Power module and energy storage converter

Abstract

This invention discloses a power module and an energy storage converter, belonging to the field of electronic device technology. The power module includes a capacitor module, an IGBT module, a heat dissipation module, and a DC bus. The heat dissipation module has two opposing mounting surfaces. The IGBT module includes a first IGBT module and a second IGBT module symmetrically mounted on the first and second mounting surfaces. The DC bus includes a DC bus center plate, a first DC bus side output terminal, and a second DC bus side output terminal. The first and second DC bus side output terminals are respectively connected to the DC terminals of the first and second IGBT modules. The AC terminals of the first and second IGBT modules are connected to the AC input / output terminals. The DC bus center plate is connected to the capacitor module. The power module of this invention has a compact structure, effectively reducing stray inductance and lowering the overall cost.

Description

Technical Field

[0001] This invention belongs to the field of electronic device technology and relates to a power module and an energy storage converter. Background Technology

[0002] Energy storage converters are core interface devices for enabling bidirectional energy exchange between the power grid and energy storage battery systems. They are widely used in large-scale energy storage fields such as new energy distribution and storage, shared energy storage, and thermal power auxiliary frequency regulation. In medium- and high-power applications, energy storage converters often adopt NPC or ANPC three-level topologies, which can effectively improve the shortcomings of two-level topologies, such as high harmonics, high losses, and high device withstand voltage requirements. By increasing the output level, they reduce the voltage stress on the switching transistors and improve the system output voltage and power level.

[0003] The power module of the energy storage converter is used for bidirectional AC / DC power conversion, and its conventional structure is as follows: Figure 1 As shown, the power module mainly consists of a DC capacitor assembly 01, a DC busbar 02, an IGBT assembly 03, an input busbar 04, a snubber capacitor 05, an output busbar 06, and a heatsink 07. The DC capacitor assembly and the DC busbar form a capacitor module; the IGBT assembly, input busbar, snubber capacitor, output busbar, and heatsink form an IGBT module. The IGBT assembly is connected to the input busbar, snubber capacitor, and output busbar respectively and mounted on the front of the heatsink. The input busbar is connected to the DC busbar. Due to the three-phase output, the power module contains three IGBT modules, all connected to the DC busbar via the input busbar. Traditional power modules suffer from varying current path lengths for each IGBT module due to their layout. The further away from the capacitor module, the greater the stray inductance, leading to uneven current distribution and further exacerbating the inductance effect. Currently, snubber capacitors are typically added between the IGBT and the input busbar to suppress voltage spikes, but this method only alleviates local problems and cannot fundamentally eliminate the defects caused by stray inductance.

[0004] Figure 2 The diagram illustrates an ANPC three-level topology circuit. In a complete three-level topology, the IGBT bank of the power module typically includes three groups of switches: D1 and D5 in one group, D2 and D3 in another, and D4 and D6 in yet another. Due to the large number of components and complex circuitry, the three-level topology presents a significant problem with stray inductance. Stray inductance is a parasitic inductance formed by magnetic field coupling in conductors within the circuit. It primarily originates from the busbar, IGBT package, and multi-loop coupling. Under high-frequency switching, it can cause increased IGBT voltage spikes, higher switching losses, and enhanced electromagnetic interference, potentially leading to device breakdown in severe cases. Summary of the Invention

[0005] The purpose of this invention is to provide a power module and energy storage converter to solve the problems of existing power modules having complex structures, stray inductance, and easy damage to devices.

[0006] To achieve the above objectives, the technical solution of the present invention is as follows:

[0007] In a first aspect, the present invention provides a power module, comprising: a capacitor module, an IGBT module, a heat dissipation module, and a DC bus;

[0008] The heat dissipation module is provided with a mounting surface one and a mounting surface two facing away from each other. The IGBT module includes a first IGBT module and a second IGBT module, which are symmetrically mounted on the mounting surface one and the mounting surface two, respectively.

[0009] The DC busbar includes a DC busbar middle plate and DC busbar side output terminals one and two connected to both sides of the DC busbar middle plate; the DC busbar middle plate is connected to the capacitor module; DC busbar side output terminals one and two are respectively connected to the DC terminals of the first IGBT module and the second IGBT module, and the AC terminals of the first IGBT module and the second IGBT module are connected to the AC input / output terminals.

