JP4581761B2 - High voltage inverter device - Google Patents

Description

  The present invention relates to a high voltage inverter device that obtains a high voltage output of several kV.

  In a high voltage inverter device which is a semiconductor application device, a high voltage transformer is used as an input. FIG. 11A is a connection diagram of a conventional transformer-coupled high-voltage inverter device. Between the AC power source 1 and the AC motor 2, an inverter consisting of a converter unit 3 consisting of a sine wave input PWM converter and a voltage-type PWM inverter. The converter unit 3 includes an input transformer 5, an input filter 6, a forward conversion unit 7, and a smoothing capacitor 8. The inverter unit 4 includes an inverse conversion unit 9, and an output filter. 10 and an output transformer 11. The forward conversion unit 7 and the reverse conversion unit 9 have the same configuration as shown in FIG. 11B, and the self-extinguishing semiconductor switching elements (IGBTs) T1 to T6 and the diodes D1 to D6 are connected in antiparallel. It consists of a connected bridge circuit.

  Further, the high-voltage transformer has a primary side of, for example, 3 kV, 6 kV and a secondary side of a multi-phase such as 9-phase and 18-phase, and the low-pressure side of this multi-phase is connected to a semiconductor conversion unit. For example, in the case of 18 phases, six single-phase inverter cells are connected in series in the U phase. In such a high-voltage inverter device, effective insulation is important due to the large number of single-phase inverter cells and the sharing voltage, and the insulation method determines the size of the device. Insulation is not only a problem between structures but also between wires and between wires and structures.

  FIG. 12 is a connection diagram of a conventional high voltage inverter device for 3.3 kV output. The AC power supply 1 is connected to the U-phase, V-phase, and W-phase single-phase inverter cells U1, U2, V1, via an input transformer 12. The single-phase inverter cells of each phase are connected in series and connected in a multiple configuration and connected to the AC motor 2. Each single-phase inverter cell includes a forward conversion unit, a smoothing capacitor, and an inverse conversion unit, and an IGBT as a semiconductor switching element used in each single-phase inverter cell is used for a withstand voltage of 1.4 kV. FIG. 13 is a connection diagram of a conventional high-voltage inverter device for 6.6 kV output. The input transformers 13 and 14 are divided into two, and the AC power source 1 is a single-phase inverter cell of each phase via the input transformers 13 and 14. Connected to U1 to U4, V1 to V4, and W1 to W4, the single-phase inverter cells of each phase are connected in series and connected to the AC motor 2. An IGBT with a withstand voltage of 1.4 kV is used.

  FIG. 14 is a connection diagram of a conventional high voltage inverter device for 3.3 kV output, and the AC power source 1 is connected to each single-phase inverter cell U1 to U4, V1 to V4, W1 to W4 via an input transformer 12, Single-phase inverter cells for each phase are connected in series and connected to AC motor 2. FIG. 15 is a connection diagram of a conventional high voltage inverter device for 6.6 kV output. The AC power source 1 is connected to each single-phase inverter cell U1 to U8, V1 to V8, W1 to W8 via input transformers 13 and 14. These are connected in series for each phase and connected to the AC motor 2. 14 and 15, the IGBT is for 1.2 kV withstand voltage.

  FIG. 16 is a connection diagram of a conventional high voltage inverter device for 3.3 kV output, and the AC power source 1 is connected to each single-phase inverter cell U1 to U3, V1 to V3, W1 to W3 via an input transformer 15, Each is connected in series and connected to the AC motor 2. FIG. 17 is a connection diagram of a conventional high voltage inverter device for 6.6 kV output. The AC power source 1 is connected to each single-phase inverter cell U1 to U6, V1 to V6, W1 to W6 via input transformers 16 and 17. These are connected in series and connected to the AC motor 2. In FIGS. 16 and 17, an IGBT with a 1.7 kV breakdown voltage is used.

