JPH098277A - Deterioration detection device for light emitting element for optical thyristor - Google Patents

Abstract

(57) [Abstract] [Purpose] Deterioration of a light emitting element for an optical thyristor that can detect a deterioration failure of the light emitting element early in its early stage and can provide information support for maintenance so that optimal measures can be taken. Get the detector. A plurality of light emitting elements L1 to Ln having substantially the same characteristics are connected to the same power source 5, and by turning on and off the power source 5, optical signals respectively obtained from the light emitting elements L1 to Ln are sent to the same circuit. Is connected to the light emitting element L1.
In a light emitting element for an optical thyristor which is supplied to the gates of a plurality of optical thyristors T1 to Tn corresponding to Ln, it is connected to a circuit to which the light emitting elements L1 to Ln are connected, and is almost connected to each of the light emitting elements L1 to Ln. A monitor light emitting element Lm having the same characteristics and a light emitting element deterioration detection circuit 2 for outputting an electric signal proportional to the peak value of the optical pulse signal output from Lm and detecting deterioration of the light emitting element based on this output are provided. What

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a light emitting device for an optical thyristor which generates a gate signal in a semiconductor converter using an optical thyristor having an optical ignition function, which is used for direct current transmission or compensation of reactive power. Of the deterioration detecting device.

[0002]

2. Description of the Related Art A large number of series or series-parallel connected thyristors are used in high voltage thyristor converters used for DC power transmission, frequency conversion, reactive power compensation and the like.
The signal for firing this thyristor is output from the gate signal generation circuit, but in order to insulate the thyristor of the high voltage part from the gate signal generation circuit installed at the ground potential, the point generated by the optical pulse signal is used. The arc method is adopted.

FIG. 8 shows a gate signal generating circuit for outputting an optical pulse signal to a conventional optical thyristor converter. The optical thyristor bulb 9 is an optical thyristor T connected in series.
1, T2, T3, ... Tn, which are ignited by guiding the optical pulse signal output from the optical pulse signal generation circuit 10 to the light guide 1 to the gate of each optical thyristor T.

The optical pulse signal generating circuit 10 includes a plurality of light emitting element groups 11 connected in series, turning on the light emitting element group 11,
It is composed of a switching element 4 to be turned off, a gate control circuit 3 that determines the timing of an optical pulse signal and drives the switching element 4, and a DC power supply 5 that supplies a current to the light emitting element group 11.

In the light emitting element group 11, n light emitting elements L1, L2, L3, ... Ln, which are, for example, light emitting diodes, are connected in series, and the light pulse signal output from each of the light emitting elements L1 to Ln is the light guide 1. Are transmitted to the corresponding optical thyristors T1 to Tn, respectively, and the optical thyristors T1 to Tn are transmitted.
Is fired.

Generally, in the high voltage thyristor valve 9, the number of series connected thyristors in the valve has a certain redundant thyristor. Therefore, if the number of redundant thyristors is less than the number of redundant thyristors, it is possible to continue the operation without stopping the operation of the thyristor converter.

However, even if the number of redundant thyristors is increased, the reliability of the system cannot be expected if the reliability of the optical pulse signal generation circuit 10 is low. Now, in FIG. 8, if any one of the light emitting element groups 11 fails (opening failure), all the light emitting elements L1 to Ln cannot output the light pulse signal, and the light thyristor bulb 9 cannot be fired.
Thus, even if the thyristor is provided with the redundant thyristor, the light emitting elements L1 to Ln in the optical pulse signal generating circuit 10 are provided.
Only one failure will result in stopping the system.

For this reason, conventionally, the light ignition system (light emitting element or optical pulse signal generating circuit) is multiplexed, and further, all light emitting elements are inspected at the time of periodic inspection to confirm the soundness thereof. However, when the voltage of the thyristor converter is increased and the number of serially connected thyristor converters is increased, the number of light emitting elements that generate optical pulse signals is also increased, resulting in an increase in inspection and maintenance time, and improvement is desired.

