A stator for an electrical machine has a stator core (16) with stator grooves (19). Stator windings (17) are received in the stator grooves (19) of the stator core (16). Groove insulators (20) are received in the stator grooves (19) of the stator core (16) such that the groove insulators (20) are arranged between the stator core (16) and the stator windings (17). The groove insulators (20) are made of of plastic, namely a first plastic that provides the isolation function of the groove insulator (20) and a second plastic and/or a third plastic that provides a function of the respective groove insulator (20) differing from the isolating function.

Various embodiments of the teachings herein include an apparatus for voltage equalization in square-wave voltages of electric motors. The apparatus may include: a terminal board circuit wherein phases U, V, and W each comprises input and output cabled conductors summing to at least 6 cables; and a bridge between two of the at least six cables connecting two or more of the at least 6 cable inputs and outputs. The bridge is partially conductive such that its electrical resistance markedly reduces above a threshold value. The partial conductivity results from filler particles in an embedding matrix determining a reduction of the resistance in the bridge above the threshold value.

Various embodiments of the teachings herein include an apparatus for voltage equalization in square-wave voltages of electric motors. The apparatus may include: a terminal board circuit wherein phases U, V, and W each comprises input and output cabled conductors summing to at least 6 cables; and a bridge between two of the at least six cables connecting two or more of the at least 6 cable inputs and outputs. The bridge is partially conductive such that its electrical resistance markedly reduces above a threshold value. The partial conductivity results from filler particles in an embedding matrix determining a reduction of the resistance in the bridge above the threshold value.

A stator of an electric machine includes a laminated core having slots for receiving windings of a multiphase winding system. The windings have winding ends, which are encased with an insulator across a partial length. In order to encase the winding ends with the insulator, a strand of a thermoplastic material is extruded onto the winding ends via a nozzle. During extrusion, the nozzle is moved relative to the winding end along the longitudinal extent thereof and an oscillating movement of the nozzle transversely to the longitudinal extent of the winding end overlays the movement along the longitudinal extent. As a result the thermoplastic material lies on the winding end and around the respective winding end in the form of loops.

A stator of an electric machine includes a laminated core having slots for receiving windings of a multiphase winding system. The windings have winding ends, which are encased with an insulator across a partial length. In order to encase the winding ends with the insulator, a strand of a thermoplastic material is extruded onto the winding ends via a nozzle. During extrusion, the nozzle is moved relative to the winding end along the longitudinal extent thereof and an oscillating movement of the nozzle transversely to the longitudinal extent of the winding end overlays the movement along the longitudinal extent. As a result the thermoplastic material lies on the winding end and around the respective winding end in the form of loops.

A winding insulation system includes a set of insulated conductors, main wall insulation provided around the conductors, corona shield tape provided around the main wall insulation, stress grading tape provided around the corona shield tape, and sealing tape provided around the stress grading tape. The main wall insulation includes inner, intermediate, and outer sections. The inner section includes polyimide mica paper reinforced with any combination of the group consisting of: glass cloth, polyester film, and polyester mat, the inner section being provided in half-lap layer(s). The intermediate section includes mica paper reinforced with any combination of the group consisting of: glass cloth, polyester film, and polyester mat, the intermediate section being provided in half-lap layer(s). The outer section includes mica tape backed with aramid and reinforced with any combination of the group consisting of: glass cloth, polyester film, and polyester mat, the outer section being provided in half-lap layer(s).

A winding insulation system includes a set of insulated conductors, main wall insulation provided around the conductors, corona shield tape provided around the main wall insulation, stress grading tape provided around the corona shield tape, and sealing tape provided around the stress grading tape. The main wall insulation includes inner, intermediate, and outer sections. The inner section includes polyimide mica paper reinforced with any combination of the group consisting of: glass cloth, polyester film, and polyester mat, the inner section being provided in half-lap layer(s). The intermediate section includes mica paper reinforced with any combination of the group consisting of: glass cloth, polyester film, and polyester mat, the intermediate section being provided in half-lap layer(s). The outer section includes mica tape backed with aramid and reinforced with any combination of the group consisting of: glass cloth, polyester film, and polyester mat, the outer section being provided in half-lap layer(s).

The invention relates to an electric winding body which has improved performance characteristics as a result of being impregnated with a thermoplastic material filled with phase change material. These performance characteristics relate to improved heat dissipation, vibration damping, fixing of the coils, and improved protection against overheating by utilizing the sensitive and latent heat storage properties when the polymer units transition from the semi-crystalline state into the amorphous state.

The invention relates to an electric winding body which has improved performance characteristics as a result of being impregnated with a thermoplastic material filled with phase change material. These performance characteristics relate to improved heat dissipation, vibration damping, fixing of the coils, and improved protection against overheating by utilizing the sensitive and latent heat storage properties when the polymer units transition from the semi-crystalline state into the amorphous state.

A stator assembly for an electric machine includes stator teeth connected to a stator yoke to form a stator core. Adjacent teeth define a stator slot. Stator windings are disposed within the slot. A molding material fills the slot around the windings, providing a desired thermoelectrical performance level at different slot regions, including electrical insulation, thermal conductivity, and/or electrostatic shielding levels. A method insulates the stator assembly by inserting a molding tool(s) into the slot to define a void volume, filling the void volume with the dielectric molding material, and curing the dielectric molding material to form a slot liner layer adjacent to the tooth walls. A slot opening between adjacent teeth is filled with an electrically-conductive resin to form an electrostatic shielding layer. An electrical system includes an AC voltage bus connected to a power inverter module and to the electric machine having the above-described stator assembly.