CN107634670B

CN107634670B - Monomer unit

Info

Publication number: CN107634670B
Application number: CN201710573605.3A
Authority: CN
Inventors: 杷野满; 上谷贤司
Original assignee: Toshiba Mitsubishi Electric Industrial Systems Corp
Current assignee: Toshiba Mitsubishi Electric Industrial Systems Corp
Priority date: 2016-07-15
Filing date: 2017-07-14
Publication date: 2020-03-17
Anticipated expiration: 2037-07-14
Also published as: JP6735708B2; JP2018019587A; CN107634670A

Abstract

The present invention relates to a monomer unit. Provided is a unit cell in which a unit bypass IGBT is disposed between IGBT cells disposed downstream and upstream in the ventilation direction, and inductance can be reduced without reducing cooling performance. The air-cooled single unit is provided with a plurality of IGBT modules and a single unit bypass unit, wherein the IGBT module for the 1 st phase is arranged at the downstream side in the ventilation direction, the IBT module for the 2 nd phase is arranged at the upstream side in the ventilation direction, the single unit bypass unit is arranged between the IGBT modules for the 1 st phase and the IGBT modules for the 2 nd phase, the output of the IGBT module for the 1 st phase and the input of the single unit bypass unit are arranged, and the output of the IGBT module for the 2 nd phase and the output of the single unit bypass unit are arranged to be opposite to each other, so that the wiring length is shortened, the inductance is reduced, and the miniaturization is realized.

Description

Monomer unit

Technical Field

Embodiments of the present invention relate to a cell unit including a cell bypass unit portion in a main circuit constituting a large-capacity inverter.

Background

A large-capacity inverter is sometimes configured by connecting a plurality of single-phase inverters called cell units (cell units) in series. In a unit cell used in such a large-capacity inverter, a plurality of IGBTs (Insulated Gate bipolar transistors) are used as switching elements.

When a fault occurs due to a dc short circuit or the like of an IGBT constituting a certain unit cell, it is required to perform continuous operation of the large-capacity inverter by short-circuiting an output of the faulty unit cell constituting the large-capacity inverter by some short-circuiting means and bypassing the faulty unit cell. The unit of such a short-circuiting mechanism is called a cell bypass unit. The cell bypass unit may be formed of an IGBT.

Fig. 5 shows an example of a conventional unit cell 300 (hereinafter referred to as a unit cell 300) constituting a large-capacity inverter. The illustrated unit 300 includes the rectifying diode portion 110, the smoothing capacitor portion 120, the IGBT unit portion 130, the heat sink 140B, the unit bypass unit portion 200, and the like.

The IGBT cell section 130 is constituted by four IGBT modules including the 1 st IGBT module IGBTU1, the 2 nd IGBT module IGBTU2, the 3 rd IGBT module IGBTU3, and the 4 th IGBT module IGBT 4. Each IGBT module is a so-called 2IN1 module IN which 2 IGBTs are connected IN series, the connection point of which is the output of the IGBT module, and diodes connected IN anti-parallel with the IGBTs are provided. Note that the description of the diode is omitted below.

The 1 st IGBT module IGBTU1 and the 2 nd IGBT module IGBTU2 are connected in parallel to constitute the 1 st phase of the single-phase output of the unit cell 300, and are arranged on the downstream side in the ventilation direction (the direction of the "wind direction" in the drawing), and the 3 rd IGBT module IGBTU3 and the 4 th IGBT module IGBTU4 are connected in parallel to constitute the 2 nd phase of the single-phase output of the unit cell 300, and are arranged on the upstream side in the ventilation direction.

The cell bypass unit 200 is composed of 2 cell bypass IGBT modules including a 1 st bypass IGBT module IGBT1 and a 2 nd bypass IGBT module IGBT 2. The 1 st bypass IGBT module 1 and the 2 nd bypass IGBT module IGBT2 are so-called 1IN1 modules and include diodes connected IN antiparallel with the IGBTs IN their respective packages, and the description thereof will be omitted below.

