secondary auxiliary converter circuit includes a low-voltage, high-current regulation unit for dynamically adjusting the output voltage, current, and driving capability. In this embodiment, the secondary auxiliary converter circuit preferably employs an auxiliary power conversion structure suitable for low-voltage, high-current output scenarios. This auxiliary power conversion structure includes a power switch unit, an energy storage and filtering unit, and an output regulation unit. The output regulation unit dynamically adjusts the output current to improve operational stability under low-voltage, high-current output conditions. During system operation, the auxiliary power conversion structure continuously adjusts the output voltage and current by regulating the conduction state of the power switch unit to meet the driving requirements of the DC electromagnetic pump under different operating conditions.

[0039] The liquid metal cooling loop uses conductive, high thermal conductivity liquid metal as the circulating cooling medium. The loop includes a DC electromagnetic pump, delivery pipes, a heat-absorbing cold plate, and a heat sink. The heat-absorbing cold plate is attached to the surface of the heat-generating power devices in the high-power-density converter via a high thermal conductivity insulating interface material, achieving electrical isolation and heat coupling between the main circuit's electrical domain and the heat dissipation fluid domain. Microchannels for liquid metal flow are incorporated within the heat-absorbing cold plate to enhance convective heat transfer between the liquid metal and the cold plate. The liquid metal cooling medium is a conductive, high thermal conductivity fluid, preferably a gallium-based liquid metal alloy or other liquid metal materials with high thermal conductivity. The DC electromagnetic pump has no internal moving parts; its input is connected to the output of the secondary auxiliary converter circuit. It utilizes the Lorentz force generated by electromagnetic fluid dynamics to drive the conductive liquid metal cooling medium to circulate within the closed delivery pipes and heat-absorbing cold plate channels, thereby reducing mechanical vibration, operating noise, and mechanical wear problems generated during the operation of traditional mechanical pumps.

[0040] The temperature feedback control module includes a temperature sensor and a system control unit. The temperature sensor collects the operating temperature of the heat-generating power device or the heat-absorbing cold plate in real time and feeds the temperature signal back to the system control unit. The system control unit dynamically adjusts the control signal of the secondary auxiliary converter circuit according to the preset target temperature to change the drive current of the DC electromagnetic pump and the liquid metal flow rate, thereby achieving closed-loop regulation of the heat dissipation capacity. To reduce frequent adjustments and flow oscillations in the liquid metal cooling loop near the temperature equilibrium point, the system control unit of the temperature feedback control module adopts a PID closed-loop control strategy with a temperature control dead zone: when the operating temperature is higher than the preset upper temperature limit, the PWM duty cycle of the secondary auxiliary converter circuit is dynamically increased; when the operating temperature is lower than the preset lower temperature limit, the PWM duty cycle is decreased; when the operating temperature is within the preset temperature dead zone, the current drive state remains unchanged.

[0041] To further explain the implementation process of the present invention, in this embodiment, a triple active bridge (TAB) converter formed by extending a dual active bridge (DAB) converter is used as a specific implementation of the high power density converter, and a three-phase series capacitor converter is used as a specific implementation of the secondary auxiliary conversion circuit for illustration:

[0042] As shown in Figure 2(a), the TAB converter includes a primary-side full-bridge, a secondary-side full-bridge, and an auxiliary-side full-bridge. The three bridge arms are respectively connected to the primary winding, secondary winding, and auxiliary power supply winding of the three-port high-frequency transformer. The primary side is used to connect to the high-voltage DC input terminal, the secondary side is used to output main power to the load, and the auxiliary side is used to construct the auxiliary power supply channel and provide auxiliary power supply voltage to the secondary auxiliary conversion circuit.

[0043] Furthermore, the three-port high-frequency transformer adopts an asymmetric leakage inductance matching scheme. By adjusting the equivalent leakage inductance parameters of each port, relatively independent energy regulation between the main power channel and the auxiliary power supply channel is achieved, thereby reducing the coupling effect of the auxiliary power supply branch on the main power output under asymmetric load conditions.

[0044] As shown in Figure 2(b), in order to achieve precise decoupling control of the power flow direction of the converter, a virtual central interconnection point v was established. x The star-shaped (Wye) equivalent leakage inductance model is used. In this model, the complex magnetic coupling of the transformer is equivalent to three independent branches, where L... 1(act) L 2(act) and L 3(act) These represent the total equivalent leakage inductance (including transformer leakage inductance and external auxiliary inductance) referred to the original side at each port. Each port transmits independently to the center point v. x Power P i Expressed as:

[0045]

[0046] In the formula, V i 'L' represents the DC voltage at each port converted to the original side. i For the equivalent leakage inductance of each port, ɸ ix This represents the actual phase shift angle between the voltage at each port and the voltage at the center point.

