A crimping IGBT three-level power unit structure based on phase change cooling

Abstract

The application relates to a crimping IGBT three-level power unit structure based on phase change cooling, wherein a phase change cooling power assembly and a supporting capacitor assembly are arranged in sequence from front to back, a three-level valve string is horizontally placed, power devices are arranged between adjacent phase change cooling radiators, the phase change cooling radiators are vertically placed, phase change working medium connecting pipes are arranged at the upper part and the lower part of the three-level valve string, a valve string direct current connection row is arranged at the rear end of the three-level valve string, the connection terminals of the valve string direct current connection row are located above the three-level valve string and are in a leading direction, an output row is arranged at the front end of the three-level valve string, and the connection terminals of the output row are located on the side of the three-level valve string. The application has the advantages that the valve string direct current connection row and the valve string capacitor connection row of the supporting capacitor assembly are overlapped on the top between the phase change cooling power assembly and the supporting capacitor assembly, the connection terminals of the valve string capacitor connection row are in a leading direction, the phase change cooling power assembly can be disassembled on the front side of a cabinet body, and maintenance is easy.

Description

Technical Field

[0001] This invention relates to an IGBT unit structure, and more particularly to a press-fit IGBT three-level power unit structure based on phase change cooling. Background Technology

[0002] As the core equipment of frequency converters or power converters, the power unit's basic function is to convert the frequency and amplitude of electrical energy, cooperating with the motor or power grid to operate under the required conditions. Press-fit IGBTs feature high voltage, large current, and double-sided heat dissipation. Combined with a three-level power unit topology, they can significantly improve the power density of the entire converter device. However, with the increase in power density, conventional water-cooled press-fit IGBT power unit solutions suffer from large temperature differences between the inlet and outlet of the radiator and various points on the heat dissipation surface due to the heat capacity of water and the flow channel structure of the radiator. Furthermore, due to the conductivity of water and the potential differences between the heat sinks of the press-fit devices, high-purity deionized water is used in the water cooling system to meet insulation requirements. This necessitates the addition of a deionization device and corresponding monitoring equipment. The deionized resin used in the deionization device needs to maintain a certain level of activity and requires periodic replacement, which affects the maintenance cycle of the water cooling system. Additionally, the circulating power device providing stable flow and pressure to multiple power units in the system requires a water pump with rotating parts, which has a high failure rate. A water pump failure can cause the entire frequency converter or power converter to shut down.

[0003] Self-circulating phase change cooling systems have advantages such as almost non-conductive cooling working fluid, cooling circulation that does not depend on external circulation power devices, and adaptive coolant flow that does not require flow matching. Therefore, there is an urgent need for a phase change cooling-based press-fit IGBT three-level power unit structure solution to improve the reliability of the heat dissipation system. Summary of the Invention

[0004] The purpose of this invention is to provide a three-level power unit structure for press-fit IGBTs based on phase change cooling. The phase change cooling heat dissipation scheme can solve the problems of large temperature differences caused by the heat sink affecting the internal chips of the press-fit IGBTs and system failures caused by water pump component failures. At the same time, if a phase change cooling medium with excellent insulation properties is selected, the use of deionization devices and the electrical insulation risks caused by the cooling medium can be avoided.

[0005] To achieve the above objectives, the present invention provides the following technical solution:

[0006] A three-level power unit structure for press-fit IGBTs based on phase change cooling includes a phase change cooling power component and a supporting capacitor component, which are arranged sequentially from front to back. The phase change cooling power component includes a three-level valve string, a phase change working fluid connecting tube, a secondary board assembly, a valve string DC connection bar, and an output bar. The three-level valve string is placed horizontally and includes power devices and a phase change cooling heat sink. Power devices are installed between adjacent phase change cooling heat sinks, which are placed vertically. Phase change working fluid connecting tubes are installed at the top and bottom of the three-level valve string. A secondary board assembly is installed at the front end of the three-level valve string. The valve string DC connection bar is installed at the rear end of the three-level valve string, with the connection terminals of the valve string DC connection bar located above the three-level valve string and facing forward. The output bar is installed at the front end of the three-level valve string, with the connection terminals of the output bar located on the side of the three-level valve string.