The emitters of the 1 st bypass IGBT module IGBT1 and the 2 nd bypass IGBT module IGBT2 are connected to each other. The collector of the 1 st bypass IBGT module IGBT1 is connected to the 1 st phase output of the single phase outputs of the cell 300, i.e., the output of the 1 st IGBT module IGBTU1 and the output of the 2 nd IGBT module IGBTU 2. The collector of the 2 nd bypass IBGT module IGBT2 is connected to the 2 nd phase output of the single phase output of the cell unit 300, i.e., the output of the 3 rd IGBT module IGBTU3 and the output of the 4 th IGBT module IGBTU 4. The 1 st and 2 nd bypass IGBT modules IGBT1 and IGBT2 are disposed on the downstream side in the ventilation direction of the 1 st and 2 nd IGBT modules IGBTU1 and IGBTU2 disposed on the downstream side in the ventilation direction.

Rectifying diode portion 110, IGBT unit portion 130, and unit bypass unit portion 200 are fixed to heat sink 140B.

Further, when a power conversion device is configured with a plurality of variable frequency conversion units (inverters), when the inverter fails, there is known a method of optimizing operating conditions by using the remaining units (see, for example, patent document 1); when 2 control devices control 1 power converter, when one control device detects an abnormality, the other control device switches the control device to continue the continuous operation (see, for example, patent document 2).

[ patent document 1 ] Japanese patent application laid-open No. 9-275699

[ patent document 2 ] Japanese patent application laid-open No. 2011-41404

In the heat sink 140B, the rectifying diode section 110, the IGBT unit section 130, and the unit bypass unit section 200 are heat sources, and when the heat sources are dense, there is a problem that the influence of the fan motion between the heat sources equivalently increases the thermal resistance of the semiconductors constituting the rectifying diode section 110, the IGBT unit section 130, and the like. In view of this, in the conventional unit cell 300, the IGBT cell unit 130 is divided into two parts, and predetermined gaps are provided between the 1 st IGBT module IGBTU1 and the 2 nd IGBT module IGBTU2, and the 3 rd IGBT module IGBTU3 and the 4 th IGBT module IGBTU4 in order to avoid concentration of heat sources. When the unit bypass unit section 100 is provided, the 1 st bypass IGBT module 1 and the 2 nd bypass IGBT module IGBT2 that generate no heat are always disposed at the most downstream side in the ventilation direction. The problem is to be solved by element cooling caused by adding two by-pass IGBT modules IGBT and wiring paths (increased inductance) to the IGBT for cell by-pass. Further, there is a problem that the shape of the heat sink 140B becomes larger than that of a unit without the unit bypass unit portion 200.

Disclosure of Invention

The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a single unit in which a heat sink (heat sink) having a size approximately equal to that of a single unit in which a single bypass unit is not present can be applied while inductance can be reduced by shortening the wiring between the IGBT unit portion 130 and the single bypass unit portion 200.

In order to achieve the above object, a unit cell according to claim 1 of the present invention is a unit cell constituting a single-phase output of a large-capacity inverter, the unit cell including: an IGBT unit constituting a 1 st phase, an IGBT unit constituting a 2 nd phase, and a unit bypass unit for short-circuiting an output of the unit are closely fixed to one air-cooled radiator, an IGBT module constituting the IGBT unit constituting the 1 st phase, an IGBT module constituting the IGBT unit constituting the 2 nd phase, and an IGBT module constituting the unit bypass unit are disposed between the IGBT unit constituting the 1 st phase and the IGBT unit constituting the 2 nd phase, an output terminal of the IGBT unit constituting the 1 st phase and a 1 st terminal of the unit bypass unit are disposed so as to face each other, an output terminal of the IGBT unit constituting the 2 nd phase and a 2 nd terminal of the unit bypass unit are disposed so as to face each other, and the output terminal of the IGBT unit constituting the 1 st phase and the 1 st terminal of the unit bypass unit are connected by a bus bar, the output terminal of the IGBT cell constituting the 2 nd phase and the 2 nd terminal of the cell bypass unit are connected by a bus bar.