  FIG. 18 is a connection diagram of a conventional high voltage inverter device for 3.3 kV output. The AC power source 1 is connected to each single-phase inverter cell U1, U2, V1, V2, W1, W2 through an input transformer 18. Each is connected in series and connected to the AC motor 2. FIG. 19 is a connection diagram of a conventional high-voltage inverter device for 6.6 kV output. The AC power source 1 is connected to each single-phase inverter cell U1 to U4, V1 to V4, W1 to W4 via an input transformer 19, Each is connected in series and connected to the AC motor 2. In FIG. 18 and FIG. 19, an IGBT with a withstand voltage of 3.3 kV is used.

  FIG. 20 shows a circuit configuration of a conventional three-level single-phase inverter cell, in which AC power from each AC power source 1 is converted into DC by a forward conversion unit 21 through a fuse 20, smoothed by a capacitor 22, and then semiconductor switched. The AC output obtained by the three-level inverse conversion unit 23 composed of an element (IGBT) and a diode is supplied to the AC motor 2. FIG. 21 shows a circuit configuration of a conventional two-level single-phase inverter cell, which is similarly configured by a forward conversion unit 21, a capacitor 22, and a two-level inverse conversion unit 24.

  Conventionally, as described above, AC variable speed devices are realized using various high-voltage inverter devices, but the structure of the board frame is made of sheet metal, and the high-voltage applied voltage circuit section and the ground are Insulation is mainly performed by insulators. The electric wire is not a CV cable but a single-core unshielded insulated electric wire.

  FIG. 22 is a connection diagram of a conventional high voltage inverter device of 3 kV output. A 3.3 kV, 50/60 Hz AC power supply 1 is connected to each single-phase inverter cell U1 to U3, V1 via an input surge filter 25 and an input transformer 15. To V3, W1 to W3, connected in series, and connected to the AC motor 2. A controller 26 is connected to a power source of 200/220 V, 50/60 Hz, and controls a semiconductor switching element of each single-phase inverter cell, and is connected to the monitor panel 27. 28 is a current detector, and 29 is an output surge filter. R is a resistance for floating the neutral point from the ground potential. FIG. 23 is a connection diagram of a conventional 6 kV output high-voltage inverter device. A 6.6 kV, 50/60 Hz AC power supply 1 is connected to each single-phase inverter cell U1 to U6 via an input surge filter 25 and input transformers 16 and 17. , V 1 to V 6, W 1 to W 6, and connected in series to the AC motor 2.

Further, as prior art documents related to the invention of this application, there are the following.
JP 11-122943 A JP 2000-50636 A

  In the above-described conventional high-voltage inverter device, the panel frame and the surrounding constituent members are formed of a steel plate material or a shape steel. Some of the constituent members use synthetic resin materials, but only a part of the members. In general, a high-pressure board is considered to have such a structure because it is insulated by an insulator and a space. However, a portion insulated by providing a distance by an insulator is a dead base, which is a concern for downsizing the apparatus. In addition, if there is a metal structure in such a space, it is necessary to insulate or provide an insulation distance, and the panel size tends to increase. In particular, regarding the electric wires, if the phases of the 6 kV class electric wires are different, the electric wires cannot be bundled, and it is necessary to insulate them from the ground potential. For example, as shown in FIG. 12 and FIG. 13, the high-voltage inverter device has many main circuit wires, and the wiring course becomes a problem. If there is a metal structure in the space, the wiring space becomes large.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to obtain a high-voltage inverter device that can provide a small and sufficient insulating structure.

  A high-voltage inverter device according to claim 1 of the present invention connects a plurality of single-phase inverter cells each having a forward conversion unit and an inverse conversion unit in series, and each of the single-phase inverter cells has an alternating current via an input transformer. In a high-voltage inverter device that receives power and is housed in the panel, each single-phase inverter cell is supported by an insulating support frame provided in the panel so that it can be pulled out and can be pulled out from the input transformer. Wiring to the cell and wiring between each single-phase inverter cell are performed on the front side in the panel, and these wirings are supported and fixed by an insulating support frame, and the semiconductor switching elements constituting each single-phase inverter cell are controlled. An optical cable that is a signal line to the controller is supported and fixed by an insulating support frame.