[0047] To achieve power decoupling under conditions of extreme asymmetry between the main power output and the auxiliary power supply channel load, this embodiment employs an asymmetric leakage inductance configuration scheme, ensuring that the equivalent leakage inductance of each port is proportional to its rated power P. Ni Inversely proportional, that is, satisfying:

[0048]

[0049] This configuration ensures that each branch can achieve the optimal phase shift angle α under rated conditions. N This significantly expands the operating range of zero-voltage switching (ZVS) across the entire operating range.

[0050] As shown in Figure 2(c), to intuitively represent the direct energy exchange characteristics between any two ports, the star model is equivalently converted into a delta model. In this model, the equivalent coupling leakage inductance L between the ports is... 12 , L 23 , L 31 The star-shaped parameters satisfy the following transformation relationship:

[0051]

[0052]

[0053]

[0054] Among them, P N1 P is the rated input power of the primary winding. N2 and P N3 L1, L2', and L3' are the rated output power of the first secondary winding and the auxiliary winding, respectively, and L1, L2', and L3' are the equivalent leakage inductances referred to the primary side at each port. Based on the system energy conservation relationship: L is the system's common inductance reference value, and its expression is:

[0055]

[0056] In the physical hardware implementation, the turns ratio of the primary winding, the first secondary winding, and the auxiliary winding of the three-port power transformer is assumed to be N1 : N2 : N3. The equivalent leakage inductance referred to the primary side above needs to be combined with the transformer turns ratio and restored to the actual physical inductance target value of each port (denoted as L) through the square relationship of the turns ratio. 1(act) L 2(act) and L 3(act) ):

[0057]

[0058]

[0059]

[0060] The target physical inductance value of each port is determined by the leakage inductance (L) of each port of the transformer. σ1 , L σ2 , L σ3 ) and external auxiliary inductor (L) s1 L s2 and L s3 Together they constitute the whole.

[0061] like Figure 3 As shown, the secondary auxiliary converter circuit adopts a three-phase series capacitor converter structure, including three sets of interleaved parallel switching bridge arms, three filter inductors (L1, L2, L3), and a current sharing capacitor (C). f1 and C f2 Let the average currents of the three-phase filter inductors be I...L1 , I L2 , I L3 The duty cycles of the corresponding switch arms are D1, D2, and D3, respectively. The auxiliary power supply voltage output from the auxiliary power supply port is transformed by a two-stage auxiliary converter circuit to output a low-voltage, high-current DC electromagnetic pump.

[0062] During system operation, based on the switching state transitions and node current flow directions of the circuit topology, the current sharing capacitor (C) is used. f1 C f2 Voltage across terminals (V) CF1 V CF2 The transient charge balance differential equation can be expressed as:

[0063]

[0064]

[0065] When the system enters the steady-state operating range, based on the ampere-second balance physical characteristics of capacitors, the average charge change of the current-sharing capacitor over a complete switching cycle must be zero, meaning the average capacitor voltage no longer undergoes abrupt changes (satisfying...). Substituting this steady-state boundary condition into the above transient equations, we can obtain the steady-state relationships satisfied by the currents in each phase branch:

[0066]

[0067] In conventional system control, by providing symmetrical drive signals to the three-phase bridge arms (i.e., forcing each phase to have the same duty cycle), The underlying charge balance mechanism of the system will automatically ensure that the three-phase inductor currents are consistent, thus achieving... Natural uniform flow.

[0068] like Figure 4 As shown, the liquid metal cooling loop includes a DC electromagnetic pump, a delivery pipe, a heat-absorbing cold plate, and a heat sink, forming a closed-loop heat exchange structure. The heat-absorbing cold plate is attached to the surface of the heat-generating power devices in the high-power-density converter, and its interior contains microchannels for liquid metal flow to enhance the convective heat transfer between the liquid metal and the heat-absorbing cold plate. The DC electromagnetic pump has no moving mechanical parts; its input is connected to the output of the secondary auxiliary conversion circuit, and it utilizes the Lorentz force generated by electromagnetism to drive the conductive liquid metal cooling medium to circulate within the closed delivery pipe and the microchannels of the heat-absorbing cold plate.

