An electrical power generating assembly (20) for a wind turbine (1). The electrical power generating assembly comprises a gearbox (22) comprising a gearbox output shaft, a generator (24) comprising a rotor (32) that is coupled to the gearbox output shaft; and a current measuring module (40) located between the gearbox (22) and the generator (24). The current measuring module (40) comprises: an electrical pickup (42) mounted to the electrical power generating assembly (20), wherein the electrical pickup (42) includes an electrical contact (44) that engages with a slip ring (48) associated with the rotor (32). The current measuring module further comprises: a first current measuring device (50) mounted with respect to the electrical pickup (42) to detect current flowing at least through the electrical pickup; and a second current measuring device (52) mounted with respect to the electrical pickup (42) to detect current flowing through at least a component associated with the gearbox output shaft.

A coil wire includes a core wire and a winding wire. The winding wire is wound around a circumference of the core wire so as to form a plurality of spirals. The coil wire satisfies one of: (i) an outer surface of the core wire is exposed, and a distance between the outer surface of the core wire and an inner circumferential surface of part of the winding wire is smaller than a thickness of a first insulating film coated on the winding wire; or (ii) the outer surface of the core wire is coated by a second insulating film, and a distance between an outer surface of the second insulating film and the inner circumferential surface of part of the winding wire is smaller than a thickness of a thicker one of the first insulating film and the second insulating film.

A system may include a transformer that may convert a first voltage to a second voltage, such that the second voltage is output via a conductor. The system may also include a wireless current sensor that may detect current data associated with current conducting via the conductor and a processor. The processor may receive the current data, determine one or more temperature measurements associated with the transformer based on the current data, and send a signal to a component in response to the one or more temperature measurements exceeding one or more respective threshold values.

A system may include a transformer that may convert a first voltage to a second voltage, such that the second voltage is output via a conductor. The system may also include a wireless current sensor that may detect current data associated with current conducting via the conductor and a processor. The processor may receive the current data, determine one or more temperature measurements associated with the transformer based on the current data, and send a signal to a component in response to the one or more temperature measurements exceeding one or more respective threshold values.

A current sensor includes a first component and a second component shaped to fit together to create a combined unit with multiple openings through the combined unit. The opening is bounded on a first side by the first component and on a second side by the second component. The first component and the second component are configured to be fitted together around current-carrying conductors passing through the openings. The first component includes first portions of an inductive energy harvesting device and a current sensing device, both proximal to the first side of the opening. The second component includes second portions of the inductive energy harvesting device the current sensing device, both proximal to the second side of the opening. The inductive energy harvesting device may include a split-core ferrite current transformer and the current sensing device may include a Rogowski coil.

A method for measuring electric currents and a method for measuring electrical voltages. The method uses a mathematical model of the measuring system to compensate for error effects of the real system compared to an ideal system, thereby enabling a highly accurate measuring system. An energy meter compensates for the error effects of the real measuring system.

An apparatus for measuring a flow of current through at least one electrical conductor of an electrotechnical device which is disposed in a cooling channel, wherein a non-conductive cooling medium flows through the cooling channel during operation of the electrotechnical apparatus, the apparatus including a flux conductor which is disposed around the at least one electrical conductor, and an evaluation circuit which is coupled to the flux conductor and is configured to determine the flow of current through the at least one electrical conductor by evaluating an electrical parameter of the flux conductor, wherein at least a part of the flux conductor is disposed in the cooling channel.

An apparatus for measuring a flow of current through at least one electrical conductor of an electrotechnical device which is disposed in a cooling channel, wherein a non-conductive cooling medium flows through the cooling channel during operation of the electrotechnical apparatus, the apparatus including a flux conductor which is disposed around the at least one electrical conductor, and an evaluation circuit which is coupled to the flux conductor and is configured to determine the flow of current through the at least one electrical conductor by evaluating an electrical parameter of the flux conductor, wherein at least a part of the flux conductor is disposed in the cooling channel.

A current sensing method measures a fractional current through a coil having a plurality of coil windings by using a current sensing resistor to measure a current through a subset of the plurality of coil windings and using a voltage sensor to measure a voltage drop across the current sensing resistor. The measured current and voltage values are provided to a processor to determine the fractional current and phase of the coil. For example, the fractional current and phase of the coil may be determined by calculating a total current of the coil as I=n(V/Rx), where n is the number of coil windings of the coil, V is the measured voltage, and Rx is the impedance of the current sensing resistor. The coil may be a secondary winding used in a wireless power transfer system.

A current sensing method measures a fractional current through a coil having a plurality of coil windings by using a current sensing resistor to measure a current through a subset of the plurality of coil windings and using a voltage sensor to measure a voltage drop across the current sensing resistor. The measured current and voltage values are provided to a processor to determine the fractional current and phase of the coil. For example, the fractional current and phase of the coil may be determined by calculating a total current of the coil as I=n(V/Rx), where n is the number of coil windings of the coil, V is the measured voltage, and Rx is the impedance of the current sensing resistor. The coil may be a secondary winding used in a wireless power transfer system.