Siemens Aktiengesellschaft

Christopher Fromme

Marvin Tannhäuser

Fabian Döbler

Dominic Malane

Lennart Baruschka

Michael Denzner

A method for protecting an electrical low-voltage circuit includes ascertaining the level of the voltage of the low-voltage circuit in the form of instantaneous voltage values. A change in the current is ascertained over time such that instantaneous current change values are provided. The instantaneous current change values are compared to instantaneous current change threshold values in order to recognize a short circuit in the low-voltage circuit, and if the current change thresholds are exceeded, an electronic interruption unit switches from the low-resistance state to the high-resistance state in order to interrupt the low-voltage current circuit. The process has a trigger time from the short circuit event to the high-resistance state. The trigger time is largely independent of the phase angle. A circuit breaker device for protecting an electrical low-voltage circuit is also provided.

Circuit breaker device and method

A circuit breaker device protects an electric low-voltage current circuit. A level of a voltage of a low-voltage current circuit is ascertained such that ascertained voltage values are provided. A differential voltage is ascertained from the ascertained voltage values and an expected value of the voltage such that differential voltage values are provided incrementally. Each differential voltage value is compared with a first threshold, and if at least two successive differential voltage values exceed the threshold, an interruption of the low-voltage current circuit is initiated by semiconductor-based switching elements, which are set to a high-ohmic state, in order to protect the low-voltage current circuit from a short-circuit.

The teachings herein include DC/DC converter systems. An example system may include: a full-bridge converter and a switch control circuit. The converter includes a primary side and a secondary side full-bridge circuit and a transformer. AC nodes of the primary side are connected to a primary side of the transformer and AC nodes of the secondary side to a secondary side of the transformer. The switch control circuit: controls the primary side and the secondary side circuits in a normal operating phase including modulation of an input voltage by the primary side full-bridge circuit transferring power via the transformer, control the primary side and the secondary side in a free-wheeling phase during which they are both deactivated to reduce the transformer's magnetization current; and control the full-bridge circuits to switch between the normal operating phase and the free-wheeling phase alternately.

DC/DC converter system and control method for full-bridge DC/DC converter

Various embodiments include a DC coupled electrical converter for converting an input voltage applied to first connections to an output voltage comprising: a boost converter connected on the input side to the first connections; an inverting buck-boost converter connected on the input side to the first connections; and a series circuit including two capacitors, the series circuit connected to an output-side positive pole of the boost converter and to an output-side negative pole of the inverting buck-boost converter. An output-side negative pole of the boost converter and an output-side positive pole of the inverting buck-boost converter are connected to a center connection between the capacitors.

DC coupled electrical converter

Various embodiments include a half-bridge comprising: a first power semiconductor; a second power semiconductor connected in series with the first power conductor; a controller for the power semiconductors; a line starting at connection node of the power semiconductors; and a meter for measuring the current in the line. The controller is configured to: compare the current with an upper threshold value and a lower threshold value; switch off the first power semiconductor if the upper threshold value is reached; switch on the second power semiconductor after a first dead time has elapsed; and switch off the second power semiconductor if the lower threshold value is reached; and switch on the first power semiconductor after a second dead time has elapsed.

Half-bridge having power semiconductors

A DC-DC converter and a method for operating the same are disclosed. The DC-DC converter includes an inverter, a transformer, a rectifier, a clamping assembly, and a control unit. The inverter has four interconnected primary semiconductor switches which form an inverter full bridge for converting an input DC voltage into an AC voltage. The transformer has a primary winding which is arranged in the bridge branch of the inverter full bridge. The rectifier is connected to the secondary winding of the transformer and is designed to rectify a secondary voltage of the transformer. The clamping assembly has an additional semiconductor switch and a clamping capacitor which is connected to the additional semiconductor switch in series. The rectified secondary voltage of the transformer is applied to the clamping assembly. The control unit is designed to control the primary semiconductor switches and the additional semiconductor switch.

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Fürth, Germany

Christopher Fromme