DEVICE FOR CONTROLLING SEMICONDUCTOR CIRCUIT BREAKERS IN THE HIGH-VOLTAGE RANGE

Abstract

The invention relates to a device for controlling a plurality of semiconductor circuit breakers by means of driver voltages for the synchronous operation of a plurality of loads in the high-voltage range, where the driver voltages can be provided by a transformer. According to the invention, the driver voltages for the semiconductor circuit breakers are tapped from a single secondary winding of the transformer, where electronic voltage level converter circuits are provided to obtain the driver voltages from the secondary winding of the transformer at the required magnitude.

Claims

1. A device for simultaneously controlling a plurality of semiconductor power switches in the case of pulsed loads in the high-voltage range, wherein the driver voltages of the semiconductor power switches are provided via a transformer, characterized in that the driver voltages for the semiconductor power switches are derived from the voltage of a single secondary winding of the transformer, wherein electronic voltage level shifter circuits are provided in order to obtain the driver voltages at the required magnitude from the secondary winding of the transformer.

2. The device as claimed in claim 1, wherein the electronic voltage level shifter circuits comprise a charge pump.

3. The device as claimed in claim 2, wherein the clocking of the respective load serves for the clocking of the respective charge pump.

4. The device as claimed in claim 3, wherein the clocking of the device is effected in each case via a switch which is connected to the secondary winding of the transformer, which charges the charge pump in the closed state, and which applies the driver voltage generated in the charge pump to the respective semiconductor power switch in the open state.

Description

[0018] The invention is explained in greater detail below with reference to the drawing, in which:

[0019] FIG. 1 shows generally the control of semiconductor power switches (MOSFETs, IGBTs, bipolar transistors) in accordance with the prior art,

[0020] FIG. 2 shows an application of the control from FIG. 1 in the high-voltage range by means of a transformer for the galvanic isolation of the respective driver voltages for the power switches, wherein the driver voltages for the power switches are galvanically isolated by means of secondary windings of the transformer, and

[0021] FIG. 3 shows an embodiment of the device according to the invention for controlling power switches by means of a transformer having a single secondary winding, from which the various driver voltages for the power switches are derived.

[0022] FIGS. 1 and 2 have been explained in the introductory part concerning the prior art.

[0023] An embodiment of the device according to the invention is shown in FIG. 3. This embodiment differs from the device shown in FIG. 2 in the use of a transformer having a single secondary winding for providing the driver voltage UL1 for the electronic load switches S1, S2, to put it more precisely to the two electronic load switches S1 and S2 by means of the lower secondary winding of the transformer with three levels of the zero potential HV−.

[0024] For the device in FIG. 3, the driver voltages Uh.sub.1 and Uh.sub.2 for controlling the electronic load switches S12 and S21 are not provided by further secondary windings of the transformer, but rather are derived from the single secondary winding of the transformer by means of charge pumps.

[0025] The charge pump for providing the driver voltage Uh.sub.1 comprises a capacitor C1 connected at one end to that end of the load Load 1 which is connected to the switch S1, and at the other end via a series resistor R1, the other end of which is connected to a diode D1 at UL1 potential. The driver voltage Uh.sub.1 generated from the voltage UL1 by way of the charge pump is applied via a diode D12 to the electronic switch S12 bridged by a capacitor C12 on the input side.

[0026] The charge pump for providing the driver voltage Uh.sub.2 comprises a capacitor C2 connected at one end to that end of the load Load 2 which is connected to the switch S2, and at the other end via a series resistor R2, the other end of which is connected to a diode D2 at UL1 potential. The driver voltage Uh.sub.2 generated from the voltage UL1 by way of the charge pump is applied via a diode D12 to the electronic switch S12 bridged by a capacitor C21 on the input side.

[0027] If the switch S1 is closed, the capacitor C1, C2 is charged to the driver voltage potential UL via the series resistor R1, R2 and the blocking diode D1, D2.

[0028] If the switch S1, S2 is opened, the capacitor C12, C21 is charged with the charge of the capacitor C1, C2. The potential Uh.sub.1(Uh.sub.2)=UL required for controlling the switch S12, S21 is thus available. This process is repeated cyclically with the clocking of the switches S1, S2.

[0029] The device according to the invention has been explained on the basis of an embodiment with two semiconductor power switches. However, the invention is not restricted thereto. Rather, more than two switches of this type are taken into consideration for the device for controlling semiconductor power switches.