  The high-voltage inverter device according to claim 2 is configured such that each single-phase inverter cell is grouped for each phase.

  As described above, according to the first aspect of the present invention, each single-phase inverter cell is supported by an insulation support frame with an insulation distance, and is not insulated by an existing insulator or the like. Thus, the insulation distance can be easily determined, and the apparatus can be miniaturized. In addition, it is possible to support and fix the wiring from the input transformer to each single-phase inverter cell and the wiring between each single-phase inverter cell to the insulating support frame that supports each single-phase inverter cell with a latch band made of nylon, etc. A support mechanism for wiring is not required, and the size can be reduced. Further, since the optical cable is supported and fixed to the controller by the insulating support frame, it is possible to reduce the size and provide a distance for making the bending R required by the optical cable.

  Further, since each single-phase inverter cell is supported by the insulating support frame, each single-phase inverter cell itself may be an inexpensive metal jacket, and each single-phase inverter cell can be manufactured at low cost. In addition, the high-voltage inverter device is often operated at all times and needs to be restarted promptly when a failure occurs. However, since each single-phase inverter cell has a drawer structure, maintenance and replacement are easy. In addition, if each single-phase inverter cell is pulled out, a large space appears and maintenance in the panel becomes easy, so the high-voltage inverter device can be installed along the wall surface, and can be used as a front service device. . Furthermore, wiring to each single-phase inverter cell and wiring between each single-phase inverter cell are performed on the front side in the panel and not between each single-phase inverter cell, so the necessary distance between wiring is also processed on the front side. Less space is required and miniaturization is possible.

  Further, since the single-phase inverter cells are grouped for each phase, the insulation distance can be easily determined.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 2 shows the arrangement and wiring of each single-phase inverter cell of the high-voltage inverter device according to the best mode of the present invention, and FIG. 3 shows the circuit configuration. In the figure, reference numerals 16 and 17 denote input transformers connected to the AC power source 1, which function to step down and insulate the power source. The wiring 32 is a single-core unshielded insulated wire, and an insulation distance is provided between the wirings 32 so that the length of the wiring 32 is as short as possible. The wiring 32 is held by an insulator. A total of 18 U-phase, V-phase, and W-phase single-phase inverter cells U1 to U6, V1 to V6, and W1 to W6 are connected to the secondary side of the input transformers 16 and 17, and these are connected in series for each phase. To the AC motor 2. The single-phase inverter cell includes a forward conversion unit, a smoothing capacitor, and an inverse conversion unit. The three-phase power input through the input transformers 16 and 17 is full-wave rectified by the forward conversion unit, Is then converted into single-phase alternating current by a single-phase reverse converter, and these are connected in series for each phase and supplied to the AC motor 2.

  Each single-phase inverter cell is arranged in the board frame 30 and a resistor R for floating the neutral point from the ground potential is also installed in the board frame 30. A controller 26 for controlling the semiconductor switching elements (IGBTs) constituting each single-phase inverter cell is also installed in the panel frame 30, and signal lines are connected by the optical cable 31 between the controller 26 and each semiconductor switching element and the outside. The input transformers 16 and 17 are installed in a transformer board frame arranged beside the board frame 30, and a base portion 33 is provided at the lower part of the board frame 30.

  Each single-phase inverter cell is grouped for each phase of U, V, W, and each single-phase inverter cell is stored in two rows and nine stages, with a gap between phases every three stages, and a gap between rows is required. However, the voltage for providing a gap for every three stages is an interphase voltage, and the gap between columns is determined by the voltage shared by the single-phase inverter cell, so it may be 6 kV or less. Further, since the insulation is not performed with an existing insulator, the insulation distance can be easily determined by the voltage to be insulated.