[0007] The supporting capacitor assembly includes a supporting capacitor, a DC bus, and a capacitor base plate. Two supporting capacitors are connected in series and placed horizontally. The polarity of the output terminals of the series supporting capacitors from left to right is consistent with the polarity of the three-level valve series.

[0008] A DC bus is installed on the supporting capacitor. The DC bus includes a DC P bus, a DC O bus, a DC N bus, and a valve series capacitor connection bus. The DC P bus, DC O bus, and DC N bus are U-shaped copper busbars. The middle plane of the U-shaped copper busbar is connected to the output terminal of the supporting capacitor. The two ends of the U-shaped copper busbar serve as the connection terminals for the DC P bus, DC O bus, and DC N busbar extending upward and downward. The connection terminals for the DC P bus, DC O bus, and DC N busbar of multiple upper and lower supporting capacitor assemblies are connected end to end through the external connection bus of the three-level power unit to form a three-level capacitor pool.

[0009] The valve string capacitor connection bar is installed on the DC P-bar, DC O-bar, and DC N-bar. The connection terminals of the valve string capacitor connection bar are forward and overlap with the connection terminals of the valve string DC connection bar.

[0010] The three-level valve string adopts a compact press-fit three-level valve string structure.

[0011] The supporting capacitor assembly and the phase change cooling power assembly are connected through the connection terminals of the valve string DC connection bus and the connection terminals of the valve string capacitor connection bus, with the connection terminals of the valve string DC connection bus and the connection terminals of the valve string capacitor connection bus facing forward.

[0012] The phase change working fluid connection pipe includes a gas collection manifold and a liquid collection manifold. The gas collection port of the phase change cooling radiator is located at the top of the phase change cooling radiator, and the liquid collection port of the phase change cooling radiator is located at the bottom of the phase change cooling radiator. The gas collection manifold and the liquid collection manifold are respectively installed at the top and bottom of multiple phase change cooling radiators, so that the phase change working fluid flows out from the three-level power unit through the gas collection manifold and flows into the three-level power unit through the liquid collection manifold.

[0013] The supporting capacitor assembly is mounted on the capacitor base plate, and the phase change cooling power assembly is mounted on the power assembly base plate. The capacitor base plate and the power assembly base plate are connected and fixed by positioning pins.

[0014] Compared with the prior art, the beneficial effects of the present invention are:

[0015] 1. The power unit is divided into a phase change cooling power component and a supporting capacitor component. The phase change cooling power component and the supporting capacitor component are separate structures. The valve string DC connection bar of the phase change cooling power component and the valve string capacitor connection bar of the supporting capacitor component overlap at the top between the phase change cooling power component and the supporting capacitor component. The connection terminals of the valve string capacitor connection bar face forward to ensure that the phase change cooling power component can be disassembled and installed on the front side of the cabinet for easy maintenance.

[0016] 2. The power devices (including press-fit IGBTs) and phase change cooling heat sinks are installed in the same three-level valve string. The gas manifold and liquid manifold are installed at the top and bottom of multiple phase change cooling heat sinks, respectively. The three-level valve string structure of this press-fit device is simple and has high space utilization.

[0017] 3. The three-level valve string is placed horizontally to ensure that each phase change cooling radiator is placed vertically, with the air collection port located at the top of the radiator and the liquid collection port located at the bottom of the radiator. This conforms to the self-circulating dynamic characteristics of phase change cooling and ensures that the power devices can be cooled through the self-circulating phase change cooling system.

[0018] 4. The polarity of the connection terminals supporting the capacitor assembly from left to right is consistent with that of the three-level valve series, so that the DC connection has no cross structure. At the same time, combined with the low stray inductance design concept, the low stray inductance characteristics of the power unit commutation circuit are ensured.