According to the present invention, it is possible to provide a single unit in which the wiring between the IGBT unit constituting the 1 st phase and the IGBT unit constituting the 2 nd phase and the single bypass IGBT can be shortened, the inductance can be reduced, and a small-sized heat sink can be applied to the single unit in the same degree as that in which the single bypass unit is not present even if the single bypass unit is present.

Drawings

Fig. 1 is an example of a layout of a unit cell 100 constituting a large-capacity inverter according to embodiment 1.

Fig. 2 is a circuit diagram of the unit cell 100 shown in fig. 1.

Fig. 3 is a perspective view and a front view of the unit cell 100 according to embodiment 1 before the present invention is implemented.

Fig. 4 is a perspective view and a front view of a case where the cell bypass unit portion 200 is used in the cell unit 100 according to example 1.

Fig. 5 shows an example of a conventional unit cell 300B constituting a large-capacity inverter.

Description of reference numerals:

DR, DS, DT-rectifier diodes, CF1 to CF 10-smoothing capacitors, IGBTU 1-1 st IGBT module, IGBTU 2-2 nd IGBT module, IGBTU 3-3 rd IGBT module, IGBTU 4-4 th IGBT module, A, B-output terminal, 100-cell unit, 110-rectifier diode section, 120-smoothing capacitor section, 130-IGBT cell section, 131, 132, 134, 135-bus, 151, 152-bus, 140B-heat sink, 200-cell bypass unit, IGBT 1-1 st bypass IGBT module, IGBT 2-2 nd bypass IGBT module, 201, 202-bus, 300-conventional cell.

Detailed Description

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[ example 1 ]

Fig. 1 is an example of a layout of a unit cell 100 constituting a single-phase output of a large-capacity inverter according to embodiment 1. In this regard, the same portions as those in fig. 5 are denoted by the same reference numerals, and description thereof is omitted.

The illustrated unit 100 is a box-shaped solid having a bottom surface at a lower portion, and is formed by an unillustrated ventilation mechanism in a wind direction indicated by an arrow from front to rear.

The unit cell 100 includes a heat sink 140, a rectifying diode portion 110, an IGBT unit portion 130, a unit bypass unit portion 200, a smoothing capacitor portion 120, and the like.

The semiconductor modules constituting the rectifying diode section 110, the IGBT unit section 130, and the single bypass unit section 200 are closely joined to the heat sink 140. The heat sink 140 absorbs heat generated by the above elements and dissipates the heat into the air in the unit cell 100. The released heat is cooled by wind flowing in the direction of the above-described illustrated arrows. That is, the radiator 140 is an air-cooled radiator. Heat sink 140 has a flat semiconductor mounting surface, and semiconductor modules constituting rectifying diode section 110, IGBT unit section 130, and unit bypass unit section 200 are closely bonded to heat sink 140 at this portion. The surface of the heat sink 140 facing the semiconductor mounting surface constitutes a cooling fan, and air flows to this portion, whereby the heat sink is efficiently cooled.

The illustrated rectifying diode unit 110 is composed of, for example, rectifying diodes DR, DS, and DT for generating a 3-phase ac voltage supplied from the R-phase, S-phase, and T-phase shown in fig. 2 into a dc voltage. The generated dc voltage is supplied to the cell unit 100 according to the present embodiment.

The IGBT unit 130 is configured by a 1 st IGBT module IGBTU1 and a 2 nd IGBT module IGBTU2 of the 1 st phase constituting the single-phase output of the unit cell 100 arranged on the downstream side in the ventilation direction (the direction of the "wind direction" in the drawing), and a 3 rd IGBT module IGBTU3 and a 4 th IGBT module IGBTU4 of the 2 nd phase constituting the single-phase output of the unit cell 100 arranged on the upstream side in the ventilation direction, and is arranged with a predetermined interval. In this arrangement, the 1 st IGBT module IGBTU1 and the 2 nd IGBT module IGBTU2, and the 3 rd IGBT module IGBTU3 and the 4 th IGBT module IGBTU4 are arranged at the same positions as the 1 st to 4 th IGBT modules IGBTU1 to IGBTU4 in the unit cell 300 shown in fig. 5 so as to be away from each other.

