JP2006351825A - Optical ignition semiconductor device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an optical ignition semiconductor device of which no optical ignition semiconductor element is not turned on when an anode-cathode voltage reaches a forward tolerable voltage at each cycle, even if an optical gate signal supply system fails. <P>SOLUTION: Optical trigger thyristors 211, 212, ..., 21n composed by connecting snubber circuits 26 in parallel are connected to one another in series in a plurality of numbers. Optical gate signals La and Lb from a gate signal generating part 22 are applied to light receiving parts 42 on silicon wafers 28 of the optical trigger thyristors 211, 212, ..., 21n, to ignite the optical trigger thyristors 211, 212, ..., 21n. Each of the optical trigger thyristors 211, 212, ..., 21n comprises an internal optical guide 37 comprising optical fiber bundles 40a and 40b in two systems for applying optical gate signal to the light receiving part 42. Each of the optical trigger thyristors 211, 212, ..., 21n comprises two optical signal source systems Pa and Pb corresponding to the optical fiber bundles 40a and 40b of two systems. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an optical ignition semiconductor device including an optical ignition semiconductor element such as an optical trigger thyristor in which snubber circuits are connected in parallel.

  Background art will be described with reference to FIGS. FIG. 15 is a configuration diagram illustrating a direct current power transmission system, FIG. 16 is a configuration diagram illustrating a main part of a light ignition semiconductor device, and FIG. 17 is a cross-sectional view illustrating a schematic configuration of a main part of the light trigger thyristor. FIG. 18 is a diagram illustrating operation waveforms of the light ignition semiconductor device, and FIG. 19 is a diagram for explaining a main circuit current in the light ignition semiconductor device.

  As is well known, power converters that perform AC / DC conversion in ultra high voltage direct current transmission (UHVDC), power converters for reactive power compensation, or power converters such as cycloconverters and chopper circuits include main circuits and control circuits. The light ignition semiconductor device is used because it can be electrically insulated from each other and is unlikely to malfunction due to electromagnetic induction. A light-ignited semiconductor device ignites a VBO-free light-ignited semiconductor element, such as a light-triggered thyristor (LTT), that self-turns on when an applied voltage exceeds a forward withstand voltage (VBO). And a gate signal generator for outputting a predetermined optical gate signal.

  Hereinafter, the conventional technique will be described with reference to FIGS. In the DC power transmission system shown in FIG. 15, 1 is a three-phase AC power supply system, 2 is a step-up transformer, 3 is a power converter configured by a three-phase bridge, and 4 is a voltage fluctuation. It is a reactor for smoothing. Thereby, the alternating current power from the alternating current power supply system 1 is converted into direct current by the power converter 3 and transmitted to the power receiving side (not shown) through the reactor 4 and the power transmission system (not shown).

  The power converter 3 having a three-phase bridge configuration that performs AC / DC conversion includes, as a main circuit, element blocks 6 each having a plurality of VBO-free optical trigger thyristors 51, 52,. It has six arms configured to have two. In addition, as shown in FIG. 16 showing the main part of the light-ignition semiconductor device corresponding to one element block 6, each of the light trigger thyristors 51, 52,..., 5n of the element block 6 includes a snubber capacitor 7 and a snubber. A snubber circuit 9 having resistors 8 connected in series is connected in parallel, and one optical trigger thyristor 51, 52,..., 5n and a snubber circuit 9 constitute one element unit 101, 102,. A plurality of element units 101, 102,..., 10n are connected in series to one arm.

  Further, the gate signal generator 11 that outputs optical gate signals for igniting the plurality of optical trigger thyristors 51, 52,..., 5n of the power conversion device 3 outputs a control panel 12 that outputs phase signals corresponding to the respective phases. In response to the corresponding phase signal from the control panel 12, the optical gate signal L of the phase is formed by, for example, a light emitting diode (LED) provided corresponding to each of the optical trigger thyristors 51, 52,. .., 13n, and a gate signal generation block 14 that is output from the optical signal sources 131, 132,.

  The optical gate signals L from the optical signal sources 131, 132,..., 13n are respectively provided between the corresponding optical trigger thyristors 51, 52,. The light trigger thyristors 51, 52,..., 5n are sent to the light receiving end of the internal light guide 16 through the external light guide 15. Further, the optical gate signal L is radiated from the light emitting end portion 17 of the internal light guide 16 to the light receiving portion 19 on the wafer 18 to ignite the respective light trigger thyristors 51, 52,. Yes.

  However, in the above prior art, the optical gate signal L from the gate signal generation unit 11 is for some reason, for example, the disconnection of the external light guide 15 formed of an optical fiber or the optical signal sources 131, 132, .., 13n, optical signal sources 131, 132,..., 13n, etc., due to failure of the optical signal sources 131, 132,. When the signal L is not sent, the optical trigger thyristor 52 does not fire at a predetermined timing, and further turns on itself when the anode-cathode voltage rises and exceeds the forward withstand voltage (VBO). Become.

  That is, the anode-cathode voltage V of each of the light trigger thyristors 51,..., 5n that has been normally fired excluding the light trigger thyristor 52 is as shown in FIG. I is as shown in FIG. On the other hand, the anode-cathode voltage V2 of the optical trigger thyristor 52 that has failed in the optical gate signal L at time Tx is as shown in FIG. 18C, and the optical gate signal L of the optical trigger thyristor 52 is As shown in FIG. 18D, the self-turn-on occurs when the anode-cathode voltage exceeds the forward withstand voltage (VBO) at time Tx. After that, it turns on every time the anode-cathode voltage reaches the forward withstand voltage (VBO), and the light trigger thyristor 52 is forced to turn on at a high voltage every cycle.