[0009]

As described above, in the conventional optical pulse signal generation circuit 10, in order to improve its reliability, the deterioration diagnosis of the light emitting element is performed by multiplexing and checking. The reason for this is that the light emitting elements L1 to Ln are deteriorated, and the deterioration phenomenon cannot be grasped due to the difference in the device operating condition. If the deterioration status of the light emitting elements L1 to Ln can be grasped, information support for maintenance becomes possible, the regular inspection cycle can be extended, the maintenance time can be shortened, and the merit in operating the device is large.

An object of the present invention is to detect a deterioration failure of a light emitting element at an early stage of the light emitting element and to provide information support for maintenance so that optimum measures can be taken. It is to provide a detection device.

[0011]

In order to achieve the above object, the invention according to claim 1 is such that a plurality of light emitting elements having substantially the same characteristics are connected to the same power source and the power source is turned on and off. In a light emitting element for an optical thyristor, which is connected to the same circuit and is supplied to the gates of a plurality of optical thyristors corresponding to the light emitting elements, the light emitting elements are connected. Connected to the circuit, and outputs as an electric signal proportional to the peak value of the optical pulse signal output from the monitor light-emitting element and the monitor light-emitting element having substantially the same characteristics as each of the light-emitting elements, to this output A deterioration detecting device for a light emitting element for an optical thyristor, comprising a light emitting element deterioration detecting circuit for detecting deterioration of the light emitting element based on the above.

To achieve the above object, in the invention according to claim 2, the light emitting element deterioration detection circuit outputs as an electric signal proportional to a peak value of an optical pulse signal output from the monitor light emitting element. 2. A photoelectric conversion peak detection circuit and a comparison / determination circuit for comparing the output of the photoelectric conversion peak detection circuit with an initial value and determining the condition that the deviation is equal to or greater than a predetermined value. Is a deterioration detecting device for a light emitting element for an optical thyristor.

To achieve the above object, in the invention according to claim 3, the light emitting element deterioration detection circuit outputs as an electric signal proportional to a peak value of an optical pulse signal output from the monitor light emitting element. The photoelectric conversion peak detection circuit compares the output of this photoelectric conversion peak detection circuit with the initial value, and the comparison judgment circuit that judges the condition that the deviation becomes a predetermined value or more, and the output of this comparison judgment circuit is always or periodically. 2. A recording device for physically recording data is provided.
It is a deterioration detection device for a light emitting element for an optical thyristor described.

In order to achieve the above object, in the invention according to claim 4, the light emitting element deterioration detection circuit outputs an electric signal proportional to a peak value of an optical pulse signal output from the monitor light emitting element. The photoelectric conversion peak detection circuit compares the output of this photoelectric conversion peak detection circuit with the initial value, and the comparison judgment circuit that judges the condition where the deviation is equal to or more than a predetermined value, and the output of this comparison judgment circuit is a predetermined level. The deterioration detecting device for a light-emitting element for an optical thyristor according to claim 1, further comprising an alarm for notifying when it exceeds.

[0015]

According to the invention corresponding to claim 1, the deterioration status of the monitor light emitting element can be equivalently grasped by checking the deterioration status of the monitor light emitting element by the output of the light emitting element deterioration detection circuit.

According to the invention of claim 2, the deterioration of the light emitting element can be detected at the initial stage. According to the invention corresponding to claim 3, it is possible to predict the degree of deterioration and the remaining life of the light emitting element, and it is possible to provide information support for maintenance.

According to the invention corresponding to claim 4, since the notification according to the degree of deterioration of the light emitting element, for example, the replacement time of the light emitting element is notified, the information support for the maintenance can be more effectively performed.

[0018]

Embodiments of the present invention will be described below with reference to the drawings. <First Embodiment> FIG. 1 is different from FIG. 8 in that a monitor light emitting element Lm, a monitor light guide 1A, and a light emitting element deterioration detection circuit 2 are newly provided, and other configurations are the same. is there.

