The present disclosure relates to electrical machines. The teachings thereof may be embodied in a corona shielding system for an electrical machine. For example, a corona shielding system may include: an outer corona shield and an overhang corona shielding. The outer corona shielding and the overhang corona shielding may comprise a first corona shielding material having a nonlinear field strength-dependent electrical resistance.

A motor monitoring system includes a motor unit, a plurality of sensors, and a motor controller. The motor unit includes a motor housing and a motor arranged within the motor housing. The motor includes a stator with a plurality of stator poles each having a corresponding phase coil. The plurality of sensors are arranged within the motor housing and are configured to: measure a first characteristic related to partial discharges that occur at one or more phase coils, and generate sensor data based on the measured first characteristic. The motor controller is configured to generate a plurality of pulse width modulation (PWM) control signals for controlling phase voltages of the motor, detect the partial discharges at at least one of the phase coils based on the sensor data, and adjust at least one PWM control signal of the plurality of PWM control signals based on the detected partial discharges.

A motor monitoring system includes a motor unit, a plurality of sensors, and a motor controller. The motor unit includes a motor housing and a motor arranged within the motor housing. The motor includes a stator with a plurality of stator poles each having a corresponding phase coil. The plurality of sensors are arranged within the motor housing and are configured to: measure a first characteristic related to partial discharges that occur at one or more phase coils, and generate sensor data based on the measured first characteristic. The motor controller is configured to generate a plurality of pulse width modulation (PWM) control signals for controlling phase voltages of the motor, detect the partial discharges at at least one of the phase coils based on the sensor data, and adjust at least one PWM control signal of the plurality of PWM control signals based on the detected partial discharges.

A tape having a first face comprising a continuous surface of mica paper and a second face comprising a support layer, wherein the mica paper comprises 70 to 99 weight percent mica and 1 to 30 weight percent binder and the support layer comprises a film, a paper, a nonwoven fabric, or a woven fabric; wherein the initial elongation of the support layer is equal to or less than the initial elongation of the mica paper; and wherein the support layer is demountably attached to the mica paper such that when a delamination force of 10 N/10 mm or less is imposed on the support layer it can be separated from the mica paper.

An electric compressor capable of preventing electrical discharge occurring between a coil and a stator core without increasing the size of the overall electric motor for driving a compression mechanism of the electric compressor, is provided. The electric motor of the electric compressor has a cylindrical stator, and a rotor arranged radially inside the stator. The stator includes: a stator core 52 including an annular yoke portion 52B, and multiple tooth portions 52A projecting radially inward from an inner peripheral surface of the yoke portion 52B, and arranged at predetermined intervals in a circumferential direction; a bobbin-shaped insulator 54 removably fitted on each of the multiple tooth portions 52A; a coil 56 wound around the insulator 54; and an insulating member 58 for covering an outer surface of the coil 56 in a wound state.

An electric compressor capable of preventing electrical discharge occurring between a coil and a stator core without increasing the size of the overall electric motor for driving a compression mechanism of the electric compressor, is provided. The electric motor of the electric compressor has a cylindrical stator, and a rotor arranged radially inside the stator. The stator includes: a stator core 52 including an annular yoke portion 52B, and multiple tooth portions 52A projecting radially inward from an inner peripheral surface of the yoke portion 52B, and arranged at predetermined intervals in a circumferential direction; a bobbin-shaped insulator 54 removably fitted on each of the multiple tooth portions 52A; a coil 56 wound around the insulator 54; and an insulating member 58 for covering an outer surface of the coil 56 in a wound state.

Electric coils and a method of insulating electric coils comprises copper wire with insulation, turn tape (e.g., B stage), film tape, and armor tape. In a preferred embodiment, the tape is hot-pressed after application of the B stage turn tape and again just prior to the application of the armor tape.

Electric coils and a method of insulating electric coils comprises copper wire with insulation, turn tape (e.g., B stage), film tape, and armor tape. In a preferred embodiment, the tape is hot-pressed after application of the B stage turn tape and again just prior to the application of the armor tape.

An insulation system and method are disclosed for insulating formed coils of hydroelectric machines, such as a hydroelectric generator. The system includes strand/turn insulation that may include one or more layers of different materials, depending upon the dielectric requirements. A ground wall insulation is applied over the group of turns. The coil may be sized in a slot cell section. Additional insulation layers are provided, including a slot corona suppression insulation that extends just beyond stator slots, a voltage grading layer, and an armor layer. Time temperature profiles and preheating may be used to cure coil sections via press and heat. The resulting system is suitable for installation in situ, and affords superior resistance to degradation.

An insulation system and method are disclosed for insulating formed coils of hydroelectric machines, such as a hydroelectric generator. The system includes strand/turn insulation that may include one or more layers of different materials, depending upon the dielectric requirements. A ground wall insulation is applied over the group of turns. The coil may be sized in a slot cell section. Additional insulation layers are provided, including a slot corona suppression insulation that extends just beyond stator slots, a voltage grading layer, and an armor layer. Time temperature profiles and preheating may be used to cure coil sections via press and heat. The resulting system is suitable for installation in situ, and affords superior resistance to degradation.