[0069] During system operation, the liquid metal cooling medium flows into the heat-absorbing cold plate after being driven by the DC electromagnetic pump, and absorbs heat to cool the power devices in the high power density converter. After absorbing heat, the high-temperature liquid metal flows into the radiator through the delivery pipe and exchanges heat with the external environment under the action of air cooling heat exchange. The cooled liquid metal finally flows back to the DC electromagnetic pump, thus forming a complete closed-loop heat exchange circuit.

[0070] like Figure 5 As shown, in the temperature feedback control module, the temperature sensor unit collects the operating shell temperature at the heat absorption cold plate in real time and feeds back the measured actual temperature signal T to the system control module. The system control module then determines the target temperature T based on the preset target temperature. ref , combined Figure 5 The logic block diagram shown demonstrates closed-loop stabilization of the system temperature.

[0071] After system initialization, it enters the closed-loop control process. The system control module compares the acquired current temperature T with the target temperature T. ref By comparison and judgment, the temperature deviation e = T - T is obtained. ref To avoid frequent adjustments by the system near the equilibrium point, a temperature control dead zone ∆T is introduced. This dead zone occurs when the condition T > T0 is met. ref When +∆T, the system control module dynamically increases the PWM duty cycle of the secondary auxiliary converter circuit; when the condition T < T is met... ref - When ∆T, decrease the PWM duty cycle; when the condition |T – T is met... ref When | ≤ ∆T, the PWM duty cycle remains unchanged. This PID control strategy with dead time effectively suppresses frequent oscillations in the fluid drive system while achieving closed-loop stable temperature regulation.

[0072] The dynamic adjustment of the PWM duty cycle directly alters the output current of the secondary auxiliary converter circuit, thereby controlling the flow rate of the liquid metal in the pipeline in real time. This results in a corresponding change in the heat dissipation effect of the power devices in the high-power-density converter. Finally, the system returns to perform temperature acquisition and enters the next cycle. Through this continuous feedback adjustment, closed-loop stable temperature regulation of the system is ultimately achieved.

[0073] Figure 6(a) shows the electromagnetic-fluid coupling simulation distribution of the DC electromagnetic pump under steady-state operating conditions in this embodiment of the invention. Simulation results show that when a large current is input to the electromagnetic pump by the secondary auxiliary converter circuit, this current flows in the liquid metal channel inside the pump and interacts with the applied magnetic field, generating a Lorentz force along the channel direction under the combined action of the current and the magnetic field. Driven directly by this Lorentz force, the liquid metal medium in the channel overcomes the pipe flow resistance, forming a stable velocity distribution. It can be observed from the figure that under a current of 40A, the maximum flow velocity of the liquid metal at the electromagnetic pump outlet can reach 0.433 m / s. Simultaneously, the simulation process also verifies that the pumping process relies entirely on contactless electromagnetic field drive, requiring no mechanical impellers or moving parts, thereby effectively reducing the vibration and noise generated during the operation of traditional mechanical water pumps and ensuring the long-term reliability of the system under high-frequency, high-power operating conditions.

[0074] It should be noted that the high flow rate measured in Figure 6(a) represents the basic output capability of the electromagnetic pump under low-resistance piping. However, in the complete physical embodiment of the present invention, the high-density microchannels inside the heat-absorbing cold plate, the bent tube bundles of the remote heat sink, and the complex fluid connection piping inevitably introduce large flow resistance and local pressure drop, which in turn causes the actual steady-state fluid operating point of the entire heat dissipation loop to shift. As shown in Figure 6(b), it is a simulation distribution of the steady-state temperature field of the high-power devices in the main circuit when liquid metal is used as the cooling medium in the embodiment of the present invention. When the system is running at full load, the power devices at each port will generate extremely high heat flux density. The liquid metal flows through the cold plate attached to the surface of the heat-generating device under the continuous drive of the electromagnetic pump. As can be seen from the temperature cloud map in Figure 6(b), under the complete heat dissipation loop condition, considering the flow resistance of the cold plate microchannels and the delivery piping, the highest temperature of the power device is 47.8℃ when the steady-state circulation velocity of the liquid metal is about 0.133m / s. The highest junction temperature in the central region of the heat-generating device was effectively suppressed within a safe threshold range, and the temperature gradient on the device surface was small, with no local hot spots appearing. Furthermore, compared with the temperature field simulation results of the traditional water-cooling scheme shown in Figure 6(c), the data and distribution in Figure 6(b) show that the self-powered liquid metal heat dissipation loop provided by this invention can achieve higher heat transfer capacity under the same operating conditions, improving the thermal stability of the entire converter system.