[0010] The DC busbar is C-shaped, with the C-shaped opening facing the heat dissipation module, and the middle plate of the DC busbar is perpendicular to mounting surface one and mounting surface two.

[0011] The DC busbar is formed by stacking three types of polarity plates: a positive polarity plate, a neutral polarity plate, and a negative polarity plate, which are separated from each other by insulating material.

[0012] The DC busbar side outlet one and DC busbar side outlet two are provided with connection interfaces facing the first IGBT module and the second IGBT module. The connection interfaces include three types: positive polarity connection interface, neutral polarity connection interface and negative polarity connection interface. The three types of connection interfaces are respectively set on the positive polarity plate, the neutral polarity plate and the negative polarity plate.

[0013] One end of the DC busbar plate is provided with a DC input / output terminal, which includes a positive terminal, a negative terminal, and a neutral terminal; the positive terminal, the negative terminal, and the neutral terminal are respectively disposed on the positive plate, the negative plate, and the neutral plate.

[0014] The first IGBT module and the second IGBT module each include several groups of IGBT switching devices. Each group of IGBT switching devices includes: a first IGBT unit, a second IGBT unit and a third IGBT unit. The second IGBT unit and the third IGBT unit are placed side by side and together with the first IGBT unit, they form a triangular arrangement.

[0015] The first IGBT unit, the second IGBT unit, and the third IGBT unit are connected by IGBT series copper busbars.

[0016] The AC input / output terminals include: AC series copper busbar, AC busbar one, and AC busbar two;

[0017] The AC terminal of the first IGBT unit is connected to an AC series copper busbar;

[0018] The AC busbar has a C-shaped structure, including a first busbar section, a middle section, and a second busbar section. The first busbar section and the second busbar section are respectively connected to the AC series busbar on the same side.

[0019] The second AC busbar is connected to the middle section, and the connection point is located in the middle of the first AC busbar.

[0020] The capacitor module includes a capacitor pool and a capacitor assembly installed inside the capacitor pool. The capacitor assembly includes a number of evenly distributed DC capacitors, which are vertically connected to the DC busbar center plate.

[0021] The heat dissipation module includes a housing, a phase change heat sink, a first air duct, and a second air duct. The first and second mounting surfaces are located on the outside of the housing. The phase change heat sink is installed inside the housing and is filled with a phase change working fluid. Both the top and bottom ends of the housing are designed to be open, and the first and second air ducts are respectively arranged at the openings.

[0022] Secondly, the present invention provides an energy storage converter, comprising at least one set of the aforementioned power modules.

[0023] Beneficial effects

[0024] By optimizing the structural layout of key components such as the DC bus, capacitor module, IGBT module, and heat dissipation module, the overall structural compactness is effectively improved, the module size is significantly reduced, the power density is greatly increased, and the overall cost is reduced. The distance between each IGBT switching device and the capacitor module is kept consistent, which shortens the current path and achieves path balance, effectively reduces stray inductance, improves current sharing, suppresses voltage spikes in IGBT switching, and reduces switching losses, thereby reducing IGBT junction temperature. The composite heat dissipation system of "phase change heat dissipation + air cooling heat dissipation" effectively improves heat dissipation and ensures the normal operation of the power module. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the power module structure in the background technology;

[0026] Figure 2 The background circuit diagram is a three-level topology circuit.

[0027] Figure 3 A front-view stereoscopic structural diagram of the power module in an embodiment of the present invention;

[0028] Figure 4 A rear-view stereoscopic structural diagram of the power module in an embodiment of the present invention;

[0029] Figure 5 A side view of the power module structure in an embodiment of the present invention;

[0030] Figure 6 A structural diagram of the DC busbar of the power module in this embodiment of the invention;

[0031] Figure 7 A top view of the DC busbar and capacitor module of the power module in an embodiment of the present invention.

[0032] In the diagram, 1-capacitor module; 2-IGBT module; 3-DC busbar; 4-heat dissipation module;

[0033] 11-Capacitor assembly; 12-Capacitor cell; 21-First IGBT module; 22-Second IGBT module; 211-IGBT switching device; 2111-First IGBT unit; 2112-Second IGBT unit; 2113-Third IGBT unit; 2114-IGBT series copper busbar; 2115-AC series copper busbar; 2116-AC busbar one; 2117-AC busbar two;

[0034] 31-DC busbar middle plate; 32-DC busbar side outlet terminal 1; 33-DC busbar side outlet terminal 2; 34-Positive terminal; 35-Neutral terminal; 36-Negative terminal; 37-Positive plate; 38-Negative plate; 39-Neutral plate;

[0035] 41-Housing; 42-Phase change radiator; 43-Air duct one; 44-Air duct two; 411-Mounting surface one; 412-Mounting surface two. Detailed Implementation

[0036] 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.