  4A to 4E show a front view, a side view, a rear view, a plan view, and a plan view of the base portion 33 of the insulating support frame 34 for insulatingly supporting each single-phase inverter cell and the like. Is made of an insulating material. Insulating frames 35 to 38 are erected in the panel frame 30, and four lateral frames 39 to 42 having a U-shaped cross section are attached to the front surfaces of the insulating frames 35 to 38 in the vertical direction for reinforcement. FIGS. 5A to 5D are a front view, a left side view, a right side view, and a plan view of the insulating frame 35. The insulating frame 35 is an L-shaped vertical frame 35a, 35b and an L-shaped shelf. Similarly, FIGS. 6 to 8 show insulating frames 36 to 38. These insulating frames 36 to 38 also have vertical frames 36a, 36b, 37a, 37b, 38a, 38b and shelf members 36c, 37c and 38c, each single-phase inverter cell is inserted into each of the insulating frames 35 to 38 so that the shelf members 35c to 38c can be pulled out as guides, thereby facilitating maintenance and inspection. Further, the wiring 32 between each single-phase inverter cell and the input transformers 16 and 17 and between each single-phase inverter cell is also supported and fixed to the insulating frames 35 to 38. Further, as shown in FIG. 8, an insulating rod 46 in the vertical direction is attached to the front surface of each cross member 39 to 42, and a plurality of optical cables 31 are formed by a latch band 47 made of nylon, for example, with the insulating rod 46 as a core material. Bundled and supported.

  In addition, wind tunnel insulating frames 44 and 45 are provided on the rear side of the panel frame 30, and a wind tunnel 48 is formed on the rear part thereof. An insulating frame 49 is provided on the right side of the insulating frame 38, a space 50 for control devices and input / output units is formed on the right side of the insulating frame 49, and a fan duct 51 is formed on the top of the panel frame 30. The

  FIGS. 1A and 1B are a side view and a front view showing a state in which each single-phase inverter cell, wiring 32 and optical cable 31 are supported and fixed to the insulating frames 35 to 38 and the horizontal frames 39 to 42, respectively. The transformer board 43 is arranged adjacent to 30 and the wiring 32 from the input transformers 16 and 17 accommodated in the transformer board 43 to each single-phase inverter cell is made to pass through holes provided in the board frame 30. The wiring 32 to each single-phase inverter cell and the wiring 32 between each single-phase inverter cell are performed on the front side of each single-phase inverter cell. A fan motor 52 is provided on the top of the panel frame 30 via a support portion 53.

  10A to 10D are a front view, a side view, a rear view, and a plan view of a single-phase inverter cell. 54 is an input terminal, 55 is an output terminal, 8 is a smoothing capacitor, 20 is a fuse, 57 is An optical cable connector 58 is a magnet switch that is turned on at the time of surge absorption at the start of energization, and 59 is a resistor acting at the time of surge absorption at the start of energization.

  In the above-described best embodiment, each single-phase inverter cell is supported by an insulation frame 35 to 38 with an insulation distance, and is not insulated by an existing insulator or the like. The insulation distance can be determined and the device can be miniaturized. Also, the insulation frames 35 to 38 that support each single-phase inverter cell support the wiring 32 from the input transformers 16 and 17 to each single-phase inverter cell and the wiring 32 between each single-phase inverter cell by a nylon latch band or the like. Since it can fix, the support mechanism for the wiring 32 becomes unnecessary and a miniaturization is attained. In addition, the horizontal frames 39 to 42 reinforce the insulating frames 35 to 38 and also support and fix the optical cable 31 to the controller 26, so that the size can be reduced and the bending required by the optical cable 31 is also possible. A distance for making R can be provided.

