JPS583422A - Optical trigger signal generator for thyristor valve - Google Patents

Abstract

PURPOSE:To set the power supply voltage of a trigger circuit at a low level and to increase the reliability, by having the emission of light of a number of light emitting elements connected in series to each other with a boosted signal and triggering a number of optical trigger syristors connected in series to each other with the output of light emission. CONSTITUTION:When a transistor 4 is turned on with the output of a control circuit 5, a current iL' is supplied to a pulse transformer 8 from a power supply 1 via a current limiting resistance 2. At the same time, a current iL'' flows to a group of light emitting elements 3 connected to the secondary side of the transformer 8. As the transformer 8 has a 1:n winding ratio, the group of elements 3 can be driven satisfactorily with the boosted voltage of a high level although the voltage of the power supply 1 is at a low level. The output of light emission of the element 3 is applied to an optical trigger thyristor 7 via an optical fiber 6 to trigger the thyristor 7.

Description

[Detailed description of the invention] The present invention relates to the ff of thyristor pulp for ultra-high voltage DC power transmission.
-)) A thyristor pulp optical trigger signal generator for generating a trigger signal.

An example of an optical trigger signal generator currently used for high-pressure thyristor pulp is shown in FIG. In the figure, 1 is a power supply,
2 is a current limiting resistor, 3 is a light emitting element that converts a current signal into an optical signal, and 4 is a light emitting element current 1. 6 is a control circuit that controls all of the switching elements; 6 is an optical fiber that transmits an optical signal from the light emitting element 3 to the thyristor valve; and 7 is a thyristor valve. It is Hiroyo Irista.

In FIG. 1, a current signal 1L from a power source 1 passes through a current limiting resistor 2 and drives a light emitting cord 3.
is controlled by the control circuit 5. 'When the current signal 4L flows, a light signal is sent from the light emitting element 1 to the light 7 aino f.
The light F trigger signal is transmitted as an optical F trigger signal to the optical trigger thyristor 1 corresponding to each light emitting element via the optical fiber 6, and the thyristor and the thyristor ignite. As shown in FIG. 1, the light emitting devices 3 are generally all arranged in series for the following reasons. That is, if one or more light emitting elements have an open failure, the current signal 4L will not flow, so the remaining light emitting elements will not emit light, and the optical trigger signal will not be given to all the optical triggers making up the thyristor pulp. First, the I4 loop maintains the blocked state. If a group of luminous confectionery is divided into, for example, 12 series configurations and these are connected in parallel, current will flow only to the healthy series configuration, and a phototrigger signal will be given only to half of the phototrigger thyristors among the 7 thyristor pulps. It will be done.

The remaining half of the light-triggered thyristors will bear the voltage applied to the thyristor pulp, and there is a possibility that the thyristor pulp will be destroyed.

Furthermore, in order to solve the above problem, it is possible to increase the number of divisions in the series configuration, but when the number of divisions increases, the number of series connections in one series configuration decreases and the light emitting element may cause a short-circuit failure. As a result, the voltage drop in the series configuration containing the light-emitting element becomes smaller, the current flowing to other series configurations decreases, and these healthy series configurations receive a sufficient optical trigger signal for the optical trigger thyristome. If the number of light-emitting elements connected in series is only one, the light-triggered thyristor may deteriorate and the entire thyristor pulp may be destroyed. Only the light-triggered thyristor is destroyed, and the entire thyristor pulp is hardly affected.

Recently, there has been a trend toward higher voltage and larger capacity thyristor pulp wires for DC power transmission, and those with voltage ratings of 9.200 to 300 KV or more are being put into practical use.

Considering the current thyristor rating (4 to 5 KV),
The number of thyristors in series can reach as many as 200 to 300. In this case, for the trigger system shown in Figure 1, 2
00 to 300 light emitting elements are required in series. In order to reliably fire the light-triggered thyristor, it is necessary to generate a strong light-trigger signal, which may require several micrometers of current to flow through the light-emitting element. In this case, the forward voltage drop of the light emitting element reaches 3 to 5 V per element. Therefore, if 200 light emitting elements are connected in series as described above, the forward voltage drop in the entire light emitting element string will be 600 V to 1'0 OOV. Therefore, the voltage of the power supply 1 in FIG. 1 is at least about 1500V to 2000V, taking into account the constant current characteristics due to the resistor 1.

When the source voltage becomes high in this way, the following problems occur. (2) The power source and main circuit components of the optical F trigger signal generator, including the switching elements, must have high withstand voltages.Therefore, i) The device becomes larger and its reliability decreases.

■When the voltage becomes high, the noise caused by the optical trigger signal generator itself, such as opening and closing of switching elements, becomes large, and the influence on the control circuit becomes large. ■Since the control circuit is generally configured with a low voltage level of 15V or less, voltage coordination with the main circuit consisting of the light emitting power supply, light emitting element series configuration, switch, and switching element (for example, control signals can be directly transmitted to the switching element) For example, when using a transistor as a switching element, the rating of the one currently in practical use is several hundred V.
- It is several hundred micrometers, which is sufficient in terms of current, but insufficient in terms of voltage, and it becomes necessary to connect several units in series. A series connection has the disadvantage that the control and protection of each transistor becomes very complex.