[0037] Example 1

[0038] refer to Figures 3 to 7As shown, a power module includes: a capacitor module 1, an IGBT module 2, a heat dissipation module 4, and a DC bus 3. The heat dissipation module 4 is provided with a mounting surface 411 and a mounting surface 412 facing away from each other. The IGBT module 2 includes a first IGBT module 21 and a second IGBT module 22. The first IGBT module 21 and the second IGBT module 22 are respectively symmetrically mounted on the mounting surface 411 and the mounting surface 412.

[0039] The DC busbar 3 includes a DC busbar middle plate 31 and DC busbar side output terminals 32 and 33 connected to both sides of the DC busbar middle plate 31; the DC busbar middle plate 31 is connected to the capacitor module 1; the DC busbar side output terminals 32 and 33 are respectively connected to the DC terminals of the first IGBT module 21 and the second IGBT module 22, and the AC terminals of the first IGBT module 21 and the second IGBT module 22 are connected to the AC input / output terminals.

[0040] The DC busbar 3 is C-shaped, and the C-shaped opening of the DC busbar 3 faces the heat dissipation module 4. The DC busbar middle plate 31 is perpendicular to the mounting surface 411 and the mounting surface 412. One end of the DC busbar middle plate 31 is provided with a DC input and output terminal, which includes a positive terminal 34, a negative terminal 36 and a neutral terminal 35.

[0041] The DC busbar 3 is formed by stacking three types of polarity plates; the three types of polarity plates are positive polarity plate 37, neutral polarity plate 39 and negative polarity plate 38, and are separated from each other by insulating material; positive polarity terminal 34, negative polarity terminal 36 and neutral polarity terminal 35 are respectively disposed on positive polarity plate 37, negative polarity plate 38 and neutral polarity plate 39.

[0042] In this embodiment, the DC busbar 3 is arranged in sequence with a negative plate 38, a neutral plate 39 and a positive plate 37 along the direction away from the capacitor module 1.

[0043] The DC busbar side outlet 32 ​​and DC busbar side outlet 33 are provided with connection interfaces facing the first IGBT module 21 and the second IGBT module 22. The connection interfaces include three types: positive polarity connection interface, neutral polarity connection interface and negative polarity connection interface. The three types of connection interfaces are respectively set on the positive polarity plate 37, the neutral polarity plate 39 and the negative polarity plate 38. In this embodiment, adjacent positive polarity connection interfaces, neutral polarity connection interfaces, neutral polarity connection interfaces and negative polarity connection interfaces form a group and are connected to the DC terminals of a group of IGBT switching devices 211.

[0044] The capacitor module 1 includes a capacitor pool 12 and a capacitor assembly 11. The capacitor assembly 11 includes several DC capacitors evenly distributed in the capacitor pool 12. The non-lead ends of the DC capacitors are provided with fixing bolts, which are used to connect the DC capacitors to the base of the capacitor pool 12 for fixation. The lead ends of the DC capacitors extend out of the capacitor pool 12 and are vertically connected to the capacitor interface of the DC busbar middle plate 31. The upper and lower sides of the capacitor pool 12 are equipped with handles to facilitate the insertion, removal, installation and maintenance of the entire capacitor module 1.

[0045] Both the first IGBT module 21 and the second IGBT module 22 include several groups of IGBT switching devices 211. Each group of IGBT switching devices 211 includes a first IGBT unit 2111, a second IGBT unit 2112, and a third IGBT unit 2113. The second IGBT unit 2112 and the third IGBT unit 2113 are placed side by side, forming a triangular arrangement with the first IGBT unit 2111. The IGBT switching devices 211 of each single-phase IGBT module 2 are arranged vertically, and the IGBT switching devices 211 of the three-phase single-phase IGBT module 2 are also arranged vertically.

