A high-capacity inverter module with high-current / high-voltage IGBTs directly connected in parallel

Abstract

The present invention discloses a large-capacity inverter module with large current / high voltage IGBTs directly connected in parallel, including a water-cooled plate, a discrete IGBT device, a laminated busbar, a first absorption capacitor, a drive circuit, an AC side busbar, a current sensor, a DC side laminated busbar, a second absorption capacitor, a DC side negative busbar and a DC side positive busbar, and six discrete IGBT devices are arranged uniformly on the water-cooled plate from top to bottom. The large-capacity inverter module with large current / high voltage IGBTs directly connected in parallel proposed by the present invention has accurate calculation of the current impedance of each branch connected in parallel, ensuring consistency, achieving a very high current sharing coefficient, the cable length of each phase and each device of the drive circuit is consistent, the paths are separated, and complementary interference; the main circuit layout design makes full use of space, optimizes the circuit path, has a high power density, a small overall module size, is simple, easy to maintain and install, and has good electrical characteristics.

Description

Technical Field

[0001] The invention relates to the technical field of high-power inverter power supply, and in particular to a high-capacity inverter module in which high-current / high-voltage IGBTs are directly connected in parallel. Background Art

[0002] High-power power electronic devices often need to provide large current and voltage to meet the needs of high-power or high-capacity loads. Existing IGBT devices are difficult to provide sufficient current alone, and multiple IGBT devices need to be used in parallel in the loop to provide sufficient current output.

[0003] The most important electrical parameter of high-power IGBT parallel technology is the current sharing coefficient. To achieve a higher current sharing coefficient, the current common and consensus technical solutions must consider the following points: (1) Use IGBT devices from the same batch in the parallel circuit, or keep the internal impedance parameters of the devices as consistent as possible; (2) Use uniform and symmetrical cooling equipment to ensure similar junction temperatures of each IGBT device; (3) Design the electrical circuit symmetrically, with consistent path lengths to ensure the same impedance; (4) Use the same drive unit, and design the gate drive circuit symmetrically. The biggest difference between the current technical solutions is the implementation of the above points (3) and (4). These two points need to be achieved through structural design solutions, and are also the two most difficult points; the loop layout in the existing technical solutions cannot provide equal and sufficiently small loop impedance, resulting in a low current sharing coefficient of each branch in the parallel loop. Although the total current at the parallel end can meet the load demand, the current of each branch is unbalanced, resulting in inconsistent losses and junction temperatures of each power device, or even a large difference. Devices with large currents are subject to higher losses and switching overvoltages, so these devices bear a high risk of damage and reduced reliability. Based on this, a large-capacity inverter module with large current / high voltage IGBTs directly connected in parallel is proposed. Summary of the invention

[0004] The purpose of the present invention is to provide a large-capacity inverter module with large current / high voltage IGBTs directly connected in parallel, which has a very high current sharing coefficient, and the cables of each phase and each device of the driving circuit are consistent in length, the paths are separated, and the interference is complementary; the main circuit layout design makes full use of the space, optimizes the circuit path, has a high power density, and the overall module size is small, simple, easy to maintain and install, and has good electrical characteristics, so as to solve the problem that the above-mentioned background technology cannot provide an equal and sufficiently small loop impedance, the current of each branch is unbalanced, resulting in the loss of each power device, inconsistent junction temperature, and even a large difference, and the devices with large currents are subject to higher losses and switching overvoltages, so these devices are at high risk of damage and reduced reliability.

[0005] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a large-capacity inverter module with high-current / high-voltage IGBTs directly connected in parallel, comprising a water-cooled plate, a discrete IGBT device, a laminated busbar, a first absorption capacitor, a drive circuit, an AC side busbar, a current sensor, a DC side laminated busbar, a second absorption capacitor, a DC side negative busbar and a DC side positive busbar, wherein the number of the discrete IGBT devices is six, and the six discrete IGBT devices are uniformly arranged on the water-cooled plate from top to bottom in sequence; the laminated busbar and the first absorption capacitor are both in three rows, and the three rows The model of the laminated busbar is the same as that of the first absorption capacitor. The three rows of laminated busbars are evenly arranged from top to bottom on the other side of the water-cooled plate. The three first absorption capacitors are respectively installed on the three rows of laminated busbars, and the drive circuit is installed on the water-cooled plate below the laminated busbars. The AC side busbar, the DC side negative busbar and the DC side positive busbar are installed on the other side of the water-cooled plate, and the DC side laminated busbar and the second absorption capacitor are symmetrically arranged. A support frame is provided on the outside of the water-cooled plate, and the water-cooled plate is installed in the support frame. Panels are installed on the front and left and right sides of the support frame.

