Abstract: A method for monitoring electrical insulation on a rotor of an electrical machine having in each case one coil which is connected to each end of a rotor winding and in series with therewith. For this purpose, both a magnetic conductor of the rotor, in particular a laminated core, and a rotor circuit which is closed via the two coils are electrically conductively connected to a rotor frame at a point between the two coils. A current in the rotor circuit produces a magnetic field, the magnetic field of each coil being measured without making contact by way of an appropriate magnetic field sensor. A state change in the insulation is determined from a change in at least one measurement value by way of an evaluation unit. Also proposed is an electrical machine which is suitable for carrying out the method.

Abstract: A Sensor for detecting radio-frequency oscillations of a voltage, and an arrangement of a sensor for detecting radio-frequency oscillations of the voltage in a line. The sensor (10) has a capacitor (15) whose first connection can be connected to the line (11). According to the invention, the second connection of the capacitor is associated with a current transformer (18) and a bush (19) for outputting a measured signal. The invention furthermore provides for a sensor (10) to be arranged in an intermediate space (13) between the line (11) and a shield (12).

Abstract: A Sensor for detecting radio-frequency oscillations of a voltage, and an arrangement of a sensor for detecting radio-frequency oscillations of the voltage in a line. The sensor (10) has a capacitor (15) whose first connection can be connected to the line (11). According to the invention, the second connection of the capacitor is associated with a current transformer (18) and a bush (19) for outputting a measured signal. The invention furthermore provides for a sensor (10) to be arranged in an intermediate space (13) between the line (11) and a shield (12).

Abstract: A method for decoupling a high-frequency error signal from a high-frequency electromagnetic field in a heavy electrical machine includes decoupling a high-frequency error signal with at least one temperature probe acting as an antenna and being associated with a stator carrying an electrical winding. In a heavy electrical machine having a stator carrying an electrical winding, an apparatus for decoupling a high-frequency error signal from a high-frequency electromagnetic field includes at least one temperature probe being disposed in the stator for generating a low-frequency temperature signal. The at least one temperature probe has connecting lines leading out of the stator. A diplexer decouples the error signal from the temperature signal. The diplexer has an input to which the connecting lines are connected, a first output at which the temperature signal is furnished, and a second output at which the error signal is furnished.

Abstract: A device and a method for locating partial discharges in dynamoelectric high-voltage machines and/or high-voltage systems, comprising at least two coupling units (16, 17, 18) which are coupled to mutually spaced measuring points (MP1, MP2, MP3, ES, TS, AKV) of a conductor (2) of the high-voltage machine and/or high-voltage system, and couple out a high-frequency electromagnetic signal produced upon the occurence of partial discharges. The device further comprises an evaluation device which is electrically connected to each coupling unit (16, 17, 18) and records the temporal sequence of the signals coupled out by each coupling unit (16, 17, 18). The place of origin of the partial discharges can be determined from the temporal sequence of the signals, it being possible to enhance the accuracy by additional measurements at further measuring points.

Abstract: A method and device for detecting and localizing fault in electrical installations includes performing partial discharge measurements and high-frequency measurements at least at one location in the electrical installation and optionally in all phases, selectively comparing the measurement values with each other and with calibration signals, drawing conclusions from the measurements regarding the location and the type of the fault, selectively continuously and periodically performing the measurements at least at three measuring points while the installation is in operation, simulating the electrical installation in a computer as a high-frequency network, while simulating fault with the signals originating therefrom at the measuring points, comparing any measurement values which indicate fault with the simulated signal values for different fault types and fault locations, and determining the type and location of the fault from the simulated signal values which best agree with the measurement values and from the

Abstract: A method for partial discharge detection and breaking spark measurement in a dynamo-electric high-voltage machine, especially for monitoring insulation status during operation of a stator winding and connected electrical output lines in a turbo-generator. The generator includes a stator having a stator winding and a stator housing, a rotor with an exciter winding and a shaft, defining an air gap between the rotor and the stator. At least one oil lubricated slide bearing supports the shaft of the rotor with a bearing shell being electrically insulated from the ground. The method includes decoupling the frequency spectrum of high-frequency electromagnetic oscillations resulting from the occurrence of partial discharges or breaking sparks and delivering the frequency spectrum of high-frequency electromagnetic oscillations to a partial discharge measurement apparatus.

Abstract: Coupling unit for the operational monitoring of the high-voltage winding (SW) and the connected electric output lines in electric high-voltage machines and apparatus, particularly of three-phase stator windings in turbo-generators including their generator output lines (5.1, 5.2, 5.3) and/or in transformers and converters by means of determining partial discharges and measurement of the breaking spark in the high-frequency range, where the above-mentioned machines and apparatus are connected via generator output leads or other connecting line to each other and are connected to ground potential via network protection capacitors. The respective coupling unit (AE1, AE2, AE3) is coupled to one each of the three legs (5.1, 5.2, 5.3) of the generator output lead (5), and the network protection capacitor (C.sub.1, C.sub.2, C.sub.3) of each phase are connected to ground potential (B) via a measuring impedance. Furthermore, the shielded measuring lines (4.1, 4.2, 4.