  At this time, since a high voltage is applied to the snubber circuit 9 connected in parallel to the optical trigger thyristor 52, the snubber capacitor 7 is required to have a dielectric strength corresponding to the high voltage. Further, when the optical trigger thyristor 52 is turned on by an overvoltage protection operation (VBO operation), the discharge current from the snubber capacitor 7 of the snubber circuit 9 connected in parallel increases, so that the snubber capacitor 7 can withstand this discharge current. Must be a thing. At the same time, the energy that must be consumed by the snubber resistor 8 is large, and the snubber resistor 8 is required to have a heat treatment capacity that can consume this large energy.

  Further, since the optical trigger thyristor 52 is not turned on at the time Tx, the main circuit current I of the element block 6 to which the optical trigger thyristor 52 is connected is, as shown by a broken line in FIG. .., 10n flows through the optical trigger thyristors 51,..., 5n, but the element unit 102 flows through the snubber capacitor 7 and the snubber resistor 8 and does not flow through the optical trigger thyristor 52. For this reason, the energy consumed by the snubber resistor 8 is even greater, and the snubber resistor 8 needs to have a heat treatment capacity sufficient to process this energy.

  As described above, when a failure occurs in the optical gate signal supply system and no optical gate signal is supplied to the optical trigger thyristor, the optical trigger thyristor has a forward withstand voltage between the anode and cathode. Since it will turn on when the voltage (VBO) is exceeded, excessive stress will be applied to the snubber circuit connected in parallel, and the snubber capacitor and snubber resistance must be able to withstand that stress. Will be.

  The present invention has been made in view of such circumstances, and the object of the present invention is to ensure that the anode-cathode voltage of the light-igniting semiconductor element is in order every cycle even when a failure occurs in the optical gate signal supply system. It is an object of the present invention to provide a light-igniting semiconductor device that is prevented from being turned on when a directional withstand voltage (VBO) is exceeded and an excessive stress is not applied to a snubber circuit.

The light ignition semiconductor device of the present invention includes:
A plurality of light-igniting semiconductor elements connected in parallel with a snubber circuit are connected in series, and a light gate signal from a gate signal generating unit is applied to a light receiving portion on the wafer of the light-igniting semiconductor element to thereby form the light-igniting semiconductor element. A light-ignition semiconductor device configured to ignite,
The light ignition semiconductor element includes a plurality of light guides for providing the light gate signal to the light receiving portion, and the gate signal generation unit corresponds to the light guides for the plurality of light ignition semiconductor elements. It is characterized by having a plurality of optical signal sources,
Furthermore, the range of the light emitted from the end of the light guide of a plurality of systems is within the range of the light receiving portion,
Furthermore, the light guides of a plurality of systems are characterized in that the shape of each end is adjusted so that the range of radiated light is within the range of the light receiving part,
Furthermore, the light guide has a tapered shape with a small cross-sectional shape toward the end portion,
Furthermore, the light guides of a plurality of systems are provided with an optical system for condensing radiated light at the light receiving part at the end,
Further, the light guides of a plurality of systems are characterized in that each end has an optical system that condenses radiated light on the light receiving part,
Furthermore, the gate signal generation unit is characterized in that the optical gate signal is simultaneously output from a plurality of optical signal sources of the optical signal source system to the optical guides of a plurality of systems,
Furthermore, the gate signal generation unit outputs each optical gate signal from a plurality of optical signal sources of the optical signal source system so that output timing does not overlap with respect to the plurality of optical guides. Is what
Further, the optical gate signals output from the plurality of optical signal sources are characterized in that the output timing of each optical gate signal is output with a deviation in signal width.

  According to the present invention, even if a failure occurs in the optical gate signal supply system, the light-ignited semiconductor element is turned on every cycle when the anode-cathode voltage exceeds the forward withstand voltage (VBO). There is an effect that no excessive stress is applied to the snubber circuit.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, a first embodiment will be described with reference to FIGS. FIG. 1 is a configuration diagram showing a main part of the light-igniting semiconductor device, FIG. 2 is a cross-sectional view of the light trigger thyristor, and FIG. 3 is a cross-sectional view showing a configuration of the main part of the light trigger thyristor. FIG. 4 is a diagram showing operation waveforms of the optical trigger thyristor.

  The present embodiment is a light ignition semiconductor device used in, for example, a power converter having a three-phase bridge configuration that performs AC / DC conversion in the ultrahigh-voltage DC power transmission described in the background art described above. As will be described below with reference to FIGS. 1 to 4, the light-ignition semiconductor device constitutes the main circuit of the three-phase bridge of the power converter, and the applied voltage is the forward withstand voltage (VBO). A plurality of VBO-free light-ignited semiconductor elements connected in series, such as light trigger thyristors (LTT) 211, 212,..., 21n, and these light trigger thyristors 211, 212,. The gate signal generator 22 is configured to output predetermined optical gate signals La and Lb for firing 21n.