[0019] 5. The DC P-bus, DC O-bus, and DC N-bus supporting the capacitor assembly are U-shaped copper busbars. These U-shaped busbars have upward and downward extending electrical connection terminals, facilitating electrical connection between the supporting capacitor assemblies of the upper and lower three-level power units inside the cabinet and forming a three-level capacitor pool. This ensures low stray inductance characteristics in the electrical connections between the supporting capacitor assemblies. This three-level capacitor pool can better stabilize the bus voltage of the power unit, reduce the adverse effects of DC-side oscillation current, and thus improve the electrical characteristics of the power unit and even the frequency converter.

[0020] 6. The valve string capacitor connection bar is installed on the DC P-bar, DC O-bar and DC N-bar. The connection terminals of the valve string capacitor connection bar are forward and can overlap with the connection terminals of the valve string DC connection bar, which facilitates the disassembly of the variable cooling power component and the support capacitor component in front of the frequency converter cabinet or converter cabinet, thereby improving the maintainability of the three-level power unit. Attached Figure Description

[0021] Figure 1 Phase change cooling three-level power unit structure diagram;

[0022] Figure 2 Phase change cooling power component structure diagram;

[0023] Figure 3 Schematic diagram of a crimped IGBT three-level valve string structure;

[0024] Figure 4 Support capacitor assembly structure diagram;

[0025] Figure 5 Three-level capacitor bank structure diagram.

[0026] 001-Phase Change Cooling Power Component 002-Supporting Capacitor Component 003-Power Component Base Plate 004-Capacitor Base Plate 101-Three-Level Valve String 102-Secondary Board Component 103-Phase Change Working Fluid Connection Pipe 104-Valve String DC Connection Bar 105-Output Bar 106-Supporting Fixing Structure 201-Phase Change Cooling Heat Sink 202-Power Device 203-Gas Manifold 204-Liquid Manifold 205-Valve String Press-fit Frame 301-Supporting Capacitor 302-DC P-Bar 303-DC O-Bar 304-DC N-Bar 305-Valve String Capacitor Connection Bar 401-External Connection Bar. Detailed Implementation

[0027] The present invention will now be described in detail with reference to the accompanying drawings, but it should be noted that the implementation of the present invention is not limited to the following embodiments.

[0028] A three-level power unit structure based on phase change cooling and press-fit IGBT includes a phase change cooling power component and a supporting capacitor component, arranged sequentially from front to back. The phase change cooling power component, as the core component of the three-level power unit, is used to convert the effective value and frequency of electrical energy. The supporting capacitor component, as the most basic functional component of the power unit, is used to maintain and stabilize the DC voltage of the power unit and participate in commutation. The phase change cooling power component includes a three-level valve string, a phase change working fluid connecting tube, a secondary board assembly, a valve string DC connection bus, and an output bus. The three-level valve string adopts a compact design. The three-level valve string structure is a press-fit type. The three-level valve string is placed horizontally and includes power devices and phase change cooling heat sinks. Power devices are installed between adjacent phase change cooling heat sinks. The phase change cooling heat sinks are placed vertically. Phase change working fluid connection pipes are installed at the top and bottom of the three-level valve string. A secondary board assembly is installed at the front end of the three-level valve string. The valve string DC connection bar is installed at the rear end of the three-level valve string. The connection terminals of the valve string DC connection bar are located above the three-level valve string and face forward. The output bar of the power unit is installed at the front end of the three-level valve string. The connection terminals of the output bar are located on the side of the three-level valve string.