That is, in the optical pulse signal generation circuit 10 of the optical thyristor valve 9, the optical thyristors T1 and T2 are
, Ln for providing light pulse signals to the gates of Tn (hereinafter referred to as normal light emitting elements) L1, L2, ... Ln, and a light emitting element Lm for monitoring is provided, and light emitted from this is used as a light guide for monitoring. 1A to the light emitting element deterioration detection circuit 2, where the monitor light emitting element Lm
Is output as an electric signal (voltage signal) proportional to the peak value of the optical pulse signal output from the optical pulse signal, and the deterioration of the monitor light emitting element Lm can be detected based on this output. In this case, the normal light emitting elements L1 to Ln,
As the monitor light emitting element Lm, those having the same characteristics, for example, the same manufacturing lot (having the same life) are used at the same time (use the same start time). At this time, since the elements L1 to Ln and Lm are connected in series, the same current flows and the same operation stress is applied.

With this configuration, the switching element 4 is turned on / off by the pulse signal from the gate control circuit 3, so that the same pulse shape is supplied from the DC power source 5 to the normal light emitting elements L1 to Ln and the monitor light emitting element Lm. Current flows, and the light emitting elements L1 to Ln and Lm are operated under the same conditions. When this operating state continues for a predetermined time or when the accumulated operating time exceeds a certain level, the light emitting element L
Both 1 to Ln and Lm deteriorate. Then, since the peak value of the optical pulse signal guided from the monitor light emitting element Lm to the light emitting element deterioration detecting circuit 2 via the monitor light guide 1A decreases, the output signal of the light emitting element deterioration detecting circuit 2 accordingly. Is reduced, the regular light emitting element L1
It is possible to equivalently grasp the deterioration state of Ln to .about.Ln, whereby it is possible to detect in advance a deterioration failure other than the accidental failure of the normal light emitting elements L1 to Ln, and it is possible to provide information support for maintenance.

<Second Embodiment> In the first embodiment described above, the normal light emitting elements L1 to Ln and the monitor light emitting element Lm are connected in series, but in the second embodiment shown in FIG. The elements L1 to Ln and the monitor light emitting element Lm are connected in parallel, and the other points are the same as in FIG.

Also in this case, since the normal light emitting elements L1 to Ln and the monitor light emitting element Lm are connected in parallel as in the first embodiment, the same current (the current flowing through the gate control circuit 3 is I, and the element L1 is the same). Assuming that the total number of Ln and Lm is m, I / m) flows and the same driving stress is applied.

As a result, the deterioration state of the monitor light emitting element Lm is checked by the light emitting element deterioration detecting circuit 2,
The deterioration of the normal light emitting elements L1 to Ln can be judged equivalently.

<Third Embodiment> As shown in FIG. 3, the difference from the first embodiment is that the structure of the light emitting element deterioration detection circuit 2 is
It is composed of a comparator 6, an initial value setting device 13, a difference detector 14, and a photoelectric conversion peak detection circuit 15. That is, the photoelectric conversion peak detection circuit 15 is a well-known circuit, for example, a detector that detects an optical pulse signal of the monitor light guide 1A and converts it into an electric signal, and a peak value of the electric signal from this detector. And a conversion circuit for converting an electric signal (voltage signal) proportional to the output of the peak hold circuit, and is obtained through the monitor light guide 1A.
The peak value of the output pulse is proportional to the light intensity, and the peak value is output as an electric signal (voltage signal).

The comparator 6 is an initial value K obtained from the electric signal output from the photoelectric conversion peak detection circuit 15 and the setting device 13.
Lm is compared, the output of the comparator 6 is input to the difference detector 14, and the difference detector 14 outputs a signal in which the output of the comparator 6 exceeds a predetermined value.

