JPS6013278Y2 - Dual type thyristor rectifier - Google Patents

Description

[Detailed Description of the Invention] [Technical Field of the Invention] This invention relates to a dual thyristor rectifier used as an excitation device for a synchronous generator or the like.

[Prior Art] FIG. 1 shows a conventional dual-type thyristor rectifier used in an excitation device for a synchronous generator.

In Figure 1, 1 is a synchronous generator which is a load, 1 is a generator, 2 is a field winding, 3 is a field breaker, 4 is a capacitor, 5
is a resistor and is part of the CR absorber.

The part 6 surrounded by the dotted line is the main part of the conventional dual-type Cyrisk rectifier, which is composed of a first Cyrisk rectifier 7 that allows current to flow in the normal direction and a second Cyrisk rectifier 8 that allows current to flow in the opposite direction, and has an output. At the terminal 6a, the negative output terminal of the first thyristor rectifier 7 and the positive output terminal of the second thyristor rectifier 8 are connected, and at the output terminal 6b, the positive output terminal of the first thyristor rectifier 7 and the second thyristor rectifier 7 are connected. A negative output terminal of the thyristor rectifier 8 is connected via a pointed handle 9 .

10 is a transformer for obtaining electric power from the output terminal of the generator 1 and supplying it to the first and second thyristor rectifiers 7 and 8.

The operation of the device having such a configuration will be explained.

The alternating current power obtained by the transformer 10 is converted into direct current by the first and second silice rectifiers 7 and 8.

At this time, the firing phase of each thyristor is controlled by a gate trigger pulse supplied from a gate trigger circuit (not shown), so that the first thyristor. The respective output voltages of the second thyristor rectifiers 7, 8 are controlled, and a current in the normal direction or in the reverse direction is supplied to the field winding 2 depending on the mutual relationship between these output voltages.

In such an operation, when both of the eleventh and second thyristor rectifiers 7 and 8 are in the operating state, current also flows between these two thyristor rectifiers 7 and 8.

In order to suppress this circulating current to a predetermined value, reactor 9
is inserted on the output side of the second thyrisk rectifier 8.

On the other hand, in thyristor rectifiers and the like, a gate trigger method called a high gate drive method is often adopted.

For example, if the first and second thyristor rectifiers 7 and 8 are configured to obtain a predetermined current capacity by connecting a large number of thyristors in parallel, the thyristors connected in parallel can be In order to operate as if it were a single element, a high gate drive method is required.

The waveform of the gate pulse in this high gate drive system is as shown by the symbol A in FIG. 2, and is a pulse that has a short rise time and causes a large gate current to flow.

When such a gate trigger pulse is used in a conventional dual-type thyristor rectifier, the current flowing to the newly fired thyristor in the second thyristor rectifier 8 is reduced by the glue handle 9 for suppressing the circulating current. The rise at the time of commutation becomes slow, and even when the gate pulse signal disappears, a current higher than the latching current still does not flow through the thyristor, and there is a possibility that the thyristor will not conduct.

In order to improve this drawback, it is possible to widen the width of the gate trigger pulse, but if the pulse width is widened in the high gate drive method, a pulse with the waveform shown by the symbol in Figure 2 is required. In order to obtain such a gate trigger pulse, the gate trigger circuit must be complicated and expensive, which has been a drawback of the conventional dual thyristor rectifier.

[Summary of the idea]

This invention eliminates the above-mentioned drawbacks of conventional devices and suppresses the above-mentioned circulating current and does not affect the accelerator even if the normal high gate drive method using a narrow trigger pulse as shown in Figure 2A is used. It is an object of the present invention to provide a dual type thyristor rectifying device in which the thyristor is reliably fired without being affected.

This invention applies to the output terminal of the thyristor rectifier, which has a circulating current suppressing reactor connected between the output terminal of the thyristor rectifier and the load, out of the two thyristor rectifiers that make up the dual thyristor rectifier. The above object is achieved by connecting a false load consisting of a capacitor and a resistor.

[Example of idea]

The drawings will be explained in more detail below.

FIG. 3 is a block diagram showing an embodiment of this invention, which is applied to a synchronous generator similar to that in FIG. 1.

In FIG. 3, the same symbols as those in FIG. A series circuit consisting of the resistor 12 and the resistor 12 acts as the above-mentioned false load.

When such a false load is connected, the AC impedance seen from the output terminal pair of the second thyristor rectifier 8 to the load side decreases, and the rise of the thyristor current becomes faster, resulting in a narrow width as shown in Figure 2A. Reliable ignition can now be performed even with a gate trigger pulse.

In the above embodiment, the capacitor 11 is used as a false load.
The false load is not limited to this, but it exhibits a sufficiently low impedance while the current of the Sirisk rectifier 8 fluctuates, and a high impedance for direct current. Any circuit that exhibits impedance may be used.

Further, in the above embodiment, the excitation device that supplies current to the field winding of a synchronous generator has been described, but it goes without saying that the dual thyristor rectifier of this invention can be applied to other devices.

[Effect of idea]

As explained above, according to this invention, it is possible to use the normal high gate drive type gate trigger circuit that has been conventionally used as the gate trigger pulse, so a highly reliable dual thyristor rectifier can be manufactured at low cost. There is an effect that can be done.

[Brief explanation of drawings]

Figure 1 is a block wiring diagram showing a conventional dual-type thyristor rectifier used as an excitation device for a synchronous generator;
The figure is a waveform diagram of a gate trigger pulse used in the high gate drive system, and FIG. 3 is a block diagram showing an embodiment of the dual thyristor rectifier waveform of this invention used as an excitation device for a synchronous generator. In the figure, 1 is a synchronous generator that is a load, 2 is a field winding, 3 is a field breaker, 4 and 11 are capacitors, 5 and 12 are resistors, and 6 includes the main parts of a dual-type thyristor rectifier. In the blocks, 7 is a first thyristor rectifier that allows current to flow in the normal direction, 8 is a second thyristor rectifier that allows current to flow in the opposite direction, 9 is a reactor, and 10 is a transformer. Note that the same reference numerals in each figure indicate the same or corresponding parts.

Claims (1)

[Scope of utility model registration request] A first thyristor rectifier that supplies a current in the forward direction to the load, a second thyristor rectifier that supplies current in the reverse direction to the load, and a circulating current in a closed circuit formed by the first and second thyristor rectifiers. A reactor is inserted into the closed circuit to suppress the alternating current, and the output terminal of the Sirisk rectifier to which the reactor is connected in series with the load is connected to short-circuit the alternating current with a sufficiently low impedance. A dual type Sirisk rectifier characterized by having a false load consisting of a capacitor and a resistor.