The configuration of the IGBT cell unit 130 may vary depending on the capacity and application of the inverter, and the IGBT modules constituting the IGBT cell unit 130 may have different structures.

The cell bypass unit 200 is composed of the 1 st bypass IGBT module IGBT1 and the 2 nd bypass IGBT module IGBT2, and is disposed between the 1 st IGBT module IGBTU1 and the 2 nd IGBT module IGBTU2 of the 1 st phase constituting the single-phase output of the cell unit 100, and the 3 rd IGBT module IGBTU3 and the 4 th IGBT module IGBTU4 of the 2 nd phase constituting the single-phase output of the cell unit 100.

The smoothing capacitor unit 120 is provided below the heat sink 140 disposed in the unit cell 100, and is composed of 10 smoothing capacitors.

Fig. 2 is a circuit diagram of the unit cell 100 shown in fig. 1. Hereinafter, the circuit configuration of the unit cell 100 will be briefly described with reference to fig. 1.

In the illustrated example, the 3-phase ac voltage is supplied to the terminal R (R phase), the terminal S (S phase), and the terminal T (T phase). The supplied 3-phase voltages are supplied to P-phase and N-phase dc voltages rectified by rectifying diodes DR, DS, and DT of diode unit 110.

The dc voltages supplied to the P-phase and N-phase are smoothed by capacitors CF1 to CF10 disposed in smoothing capacitor unit 120 and supplied to IGBT cell unit 130.

The 1 st IGBT module IGBTU1 has 2 IGBTs connected in series inside, and its connection point is used as an output terminal P1 of IGBTU 1. In addition, a diode is connected in reverse between collector C and emitter E of IGBTU 1. That is, the IGBT module IGBTU1 is a so-called 2IN1 module having an antiparallel diode built therein. The description of the diode is omitted below. The same applies to the other 2 nd to 3 rd IGBT modules IGBTU2 to IGBT 4.

The 1 st phase, i.e., the 1 st IGBT module IGBTU1 and the 2 nd IGBT module IGBTU2, which are the 1 st IGBT module IGBTU1 and the 2 nd IGBT module IGBTU2 connected in parallel to constitute the single-phase output of the unit cell 100, are IGBT cells constituting the 1 st phase.

The 3 rd IGBT module IGBTU3 and the 4 th IGBT module IGBTU4 are connected in parallel to constitute the 2 nd phase of the single-phase output of the unit cell 100, that is, the 3 rd IGBT module IGBTU3 and the 4 th IGBT module IGBTU4 are IGBT cells constituting the 2 nd phase.

The output terminal P1 of the 1 st IGBT module IGBTU1 is connected in parallel with the output terminal P2 of the 2 nd IGBT module IGBTU2 and is further connected to the output terminal a of the unit cell 100. The output terminal P3 of the 3 rd IGBT module IGBTU3 is connected in parallel with the output terminal P4 of the 4 th IGBT module IGBTU4 and is connected to the output terminal B of the unit cell 100.

The gate terminals G of the 1 st to 4 th IGBT modules IGBTU1 to IGBTU4 configured as described above are connected to a control unit, not shown, and are on/off controlled by the control unit to generate an ac voltage and output the ac voltage to the output terminal A, B.

The 1 st bypass IGBT module 1 and the 2 nd bypass IGBT module IGBT2 constituting the cell bypass unit 200 are so-called 1IN1 modules having a diode built IN between the collector C and the emitter E and connected IN reverse. The description of the diode is omitted below.

Output terminal a is electrically connected to input terminal (collector C) P5 of 1 st bypass IGBT module IGBT1 constituting unit bypass unit 200, and output terminal B is electrically connected to input terminal (collector C) P6 of 2 nd bypass IGBT module IGBT2 constituting unit bypass unit 200. The emitter E of the IGBT1 is connected to the emitter E of the IGBT2, and the bypass IGBT module IGBT1 and the bypass IGBT module IGBT2 are connected in series with so-called reverse polarity.