[0075] In summary, the simulation results demonstrate that the designed integrated self-powered liquid metal cooling loop can effectively handle the high heat flux density heat loss of power devices, avoiding the system redundancy and power coupling problems caused by traditional air cooling (high noise), water cooling (easy evaporation), and the need for an external independent auxiliary power supply. This significantly improves the system integration and thermal stability of the high-power power electronic converter. Furthermore, the designed self-powered topology and temperature closed-loop control strategy enable adaptive and rapid response of the heat dissipation fluid domain to the heating state of the electrical domain. Under various complex operating conditions, such as asymmetrical loads and dynamic load changes, the overall converter system maintains stable operation, demonstrating the reliability and stability of the system using this method.

[0076] The above description is only a preferred embodiment of the present invention. The present invention is not limited to the specific topology described above. Other high power density converter topologies and auxiliary power conversion structures that can achieve self-powered auxiliary ports and low-voltage high-current output can be applied to the technical solution of the present invention. The scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A port-self-powered liquid metal cooling system for high power density converters, characterized in that, include: A high power density converter is provided with power devices and multi-port magnetic components. The multi-port magnetic components include a main power winding wound with a common magnetic core and an auxiliary power supply winding. The main power winding forms the main power transmission channel, and the output end of the auxiliary power supply winding forms an auxiliary power supply port after passing through a rectifier circuit, which is used to output the auxiliary power supply voltage. A secondary auxiliary conversion circuit, wherein the input terminal of the secondary auxiliary conversion circuit is connected to the auxiliary power supply port, and is used to convert the auxiliary power supply voltage into a low-voltage, high-current output suitable for driving a DC electromagnetic pump; A liquid metal cooling loop includes a DC electromagnetic pump, a delivery pipe, a heat-absorbing cold plate, and a heat sink. The DC electromagnetic pump is connected to the output of a secondary auxiliary conversion circuit and is used to drive the liquid metal cooling medium to flow in a closed loop to dissipate heat from the power devices. The temperature feedback control module is used to collect the system operating temperature in real time and dynamically adjust the control signal of the secondary auxiliary conversion circuit according to the temperature change, so as to change the DC electromagnetic pump drive current and the liquid metal circulation flow rate, thereby realizing the closed-loop regulation of the system temperature.

2. The port self-powered liquid metal cooling system for high power density converters as described in claim 1, characterized in that: The high power density converter includes a main power transmission unit and an auxiliary power supply unit. The main power transmission unit consists of a power conversion unit and a main power winding, while the auxiliary power supply unit consists of an auxiliary power supply winding, a rectifier circuit, and an auxiliary power supply channel.

3. The port self-powered liquid metal cooling system for high power density converters as described in claim 1, characterized in that: The secondary auxiliary conversion circuit is an auxiliary power conversion structure suitable for low-voltage, high-current output, including a power conversion unit and an output adjustment unit, used to realize the conversion of auxiliary power supply voltage to low-voltage, high-current output.

4. The port self-powered liquid metal cooling system for high power density converters as described in claim 3, characterized in that: The secondary auxiliary converter circuit adopts a multi-phase parallel structure to reduce output current ripple and improve the stability of low-voltage, high-current output.

5. The port self-powered liquid metal cooling system for a high power density converter as described in claim 1, characterized in that: The heat-absorbing cold plate is attached to the surface of the power device through a highly thermally conductive insulating interface material to achieve thermal coupling and electrical isolation between the electrical domain of the main circuit and the heat dissipation fluid domain.

6. The port self-powered liquid metal cooling system for a high power density converter as described in claim 1, characterized in that: The DC electromagnetic pump has no internal moving parts and uses the Lorentz force generated by electromagnetic fluid dynamics to drive the circulation of liquid metal cooling medium.

7. The port self-powered liquid metal cooling system for a high power density converter as described in claim 1, characterized in that: The liquid metal cooling medium is a gallium-based liquid metal alloy or other conductive and highly thermally conductive liquid metal material.

8. The port self-powered liquid metal cooling system for a high power density converter as described in claim 1, characterized in that: The temperature feedback control module includes a temperature sensor unit and a system control unit. The system control unit dynamically adjusts the PWM control signal of the secondary auxiliary converter circuit based on real-time temperature information using a PID algorithm.

9. The port self-powered liquid metal cooling system for a high power density converter as described in claim 8, characterized in that: The temperature feedback control module adopts a PID closed-loop control strategy with a temperature control dead zone to reduce the adjustment oscillation of the liquid metal cooling loop near the temperature equilibrium point.

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