Abstract: A device for modifying an AC voltage has an input for connecting to an AC voltage source and an output for connecting to a load circuit. An interrupter is designed such that, within a time window, the output can be disconnected from the AC voltage source. The time window has a time delay from the zero crossing of the voltage of the AC voltage source. At the output, the device has a terminator that is designed, together with the interrupter, such that the voltage at the output has a predefined or predefinable value in the time window. The device also includes a pulse shape generator for generating a predetermined or predeterminable pulse shape, and a control that actuates the terminator and the interrupter such that the voltage curve at the output can be modified according to the pulse shape predetermined by the pulse shape generator.

Abstract: A device and method is for insulation monitoring in a power supply system composed of a main system including a neutral point that is high-resistance grounded via a neutral-point resistance and, optionally, of at least one subsystem, wherein the main system and the subsystem each have a differential current measuring device for registering a differential current. The invention is based on feeding a measuring signal into the optionally branched HRG system via an active measuring method and registering the fault current driven by the measuring signal in the outgoing power feeds to be monitored by means of a differential current measurement and using the registered fault current in an evaluating device to determine the total insulation resistance of the power supply system and to determine the partial insulation resistances of the main system and potentially present subsystems. Furthermore, the insulation monitoring device can be employed for insulation fault location.

Abstract: A method for monitoring and measuring an insulation resistance in ungrounded and grounded power supply systems includes the method steps of generating a periodic measuring signal, coupling in the measuring signal between active conductors of the power supply system to be monitored and ground, and detecting and evaluating measured values of the measuring signal. In one embodiment of the invention, the generated measuring signal is formed as a multi-frequency signal by the superposition of a finite number of harmonic oscillations with at least three harmonics. Alternatively, the multi-frequency signal can also be realized by means of a targeted, portioned construction of the signal shape in the time domain on the basis of a binary sequence optimization or by generating the measuring signal by means of the time-division multiplexing method.

Abstract: The invention relates to a device (1) for modifying an AC voltage, wherein the device (1) comprises an input (1) for connecting to an AC voltage source and an output (3) for connecting to a load circuit. The device (1) comprises an interrupter (15) that is designed such that, within at least one time window (35), the output (3) can be disconnected from the AC voltage source, wherein the time window (35) has a time delay (36) from the zero crossing (40) of the voltage of the AC voltage source. At the output (3), the device comprises a terminator (20) that is designed, in particular together with the interrupter (15), such that the voltage at the output (3) of the device (1) has a predefined or predefinable value (37) in the time window (35).

Abstract: The invention relates to a method for the data transmission from an emitter (1) to a receiver (2) in an AC voltage network, comprising a distributor (3) and at least one user group (4) with one or several users (5), wherein the emitter (1) feeds a signal to the AC voltage network by means of a power source (6).