  Further, the three-phase bridge configuration of the power conversion device is similar to the one shown in the background art, in which an element block 23 in which a plurality of optical trigger thyristors 211, 212,. Each of the two arms has a configuration. Each of the optical trigger thyristors 211, 212,..., 21n is connected in parallel to a snubber circuit 26 in which a snubber capacitor 24 and a snubber resistor 25 are connected in series, and one optical trigger thyristor 211, 212,. , 21n and the snubber circuit 26 constitute one element unit 271, 272,..., 27n, and a plurality of element units 271, 272,. Yes. In addition, since the element block 23 of each phase and each arm has the same configuration, the light ignition semiconductor device will be described below by exemplifying one element block 23.

  As shown in FIG. 2, the optical trigger thyristors 211, 212,..., 21n constituting the main circuit of the power conversion device sandwich the silicon wafer 28 between two buffer plates 29, 30 formed of tungsten or molybdenum. The outside is sandwiched between an anode post 31 and a cathode post 32 made of copper. Further, an envelope 33 is provided between the outer peripheral portions of the anode post 31 and the cathode post 32, and the light introduction portion is provided on the cathode post side of the envelope 33 so as to keep the inside and outside airtight. 34 is provided. Further, the cathode post 32 is formed with a storage groove 36 that forms a path from the light introducing portion 34 to the gate portion 35 on the upper surface of the silicon wafer 28.

  Between the light introducing portion 34 and the gate portion 35, an internal light guide 37 is provided with holding members 38, 39 so that the light receiving end side thereof is located at the light introducing portion 34 and the light emitting end side thereof is located at the gate portion 35, respectively. The bent portion 37a is provided at the intermediate portion and is stored in the storage groove 36. The internal light guide 37 is constituted by two optical fiber bundles 40a and 40b so that a plurality of systems, for example, two systems of optical paths are formed. The two light emitting end portions 41a and 41b of the optical fiber bundles 40a and 40b are arranged so as to face the light receiving portion 42 (turn-on region G) of the gate portion 35 on the upper surface of the silicon wafer 28, as shown in FIG. Has been. 43 is a P-type emitter layer, 44 is an N-type base layer, 45 is a P-type base layer, 46 is an N-type emitter layer, 47 is a P-type high concentration diffusion layer, 48 is an anode electrode, and Th is a thyristor region. It is.

  On the other hand, the gate signal generator 22 that outputs the optical gate signals La and Lb that ignite the plurality of optical trigger thyristors 211, 212,..., 21n of the power conversion device has each phase of U phase, V phase, and W phase. The control panel 50 that outputs the phase signal corresponding to the output signal through the output terminals 50u, 50v, and 50w, and the optical gate signals La and Lb of the corresponding phase at the predetermined timing in response to the corresponding phase signal from the control panel 50, The gate thyristor 211, 212,..., 21n is provided with a gate signal generation block 51.

  Further, the gate signal generation block 51 includes two optical signals corresponding to the two optical fiber bundles 40a and 40b forming a plurality of optical paths provided in each optical trigger thyristor 211, 212,. Optical signal sources 521, 522,..., 52n, 531, 532,..., 53n formed by light emitting sources such as two light emitting diodes (LEDs) constituting the source systems Pa and Pb, and .., 52n, 531, 532,..., 53n are provided with a signal source drive circuit 54 that drives the optical signal sources 521, 522,. The optical signal sources 521, 522,..., 52n, 531, 532,..., 53n are connected to the first optical signal source group A of the optical signal sources 521, 522,. Similarly, the second optical signal source group B of optical signal sources 531, 532,..., 53n connected in series is connected to the signal source driving circuit 54 in a state of being connected in parallel, and driven simultaneously.

  In addition, a plurality of external light guides 55 are disposed between the light trigger thyristors 211, 212,..., 21n and the gate signal generation block 51 of the gate signal generation unit 22. Each of the external light guides 55 has a plurality of optical paths as in the case of the internal light guide 37, that is, the same number of two optical paths as the internal light guide 37 are formed. It is constituted by two optical fiber bundles 56a and 56b constituting Pa and Pb. In the present embodiment, the external light guide 55 is configured by the two optical fiber bundles 56a and 56b, but may be configured by a single optical fiber.

  Further, the optical fiber bundles 56a and 56b of each external light guide 55 have optical gate signals La, 53n, 532, 532,. The gate signal generation block 51 is arranged to introduce Lb. The other ends of the optical fiber bundles 56a and 56b are attached to the respective light introducing portions 34 of the corresponding light trigger thyristors 211, 212,. Optical gate signals La and Lb are transmitted to the light receiving ends of the fiber bundles 40a and 40b. The light triggering thyristors 211, 212,..., And 21n on the silicon wafer 28 are respectively connected to the light emitting portions 41a and 41b of the optical fiber bundles 40a and 40b of the internal light guide 37. Optical gate signals La and Lb having a light quantity that can be turned on even at the end alone are provided.

  In the configuration as described above, when a corresponding phase signal is output from the control panel 50, the optical signal sources 521, 522,..., 52n, 531 are output from the signal source driving circuit 54 based on this signal. Drive signals for driving 532,..., 53n are output at a predetermined timing. The optical signal sources 521, 522,..., 52n, 531, 532,..., 53n of the two optical signal source groups A, B emit light by the output drive signal, and both optical signal source groups A, Optical gate signals La and Lb corresponding to B are sent to one end portions of the corresponding optical fiber bundles 56a and 56b of the external light guide 55, respectively.

