DE1270165B - Circuit arrangement with several series-connected semiconductor valves controlled by ignition pulses - Google Patents

Description

FEDERAL REPUBLIC OF GERMANY

GERMAN

PATENT OFFICE

EDITORIAL

Int. Cl .:

H02m

H02p

German class: 21 d2-12 / 04

Number:
File number:
Registration date:
Display day:

P 12 70 165.4-32
August 19, 1960
June 12, 1968

Semiconductor valves are known which, similar to gas-filled discharge vessels, are activated by ignition pulses control (so-called thyristors). Semiconductor valves of this type are currently used for load voltages up to a few 100 V effective available. Do you want to rectify or rectify larger voltages? control, you can connect a corresponding number of semiconductor valves in series. In general it proves to be necessary in parallel to the series connection of the semiconductor valves to switch a voltage divider, which has the task of distributing the applied load voltage evenly to distribute it to the semiconductor valves and to dampen high-frequency vibrations. at It is known to convert power converters with several discharge vessels connected in series for this purpose to use a voltage divider in which a capacitor and a ohmic resistance are switched.

The need to feed the ignition pulses to the individual semiconductor valves in a series circuit, So far, this has required a lot of effort, since the ignition pulse generated at ground potential by means of isolating transformers or coupling capacitors with high dielectric strength must be transferred.

To overcome this deficiency, the invention is based on a known circuit arrangement off, in which only one transistor is directly controlled in a series connection of transistors and the control currents for the other transistors in a parallel to the transistor series circuit Ohmic voltage divider can be taken. The ones required to control the transistors Base-emitter currents are taken from a voltage source that is applied to the ends of the Voltage divider is connected. A transfer of this switching method to series connections of Semiconductor valves that are controlled by ignition pulses are not easily possible because To control these elements, short-duration pulses of relatively high current strength and energy are required are. If you wanted to use an ohmic voltage divider for this, you would have to use its resistors dimensioned low resistance in order to be able to draw relatively high currents from the voltage divider for a short time. But that would mean that the voltage divider causes considerable losses.

The invention relates to a circuit arrangement with a plurality of controlled semiconductor valves located in series and with a voltage divider connected in parallel to these, in which only one semiconductor valve supplies a control current directly to a circuit arrangement with several in series
lying controlled by ignition pulses
Semiconductor valves

Applicant:

Siemens Aktiengesellschaft, Berlin and Munich, 8520 Erlangen, Werner-von-Siemens-Str. 50

Named as inventor:

Dipl.-Ing. Ludwig Filberich, 1000 Berlin

is supplied and the control currents for the other semiconductor valves indirectly from changes in potential can be derived in the voltage divider. The invention applies to such a circuit arrangement therein see that when using semiconductor valves, which are controlled by ignition pulses, the voltage divider parallel to each semiconductor valve a series connection of a capacitor and a Has ohmic resistance and that in each case the capacitor of the voltage divider lying parallel to an ignited semiconductor valve Supplies energy for the ignition pulse of the semiconductor valve to be ignited next. As for recharging the capacitors are available for relatively long periods of time, the voltage divider can are formed as a whole with high resistance and thus with little loss. You can use the ignition pulses for the indirectly controlled semiconductor valves at the resistors of the voltage divider decrease. Under Under certain circumstances, however, it can also be advantageous to use the ignition pulses for the indirectly controlled semiconductor valves to be taken from the voltage divider via an isolating transformer. For this purpose z. B. Small toroidal converters are suitable whose insulation is only for about twice the operating reverse voltage of a single valve needs to be sized.

The F i g. 1 and 2 show exemplary embodiments of the invention.

In Fig. 1, 11, 12, 13 and 14 denote four controllable semiconductor valves connected in series. The series connection can be made by any number of others at the upper limit of the figure Links are added. In parallel to the semiconductor valves 11 to 14, there is a voltage divider that is off Capacitors 15, 16, 17 and 18 and ohmic resistors 19, 20, 21 and 22 is composed.

809 559/190

The ignition pulse for the semiconductor valve 11 is generated in any way by a control unit 25 and supplied to the control path of the semiconductor valve 11 by a control transmitter 26. the Control path of the semiconductor valve 12 is connected to the ends of the resistor 19, accordingly the control path of the semiconductor valve 13 to the ends of the resistor 20, etc.

The circuit arrangement works as follows:

At the series connection of the semiconductor valves 11 to 14 there may be a voltage with the direction shown; as long as no ignition pulse is given to the semiconductor valve 11, the series connection blocks. If the semiconductor valve 11 is now ignited by an ignition pulse, the voltage existing up to then on this semiconductor valve collapses, as a result of which the potential of the point 19 α (lower connection of the resistor 19) rises suddenly. The increase in voltage at resistor 19 in turn serves to ignite semiconductor valve 12, whereupon the same process is repeated at resistor 20 or semiconductor valve 13.

In the exemplary embodiment according to FIG. 2, the control paths of the semiconductor valves 11 to 14 are connected to the voltage divider via toroidal core converters 31 to 34 which enclose the current-carrying conductor 10. The converter 31 has a secondary winding 31 a, to which the control path of the semiconductor valve 12 is connected, and a reverse magnetization winding 31 b. The other converters 32 to 34 are also designed accordingly.

When the semiconductor valve 11 is ignited, the capacitor 15 discharges via the conductor 10; Here the core of the transducer 31 is magnetized, so that a voltage pulse is generated at the winding 31 α , by which the semiconductor valve 12 is ignited the transducers 31 to 34 are magnetized back by exciting the windings b etc.

Claims (3)

Patent claims: 1. Circuit arrangement with several series-controlled semiconductor valves and with a voltage divider connected in parallel to this, with only one semiconductor valve a control current is supplied directly and the control currents for the remaining semiconductor valves be derived indirectly from potential changes in the voltage divider, thereby characterized in that when using semiconductor valves controlled by ignition pulses the voltage divider is connected in series in parallel to each semiconductor valve has a capacitor and an ohmic resistor and that in each case the one ignited Semiconductor valve parallel capacitor of the voltage divider the energy for the Supplies the ignition pulse of the semiconductor valve to be ignited next. 2. Circuit arrangement according to claim 1, characterized in that the ignition pulses for the indirectly controlled semiconductor valves removed from the resistors of the voltage divider will. 3. Circuit arrangement according to claim 1, characterized in that the ignition pulses for the indirectly controlled semiconductor valves are taken from the voltage divider via isolating converters will. Considered publications:
German Patent Nos. 972096, 1021926; Electronics, March 6, 1959, pp. 50, 51. 1 sheet of drawings 809 559/190 5.68 © Bundesdruckerei Berlin