[0046] The AC terminal of the first IGBT unit 2111 is connected to the AC series copper busbar 2115. The DC terminals of the second IGBT unit 2112 and the third IGBT unit 2113 are directly connected to the terminals of the DC busbar output terminal 32 or DC busbar output terminal 33 on the same side, without the need for intermediate busbars, effectively shortening the current path. The first IGBT unit 2111, the second IGBT unit 2112 and the third IGBT unit 2113 are connected through the IGBT series copper busbar 2114. The AC series copper busbars 2115 on both sides are respectively connected to the two ends of the AC busbar 2116. The AC busbar 2116 has a C-shaped structure. The AC busbar 2117 is connected to the middle part of the AC busbar 2116. The AC busbar 2117 is the AC input and output terminal.

[0047] The heat dissipation module 4 includes a housing 41, a phase change heat sink 42, a first air duct 43, and a second air duct 44. The phase change heat sink 42 is installed inside the housing 41 and is filled with 141B phase change working fluid. The heat dissipation capacity of a single module can reach 20kW, meeting the single-phase heat dissipation requirements of high-power applications up to 3500kW. The housing 41 has openings at both the top and bottom. The first air duct 43 and the second air duct 44 are respectively arranged at the openings at the top and bottom. The first air duct 43 and the second air duct 44, together with the housing, form a heat dissipation channel for air cooling through natural convection. The first air duct 43 and the second air duct 44, together with the phase change heat sink 42, constitute a composite heat dissipation system of "phase change heat dissipation + air cooling", which effectively improves the heat dissipation efficiency of the IGBT module and ensures the normal operation of the power module.

[0048] In one possible implementation, fans are also installed at air duct 1 43 and air duct 2 44 to form a "forced air cooling" heat dissipation structure, further improving the overall heat dissipation performance of the device.

[0049] Several heat dissipation holes are provided on the bottom surface and side walls of the capacitor cell 12 to effectively enhance the convective heat dissipation of the capacitor module 1 and ensure the normal operation of the capacitor assembly 11.

[0050] This embodiment adopts Figure 2 The three-level topology shown consists of a third IGBT unit 2113 composed of insulated gate bipolar transistors D1 and D5, a first IGBT unit 2111 composed of insulated gate bipolar transistors D2 and D3, and a second IGBT unit 2112 composed of insulated gate bipolar transistors D4 and D6.

[0051] In this embodiment, the first pin of the insulated-gate bipolar transistor (IGBT) D1 is connected to the positive plate 37 of the DC bus 3, and the second pin of IGBT D1 is connected to the first pins of IGBT D2 and IGBT D5. The second pins of IGBT D5 and IGBT D6 are connected to the neutral plate 39 of the DC bus 3. The second pins of IGBT D2 and IGBT D3 are connected to the AC busbar. The second pin of IGBT D3 is connected to the first pins of IGBT D4 and IGBT D6. The second pin of IGBT D4 is connected to the negative plate 38 of the DC bus 3. The capacitor assembly 11 includes a first capacitor C1 and a second capacitor C2. The first capacitor C1 is connected to the positive plate 37 and the neutral plate 39 of the DC bus 3, and the second capacitor C2 is connected to the neutral plate 39 and the negative plate 38 of the DC bus 3.

[0052] It should be noted that the number of IGBT switching devices or IGBT units included in the IGBT group is merely an example used to clearly illustrate the technical solution of the present invention, and is not a limitation on the number of components, nor should it be construed as a limitation on the specific scope of protection of the present invention.

[0053] The power module of this application optimizes the structural layout of key components such as the DC bus, capacitor module, IGBT module, and heat dissipation module, effectively improving the overall structural compactness, significantly reducing the module size, greatly increasing power density, and reducing the overall cost. Under the same power level, the existing conventional solution requires three sets of power modules as shown in Figure 1 to be used in parallel, with an overall power density of approximately 2848 kW / m³; while the power module provided in this application embodiment can achieve a power density of 15118 kW / m³, an increase of approximately 530%.

[0054] This application improves the relative arrangement of IGBT modules and capacitor modules, bringing the DC capacitors closer to the pin terminals of the IGBT units. In conventional solutions, the electrical distance between each IGBT switching device and the capacitor module is uneven; the farther the IGBT module is, the longer the current path and the larger the stray inductance. In this application, the distance between each IGBT switching device and the capacitor module is consistent, shortening the current path while achieving path balance, effectively reducing stray inductance, improving current sharing, suppressing voltage spikes during IGBT switching, and reducing switching losses. This, in turn, lowers the IGBT junction temperature, eliminating the need for the IGBT snubber capacitors configured in conventional solutions, and further reducing the overall cost.