  Further, the optical gate signals La and Lb transmitted through the optical fiber bundles 56a and 56b of the external light guide 55 are transmitted from the other ends of the optical fiber bundles 56a and 56b to the light of the respective optical trigger thyristors 211, 212,. The optical fiber bundles 40a and 40b of the corresponding internal light guide 37 located at the introduction part 34 are sent to the light receiving ends. The optical gate signals La and Lb are transmitted through the optical fiber bundles 40a and 40b of the internal light guide 37, and are simultaneously radiated from the light emitting end portions 41a and 41b to the light receiving portion 42 on the silicon wafer 28. 211, 212,..., 21n are normally fired by the two optical gate signals La and Lb.

  Further, the optical gate signals La and Lb from the gate signal generation unit 22 are for some reason, for example, the disconnection of the external light guide 55, the optical signal sources 521, 522,..., 52n, 531, 532,. If the optical fiber bundle 56a of the external light guide 55 is disconnected at the light receiving end of the optical fiber bundle 40a of the internal light guide 37 corresponding to the light trigger thyristor 212, for example, the time Ty. It is assumed that the optical gate signal La has not been transmitted from the point of time. In this case, only the optical gate signal Lb is sent to the light receiving end of the optical fiber bundle 40b through the optical fiber bundle 56b, and the optical trigger thyristor 212 is fired only by the optical gate signal Lb.

  The operation waveforms when normally fired by the above-described optical gate signals La and Lb and when fired only by the optical gate signal Lb due to failure are shown in FIG. 4 with the elapsed time t on the horizontal axis. It is as shown. That is, the anode-cathode voltage V of each of the light trigger thyristors 211,..., 21n that is normally fired by the light gate signals La and Lb except for the light trigger thyristor 212 is shown in FIG. The main circuit current I is as shown in FIG. In addition, the normal optical gate signals La and Lb given to the light receiving portions 42 of the gate portions 35 of the optical trigger thyristors 211,..., 21n in the meantime are as shown in FIG.

  On the other hand, in the external light guide 55 corresponding to the light trigger thyristor 212, when the disconnection of the optical fiber bundle 56a occurs at the time Ty, the optical gate signal La becomes as shown in FIG. Thereafter, the light receiving part 42 is not given. On the other hand, the normal optical gate signal Lb shown in FIG. 4E continues to be given to the light receiving portion 42 of the optical trigger thyristor 212 through the optical fiber bundle 56b where no abnormality has occurred. Then, since the light amount of the optical gate signal Lb is a value sufficient to turn on the optical trigger thyristor 212, the optical trigger thyristor 212 is normally turned on after the time Ty. FIG. 4F shows the state of the optical gate signals La and Lb given to the light receiving portion 42 of the optical trigger thyristor 212. The anode-cathode voltage V2 is as shown in FIG. 4C, and the main circuit thereof is the same as the other optical trigger thyristors 211,..., 21n connected in series, FIG. The main circuit current I shown in FIG.

  As a result, the light trigger thyristor 212 is not turned on every time the anode-cathode voltage reaches the forward withstand voltage (VBO), and is not forced to turn on at a high voltage every cycle. Further, since a high voltage is not applied to the snubber circuit 26 connected in parallel to the optical trigger thyristor 212, the snubber capacitor 24 does not endure a particularly large discharge current even if it does not have a particularly high dielectric strength. Also good. Further, the snubber resistor 25 does not have to have a particularly large heat treatment capability.

  In the above embodiment, the optical signal sources 521, 522,..., 52n, 531, 532,..., 53n are respectively connected in series with the optical signal sources 521, 522,. 53, 532,..., 53n, and these two optical signal source groups A and B are connected in parallel and connected to the signal source drive circuit 54 to drive them simultaneously. Based on the above, the individual optical signal sources 521, 522,..., 52 n, 531, 532,.

  Next, a second embodiment will be described with reference to FIG. This embodiment is different from the first embodiment in the configuration of the light trigger thyristor, particularly the configuration of the internal light guide, and the other configurations are the same. FIG. 5 is a cross-sectional view showing a configuration of a main part of the optical trigger thyristor. In addition, the same code | symbol is attached | subjected to the same part as 1st Embodiment, description is abbreviate | omitted, and the structure of this embodiment different from 1st Embodiment is demonstrated.

  In FIG. 5, reference numeral 61 denotes an internal light guide, which is disposed between the light introducing portion of the light trigger thyristor and the gate portion 35 with a bent portion at an intermediate portion. The internal light guide 61 is constituted by two optical fiber bundles 62a and 62b so that a plurality of systems, for example, two systems of optical paths are formed. Further, the two light emitting end portions 63a and 63b of the optical fiber bundles 62a and 62b are disposed so as to face the light receiving portion 42 (turn-on region G) of the gate portion 35 on the upper surface of the silicon wafer 28, respectively. Further, the end portions of the light emitting end portions 63a and 63b are adjusted to a size equal to or smaller than the shape of the light receiving portion 42 so that the emitted light gate signals La and Lb are all given to the light receiving portion 42. It has become.

  In such a configuration, the optical gate signals La and Lb are transmitted from the optical signal source of the gate signal generation unit based on the phase signal from the control panel, and through the corresponding optical fiber bundle of the external light guide. Introduced into the internal light guide 61. Further, the optical gate signals La and Lb introduced into the internal light guide 61 are transmitted through the optical fiber bundles 62a and 62b, are radiated from the light emitting ends 63a and 63b, and are all given to the opposing light receiving portions 42. Thus, each trigger thyristor is normally fired by the two optical gate signals La and Lb.

