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

Patent metadata

Field	Value
Publication number	US-10024896-B2
Application number	US-201114112828-A
Country	US
Kind code	B2
Filing date	Apr 26, 2011
Priority date	Apr 26, 2011
Publication date	Jul 17, 2018
Grant date	Jul 17, 2018

Abstract

A phase-to-phase insulation partial discharge inspection apparatus includes: an impulse power supply (1) configured to apply an impulse voltage having a voltage rise time period tr which satisfies an expression “tr>(τcoil·Vmax)/(PDIV)” to a rotary electric machine (2); a measurement section (12) configured to measure partial discharge which occurs when the impulse voltage is applied to the rotary electric machine (2); and a decision section (15) configured to determine that, when partial discharge is not measured by the measurement section (12), a phase-to-phase insulation performance is acceptable. In the expression, 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.

First claim

The invention claimed is:

1. 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 confirmed, the partial discharge did not occur in winding insulation, and occurred in insulation of the rotary electric machine other than winding insulation,
tr>( t coil ·V max )/(PDIV)  (A1)

where t coil 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 V max a peak of a partial discharge testing voltage for the phase-to-phase insulation.

2. The phase-to-phase insulation partial discharge inspection method for an inverter-driven rotary electric machine according to claim 1 , wherein
the impulse voltage is an oscillation voltage having an oscillation frequency f, and
the voltage rise time period tr is set so as to satisfy the following expression (A2):
tr≤1/(4 f )  (A2).

3. The phase-to-phase insulation partial discharge inspection method for an inverter-driven rotary electric machine according to claim 2 , wherein
the impulse voltage is a damped oscillation voltage having the oscillation frequency f and a time constant K, and
the oscillation frequency f is set so as to satisfy the following expression (A3):
−1/(2 K· 1 n (( V test /V max )−1)≤ f≤ 1/(2√( L·C ))  (A3),

where V test is a peak-to-peak voltage of the damped oscillation voltage given by V test =V max (1+exp(−(1/2f)/k)), L is an overall inductance of the winding turns, and C is an overall capacitance between the winding turns and a core or ground of the rotary electric machine.

4. 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 occurrence of partial discharge is confirmed, the partial discharge did not occur in winding insulation, and occurred in insulation of the rotary electric machine other than winding insulation,
tr>( t coil ·V max )/(PDIV)  (A1)

where t coil 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 V max a peak of a partial discharge testing voltage for the phase-to-phase insulation.

5. The phase-to-phase insulation partial discharge inspection apparatus for an inverter-driven rotary electric machine according to claim 4 , wherein
the impulse voltage is an oscillation voltage having an oscillation frequency f, and
the voltage rise time period tr is set so as to satisfy the following expression (A2):
tr≤1/(4 f )  (A2).

6. The phase-to-phase insulation partial discharge inspection apparatus for an inverter-driven rotary electric machine according to claim 5 , wherein
the impulse voltage is a damped oscillation voltage having the oscillation frequency f and a time constant K, and
the oscillation frequency f is set so as to satisfy the following expression (A3):
−1/(2 K· 1 n (( V test /V max )−1)≤ f≤ 1/(2√( L·C ))  (A3),

where V test is a peak-to-peak voltage of the damped oscillation voltage given by V test =V max (1+exp(−(1/2f)/k)), L is an overall inductance of the winding turns, and C is an overall capacitance between the winding turns and a core or ground of the rotary electric machine.

Assignees

• Obata Koji
• Hitachi Automotive Systems Ltd

Inventors

• Obata Koji

Classifications

• G01R31/1272 Primary

  of cable, line or wire insulation, e.g. using partial discharge measurements (locating faults in cables G01R31/083) · CPC title

• H02K3/00

  Details of windings · CPC title

• G01R31/346

  Testing of armature or field windings · CPC title

• G01R31/343

  in operation · CPC title

• G01R25/00 Primary

  Arrangements for measuring phase angle between a voltage and a current or between voltages or currents · CPC title