Siemens Aktiengesellschaft

Siemens Aktiengesell Schaft

Gerd Thiele

Manfred Schraudolph

Jurgen Weber

Kurt Schilling

Erwin Keyl

Wilfried Rameil

Disclosed is a circuit arrangement for monitoring a thyristor via a signal transmitting device which is connected on its input side in shunt with the thyristor and to the output of which a light emitting diode is connected for sending light signals to an evaluating device. To obtain a particularly simple and therefore operationally reliable design of such a circuit arrangement, and to achieve the emission of light signals with particularly high light output, the signal transmitting device contains a rectifier arrangement followed by an integrating stage, followed in turn by a threshold voltage switch which changes to a current-conducting state as soon as the voltage drop across it exceeds a predetermined threshold value. No separate power supply is required.

Circuit arrangement for monitoring a thyristor

A protection circuit for use with a thyristor having several break over diode, BOD, elements is connected between the anode and the gate of a thyristor providing static and dynamic overvoltage protection. With the exception of the BOD element connected to the gate, all the BOD elements have RC circuits connected in parallel, whose respective resistance and capacitance values are essentially identical. The BOD element connected to the gate and the cathode-gate portion of the thyristor has an additional RC circuit connected in parallel, whose resistance value is smaller or the same and whose capacitance value is smaller than the respective resistance and capacity values of the other RC circuits. Preferably, in this last RC circuit the resistance value is very small in contrast to the resistance values of the other RC circuits, and the capacitance value is negligible. In this preferred embodiment, the static actuation voltage is determined by the BOD elements not directly connected to the gate, and the dynamic actuation characteristic is determined by an equivalent series RC circuit which is determined by the capacitances of all the RC circuits and by the resistance, which is connected in parallel to the series connection of the BOD element connected to the gate and the thyristor gate-cathode portion.

Protective circuitry for a thyristor

A firing circuit for two antiparallel-connected power thyristors. Each of the power thyristors has a gate terminal; the gate terminals being connected by a series combination of auxiliary thyristors. Each of the auxiliary thyristors is of the type which can withstand firing resulting from excessive anode cathode potential; the sum total of the anode cathode potentials of the series-connected auxiliary thyristors being less than the anode-cathode breakdown voltages of the power thyristors. This, while a power thyristor is in a nonconductive state, an anode-cathode voltage is impressed thereacross in the forward conduction direction. At an anode-cathode voltage which is less than the breakdown voltage of the power thyristor, the auxiliary thyristors are fired so as to form a conductive path which includes the cathode-gate path of the other power thyristor, the auxiliary thyristors, and the gate-cathode path of the protected thyristor. Normal firing of the power thyristor is achieved via the auxiliary thyristors, which may be fired by light pulses or current pulses. Thus, the auxiliary thyristors perform protective and normal firing operations.

Firing circuit for power thyristors

A twelve pulse converter system is disclosed in which the two three-phase converter bridges forming the system are arranged one on top of the other in a single tower-like assembly and the valves of the bridges are disposed successively and separately as to phase. Additionally, the DC and AC terminals of one of the converter bridges are disposed on the one side of the tower-like assembly and the DC and AC terminals of the other of the converter bridges are disposed on the other side of the tower-like assembly, the DC terminals located on opposite sides being connected to each other by a DC lead.

Spatial arrangement of the valves of a three-pulse converter system

A converter valve which is constructed from modular elements is disclosed. Each of these modular elements comprises a group of thyristors arranged in side-by-side relationship and the drive means and circuit component group associated with such thyristor group. A metallic shield surrounds the thyristor group and its associated drive means and a portion of its associated component group. The shield, in turn, is supported within a metallic pressure tube which has both its ends closed off by bulkheads and is adapted to receive SF.sub.6 gas. The aforesaid bulkheads may be separate connecting members which, in addition, may also be designed as nodal elements and mechanical support points. The converter valve is constructed from a small number of the aforesaid modular elements, each element being replaceable without removing the gas from the entire valve.

Converter valve comprised of a plurality of modular elements

A gas-insulated thyristor arrangement with at least one thyristor column which is constructed of disk-type thyristors and is arranged, together with its associated drive and external-circuit modules, in a rotationally-symmetric shield which is fastened via at least one insulating standoff to the pressure tube of an electrically conductive pressure encapsulation. One end of the pressure tube is closed off by an end plate integrally formed therewith in the manner of a tank and the other end is closed off by means which includes at least one bulkhead of insulating material. The entire arrangement is filled with gaseous SF.sub.6 under pressure and detachable electrical connecting leads are extended through the bulkhead.

Gas-insulated thyristor arrangement comprising a pressure encapsulation

A gas-insulated thyristor assembly is disclosed. The assembly comprises at least one thyristor column which includes disk-type thyristors which are arranged in side by side relationship. The assembly further includes drive and circuit component modules associated with the thyristors. In accordance with the invention, a rotationally-symmetric metallic shield surrounds the disk-type thyristors and is supported within a cylindrical metallic pressure tube by insulating posts. The opposite ends of the aforesaid pressure tube are closed off by bulkheads comprised of insulating material and the tube is adapted to receive SF.sub.6 gas under pressure. A detachable electrical connecting line is passed through each bulkhead and the pressure tube is adapted to be detachably connectable with adjoining pressure tubes.

Gas-insulated thyristor assembly

This invention concerns a protective device for at least one thyristor. Separate measuring sensors are provided for determining the thyristor parameters of current and the magnitude and rising slope of the thyristor voltage. The measuring sensors are followed by a comparison stage which compares the parameters with definite, predetermined conditions, and transmits a trigger pulse for the thyristor. With the protective device according to the invention, the thyristor can be fired by means of its control electrode during the recovery time of the thyristor, if an overvoltage occurs.

Protective device for at least one thyristor

The invention concerns a thyristor column with disc thyristors which are stacked on top of each other and are mounted resiliently. A heat sink, which serves simultaneously as a conductor of electric current, is interposed on each side of each disc thyristor. Between the heat sinks of succeeding disc thyristors, a spacer element is inserted, on which ferrite cores are lined up. In this embodiment, the transient current is limited by the choke formed by the spacer element and the ferrite cores. The resistors of the external R-C components can therefore be designed for less power.

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Erlangen, Germany

Gerd Thiele