  At this time, for example, when one optical fiber bundle 63a of the external light guide is disconnected, the light gate signal La is not given to the light receiving portion 42 of the corresponding light trigger thyristor. However, since the light gate signal Lb continues to be normally applied to the light receiving portion 42, the corresponding light trigger thyristor is normally fired, and the same effect as in the first embodiment can be obtained. In addition, since the shapes of the light emitting end portions 63a and 63b of the optical fiber bundles 62a and 62b are adjusted so that the optical gate signals La and Lb are all given to the opposing light receiving parts 42, the first embodiment. As a result, it is possible to save power of the optical gate signals La and Lb.

  The adjustment of the light emitting ends 63a and 63b of the optical fiber bundles 62a and 62b of the internal light guide 61 so that the optical gate signals La and Lb are all given to the opposing light-receiving portions 42 The fiber bundles 62a and 62b may be formed to have an equal cross-sectional shape over the entire length, and a taper shape having a gradually smaller cross-sectional shape toward the light emitting end portions 63a and 63b may be provided over the entire length or partially. You may do it.

  Next, a third embodiment will be described with reference to FIG. This embodiment is different from the first embodiment in the configuration of the light trigger thyristor, particularly the configuration of the internal light guide, and the other configurations are the same. FIG. 6 is a cross-sectional view showing a configuration of a main part of the optical trigger thyristor. In addition, the same code | symbol is attached | subjected to the same part as 1st Embodiment, description is abbreviate | omitted, and the structure of this embodiment different from 1st Embodiment is demonstrated.

  In FIG. 6, reference numeral 65 denotes an internal light guide, which is disposed between the light introducing portion of the light trigger thyristor and the gate portion 35 with a bent portion at an intermediate portion. The internal light guide 65 is constituted by two optical fiber bundles 40a and 40b so that a plurality of systems, for example, two systems of optical paths are formed. Further, a condensing optical system 66 such as a plano-convex lens, a meniscus lens, and a gradient index lens is provided at the tip of the two light emitting ends 41a and 41b of the optical fiber bundles 40a and 40b, respectively. .

  Furthermore, the light emitting end portions 41a and 41b provided with the condensing optical system 66 are arranged so as to face the light receiving portion 42 (turn-on region G) of the gate portion 35 on the upper surface of the silicon wafer 28, respectively. All of the optical gate signals La and Lb emitted from the end portions 41a and 41b through the condensing optical system 66 are given to the light receiving portion 42.

  In such a configuration, the optical gate signals La and Lb are transmitted from the optical signal source of the gate signal generation unit based on the phase signal from the control panel, and through the corresponding optical fiber bundle of the external light guide. Introduced into the internal light guide 65. Further, the optical gate signals La and Lb introduced into the internal light guide 65 are transmitted through the optical fiber bundles 40a and 40b, and are radiated from the light emitting end portions 41a and 41b through the condensing optical system 66, and are opposed to the light receiving portions. All are given to 42. Thus, each trigger thyristor is normally fired by the two optical gate signals La and Lb.

  At this time, for example, when one optical fiber bundle 40a of the external light guide is disconnected, the light gate signal La is not given to the light receiving portion 42 of the corresponding light trigger thyristor. However, since the light gate signal Lb continues to be normally applied to the light receiving portion 42, the corresponding light trigger thyristor is normally fired, and the same effect as in the first embodiment can be obtained. Further, since the condensing optical system 66 is provided at the light emitting end portions 41a and 41b so that the optical gate signals La and Lb are all given to the opposing light receiving portions 42, the optical gate signals La and Lb are more effective than those of the first embodiment. It is possible to save power.

  Next, a fourth embodiment will be described with reference to FIG. This embodiment is different from the first embodiment in the configuration of the light trigger thyristor, particularly the configuration of the internal light guide, and the other configurations are the same. FIG. 7 is a cross-sectional view showing the configuration of the main part of the optical trigger thyristor. In addition, the same code | symbol is attached | subjected to the same part as 1st Embodiment, description is abbreviate | omitted, and the structure of this embodiment different from 1st Embodiment is demonstrated.

  In FIG. 7, reference numeral 68 denotes an internal light guide, which is disposed between the light introducing portion of the light trigger thyristor and the gate portion 35 with a bent portion at an intermediate portion. The internal light guide 68 is constituted by two optical fiber bundles 40a and 40b so as to form a plurality of systems, for example, two systems of optical paths. Furthermore, at one end portion of the two light emitting end portions 41a and 41b of the optical fiber bundles 40a and 40b, one condensing optical system 69 composed of, for example, a plano-convex lens, a meniscus lens, a refractive index distribution type lens, etc. It is provided at the radiation end portions 41a and 41b.

  Furthermore, the light emitting end portions 41a and 41b provided with the condensing optical system 69 are arranged so as to face the light receiving portion 42 (turn-on region G) of the gate portion 35 on the upper surface of the silicon wafer 28, respectively. All of the optical gate signals La and Lb emitted from the end portions 41a and 41b through the condensing optical system 69 are supplied to the light receiving portion.

  In such a configuration, the optical gate signals La and Lb are transmitted from the optical signal source of the gate signal generation unit based on the phase signal from the control panel, and through the corresponding optical fiber bundle of the external light guide. , Introduced into the internal light guide 68. Further, the optical gate signals La and Lb introduced into the internal light guide 68 are transmitted through the optical fiber bundles 40a and 40b, and are radiated from the light emitting end portions 41a and 41b via the condensing optical system 69, and are opposed to the light receiving portions. All are given to 42. Thus, each trigger thyristor is normally fired by the two optical gate signals La and Lb.