  Further, since each single-phase inverter cell is supported by the insulating frames 35 to 38, each single-phase inverter cell itself may be an inexpensive metal jacket, and each single-phase inverter cell can be manufactured at low cost. In addition, the high-voltage inverter device is often operated at all times and needs to be restarted promptly when a failure occurs. However, since each single-phase inverter cell has a drawer structure, maintenance and replacement are easy. In addition, if each single-phase inverter cell is pulled out, a large space appears and maintenance in the panel becomes easy, so the high-voltage inverter device can be installed along the wall surface, and can be used as a front service device. . Further, since wiring 32 to each single-phase inverter cell and wiring 32 between each single-phase inverter cell are performed on the front side in the panel and not between each single-phase inverter cell, the required distance between the wirings 32 is also on the front side. In this way, there is little unnecessary space and miniaturization is possible.

  Moreover, since the single-phase inverter cells are arranged in groups for each phase, the insulation distance can be easily determined.

It is the side view and front view which show the state which supported and fixed each single phase inverter cell etc. to the insulation frame etc. in the high voltage inverter apparatus by this Embodiment best mode. It is a figure which shows arrangement | positioning and wiring of each single phase inverter cell of the high voltage | pressure inverter apparatus by embodiment best. It is a circuit block diagram of the high voltage inverter apparatus by embodiment. 1 is a front view, a side view, a rear view, a plan view, and a plan view of a base portion of an insulating support frame and the like of a high-voltage inverter device according to an embodiment. It is the front view, side view, and top view of the insulation frame of the high voltage inverter apparatus by embodiment best. It is the front view, side view, and top view of the insulation frame of the high voltage inverter apparatus by embodiment best. It is the front view, side view, and top view of the insulation frame of the high voltage inverter apparatus by embodiment best. It is the front view, side view, and top view of the insulation frame of the high voltage inverter apparatus by embodiment best. It is a top view of the state which attached the optical cable to the horizontal frame of the high voltage inverter apparatus by embodiment best. It is the front view, side view, back view, and top view of the single phase inverter cell of the high voltage inverter apparatus by embodiment best. It is the connection diagram of the conventional high voltage inverter device of a transformer coupling system, and the circuit block diagram of the forward conversion part and reverse conversion part. It is a connection diagram of a conventional high-voltage inverter device. It is a connection diagram of a conventional high-voltage inverter device. It is a connection diagram of a conventional high-voltage inverter device. It is a connection diagram of a conventional high-voltage inverter device. It is a connection diagram of a conventional high-voltage inverter device. It is a connection diagram of a conventional high-voltage inverter device. It is a connection diagram of a conventional high-voltage inverter device. It is a connection diagram of a conventional high-voltage inverter device. It is a circuit block diagram of the 3-level inverter cell of the conventional high voltage inverter apparatus. It is a circuit block diagram of the 2-level inverter cell of the conventional high voltage inverter apparatus. It is a connection diagram of a conventional high-voltage inverter device. It is a connection diagram of a conventional high-voltage inverter device.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... AC power source 2 ... AC motor 16, 17 ... Input transformer 26 ... Controller 30 ... Board frame 31 ... Optical cable 32 ... Wiring 34 ... Insulation support frame 35-38 ... Insulation frame 39-42 ... Horizontal frame U1-U8, V1- V6, W1-W6 ... single-phase inverter cell

Claims (2)

  A plurality of single-phase inverter cells having a forward conversion part and an inverse conversion part are connected in series, AC power is input to the forward conversion part of each single-phase inverter cell via an input transformer, and the high voltage stored in the panel In the inverter device, each single-phase inverter cell is supported by an insulating support frame provided in the panel so that it can be pulled out with an insulation distance. Wiring from the input transformer to each single-phase inverter cell and wiring between each single-phase inverter cell The optical cable, which is a signal line to the controller that controls the semiconductor switching elements constituting each single-phase inverter cell, is supported by the insulating support frame. A high-voltage inverter device characterized by supporting and fixing. 2. The high-voltage inverter device according to claim 1, wherein the single-phase inverter cells are arranged in groups for each phase.

Images