[0055] Simulation analysis was performed on the stray inductance of the DC bus between the IGBT module and the capacitor module. Under the conventional scheme, the overall stray inductance is composed of the DC bus and the input bus, with a value of about 129.376nH. In this scheme, the stray inductance is determined only by the DC bus, which is about 49.032nH, and the stray inductance is reduced by about 62.1%.

[0056] Example 2

[0057] This embodiment provides a power module. The difference between this embodiment and embodiment 1 is that the DC bus 3 has a positive plate, a neutral plate and a negative plate stacked sequentially along the direction away from the capacitor module 1.

[0058] Example 3

[0059] An energy storage converter includes at least one set of power modules as described in Embodiment 1.

[0060] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0061] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art will understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0062] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the technical principles of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A power module, characterized by include: Capacitor modules, IGBT modules, heat dissipation modules, and DC busbars; The heat dissipation module is provided with a mounting surface one and a mounting surface two facing away from each other. The IGBT module includes a first IGBT module and a second IGBT module, which are symmetrically mounted on the mounting surface one and the mounting surface two, respectively. The DC busbar includes a DC busbar middle plate and DC busbar side output terminals one and two connected to both sides of the DC busbar middle plate; the DC busbar middle plate is connected to the capacitor module; DC busbar side output terminals one and two are respectively connected to the DC terminals of the first IGBT module and the second IGBT module, and the AC terminals of the first IGBT module and the second IGBT module are connected to the AC input / output terminals.

2. The power module of claim 1, wherein, The DC busbar is C-shaped, with the C-shaped opening facing the heat dissipation module, and the middle plate of the DC busbar is perpendicular to mounting surface one and mounting surface two.

3. The power module of claim 1, wherein, The DC busbar is formed by stacking three types of polarity plates: a positive polarity plate, a neutral polarity plate, and a negative polarity plate, which are separated from each other by insulating material.

4. The power module of claim 3, wherein, The DC busbar side outlet one and DC busbar side outlet two are provided with connection interfaces facing the first IGBT module and the second IGBT module. The connection interfaces include three types: positive polarity connection interface, neutral polarity connection interface and negative polarity connection interface. The three types of connection interfaces are respectively set on the positive polarity plate, the neutral polarity plate and the negative polarity plate.

5. The power module of claim 3, wherein, One end of the DC busbar plate is provided with a DC input / output terminal, which includes a positive terminal, a negative terminal, and a neutral terminal; the positive terminal, the negative terminal, and the neutral terminal are respectively disposed on the positive plate, the negative plate, and the neutral plate.

6. The power module of claim 1, wherein, The first IGBT module and the second IGBT module each include several groups of IGBT switching devices. Each group of IGBT switching devices includes: a first IGBT unit, a second IGBT unit and a third IGBT unit. The second IGBT unit and the third IGBT unit are placed side by side and together with the first IGBT unit, they form a triangular arrangement. The first IGBT unit, the second IGBT unit, and the third IGBT unit are connected by IGBT series copper busbars.

7. The power module of claim 6, wherein, The AC input / output terminals include: AC series copper busbar, AC busbar one, and AC busbar two; The AC terminal of the first IGBT unit is connected to an AC series copper busbar; The AC busbar has a C-shaped structure, including a first busbar section, a middle section, and a second busbar section. The first busbar section and the second busbar section are respectively connected to the AC series busbar on the same side. The second AC busbar is connected to the middle section, and the connection point is located in the middle of the first AC busbar.

8. The power module of claim 1, wherein, The capacitor module includes a capacitor pool and a capacitor assembly installed inside the capacitor pool. The capacitor assembly includes a number of evenly distributed DC capacitors, which are vertically connected to the DC busbar center plate.

9. The power module according to claim 1, characterized in that, The heat dissipation module includes a housing, a phase change heat sink, a first air duct, and a second air duct. The first and second mounting surfaces are located on the outside of the housing. The phase change heat sink is installed inside the housing and is filled with a phase change working fluid. Both the top and bottom ends of the housing are designed to be open, and the first and second air ducts are respectively arranged at the openings.

10. An energy storage converter, characterized in that, It includes at least one set of power modules as described in any one of claims 1 to 9.

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