[0006] Preferably, the working layout of the discrete IGBT device adopts a circuit layout method in which discrete IGBT elements constitute a converter unit. The six discrete IGBT devices are sequentially recorded as S11, S21, S12, S22, S13 and S23. S11 and S21, S12 and S22, and S13 and S23 are respectively connected in series to form three groups of bridge arms. The installation directions of the upper bridge arms S11, S12 and S13 in the three groups of bridge arms are consistent, and the installation directions of the lower bridge arms S21, S22 and S23 in the three groups of bridge arms are rotated 180° relative to their respective upper bridge arms.

[0007] Preferably, the flow channel inside the water cooling plate is uniform.

[0008] Preferably, there are three groups of DC side laminated busbars and second absorption capacitors, and the three groups of DC side laminated busbars and second absorption capacitors are respectively installed on three groups of bridge arms. The drive circuit is located on the upper and lower sides of each bridge arm, outside the coverage range of the laminated busbars, and routed to both sides.

[0009] Preferably, the drive circuit adopts 1SP0635 type drive.

[0010] Preferably, the negative busbar on the DC side and the positive busbar on the DC side both work in a manner of first merging three paths into two paths, and then merging two paths into one path.

[0011] Preferably, the AC side busbars are arranged in an overlapping manner.

[0012] Preferably, the support frame and the panel both have sheet metal components.

[0013] Compared with the prior art, the beneficial effects of the present invention are: the large-capacity inverter module with high-current / high-voltage IGBTs directly connected in parallel proposed by the present invention has accurate calculation of the current impedance of each parallel branch to ensure consistency, achieve a very high current sharing coefficient, and the cable lengths of each phase and device in the driving circuit are consistent, the paths are separated, and complementary interference is achieved; the main circuit layout design makes full use of space, optimizes the circuit path, has high power density, and the overall module size is small, simple, easy to maintain and install, and has good electrical characteristics; the module outer frame and internal support parts are sheet metal, which can effectively reduce external electromagnetic interference and also shield the internal electromagnetic interference of the module from the outside. Sheet metal is universal, beautiful, easy to manufacture, and cost-effective. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 It is a left view of the overall structure of the present invention;

[0015] Figure 2 It is a right view of the overall structure of the present invention;

[0016] Figure 3 It is a rear view of the overall structure of the present invention;

[0017] Figure 4 It is a left view of the overall structure of the present invention when no panel is installed;

[0018] Figure 5 It is a right view of the overall structure of the present invention when the panel is not installed;

[0019] Figure 6 It is a rear view of the overall structure of the present invention when no panel is installed;

[0020] Figure 7 It is a front view of the water cooling plate of the present invention;

[0021] Figure 8 It is a rear view of the water cooling plate of the present invention;

[0022] Fig. 9 It is a schematic diagram of the laminated busbar structure of the present invention;

[0023] Fig.10 This is a front view of the installation of the AC side busbar of the present invention;

[0024] Fig.11 This is a rear view of the AC side busbar of the present invention after installation;

[0025] Fig.12 This is a side view of the installation of the AC side busbar of the present invention;

[0026] Fig.13 It is a schematic diagram of the DC side laminated busbar structure of the present invention;

[0027] Fig.14It is a schematic diagram of the structure of the AC side busbar, the DC side positive busbar and the DC side negative busbar of the present invention;

[0028] Fig.15 A circuit layout diagram of the converter unit of the present invention.