[0029] The supporting capacitor assembly includes supporting capacitors, DC busbars, and capacitor base plates. Two supporting capacitors are connected in series and placed horizontally. The polarity of the output terminals of the series supporting capacitors from left to right is consistent with the polarity of the three-level valve string. A DC busbar is installed on the supporting capacitors. The DC busbar includes a DC P busbar, a DC O busbar, a DC N busbar, and a valve string capacitor connection busbar. The DC P busbar, DC O busbar, and DC N busbar are U-shaped copper busbars. The middle plane of the U-shaped copper busbar is connected to the output terminals of the supporting capacitors. The two ends of the U-shaped copper busbar serve as connection terminals for the DC P busbar, DC O busbar, and DC N busbar extending upward and downward, respectively. The connection terminals of the DC P busbar, DC O busbar, and DC N busbar extending upward and downward from multiple upper and lower supporting capacitor assemblies are connected end to end through the external connection busbar of the three-level power unit to form a three-level capacitor pool. The three-level capacitor pool can better stabilize the bus voltage of the power unit and reduce the adverse effects of DC side oscillation current.

[0030] The valve string capacitor connection bar is installed on the DC P-bar, DC O-bar, and DC N-bar. The connection terminals of the valve string capacitor connection bar are forward and overlap with the connection terminals of the valve string DC connection bar.

[0031] The supporting capacitor assembly and the phase change cooling power assembly are connected through the connection terminals of the valve string DC connection bus and the valve string capacitor connection bus. The connection terminals of the valve string DC connection bus and the valve string capacitor connection bus are forward-facing to facilitate front maintenance of the power unit.

[0032] The phase change working fluid connection pipe includes a gas collection manifold and a liquid collection manifold. The gas collection port of the phase change cooling radiator is located at the top of the phase change cooling radiator, and the liquid collection port of the phase change cooling radiator is located at the bottom of the phase change cooling radiator. The gas collection manifold and the liquid collection manifold are respectively installed at the top and bottom of multiple phase change cooling radiators, so that the phase change working fluid flows out from the three-level power unit through the gas collection manifold and flows into the three-level power unit through the liquid collection manifold.

[0033] The output bus is installed at the front end of the three-level valve string, with its output terminals located on the side of the valve string. The output bus is far from the secondary board assembly and facilitates electrical connection from the side. The secondary board assembly supplies power to the entire power unit control circuit and realizes the electrical control, signal monitoring and signal feedback functions of the power unit. It is installed in front of the three-level valve string for front maintenance.

[0034] The supporting capacitor assembly is mounted on the capacitor base plate, and the phase change cooling power assembly is mounted on the power assembly base plate. The capacitor base plate and the power assembly base plate are connected and fixed by positioning pins.

[0035] The following embodiments are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operation processes. However, the scope of protection of the present invention is not limited to the following embodiments. Unless otherwise specified, the methods used in the following embodiments are conventional methods.

[0036]

Example 1

[0037] See Figure 1 A three-level power unit structure for press-fit IGBTs based on phase change cooling includes a phase change cooling power component 001 and a supporting capacitor component 002. The phase change cooling power component 001 and the supporting capacitor component 002 are arranged sequentially from front to back and connected by a DC copper busbar. Both can be disassembled and maintained from the front of the power unit. The phase change cooling power component 001 is mounted on a power component base plate 003, and the supporting capacitor component 002 is mounted on a capacitor base plate 004. The power component base plate 003 and the capacitor base plate 004 are connected and fixed by a positioning pin.

[0038] See Figure 1 ,See Figure 2The phase change cooling power assembly 001 includes a three-level valve string 101, a secondary board assembly 102, two phase change working fluid connecting pipes 103, three valve string DC connection bars 104, an output bar 105, and a set of supporting and fixing structures 106. The three-level valve string 101 adopts a compact crimp-type three-level valve string structure. The crimp-type three-level valve string 101 is placed horizontally, with one phase change working fluid connecting pipe 103 installed above and below the valve string. The secondary board assembly 102 is installed in front of the crimp-type three-level valve string 101. The valve string DC connection bar 104 is installed on the rear side of the crimp-type three-level valve string 101, and its connection terminal is located above the crimp-type three-level valve string 101. The output bar 105 is installed on the front side of the valve string, and its connection terminal is located on the side of the crimp-type three-level valve string 101. The above components are connected and fixed into a phase change cooling power assembly 001 by a set of supporting and fixing structures 106.