  At this time, for example, when one optical fiber bundle 40a of the external light guide is disconnected, the light gate signal La is not given to the light receiving portion 42 of the corresponding light trigger thyristor. However, since the light gate signal Lb continues to be normally applied to the light receiving portion 42, the corresponding light trigger thyristor is normally fired, and the same effect as in the first embodiment can be obtained. In addition, since the condensing optical system 69 is provided at the light emitting end portions 41a and 41b so that the optical gate signals La and Lb are all given to the opposing light receiving portions 42, the optical gate signals La and Lb are more effective than those in the first embodiment. It is possible to save power.

  Next, a fifth embodiment will be described with reference to FIGS. FIG. 8 is a block diagram showing the main part of the light ignition semiconductor device, FIG. 9 is a cross-sectional view showing the structure of the main part of the optical trigger thyristor, and FIG. 10 is a block diagram showing the gate signal generating part. 11 is a diagram showing signal waveforms in the gate signal generation unit, FIG. 12 is a diagram showing operation waveforms of the optical trigger thyristor, and FIG. 13 is a diagram showing an optical gate signal in the gate unit in a normal state. 14 is a diagram showing optical gate signals when a failure occurs in the gate section and thereafter. In addition, the same code | symbol is attached | subjected to the same part as 1st Embodiment, description is abbreviate | omitted, and the structure of this embodiment different from 1st Embodiment is demonstrated.

  As in the first embodiment, the present embodiment is a light ignition semiconductor device used in, for example, a three-phase bridge-structured power conversion device that performs AC / DC conversion in the ultrahigh-voltage DC power transmission described in the background art above. . As will be described below with reference to FIGS. 8 to 14, the light-ignited semiconductor device constitutes the main circuit of the three-phase bridge of the power converter, and the applied voltage is the forward withstand voltage (VBO). A plurality of series-connected VBO-free light-ignited semiconductor elements, such as light trigger thyristors (LTT) 211, 212,..., 21n, and these light trigger thyristors 211, 212,. The gate signal generating unit 71 is configured to output predetermined optical gate signals Lm and Ln for firing 21n. Also in this embodiment, since the element block 23 of each phase and each arm is the same structure in the three-phase bridge configuration of the power conversion device, the light ignition semiconductor is illustrated by exemplifying one element block 23. The apparatus is described below.

  The gate signal generator 70 for outputting the optical gate signals Lm and Ln for igniting the plurality of optical trigger thyristors 211, 212,..., 21n of the power converter corresponds to each of the U phase, V phase, and W phase. The control panel 50 that outputs the phase signal to be transmitted through the output terminals 50u, 50v, and 50w, and the corresponding phase signal from the control panel 50, and the optical gate signals Lm and Ln of the phase at the predetermined timing, 21, 212,..., 21 n are provided with a gate signal generation block 71.

  8, 10, and 11, the gate signal generation block 71 of the gate signal generation unit 70 includes optical trigger thyristors 211, 212,..., 21 n that output optical gate signals Lm and Ln. Corresponding to the two optical fiber bundles 40a and 40b forming the plurality of optical paths provided, there are two light-emitting diodes (LEDs) provided for each of the two optical signal source systems Pm and Pn. Optical signal sources 721, 722,..., 72n, 731, 732,. These optical signal sources 721, 722,..., 72n, 731, 732,..., 73n are connected in series as the first optical signal source group A. Similarly, optical signal sources 731, 732,..., 73 n are connected in series as a second optical signal source group B.

  Further, the gate signal generation block 71 includes optical trigger thyristors 211, 212,..., 21n, and optical signal sources 721, 722,..., 72n, 731, 732,. A gate logic circuit 74, a first one-shot circuit 75, an on-delay circuit 76 that causes a predetermined time delay in the output, and a second one-shot circuit 77 so that the optical gate signals Lm and Ln are sent and turned on. Is provided.

  That is, the gate logic circuit 74 receives the phase signal S1 output from the control panel 50, and the first one-shot circuit 75 and the on-delay circuit 76 output signals having a predetermined signal width output from the gate logic circuit 74. The second one-shot circuit 77 receives the output signal S4 that is the output of the on-delay circuit 76 as input. The first one-shot circuit 75 outputs a drive signal S3 having a signal width of about 10 μs to 15 μs, for example, and the optical signal sources 721, 722,. Driven. The on-delay circuit 76 outputs a signal width of the drive signal S3, for example, about 10 μs to about 10 μs output from the second one-shot circuit 77 based on the output signal S4 output at a timing delayed by about 10 μs to 15 μs. A drive signal S5 having a signal width of 15 μs is output, and the optical signal sources 731, 732,..., 73 n of the second optical signal source group B are driven.

  Thereby, the optical gate signal Lm transmitted from the optical signal sources 721, 722,..., 72n of the first optical signal source group A and the optical signal sources 731, 732,. .., 73n and the optical gate signal Ln sent from the optical trigger thyristors 211, 212,. The transmission of the optical gate signals Lm, Ln from the optical signal sources 721, 722,..., 72n, 731, 732,..., 73n to the respective optical trigger thyristors 211, 212,. Are arranged in the gate signal generating block 71 so as to introduce the corresponding optical gate signals Lm and Ln, respectively, and the other end is attached to each optical introducing portion of the corresponding optical trigger thyristor 211, 212,. This is performed via each external light guide 55 formed by two optical fiber bundles 56a and 56b of the optical signal source systems Pm and Pn.