[0029] In the figure: 1. Water cooling plate; 2. Discrete IGBT device; 3. Laminated busbar; 4. First absorption capacitor; 5. Drive circuit; 6. AC side busbar; 7. Current sensor; 8. DC side laminated busbar; 9. Second absorption capacitor; 10. DC side negative busbar; 11. DC side positive busbar; 12. Support frame; 13. Panel. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] See also Figure 1-15 A large-capacity inverter module with high-current / high-voltage IGBTs directly connected in parallel, comprising a water-cooled plate 1, a discrete IGBT device 2, a laminated busbar 3, a first absorption capacitor 4, a drive circuit 5, an AC side busbar 6, a current sensor 7, a DC side laminated busbar 8, a second absorption capacitor 9, a DC side negative busbar 10 and a DC side positive busbar 11, six discrete IGBT devices 2, and the six discrete IGBT devices 2 are uniformly arranged on the water-cooled plate 1 from top to bottom; the laminated busbar 3 and the first absorption capacitor 4 are both three rows, and the model of the three-row laminated busbar 3 and the first absorption capacitor 4 are The models of the capacitors 4 are the same, the three rows of laminated busbars 3 are uniformly arranged from top to bottom on the other side of the water-cooled plate 1, the three first absorption capacitors 4 are respectively installed on the three rows of laminated busbars 3, and the drive circuit 5 is installed on the water-cooled plate 1 at the lower side of the laminated busbars 3; the AC side busbar 6, the DC side negative busbar 10 and the DC side positive busbar 11 are installed on the other side of the water-cooled plate 1, and the DC side laminated busbar 8 and the second absorption capacitor 9 are symmetrically arranged; a supporting frame 12 is provided on the outside of the water-cooled plate 1, the water-cooled plate 1 is installed in the supporting frame 12, and panels 13 are installed on the front and left and right sides of the supporting frame 12.

[0032] The working layout of the discrete IGBT device 2 adopts the circuit layout mode of the converter unit composed of discrete IGBT components. The six discrete IGBT devices 2 are marked as S11, S21, S12, S22, S13 and S23 in sequence, corresponding to Fig.15Among them, S11, S21, S12, S22, S13 and S23, S11 and S21, S12 and S22, and S13 and S23 are connected in series to form three groups of bridge arms, the upper bridge arms S11, S12 and S13 in the three groups of bridge arms are installed in the same direction, and the lower bridge arms S21, S22 and S23 in the three groups of bridge arms are installed 180° rotated relative to their respective upper bridge arms, so that the control drive ports of the two IGBT devices of each group of bridge arms are located on the upper and lower sides of the bridge arm, so as to achieve the same path of the drive signal; the circuit layout of the converter unit composed of discrete IGBT components is as follows Fig.15 As shown by Fig.15 It can be seen that the converter unit composed of discrete IGBT components uses three identical half-bridge modules in parallel to obtain a larger output current. The half-bridge module consists of two discrete IGBT components, a buffer capacitor, and an output current sensor. The two discrete IGBT components are connected in series. Fig.15 The middle component X11 is the equivalent RL parameter of the line from the lower end of the switch tube S11 to the output point, and the component X21 is the equivalent RL parameter of the line from the upper end of the switch tube S21 to the output point. In order to ensure the consistency of their own parameters, the RL parameters of the components X11 and X21 should be the same; the buffer capacitor is connected in parallel to the upper end of the IGBT switch tube S11 and the lower end of the switch tube S21, the component X31 is the equivalent RL parameter of the capacitor's own parasitic and parallel lines, the component X41 is the equivalent RL parameter of the line from the upper end of the switch tube S11 to the DC bus DC+ end, the component X51 is the equivalent RL parameter of the line from the lower end of the switch tube S21 to the DC bus DC- end, and the component X61 is the equivalent RL parameter of the line from the output point of each module to the parallel point; the output current sensor is mainly used to detect the output current value of each module, and the current equality between the modules can be further ensured by adjusting the conduction time of each module at a certain moment. In order to ensure the current sharing between each bridge arm unit, the parameter values ​​of the corresponding components in each bridge arm should be consistent, and the paths of the driving signals of the corresponding switch tubes of each bridge arm unit should be the same to ensure the same initial conduction moment; the internal flow channel of the water cooling plate 1 is uniform, which can provide the same cooling conditions for the 6 discrete IGBT devices, ensuring the same junction temperature of the 6 discrete IGBT devices during operation, the symmetrical layout of the 6 discrete IGBT devices and the symmetrical layout of the stacked busbar 3, the layout of the drive circuit 5 realizes Fig.15The values ​​of X11, X21, X12, X22, X13, and X23 are consistent; there are three groups of DC side laminated busbars 8 and second absorption capacitors 9, and the three groups of DC side laminated busbars 8 and second absorption capacitors 9 are respectively installed on three groups of bridge arms. The drive circuit 5 is located on the upper and lower sides of each bridge arm, outside the coverage range of the laminated busbar 3, so that the path of the drive circuit 5 is consistent and the wiring is respectively arranged on both sides to avoid mutual interference between the drive signals. Secondly, the drive circuit 5 is avoided from being covered by the laminated busbar 3, which avoids the interference of the drive signal by the laminated busbar 3 and facilitates the installation and maintenance of the drive circuit 5; the drive circuit 5 adopts 1SP0635 type drive; the working mode of the DC side negative busbar 10 and the DC side positive busbar 11 is to first merge three roads into two roads, then merge two roads into one road, and when merging three roads into two roads and then into one road, the busbar cross-section size of each road and the distance of the confluence point are as follows Fig.13 As shown, according to this rule, Fig.15 The values ​​of X61, X62 and X63 are consistent; the AC side busbars 6 are arranged in an overlapping manner, and a current sensor 7 is installed on the AC output side of each bridge arm to detect the output current value of each bridge arm. The current equality between the modules can be further ensured by adjusting the conduction time of each discrete IGBT device at a certain moment; the main drive board is used on the middle group of drive circuits 5, and the auxiliary drive board is used on the upper and lower groups of drive circuits 5. The connection line between the main drive board and the auxiliary drive board is supported by an insulating board and isolated from the cabinet, which ensures the consistency of the gate drive signal of the parallel IGBT from the perspective of drive and structure.

