Siemens Aktiengesellschaft

Peter Jänicke

Günter Schwesig

Dieter Eckardt

Kurt Göpfrich

Markus Frühauf

Franz Imrich

Melanie Eckert

Susanne Gaksch

Peter Heidrich

A circuit for balancing capacitor voltages at capacitors in a DC circuit includes a first circuit path having first and second capacitors connected in series between first and second potentials of a DC voltage of the DC circuit, with a first center tap arranged between the first and second capacitors. A second circuit path includes first and second switchable semiconductors and first and second balancing elements which are connected in series between the first and second potentials. The first switchable semiconductor is arranged at the first potential, the second switchable semiconductor at the second potential, and the first and second balancing elements are arranged between the first and second switchable semiconductors, with a second center tap arranged between the balancing elements. A first electrical connection is established between the first center tap in the first circuit path and the second center tap in the second circuit path.

Circuit for balancing capacitor voltages at capacitors in a DC circuit

A method for operating an automation system with a plurality of communication users linked for communication purposes via a serial connection, of which at least one functions as sender and at least one as a receiver, includes determining at a sender an offset value between an occurrence of a synchronous signal and a communication clock cycle, transmitting the determined offset value in a data transmission to the at least one receiver, waiting at the at least one receiver until a time period commensurate with the offset value has elapsed, and generating at the at least one receiver an output signal after the time period has elapsed.

Method for operating an automation system

The invention relates to a drive control for an electric drive with a secure electrical separation of power element and control element. The aim of the invention is to reduce the number of components such as optic couplers and buffer amplifiers between the power element and a control electronics. To this end, a suitable electrical transformer (U) is inserted in a digital communication interface (K) between the control unit (R) and the control electronics (A) for the purpose of providing a secure electrical separation. To make use of a transformer (U) possible, a non-zero frequency encoding, for example a Manchester encoding, is carried out. Alternatively, an Ethernet physics can be used to provide a suitable communication interface. The transformer electrically insulates the two communication paths from each other that are provided in an Ethernet physics and preferably has little coupling capacity and a low attenuation factor.

Drive control for an electric drive with a secure electrical separation of power element and control element

A drive controller for a self-commutated converter is described. The converter has two half-bridges, and the drive controller includes a corresponding control circuit for the converter valves of each half-bridge. Each control circuit can be connected via first switches to an external voltage. Each first switch is connected in parallel with a second switch, wherein the second switches are decoupled by way of decoupling diodes. The first and second switches can be alternatingly switched on and off. The switches can therefore be cyclically tested without interrupting service.

Drive controller for a self-commutated converter

A drive controller for a self-commutated converter having two half-bridges with converter valves, includes two control circuits, with each control circuit associated with a corresponding half-bridge and operatively connected with the converter valves of that half-bridge, and at least two switches, wherein an input of each switch is directly or indirectly connected to an external voltage, and an output of each switch is directly or indirectly connected to a pulse-inhibiting path. Further provided are at least two pulse-inhibiting controllers, wherein each switch receives control signals from a corresponding one of the pulse-inhibiting controllers. Arranged in the pulse-inhibiting path is a buffer unit for briefly maintaining a supply voltage of the control circuits if a pulse-inhibiting path electrically disconnects at least one of the control circuits from the external voltage. Thus, the drive controller, and more particularly its pulse-inhibiting paths, can be tested cyclically without interrupting the operation of the drive controller.

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Erlangen, Germany

Peter Jänicke