In the device thus constructed, the light of the monitor light emitting element Lm is detected constantly or periodically for a certain period of time, and this light pulse signal is inputted to the light emitting element deterioration detecting circuit 2.

Here, as a certain fixed period,
For example, once / a day, a large value may be set so as not to burden the data processing of the detection device within a range where the life of the light emitting element does not matter.

In the light emitting element deterioration detection circuit 2,
Initial value KLm of setter 13 and photoelectric conversion peak detection circuit 1
5, the output of the comparator 6 is almost "0" in the normal state as shown in FIG. 4, but when the light emitting element deteriorates, the intensity of the optical pulse signal decreases. As a result, the peak value decreases and the difference from the initial value KLm is output. When this difference output exceeds point A (difference point A with the initial value) in FIG. 4, a signal is output from the difference detector 14. It As a result, the "deterioration initial stage" of the normal light emitting elements L1 to Ln can be detected. As a result, early countermeasures can be taken for the light emitting elements L1 to Ln.

<Fourth Embodiment> As shown in FIG. 5, the difference from the first embodiment is that the structure of the light emitting element deterioration detection circuit 2 is
It comprises a comparator 6, an initial value setting device 13, a level detector 8 and a photoelectric conversion peak detection circuit 15. That is, the comparator 6 compares the output of the photoelectric conversion peak detection circuit 15 with the initial value KLm of the initial value setting device 13, inputs the output of the comparator 6 into the level detector 8, and determines the degree of deterioration of the light emitting elements L1 to Ln. It is configured so that it can be judged. For example, an alarm is output at a time of -10% with respect to the output 7 of the comparator 6 as shown in FIG. 15% time point) and D time point (-20% time point) so that different signals that can be respectively identified are output,
It is provided with a recorder (not shown) for recording the output of the level detector 8 constantly or periodically.

Here, the recording device used may be at least one of a recording device for recording on recording paper and a recording medium for recording. With such a configuration, as shown in FIG.
Since it becomes possible to detect the deterioration state of the light emitting elements L1 to Ln at time C, the time history of the deterioration of the light emitting elements L1 to Ln (Tc-TB = ΔT, −10% → −1 in the ΔT period)
It is also possible to understand (deterioration to 5%).

Further, the deterioration allowable value (for example, -20 in FIG. 6) is used.
%) It is also possible to predict the remaining life time.
As described above, according to the fourth embodiment, it is possible to provide information support for maintenance and to make a maintenance execution plan. Therefore, deterioration detection of a highly reliable light emitting element for an optical thyristor with an increased degree of freedom in operation can be detected. The device is obtained.

<Fifth Embodiment> As shown in FIG. 7, an alarm 12 for outputting a status signal according to the level of the output 7 of the comparator 6 is provided on the output side of the comparator 6. In this case, an alarm signal is output when the state of points B, C, and D in FIG. 6 is reached. in this case,
The output of the alarm signal may be an alarm sound, characters or voice.

As described above, since the notification according to the degree of deterioration of the light emitting element, for example, the replacement time of the light emitting element is notified, information support for maintenance can be more effectively performed. <Modification> The initial value of the initial value setting device 13 used in the above-described embodiment is set based on the design data of the light emitting element,
Alternatively, the output of the photoelectric conversion peak detection circuit 15 obtained at the time of site adjustment after installation may be used as the initial value.

[0034]

According to the present invention described above, an optical thyristor capable of detecting a deterioration failure of a light emitting element at an early stage and providing information support for maintenance so that an optimum countermeasure can be taken. It is possible to provide a deterioration detecting device for a light emitting element for use in a vehicle.

[Brief description of drawings]

FIG. 1 is a schematic configuration diagram showing a first embodiment of a deterioration detecting device for a light emitting element for an optical thyristor according to the present invention.

FIG. 2 is a schematic configuration diagram showing a second embodiment of a deterioration detecting device for a light emitting element for an optical thyristor according to the present invention.

