Compared with the requirements for ground and turn-to-turn insulation in single-phase motors, phase-to-phase insulation is a unique electrical performance requirement for three-phase asynchronous motors. Because of the operating characteristics of variable frequency motors, the control of the phase-to-phase insulation is particularly critical.
The phase-to-phase insulation of the variable frequency motor mainly involves the stator and rotor winding ends, the motor lead wire part, and the interlayer insulation in the iron core slot of the winding.
The phase-to-phase insulation control of the winding ends of the inverter motor, on the one hand, lies in the material of the phase-to-phase insulation and the protection of the insulation during the operation process, and more importantly, the shape and size of the phase-to-phase insulation. Many inter-phase insulation problems are found in the semi-finished product test stage. No, the fault occurs when the motor is loaded, mainly at the intersection of the two phases at the slot, and some faults are at the intersection of the two phases outside the end; because the end insulation will also involve friction with the rotor And the noise problem, it is more difficult to control; especially for the frequency conversion speed motor of 2 great power, because of the particularity of the winding span, there are relatively more problems between the end phases.