With the above configuration, when the unit cell 100 including the 1 st to 4 th IGBT modules IGBTU1 to IGBTU4 constituting the IGBT cell unit 130 has failed, the output of the failed unit cell 100 can be short-circuited by turning off the gates G of the 1 st to 4 th IGBT modules IGBTU1 to IGBTU4 constituting the unit cell 100 and turning on the gates G of the 1 st bypass IGBT module IGBT1 and the 2 nd bypass IGBT module IGBT2 constituting the unit bypass cell unit 200 connected to the output terminal a or the output terminal B.

The above-described processing is performed by the control of the control unit, not shown, and the unit cell 100 can be bypassed by turning on the IGBT modules IGBT1 and IGBT2 for bypassing constituting the unit bypass cell unit 200.

In terms of physical arrangement, the bypass IGBT module IGBT1 and the bypass IGBT module IGBT2 are arranged between the 1 st IGBT module IGBTU1 and the 2 nd IGBT module IGBTU2 of the 1 st phase constituting the single-phase output of the unit cell 100, and the 3 rd IGBT module IGBTU3 and the 4 th IGBT module IGBTU4 of the 2 nd phase constituting the single-phase output of the unit cell 100. The output terminal (P1) of the 1 st IGBT module and the output terminal (P2) of the 2 nd IGBT module are arranged to face in the same direction and to face the input terminal P5 (collector C of IGBT 1) of the 1 st bypass IGBT module IGBT1, and the output terminal (P3) of the 3 rd IGBT module and the output terminal (P4) of the 4 th IGBT module are arranged to face in the same direction and to face the input terminal P6 (collector C of IGBT 2) of the 2 nd bypass IGBT module 2.

Fig. 3 is a perspective view and a front view of the unit 100 before the implementation of the present invention without the unit bypass unit portion 200 according to example 1, fig. 3(1) is a perspective view of the unit 100, and fig. 3(2) is a front view of the unit 100. In the unit 100 shown in fig. 3, the unit bypass unit portion 200 is removed. Hereinafter, a main connection state in the unit cell 100 will be described with reference to fig. 1 and 2.

The connections of rectifier diode unit 110, smoothing capacitor unit 120, IGBT cell unit, and the like, which are not directly related to the present invention, are omitted from illustration.

(1) Emitters E and collectors C of the two IGBTs constituting the 1 st IGBT module IGBTU1 are connected by a connection point P1 (see fig. 2). Similarly, the emitters E and the connectors C of the two IGBTs constituting the 2 nd IGBT module IGBTU2, the 3 rd IGBT module IGBTU3, and the 4 th IGBT module IGBTU4 are connected by connection points P2, P3, and P4.

(2) The P1 of the 1 st IGBT module IGBTU1 and the P2 of the 2 nd IGBT module IGBTU2 of the 1 st phase constituting the single-phase output of the unit cell 100 are connected, and are connected to the output terminal a of the unit cell 100 via a bus bar (busbar) 151.

(3) The P3 of the 3 rd IGBT module IGBTU3 of the 2 nd phase and the P4 of the 4 th IGBT module IGBTU4 that constitute the single-phase output of the unit cell 100 are connected, and are connected to the output terminal B of the unit cell 100 by the bus bar 152.

Fig. 4 is a perspective view and a front view of the unit bypass unit 200 attached to the unit 100 according to example 1, fig. 4(1) is a perspective view of the unit 100, and fig. 4(2) is a front view of the unit 100. The connections of rectifier diode unit 110, smoothing capacitor unit 120, IGBT cell unit, and the like, which are not directly related to the present invention, are omitted from illustration.

Hereinafter, a main connection state in the unit 100 in a state where the unit bypass unit portion 200 is mounted will be described with reference to fig. 1 to 3.

(4) The emitters and collectors of the two IGBTs constituting the 1 st IGBT module IGBTU1 are connected to each other via a connection point P1 (see fig. 2). Similarly, the emitters and collectors of the two IGBTs constituting the 2 nd IGBT module IGBTU2, the 3 rd IGBT module IGBTU3, and the 4 th IGBT module IGBTU4 are connected to each other via connection points P2, P3, and P4.