  Further, the optical gate signals Lm, Ln are sent to the light emitting ends of the optical fiber bundles 40a, 40b of the internal light guide 37 with respect to the light receiving portions 42 on the silicon wafer 28 of the respective optical trigger thyristors 211, 212,. From the portions 41a and 41b, the light trigger thyristors 211, 212,..., 21n can be turned on even at each end alone.

  In the configuration as described above, when the corresponding phase signal S1 is output from the control panel 50, the gate signal generation block 71 based on the phase signal S1 outputs the optical signal of the first optical signal source group A. A drive signal S3 having a signal width of about 10 μs to 15 μs for driving the sources 721, 722,..., 72n is output, and the light gate signal Lm is emitted to one end of the corresponding optical fiber bundle 56a of the external light guide 55. Sent to the department. Further, a drive signal S5 having a signal width of about 10 μs to 15 μs delayed by the signal width of the drive signal S3 for driving the optical signal sources 731, 732,. Then, the optical gate signal Ln is sent to one end of the corresponding optical fiber bundle 56b of the external light guide 55, respectively.

  Further, the optical gate signals Lm and Ln transmitted through the optical fiber bundles 56a and 56b of the external light guide 55 are transmitted from the other ends of the optical fiber bundles 56a and 56b to the light of the respective optical trigger thyristors 211, 212,. It is sent to the light receiving ends of the optical fiber bundles 40a and 40b of the corresponding internal light guide 37 located at the introduction portion. The optical gate signals Lm and Ln are transmitted through the optical fiber bundles 40a and 40b of the internal light guide 37, and are emitted from the light emitting end portions 41a and 41b to the light receiving portion 42 on the silicon wafer 28 at predetermined timings, respectively. Each of the optical trigger thyristors 211, 212,..., 21n receives the two optical gate signals Lm and Ln and is normally fired.

  Further, the optical gate signals Lm and Ln from the gate signal generating unit 70 are for some reason, for example, the disconnection of the external light guide 55, the optical signal sources 721, 722,..., 72n, 731, 732,. If the optical fiber bundle 56a of the external light guide 55 is disconnected at the light receiving end of the optical fiber bundle 40a of the internal light guide 37 corresponding to the light trigger thyristor 212, for example, the time Tz. It is assumed that the optical gate signal Lm has not been sent from the point of time. In this case, the optical trigger thyristor 212 transmits only the optical gate signal Ln to the light receiving end of the optical fiber bundle 40b through the optical fiber bundle 56b, and is fired only by the optical gate signal Ln.

  The operation waveforms when normally fired by the above-described optical gate signals Lm and Ln and when fired only by the optical gate signal Ln due to failure are shown in FIG. The state of the optical gate signal is as shown in FIGS. That is, the anode-cathode voltage V of each of the light trigger thyristors 211,..., 21n that is normally fired by the light gate signals Lm, Ln, excluding the light trigger thyristor 212, is shown in FIG. The main circuit current I is as shown in FIG. In addition, normal optical gate signals Lm and Ln given to the light receiving portions 42 of the gate portions 35 of the optical trigger thyristors 211,..., 21n in the meantime are shown in FIGS. 12 (e), 13 (d) and 13 (e), respectively. The state of the optical gate signals Lm and Ln given to the light receiving portion 42 is as shown in FIG.

  On the other hand, in the external light guide 55 corresponding to the light trigger thyristor 212, when the disconnection of the optical fiber bundle 56a occurs at the time Tz, the optical gate signal Lm becomes as shown in FIG. Thereafter, the light receiving part 42 is not given. On the other hand, the normal optical gate signal Ln shown in FIG. 12E continues to be given to the light receiving portion 42 of the optical trigger thyristor 212 through the optical fiber bundle 56b where no abnormality has occurred.

  The light trigger signal thyristor 212 is normally turned on after the time Tz because the light amount of the optical gate signal Ln is a value sufficient to turn on the light trigger thyristor 212. At this time, the optical gate signals Lm and Ln given to the light receiving portion 42 of the gate portion 35 of the optical trigger thyristor 212 are as shown in FIGS. 12 (f), 14 (d) and 14 (e), respectively. The state of the optical gate signals Lm and Ln given to the part 42 is as shown in FIG. Further, the anode-cathode voltage V2 is as shown in FIG. 12C, and the main circuit thereof is the same as the other optical trigger thyristors 211,..., 21n connected in series, FIG. The main circuit current I shown in FIG.

  As a result, as in the first embodiment, the optical trigger thyristor 212 does not turn on every time the anode-cathode voltage reaches the forward withstand voltage (VBO), and turns on at a high voltage every cycle. It will not be forced. Further, since a high voltage is not applied to the snubber circuit 26 connected in parallel to the optical trigger thyristor 212, the snubber capacitor 24 does not endure a particularly large discharge current even if it does not have a particularly high dielectric strength. Also good. Further, the snubber resistor 25 does not have to have a particularly large heat treatment capability.

  Furthermore, by shifting the optical gate signals Lm and Ln so that they do not overlap in time within a range that does not affect the operation of the entire system, a phenomenon such as loss of the optical gate signal due to light interference can be avoided.

