Abstract: A method is provided for monitoring and/or analysis of electrical machines during operation. An electrical machine has at least one generator with a shaft, an exciter system and drive device that drives the shaft. In this case, a first signal, which describes a voltage across a rotor winding, and a second signal, which describes a current flowing through the rotor winding, are measured simultaneously. The two signals are supplied to an analysis unit. The signals are split into individual frequency components in the analysis unit. The impedance of the rotor winding is then determined in order to identify fault states in the electrical machine.

Abstract: A method for monitoring an electrodynamic machine a stator and a rotor arrangement mounted along a rotatable shaft. The rotor arrangement is disposed within the stator and forms an air gap between the rotor arrangement and the stator. At least one sensor is disposed in the air gap and/or within the stator. Measurement signals are detected that are dependent on a magnetic field produced by the electrodynamic machine. The measurement signals are used as a basis for detecting oscillations of the shaft.

Abstract: An apparatus for inspection of a gap between two surfaces, at least one of which is ferromagnetic, for example in a generator, includes a sensor platform (26) for one or more sensors (26a) and an elongated mount (23), which can be moved out, for the sensor platform (26). The mount (23) can be moved in and out of the gap through an access opening, can be moved out over the length of the gap and can be rolled up outside the gap by a drive (24). In its moved-out state, the mount (23) has a curvature in a lateral cross section. In addition, the mount (23) has a plurality of magnets (27) by which the mount (23) is brought into contact with a ferromagnetic surface. The magnets (27) are attached to the side of the mount (23) facing away from the ferromagnetic surface, ensuring that the mount (23) slides along a ferromagnetic surface. The apparatus allows inspection of gaps from a height of 4 mm and is distinguished by a simple and physically small design.

Abstract: A worn brush monitoring system for monitoring a plurality of brushes of an electrical machine comprises a plurality of mounted flags configured to be in moveable communication relative to a wear of each of the plurality of brushes and an electrical recording circuit. The electrical recording circuit includes at least one impedance device configured to provide impedance data, at least one switch having a contact plate interactable with at least two of the plurality of mounted flags at different points along a length of the contact plate and an impedance dependent on the length of the contact plate, and a recording device configured to detect changes in electrical characteristics in the electrical recording circuit resulting from changes in a switch state, the switch state defined by the interaction between the mounted flags and the electrical recording circuit, as a result of brush wear.

Abstract: A switch for a brush wear monitoring recording circuit for monitoring wear of at least one brush, the switch having an open and a closed state, comprises a fixed part including a switch plate having a switch face and a moving part including a capacitive flag disposed on a brush so as to move the capacitive flag corresponding to a brush wear movement in a brush wear direction and a capacitive plate having a capacitive face, wherein the capacitive face and the switch face are disposed parallel to each other and provide capacitance to the switch, and further wherein the capacitive flag is disposed on the brush so as to bring the capacitive face and the switch face in proximity to each other so as to face each other and increase capacitance, thereby changing the switch state.

Abstract: A method is provided for monitoring and/or analysis of electrical machines during operation. An electrical machine has at least one generator with a shaft, an exciter system and drive device that drives the shaft. In this case, a first signal, which describes a voltage across a rotor winding, and a second signal, which describes a current flowing through the rotor winding, are measured simultaneously. The two signals are supplied to an analysis unit. The signals are split into individual frequency components in the analysis unit. The impedance of the rotor winding is then determined in order to identify fault states in the electrical machine.

Abstract: A method for monitoring an electrodynamic machine a stator and a rotor arrangement mounted along a rotatable shaft. The rotor arrangement is disposed within the stator and forms an air gap between the rotor arrangement and the stator. At least one sensor is disposed in the air gap and/or within the stator. Measurement signals are detected that are dependent on a magnetic field produced by the electrodynamic machine. The measurement signals are used as a basis for detecting oscillations of the shaft.

Abstract: A switch for a recording circuit used to determine brush wear of an electrical brush comprises a flag having a first end and a second end defining distal ends of the flag. The flag is mounted on the electrical brush at the first end so as to move in unison with brush wear while being in electrical communication with the electrical brush and has a piercing feature on the second end. The switch further comprises a contact plate arrange relative to the flag so as to bring the flag in contact with the contact plate at a predetermined brush wear and includes an inner conductive core encased by a cover forming an outer layer of the contact plate, wherein the piercing feature is configured to penetrate the cover and to contact the conductive core to cause electrically continuous contact between the flag and the contact plate and close the switch.