[0033] The high-capacity inverter module with high-current / high-voltage IGBTs directly connected in parallel has the following advantages as a whole:

[0034] 1: The circuit layout of the converter unit is composed of discrete IGBT components. The drive circuit 5 is located on the upper and lower sides of each bridge arm, outside the coverage of the laminated busbar 3, achieving a high current sharing coefficient of the parallel circuit of this module and a very small impedance of each branch, ensuring that the inverter module can output a larger current.

[0035] 2: The water-cooled radiator channels at the bottom of the six IGBTs are arranged in a balanced and symmetrical manner, with consistent heat exchange coefficients, thus ensuring the dynamic and static current equalization performance of the parallel IGBTs in terms of heat dissipation.

[0036] 3: Drive circuit 5 adopts 1SP0635 type drive. The main drive board is used on the middle group of IGBTs in the module, and the auxiliary drive board is used on the upper and lower groups of IGBTs. The connection line between the main drive board and the auxiliary drive board is supported by an insulating board and isolated from the cabinet. Therefore, the consistency of the gate drive signal of the parallel IGBT is guaranteed from the perspective of drive and its structural layout.

[0037] 4: From top to bottom, every two IGBTs are used in a group Fig. 9The stacked busbars 3 are connected to form a bridge arm. Three absorption capacitors are installed between the positive and negative layers of the stacked busbars 3, with a total of three bridge arms. Fig.15 The consistency of X11, X21, X12, X22, X13, X23 in the circuit is ensured, and X11~X23 are made as small as possible to reduce the overvoltage of IGBT switch. Each bridge arm adopts the same structure and is equipped with independent DC support capacitors. Fig.13 The stacked busbar 3 is connected as shown, thereby ensuring the consistency of the impedance parameters of X31, X32, and X33.

[0038] 5: The DC input part of the three bridge arms passes through Fig.14 The symmetrical DC side negative busbar 10 and the DC side positive busbar 11 are respectively connected to the DC- and DC+ parts, thereby ensuring the consistency of input impedance parameters such as X41~X43 and X51~X53.

[0039] 6: The AC output of the three bridge arms passes through Fig.13 The symmetrical bus shown collects the three branch currents i1, i2, and i3 into a total circuit i0, thereby ensuring the consistency of the impedance parameters of the three AC branches X61 to X63, wherein i1, i2, and i3 represent the currents detected by the corresponding position sensors.

