Inverter-driven rotary electric machine, phase-to-phase insulation partial discharge inspection method and phase-to-phase insulation partial discharge inspection apparatus

A phase-to-phase insulation partial discharge inspection method for an inverter-driven rotary electric machine, comprising:

• a step of applying an impulse voltage having a voltage rise time period tr which satisfies an expression (A1) given below to the rotary electric machine;
• a step of confirming whether or not partial discharge occurs;
• and
• a step of determining that, when occurrence of partial discharge is not confirmed, a phase-to-phase insulation performance of the rotary electric machine is acceptable,
• tr>(τcoilVmax)/(PDIV) (A1)
• where τcoil is a surge propagation time period of one coil of a rotary electric machine winding, PDIV a partial discharge inception voltage between winding turns, and Vmax a peak of a partial discharge testing voltage for the phase-to-phase insulation.

A phase-to-phase insulation partial discharge inspection apparatus for an inverter-driven rotary electric machine, comprising:

• an impulse power supply configured to apply an impulse voltage having a voltage rise time period tr which satisfies an expression (A1) given below to the rotary electric machine;
• a measurement section configured to measure partial discharge which occurs when the impulse voltage is applied to the rotary electric machine;
• and
• a decision section configured to determine that, when partial discharge is not measured by the measurement section, a phase-to-phase insulation performance is acceptable,
• tr>(τcoil·Vmax)/(PDIV) (A1)
• where τcoil is a surge propagation time period of one coil of a rotary electric machine winding, PDIV a partial discharge inception voltage between winding turns, and Vmax a peak of a partial discharge testing voltage for the phase-to-phase insulation.