Abstract: A drive unit (10) for an inspection vehicle which can be used on ferromagnetic bases (19), especially in generators, which drive unit includes a motor-powered crawler track (18) and also magnetic devices for holding the drive unit (10) on the base (19). An improved insensitivity to uneven spots in the base is achieved by the crawler track (18), in the region where it bears upon the base (19), being guided via inner, spring-mounted running wheels (12), and by the magnetic devices being integrated in the running wheels (12).

Abstract: A switch for a recording circuit used to determine brush wear of an electrical brush comprises a flag having a first end and a second end defining distal ends of the flag. The flag is mounted on the electrical brush at the first end so as to move in unison with brush wear while being in electrical communication with the electrical brush and has a piercing feature on the second end. The switch further comprises a contact plate arrange relative to the flag so as to bring the flag in contact with the contact plate at a predetermined brush wear and includes an inner conductive core encased by a cover forming an outer layer of the contact plate, wherein the piercing feature is configured to penetrate the cover and to contact the conductive core to cause electrically continuous contact between the flag and the contact plate and close the switch.

Abstract: A worn brush monitoring system for monitoring a plurality of brushes of an electrical machine comprises a plurality of mounted flags configured to be in moveable communication relative to a wear of each of the plurality of brushes and an electrical recording circuit. The electrical recording circuit includes at least one impedance device configured to provide impedance data, at least one switch having a contact plate interactable with at least two of the plurality of mounted flags at different points along a length of the contact plate and an impedance dependent on the length of the contact plate, and a recording device configured to detect changes in electrical characteristics in the electrical recording circuit resulting from changes in a switch state, the switch state defined by the interaction between the mounted flags and the electrical recording circuit, as a result of brush wear.

Abstract: A switch for a brush wear monitoring recording circuit for monitoring wear of at least one brush, the switch having an open and a closed state, comprises a fixed part including a switch plate having a switch face and a moving part including a capacitive flag disposed on a brush so as to move the capacitive flag corresponding to a brush wear movement in a brush wear direction and a capacitive plate having a capacitive face, wherein the capacitive face and the switch face are disposed parallel to each other and provide capacitance to the switch, and further wherein the capacitive flag is disposed on the brush so as to bring the capacitive face and the switch face in proximity to each other so as to face each other and increase capacitance, thereby changing the switch state.

Abstract: An apparatus for inspection of a gap between two surfaces, at least one of which is ferromagnetic, for example in a generator, includes a sensor platform (26) for one or more sensors (26a) and an elongated mount (23), which can be moved out, for the sensor platform (26). The mount (23) can be moved in and out of the gap through an access opening, can be moved out over the length of the gap and can be rolled up outside the gap by a drive (24). In its moved-out state, the mount (23) has a curvature in a lateral cross section. In addition, the mount (23) has a plurality of magnets (27) by which the mount (23) is brought into contact with a ferromagnetic surface. The magnets (27) are attached to the side of the mount (23) facing away from the ferromagnetic surface, ensuring that the mount (23) slides along a ferromagnetic surface. The apparatus allows inspection of gaps from a height of 4 mm and is distinguished by a simple and physically small design.

Abstract: A drive unit (10) for an inspection vehicle which can be used on ferromagnetic bases (19), especially in generators, which drive unit includes a motor-powered crawler track (18) and also magnetic devices for holding the drive unit (10) on the base (19). An improved insensitivity to uneven spots in the base is achieved by the crawler track (18), in the region where it bears upon the base (19), being guided via inner, spring-mounted running wheels (12), and by the magnetic devices being integrated in the running wheels (12).

Abstract: In a device for the investigation of components of a generator which border on a machine air gap (29) between stator and rotor (22), with the rotor (22) built in, by means of at least one moveable inspection probe (35), a simple, flexible and rapid mounting is ensured in that the device comprises a base unit (31) which can be secured to the rotor (22) on both sides, and which permits at least one inspection probe (35) to move in the machine air gap (29), both in an axial direction with respect to the generator axis and also in the circumferential direction of the machine air gap (29) over the whole circumference of the rotor.

Abstract: In a device for the investigation of components of a generator which border on a machine air gap (29) between stator and rotor (22), with the rotor (22) built in, by means of at least one movable inspection probe (35), a simple, flexible and rapid mounting is ensured in that the device comprises a base unit (31) which can be secured to the rotor (22) on both sides, and which permits at the least one inspection probe (35) to move in the machine air gap (29), both in an axial direction with respect to the generator axis and also in the circumferential direction of the machine air gap (29) over the whole circumference of the rotor.