[0039] See Figure 2 ,See Figure 3 The three-level valve string 101 is placed horizontally. The power device 202, the phase change cooling radiator 201, and other press-fit structural components are assembled into a three-level valve string 101 based on phase change cooling press-fit device through the valve string press-fit frame 205. Each phase change cooling radiator 201 in the valve string is placed vertically. The phase change working fluid gas collection port of the phase change cooling radiator 201 is located at the top of the phase change cooling radiator 201, and the phase change working fluid liquid collection port of the phase change cooling radiator 201 is located at the bottom of the phase change cooling radiator 201. The gas collection manifold 203 and the liquid collection manifold 204 are respectively installed at the top and bottom of multiple phase change cooling radiators (201) and maintain good sealing performance, serving as the overall gas collection pipe and liquid collection pipe of the power unit.

[0040] See Figure 1 , Figure 4 and Figure 5The supporting capacitor assembly 002 includes two supporting capacitors 301, which are placed horizontally. The polarity of the output terminals of the supporting capacitor assembly 002 from left to right is consistent with the polarity of the three-level valve string 101. The supporting capacitors 301 are equipped with DC P-bar 302, DC O-bar 303, DC N-bar 304 and valve string capacitor connection bar 305. The DC P-bar 302, DC O-bar 303 and DC N-bar 304 are all U-shaped copper bars. The middle plane of the U-shaped copper bar is connected to the output terminals of the supporting capacitors. The two ends of the U-shaped copper bar serve as the connection terminals of the DC P-bar 302, DC O-bar 303 and DC N-bar 304 extending upward and downward. The connection terminals of the upper and lower supporting capacitor assemblies 002 are connected end to end through the external connection bar 401 to form a three-level capacitor pool. The valve string capacitor connection bar 305 is installed on the DC P bar 302, DC O bar 303 and DC N bar 304. The connection terminals of the valve string capacitor connection bar 305 are forward and can overlap with the connection terminals of the valve string DC connection bar 104.

[0041] This invention divides the power unit into a phase-change cooling power assembly and a supporting capacitor assembly. These are separate, independent structures. The valve string DC connection bus of the phase-change cooling power assembly and the valve string capacitor connection bus of the supporting capacitor assembly overlap at the top between the two assemblies. The connection terminals of the valve string capacitor connection bus face forward, ensuring that the phase-change cooling power assembly can be disassembled and installed from the front of the cabinet for easy maintenance. The power devices (including press-fit IGBTs) and the phase-change cooling radiators are installed in the same three-level valve string. The gas manifold and liquid manifold are installed at the top and bottom of multiple phase-change cooling radiators, respectively. This press-fit three-level valve string structure is simple and has high space utilization. The three-level valve string is placed horizontally, ensuring that each phase-change cooling radiator is vertically aligned. The system is vertically positioned with the air inlet at the top of the radiator and the liquid inlet at the bottom, conforming to the self-circulating dynamic characteristics of phase change cooling. This ensures that the power devices can be cooled through the self-circulating phase change cooling system. The polarity of the connection terminals supporting the capacitor assembly from left to right is consistent with the three-level valve string, eliminating any crossover structure in the DC connection. Combined with a low stray inductance design, this ensures the low stray inductance characteristics of the power unit's commutation circuit. The DC P-bar, DC O-bar, and DC N-bar of the supporting capacitor assembly are U-shaped copper busbars. These U-shaped copper busbars have electrical connection terminals extending upwards and downwards, facilitating electrical connection between the supporting capacitor assemblies of the upper and lower three-level power units inside the cabinet and forming a three-level capacitor pool. This ensures the low stray inductance characteristics of the electrical connection between the supporting capacitor assemblies. The three-level capacitor bank can better stabilize the bus voltage of the power unit and reduce the adverse effects of DC side oscillation current, thereby improving the electrical characteristics of the power unit and even the frequency converter. The valve string capacitor connection bar is installed on the DC P-bar, DC O-bar and DC N-bar. The connection terminals of the valve string capacitor connection bar are forward and can overlap with the connection terminals of the valve string DC connection bar, which facilitates the disassembly of the cooling power component and the support capacitor component in front of the frequency converter cabinet or converter cabinet, thereby improving the maintainability of the three-level power unit.