An object of the present invention is to eliminate the above-mentioned disadvantages and provide a highly reliable thyristor pulp optical trigger signal generator.

The present invention will be explained below with reference to the embodiment shown in FIG. FIG. 2 is an example of an optical trigger signal generator that provides an optical trigger signal to an optically triggered thyristor pulp. In Fig. 2, a current flows from the power supply 1 through the current limiting resistor 2 to the primary side of the armature transformer 8 (with a transformation ratio of 1:n) and to the secondary side of the transformer 80. A current (L" flows through the light emitting element 3 connected to form a long path, and the optical trigger signal from the light emitting element 3 is transmitted through the optical fiber 6, and the optical trigger reaches the thyristor 1. The current L' and f" are , the switch controlled by the control circuit 5.

The current flows through or is expanded and blocked by the switching element 4.

A feature of the present invention is that, as mentioned above, a high voltage is required to drive the light emitting element series configuration, but when supplying this high voltage, the voltage on the secondary side becomes higher than the voltage on the primary side. The point is to use a step-up transformer 8 with a metamorphic ratio selected as follows.

Conventionally, pulse transformers have the main purpose of insulating between the primary and secondary, and the transformation ratio is generally lower on the secondary side, or at most the same voltage as the primary side. 0 In the present invention, a pulse transformer 8 is used for boosting the voltage, and 1
Used to lower the voltage of the next drive circuit. For example, if the transformation ratio of the pulse transformer 8 is selected as 1:10, 2
Even when a high voltage of 1000V is required for the series configuration of the light emitting elements 3 on the next side, the voltage level on the primary side may be 100V. That is, using a much smaller voltage than the conventional example (Fig. 1),
It is possible to drive a series configuration of a very large number of light emitting elements connected in series.

Therefore, the primary side drive circuit can be kept at a low voltage without losing the advantage of connecting conventional light emitting elements in series.

In the present invention, an optically triggered thyristor is used as the thyristor constituting the thyristor pulp, but as shown in FIG. 1
A similar implementation can be achieved by adding a conversion circuit for converting the voltage to a DC voltage using the terminal voltage sensor 11 of '. Also, Figure 4(a),
As in the embodiment shown in (b), one light emitting element and two light trigger thyristors (1) in the thyristor pulp, or
It is clear that it can be employed to drive an electrically triggered thyristor (b). In addition, the explanation was made assuming that there is only one optical trigger signal generator for one thyristor valve.
As shown in Figure 5, multiple optical trigger signal generators are assembled,
The optical trigger signals from each trigger signal generator are combined into one
The present invention can be similarly applied even when optical trigger signal generators are configured to be multiplexed so as to be applied to multiple thyristor valves.

As described above, when the present invention is applied to a thyristor valve moonlight trigger signal generator, the withstand voltage of the switching elements and other main circuit components of the optical trigger signal generator becomes low, resulting in a smaller device. Reliability is also improved. Furthermore, in general, voltage coordination between a low-voltage control circuit (TTL level, etc.) and an optical trigger generator circuit can be easily achieved, making it possible to directly connect the control circuit and switching elements. It can have a great effect on overall miniaturization and high reliability.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a schematic configuration of a conventional optical trigger signal generator, FIG. 2 is a configuration diagram showing an embodiment of the present invention, and FIG. 3 is a diagram showing an embodiment in which the present invention is applied to an electric trigger thyristor. Fig. 4 is a block diagram showing another embodiment of the present invention in which two thyristors are driven by one optical trigger signal, and Fig. 5 is a block diagram showing another embodiment of the present invention.
The figure is a configuration diagram showing another embodiment on the page of the present invention showing various configurations of the optical trigger signal generator. 1...Power supply, 2-Current limiting abrasive resistor, 3"...Light emitting element 14.
- switching element, 5- control circuit, 6... optical fiber, rP optical trigger thyristor, 1' - electric trigger thyristor, 8... l:m step-up pulse transformer, 9...
- Impedance for high voltage section power supply, 10... High voltage section power supply rectifier circuit, J J-... High voltage section power supply capacitor, j2.
... Light receiving element, 13 ... Insulating i4 transformer, 1
4... High-voltage part light emitting element, 15... High-voltage part Optical fiber Applicant's agent Patent attorney Suzue Takehiko I Figure 12 Figure 3

Claims (1)

[Claims] Thyristor pulse fl consisting of a large number of optically triggered thyristors or electrically triggered thyristors connected in series or parallel.
lc? ``-)) In an optical VTR signal generator that provides a trigger signal, a group of light emitting elements for converting an electric signal into an optical signal is driven by a high voltage winding of a step-up/l transformer. Thyristor pulp optical trigger signal generator.