(5) The P1 (output terminal of IGBT unit) of the 1 st IGBT module IGBTU1 of the 1 st phase and the P2 (output terminal of IGBT unit) of the 2 nd IGBT module IGBTU2 constituting the single-phase output of the unit cell 100 are connected to the output terminal a of the unit cell 100 via the bus bar 151, and to the collector C (1 st terminal, P5 of the unit bypass unit) of the 1 st bypass IGBT module IGBT1 of the unit bypass unit section 200 via the bus bar 201.

(6) The P3 (output terminal of IGBT unit) of the 3 rd IGBT module IGBTU3 of the 2 nd phase and the P4 (output terminal of IGBT unit) of the 4 th IGBT module IGBTU4 constituting the single-phase output of the unit cell 100 are connected to the output terminal B of the unit cell 100 via the bus bar 152, and to the collector C (1 st terminal, P6 of the unit bypass unit) of the 2 nd bypass IGBT module IGBT2 of the unit bypass unit section 200 via the bus bar 202.

(7) The output voltages of the output terminals a and B of the unit cells 100 are the output voltages of the 1 st to 4 th IGBT modules IGBTU1 to IGBTU4, and the outputs (P1, P2) of the 1 st IGBT module IGBTU1 and the 2 nd IGBT module IGBTU2 and the input (collector C, P5 of IGBT 1) of the bypass IGBT module IGBT1 are arranged so as to face each other by the connection method (4) to (6) described above and are connected by the bus bar 201. Similarly, the outputs (P3, P4) of the P3 of the 3 rd IGBT module IGBTU3 and the 4 th IGBT module IGBTU4 are arranged to face the input (collector C, P6 of IGBT 2) of the 2 nd bypass IGBT module IGBT2, and are connected by the bus bar 202.

The present embodiment is characterized in that the wiring length of the bus bar 201 and the bus bar 202 can be shortened by arranging the outputs (P1, P2) of the 1 st and 2 nd IGBT modules (IGBTU1 and IGBTU2) to face the input (collector C of IGBT 1) of the 1 st bypass IGBT module IGBT1 and arranging the outputs of the 3 rd and 4 th IGBT modules (IGBTU3 and IGBTU4) to face the input (collector C of IGBT 2) of the 2 nd bypass IGBT module IGBT2, and thus the problem of an increase in inductance due to the wiring length can be solved.

(8) Next, a method of operating the unit cell 100 by switching the operation mode of the 1 st bypass IGBT module 1 and the 2 nd bypass IGBT module IGBT2 by the switching mechanism during normal operation and during a failure due to a short circuit of the IGBTs and the like constituting the IGBT cell unit 130 in the unit cell 100 described in the above (4) to (7) will be described.

The control unit (not shown) has a switching mechanism for switching the usage mode to the following mode a and mode b.

In the normal operation, the mode a switching mechanism turns off the 2 unit-bypass IGBTs by controlling the unit-bypass IGBTs to an off state, and sets the output voltage of the IGBT unit 130 as the output voltage of the unit 100 by PWM controlling the IGBT unit 130. In this state, since 1 st bypass IGBT module IGBT1 and 2 nd bypass IGBT module IGBT2 are in an off state and almost no loss occurs, IGBT cell unit 130 is not affected by the heat generation.

In the case of a failure caused by a dc short circuit of the IGBT in the cell unit 100, the mode b switching mechanism turns off the 1 st to 4 th IGBT modules IGBTU1 to IGBTU4 by turning off the gates G of all IGBTs constituting the IGBT unit section 130 of the failed cell unit 100, and further turns on the gates G of the 1 st bypass IGBT module IGBT1 and the 2 nd bypass IGBT module IGBT2 of the cell bypass unit 200 of the failed cell unit 100 to turn on the cell bypass unit, thereby short-circuiting the output of the failed cell unit 100. By performing the above processing, since IGBT cell unit 130 is in the off state in pattern b and there is almost no heat loss, 1 st bypass IGBT module IGBT1 and 2 nd bypass IGBT module IGBT2 are not affected by the heat generation.

Since the portion that generates heat during normal operation and the portion that generates heat during failure are different as described above, there is no concentration of heat generation sources, and the cooling performance of the radiator is not degraded (the performance of the radiator 140 (cooling performance) can be ensured).