[0040] In summary, the large-capacity inverter module with large current / high voltage IGBTs directly connected in parallel proposed by the present invention has the accurate calculation of the current impedance of each parallel branch to ensure consistency, and achieve a very high current sharing coefficient. The cable lengths of each phase and device in the drive circuit 5 are consistent, the paths are separated, and the interference is complementary. The main circuit layout design makes full use of the space, optimizes the circuit path, has a high power density, a small overall module size, is simple, easy to maintain and install, and has good electrical characteristics. The module frame and internal support parts are sheet metal, which can effectively reduce external electromagnetic interference and shield the internal electromagnetic interference of the module. Sheet metal is universal, beautiful, easy to manufacture, and cost-effective.

[0041] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A large-capacity inverter module with high-current / high-voltage IGBTs directly connected in parallel, characterized in that: The invention comprises a water-cooling plate (1), a discrete IGBT device (2), a laminated busbar (3), a first absorption capacitor (4), a drive circuit (5), an AC side busbar (6), a current sensor (7), a DC side laminated busbar (8), a second absorption capacitor (9), a DC side negative busbar (10) and a DC side positive busbar (11), wherein the discrete IGBT devices (2) are six, and the six discrete IGBT devices (2) are arranged uniformly from top to bottom on one side of the water-cooling plate (1); the laminated busbar (3) and the first absorption capacitor (4) are arranged in three rows, the three rows of laminated busbars (3) are of the same model, the three rows of first absorption capacitors (4) are of the same model, and the three rows of laminated busbars (3) are of the same model. The layered busbars (3) are evenly arranged from top to bottom on the other side of the water-cooled plate (1); the three first absorption capacitors (4) are respectively installed on the three rows of the layered busbars (3); the drive circuit (5) is installed on the water-cooled plate (1) below the layered busbars (3); the AC side busbar (6), the DC side negative busbar (10) and the DC side positive busbar (11) are installed on the other side of the water-cooled plate (1); the DC side layered busbar (8) and the second absorption capacitor (9) are symmetrically arranged; a support frame (12) is provided on the outside of the water-cooled plate (1); the water-cooled plate (1) is installed in the support frame (12); and panels (13) are installed on the front and left and right sides of the support frame (12).

2. A large-capacity inverter module with high-current / high-voltage IGBTs directly connected in parallel as claimed in claim 1, characterized in that: The working layout of the discrete IGBT device (2) adopts a circuit layout method in which discrete IGBT elements constitute a converter unit. The six discrete IGBT devices (2) are sequentially recorded as S11, S21, S12, S22, S13 and S23. S11 and S21, S12 and S22, and S13 and S23 are respectively connected in series to form three groups of bridge arms. The upper bridge arms S11, S12 and S13 in the three groups of bridge arms have the same installation direction. The lower bridge arms S21, S22 and S23 in the three groups of bridge arms are installed in directions rotated 180 degrees relative to their respective upper bridge arms.

3. A large-capacity inverter module with high-current / high-voltage IGBTs directly connected in parallel as claimed in claim 1, characterized in that: The internal flow channel of the water cooling plate (1) is uniform.

4. A large-capacity inverter module with high-current / high-voltage IGBTs directly connected in parallel as claimed in claim 1, characterized in that: The DC side laminated busbars (8) and the second absorption capacitors (9) are each provided in three groups. The three groups of DC side laminated busbars (8) and the second absorption capacitors (9) are respectively installed on three groups of bridge arms. The drive circuit (5) is located on the upper and lower sides of each bridge arm, outside the coverage range of the laminated busbars (3), and is routed to both sides.

5. A large-capacity inverter module with high-current / high-voltage IGBTs directly connected in parallel as claimed in claim 1, characterized in that: The driving circuit (5) adopts a 1SP0635 type drive.

6. A large-capacity inverter module with high-current / high-voltage IGBTs directly connected in parallel as claimed in claim 1, characterized in that: The working mode of the DC side negative busbar (10) and the DC side positive busbar (11) is to first merge three paths into two paths, and then merge two paths into one path.

7. A large-capacity inverter module with high-current / high-voltage IGBTs directly connected in parallel as claimed in claim 1, characterized in that: The AC side busbars (6) are arranged in an overlapping manner.

8. A large-capacity inverter module with high-current / high-voltage IGBTs directly connected in parallel as claimed in claim 1, characterized in that: The support frame (12) and the panel (13) both have sheet metal components.

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