  In the above embodiment, the two optical gate signals Lm and Ln are shifted so as not to overlap in time in accordance with the number of two optical paths provided in the optical trigger thyristors 211, 212,. However, a plurality of optical paths may be provided and the optical gate signal may be shifted so as not to overlap in time according to the number of optical paths.

  Further, in the above-described embodiment, the light emitting end portions 41a of the optical fiber bundles 40a and 40b of the internal light guide 37 as shown in FIG. 9 with respect to the light receiving portions 42 of the light trigger thyristors 211, 212,. A part of the optical gate signals Lm and Ln from 41b leaks out of the light receiving portion 42, but it is formed in the same manner as in the second, third and fourth embodiments described above, and the internal light guide The optical gate signals Lm and Ln from the light emitting end of the optical fiber bundle may all be given to the light receiving portions 42 of the optical trigger thyristors 211, 212,.

It is a block diagram which shows the principal part of the optical ignition semiconductor device of the 1st Embodiment of this invention. It is sectional drawing of the optical trigger thyristor which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the principal part of the optical trigger thyristor which concerns on the 1st Embodiment of this invention. It is a figure which shows the operation | movement waveform of the optical trigger thyristor which concerns on the 1st Embodiment of this invention. It is sectional drawing which shows the structure of the principal part of the optical trigger thyristor which concerns on the 2nd Embodiment of this invention. It is sectional drawing which shows the structure of the principal part of the optical trigger thyristor which concerns on the 3rd Embodiment of this invention. It is sectional drawing which shows the structure of the principal part of the optical trigger thyristor which concerns on the 4th Embodiment of this invention. It is a block diagram which shows the principal part of the optical ignition semiconductor device of the 5th Embodiment of this invention. It is sectional drawing which shows the structure of the principal part of the optical trigger thyristor which concerns on the 5th Embodiment of this invention. It is a block diagram which shows the gate signal generation part of the 5th Embodiment of this invention. It is a figure which shows the signal waveform in the gate signal generation part of the 5th Embodiment of this invention. It is a figure which shows the operation | movement waveform of the optical trigger thyristor which concerns on the 5th Embodiment of this invention. It is a figure which shows the optical gate signal at the time of normal in the gate part of the optical trigger thyristor which concerns on the 5th Embodiment of this invention. It is a figure which shows the optical gate signal at the time of the failure occurrence in the gate part of the optical trigger thyristor concerning the 5th Embodiment of this invention, and after that. It is a lineblock diagram showing a direct-current power transmission system. It is a block diagram which shows the principal part of the optical ignition semiconductor device of a prior art. It is sectional drawing which shows schematic structure of the principal part of the optical trigger thyristor of a prior art. It is a figure which shows the operation | movement waveform of the optical ignition semiconductor device of a prior art. It is a figure for demonstrating the main circuit current in the optical ignition semiconductor device of a prior art.

Explanation of symbols

211, 212,..., 21n ... optical trigger thyristors 22, 70 ... gate signal generator 26 ... snubber circuit 28 ... silicon wafer 37 ... internal light guide 40a, 40b ... optical fiber bundle 42 ... light receiving part 51, 71 ... gate signal Generation blocks 521, 522,..., 52n, 531, 532,..., 53n, optical signal sources 721, 722,..., 72n, 731, 732, ..., 73n, optical signal sources A, first signal Source group B: Second signal source group La, Lb, Lm, Ln: Optical gate signal Pa, Pb, Pm, Pn: Optical signal source system

Claims (9)

A plurality of light-igniting semiconductor elements connected in parallel with a snubber circuit are connected in series, and a light gate signal from a gate signal generating unit is applied to a light receiving portion on the wafer of the light-igniting semiconductor element to thereby form the light-igniting semiconductor element. A light-ignition semiconductor device configured to ignite,
The light ignition semiconductor element includes a plurality of light guides for providing the light gate signal to the light receiving portion, and the gate signal generation unit corresponds to the light guides for the plurality of light ignition semiconductor elements. An optical ignition semiconductor device comprising a plurality of optical signal source systems.   2. The light-igniting semiconductor device according to claim 1, wherein a range of light emitted from an end portion of the light guides of a plurality of systems is within a range of the light receiving part.   3. The light-igniting semiconductor device according to claim 2, wherein the plurality of light guides are formed by adjusting the shape of each end so that the range of radiated light is within the range of the light receiving part.   4. The light-igniting semiconductor device according to claim 3, wherein the light guide has a tapered shape having a small cross-sectional shape toward the end portion.   The light-igniting semiconductor device according to claim 2, wherein the light guides of a plurality of systems are provided with an optical system that collects radiated light at the light receiving portion at the end.   6. The light-igniting semiconductor device according to claim 5, wherein each of the plurality of light guides includes an optical system that collects radiated light at the light receiving portion at each of the end portions.   2. The light according to claim 1, wherein the gate signal generation unit outputs the optical gate signal simultaneously from a plurality of optical signal sources of the optical signal source system to the optical guides of a plurality of systems. Ignition semiconductor device.   The gate signal generator outputs each optical gate signal from a plurality of optical signal sources of the optical signal source system so that output timings do not overlap with each other for the light guides of a plurality of systems. Item 2. A light-ignition semiconductor device according to Item 1.   9. The optical ignition according to claim 8, wherein the optical gate signals output from the plurality of optical signal sources are output with the output timing of each optical gate signal having a difference in signal width. Semiconductor device.

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