SU725159A1 - Device for forced switching of thyristors - Google Patents

Description

one

The invention relates to converter technology and can be used in inverters, pulse-width converters of direct current, i.e., where forced switching of power thyristors is required.

Known devices for pushing thyristor switching.

One of the known switching devices contains a switching capacitor, thyristors and chokes, one of the terminals of the capacitor connected to the midpoint of the power source, and the other to the common point of two series-connected centers formed by each switching thyristor and choke.

The switching capacity of such a device is uncontrollable, and the device must be calculated by switching the maximum load current 1.

In another of the known switching devices, additional thyristors and chokes are used to change the switching capacity when the supply voltage is changed, with which the switching capacitor is measured.

And the closest to the technical essence of the invention is a thyristor forced switching device comprising a serial chain connected between the first and second inlet pins, forming a dosing thyristor switched on in the direct direction, a choke and a capacitor and a reverse thyristor, the anode of which is connected to the second input terminal wherein the choke is connected to the output terminals. The choke 3 is also connected in series with the reverse tyrnstor.

However, in such a device, the use of separate elements of charge circuits that are not used for switching power thyristors. This worsens the weight and dimensions of the device.

The purpose of the invention is to improve the weight and size parameters.

The goal is achieved by the fact that the device is an impulse-switching device containing a connecting circuit connected between the first and second input pins, formed in the forward direction of the first reference thyristor, the first throttle and capacitor, and the first reverse thyristor, the anode of which is connected to the second input output the nerve choke is connected to the output pins, provided with an additional sequential chain formed by the second choke and the second charge connected in the MOM section. a thyristor connected between the common point of the first throttle and the capacitor and an additional third input terminal, and the second reverse thyristor, the cathode of which is connected to the second input terminal. In this case, the cathode of the first reverse thyristor is connected to the cathode of the first charge thyristor, the anode of the second reverse thyristor is connected to the anode of the second charge thyristor, and the second choke is also connected to the corresponding output terminals.

The chokes in the switching device can be double-wound, and the windings of both chokes can be placed on a common magnetic conductor.

The circuit diagram of the switching device is shown in the drawing.

The device contains a capacitor 1, connected by a single plate to the middle point of the power supply source 2, chokes - transformers 3, 4, reverse thyristors 5, 6, connected anti-parallel to the capacitor 1 and connected to the middle point of source 2, and charge thyristors 7, 8 The anode of the thyristor 7 is connected to the positive output of the source, the cathode to the cathode of thyristor 5, the cathode of the thyristor 8 to the negative output of the source, and the anode to the anode of the thyristor 6. The secondary windings of transformers 3 and 4 are connected to the switched thyristors of the power section through working conclusions. Depending on the configuration of the power section, the transformers can be replaced with chokes or made on the same core.

The forced switching device operates as follows.

The thyristors are controlled as a sign of the voltage across the capacitor. With a positive voltage, control pulses are applied either to the thyristor 7 or to the thyristor 5, with negative polarity to either the thyristor 8 or to the thyristor 6.

The switching of the power thyristors is carried out upon the opening of any of the thyristors of the circuit, since this always forms a non-resistor circuit and a capacitor, which includes one of the switching transformers. The switching capacity of the node, which is determined by the magnitude of the voltage on the secondary windings of transformers 3 and 4, when unlocking the thyristors 7 and 8 is greater than when rejecting the thyristors 5 and 6, since in this case the capacitor of the capacitor includes a power source, thanks to The switching voltage on the secondary windings of transformers is large. Therefore, thyristors 5 and 6 need only be unlocked if the voltage on the capacitor is sufficient.

for switching given load current. Otherwise, it is necessary to unlock the thyristors 7 or 8, providing a greater switching voltage to the transformers. When this happens, the dispensing of the switching capacitor also occurs.

Thus, the use, depending on the magnitude of the capacitor on the two different circuits, is recharged

allows you to adjust the switching capacity of the device. Since the voltage across the switching capacitor is close to the minimum required, the switching current amplitude

therefore, the losses in the elements of the device are reduced. This improves weight and size indicators.

Claims (3)

Invention Formula A thyristor switching commutation device, containing a successive cenochka, connected between the first and second input pins, formed by the first connected in the forward direction the first thyristor, the first choke and the capacitor, and the first reverse thyristor, the anode of which is connected to the second input terminal, the first choke being connected to the output terminals, characterized in that, in order to improve the weight and size indicators, it is equipped with an additional sequential chain formed by the second a choke and a forward-connected second charge thyristor, connected between the common point of the first throttle and the capacitor and the additional third input terminal, and the second reverse thyristor, atod is connected to the second input terminal, the cathode nerve reverse thyristor connected to the cathode of the first charging thyristor, the anode of the second reverse thyristor is connected to the anode of the second charging thyristor and a second inductor also connected with appropriate output pins. 2. A device of claim 1, characterized in that the chokes are wired with double-winding, and the secondary windings of the chokes are connected with the corresponding output conclusions. 3. The device according to paragraphs. 1 and 2, characterized in that the windings of both chokes are placed on a common magnetic core. Sources of information taken into account in the examination 1. Glasenko, T. A. Semiconductor converters in direct current electric wires. L., “Energie, 1973, p. 239, fig. 4-30, b. 2. Zabrodin Yu. S. Nodes forcing capacitor switching of thyristors., M., “Energy, 1974, p. 116, fig. 3-8. 3. USSR author's certificate in application number 2008969, cl. H 02M 1/00, 1975