FIG. 3 is a schematic configuration diagram showing a third embodiment of a deterioration detecting device for a light emitting element for an optical thyristor according to the present invention.

FIG. 4 is a characteristic diagram for explaining the operation of FIG.

FIG. 5 is a schematic configuration diagram showing a fourth embodiment of a deterioration detecting device for a light emitting element for an optical thyristor according to the present invention.

6 is a characteristic diagram for explaining the operation of FIG.

FIG. 7 is a schematic configuration diagram showing a fifth embodiment of a deterioration detecting device for a light emitting element for an optical thyristor according to the present invention.

FIG. 8 is a schematic configuration diagram of an optical gate system for explaining a conventional technique.

[Explanation of symbols]

 L1 to Ln ... Regular light emitting element, Lm ... Monitor light emitting element, T1 to Tn ... Optical thyristor, 1 ... Light guide, 1A ... Monitor light guide, 2 ... Light emitting element deterioration detection circuit, 3 ... Gate control circuit, 4 ... Switching element, 5 ... DC power supply, 6 ... Comparator, 7 ... Comparator output, 8 ... Level detector, 9 ... Optical thyristor valve, 10 ... Optical pulse signal generation circuit 13 ... Setting device, 14 ... Difference detector, 15 ... Photoelectric conversion peak detection circuit.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Masanori Yoshino 1-3-1 Uchisaiwaicho, Chiyoda-ku, Tokyo Tokyo Electric Power Company (72) Kazuma Mukai 1-1-1 Shibaura, Minato-ku, Tokyo (72) Inventor, Kazuhiko Murabayashi, No. 1, Toshiba-cho, Fuchu-shi, Tokyo Inside Toshiba-Fuchu factory

Claims (4)

[Claims] 1. A plurality of light-emitting elements having substantially the same characteristics are connected to the same power source, and optical signals obtained from the respective light-emitting elements are connected to the same circuit by turning on and off the power source. A light-emitting element for an optical thyristor adapted to be supplied to each of the gates of a plurality of optical thyristors corresponding to the light-emitting element, which is connected to a circuit to which the light-emitting element is connected, and which has almost the same characteristics as each of the light-emitting elements. An optical thyristor equipped with an element and a light emitting element deterioration detection circuit that outputs an electric signal proportional to the peak value of the optical pulse signal output from the monitoring light emitting element and detects deterioration of the light emitting element based on this output. Deterioration detection device for light emitting devices. 2. A photoelectric conversion peak detection circuit for outputting the light emitting element deterioration detection circuit as an electric signal proportional to a peak value of an optical pulse signal output from the monitor light emitting element, and the photoelectric conversion peak detection circuit. 2. The deterioration detecting device for a light emitting element for an optical thyristor according to claim 1, further comprising a comparison / determination circuit that compares the output with an initial value and determines a condition in which the deviation is equal to or larger than a predetermined value. 3. A photoelectric conversion peak detection circuit for outputting the light emitting element deterioration detection circuit as an electric signal proportional to a peak value of an optical pulse signal output from the monitor light emitting element, and the photoelectric conversion peak detection circuit. The present invention is characterized by comprising a comparison / judgment circuit for comparing the output with an initial value and judging the condition in which the deviation exceeds a predetermined value, and a recorder for constantly or periodically recording the output of this comparison / judgment circuit. A deterioration detecting device for a light emitting element for an optical thyristor according to claim 1. 4. A photoelectric conversion peak detection circuit for outputting the light emitting element deterioration detection circuit as an electric signal proportional to a peak value of an optical pulse signal output from the monitor light emitting element, and the photoelectric conversion peak detection circuit. A comparison judgment circuit that compares the output with an initial value and judges the condition that the deviation is equal to or larger than a predetermined value, and an alarm that notifies when the output of the comparison judgment circuit exceeds a predetermined level. The deterioration detecting device for a light emitting element for an optical thyristor according to claim 1.