Claims

1. A press-fit IGBT three-level power unit structure based on phase change cooling, characterized in that, It includes a phase change cooling power assembly and a supporting capacitor assembly, which are arranged sequentially from front to back. The phase change cooling power assembly includes a three-level valve string, a phase change working fluid connecting tube, a secondary board assembly, a valve string DC connection bar, and an output bar. The three-level valve string is placed horizontally and includes power devices and a phase change cooling heat sink. Power devices are installed between adjacent phase change cooling heat sinks. The phase change cooling heat sink is placed vertically. Phase change working fluid connecting tubes are installed at the top and bottom of the three-level valve string. A secondary board assembly is installed at the front end of the three-level valve string. The valve string DC connection bar is installed at the rear end of the three-level valve string. The connection terminals of the valve string DC connection bar are located above the three-level valve string and face forward. The output bar is installed at the front end of the three-level valve string. The connection terminals of the output bar are located on the side of the three-level valve string. The DC P-type busbar, DC O-type busbar, and DC N-type busbar are U-shaped copper busbars. The middle plane of the U-shaped copper busbar is connected to the output terminal of the supporting capacitor. The two ends of the U-shaped copper busbar serve as the connection terminals for the DC P-type busbar, DC O-type busbar, and DC N-type busbar extending upward and downward, respectively. The external connection bar of the three-level power unit connects the DC P-bar, DC O-bar, and DC N-bar of multiple upper and lower supporting capacitor components, with the connection terminals extending upward and downward to form a three-level capacitor pool.

2. The structure of a press-fit IGBT three-level power unit based on phase change cooling according to claim 1, characterized in that, The supporting capacitor assembly includes a supporting capacitor, a DC bus, and a capacitor base plate. Two supporting capacitors are connected in series and placed horizontally. The polarity of the output terminals of the series supporting capacitors from left to right is consistent with the polarity of the three-level valve series. The supporting capacitor is equipped with a DC bus, which includes a DC P bus, a DC O bus, a DC N bus, and a valve series capacitor connection bus. The valve string capacitor connection bar is installed on the DC P-bar, DC O-bar, and DC N-bar. The connection terminals of the valve string capacitor connection bar are forward and overlap with the connection terminals of the valve string DC connection bar.

3. The structure of a press-fit IGBT three-level power unit based on phase change cooling according to claim 1, characterized in that, The aforementioned three-level valve string adopts a compact press-fit three-level valve string structure.

4. The structure of a press-fit IGBT three-level power unit based on phase change cooling according to claim 2, characterized in that, The supporting capacitor assembly and the phase change cooling power assembly are connected through the connection terminals of the valve string DC connection bus and the connection terminals of the valve string capacitor connection bus, with the connection terminals of the valve string DC connection bus and the connection terminals of the valve string capacitor connection bus facing forward.

5. The structure of a press-fit IGBT three-level power unit based on phase change cooling according to claim 1, characterized in that, The phase change working fluid connecting pipe includes a gas collecting manifold and a liquid collecting manifold. The gas collecting port of the phase change cooling radiator is located at the top of the phase change cooling radiator, and the liquid collecting port of the phase change cooling radiator is located at the bottom of the phase change cooling radiator. The gas collecting manifold and the liquid collecting manifold are respectively installed at the top and bottom of multiple phase change cooling radiators, so that the phase change working fluid flows out from the three-level power unit through the gas collecting manifold and flows into the three-level power unit through the liquid collecting manifold.

6. The structure of a press-fit IGBT three-level power unit based on phase change cooling according to claim 1, characterized in that, The supporting capacitor assembly is mounted on the capacitor base plate, and the phase change cooling power assembly is mounted on the power assembly base plate. The capacitor base plate and the power assembly base plate are connected and fixed by positioning pins.

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