Further, by arranging the outputs (P1, P2) of the 1 st IGBT module IGBTU1 and the 2 nd IGBT module IGBTU2 to face the input (collector C of IGBT 1) of the 1 st bypass IGBT module IGBT1 and arranging the outputs of the 3 rd IGBT module IGBTU3 and the 4 th IGBT module IGBTU4 to face the input (collector C of IGBT 2) of the 2 nd bypass IGBT module IGBT2, the bus connection length between the IGBT unit section 130 and the cell bypass unit section can be shortened, and therefore, the cell unit 100 capable of reducing the inductance due to the wiring length can be provided. In the present embodiment, the example in which the 1 st IGBT module IGBTU1 and the 2 nd IGBT module IGBTU2 are connected in parallel and the 3 rd IGBT module IGBTU3 and the 4 th IGBT module IGBTU4 are connected in parallel has been described, but a configuration without parallel connection is also possible.

As described above, according to the present invention, it is possible to provide a unit cell in which inductance can be reduced by setting the shortest wiring between the IGBT cell and the unit bypass IGBT, and the heat sink can be miniaturized.

Claims

1. A unit cell constituting a single-phase output of a large-capacity inverter, comprising:

an IGBT cell constituting a phase 1;

an IGBT cell constituting a 2 nd phase; and

a unit bypass unit for short-circuiting the output of the unit,

an IGBT module constituting the IGBT unit constituting the 1 st phase, an IGBT module constituting the IGBT unit constituting the 2 nd phase, and an IGBT module constituting the unit bypass unit are fixed to one air-cooled radiator,

the unit bypass unit is disposed between the IGBT unit constituting the 1 st phase and the IGBT unit constituting the 2 nd phase,

the output terminal of the IGBT unit constituting the 1 st phase is arranged to face the 1 st terminal of the unit bypass unit,

the output terminal of the IGBT unit constituting the 2 nd phase is arranged to face the 2 nd terminal of the unit bypass unit,

the output terminal of the IGBT unit constituting the 1 st phase is connected to the 1 st terminal of the unit bypass unit via a bus bar,

the output terminal of the IGBT unit constituting the 2 nd phase is connected to the 2 nd terminal of the unit bypass unit via a bus bar,

the IGBT unit constituting the 1 st phase, the IGBT unit constituting the 2 nd phase, and the unit bypass unit are closely fixed to one air-cooled radiator,

the unit includes a switching mechanism for switching a usage pattern of the unit bypass IGBT constituting the unit bypass unit when the unit is in normal operation and when the IGBT unit constituting the 1 st phase or the IGBT unit constituting the 2 nd phase fails,

in a normal operation, the switching mechanism turns off the gates of the IGBT for cell bypass constituting the cell bypass unit, thereby setting the output voltages of the IGBT unit constituting the 1 st phase and the IGBT unit constituting the 2 nd phase to the output voltages of the cell units,

when the IGBT unit constituting the 1 st phase or the IGBT unit constituting the 2 nd phase fails, the output of the single unit cell is brought into a short-circuit state by turning off all gates of the IGBT unit constituting the 1 st phase and the IGBT unit constituting the 2 nd phase and turning on the gate of the single bypass IGBT constituting the single bypass unit,

the IGBT units constituting the 2 nd phase, the unit bypass unit, and the IGBT unit constituting the 1 st phase are arranged in this order from the upstream direction toward the downstream direction in the ventilation direction.

2. A unit cell constituting a single-phase output of a large-capacity inverter, comprising:

an IGBT cell constituting a phase 1;

an IGBT cell constituting a 2 nd phase; and

a unit bypass unit for short-circuiting the output of the unit,

an IGBT module constituting the IGBT unit constituting the phase 1, an IGBT module constituting the IGBT unit constituting the phase 2, an IGBT module constituting the cell bypass unit, and a diode module constituting a rectifying diode section are closely fixed to one air-cooled radiator, and the rectifying diode section, the IGBT unit constituting the phase 2, the cell bypass unit, and the IGBT unit constituting the phase 1 are arranged in this order from an upstream direction to a downstream direction in a ventilation direction.