Field coil type rotating electric machine

Patent metadata

Field	Value
Publication number	US-11218065-B2
Application number	US-202016881426-A
Country	US
Kind code	B2
Filing date	May 22, 2020
Priority date	May 22, 2019
Publication date	Jan 4, 2022
Grant date	Jan 4, 2022

Abstract

A field coil type rotating electric machine includes a rotor where both a series resonant circuit including a first winding and a capacitor and a parallel resonant circuit including a second winding and the capacitor are formed. The first winding is radially located closer than the second winding to a stator. The capacitance of the capacitor and the ratio of the number of turns of the second winding to the number of turns of the first winding are set to have the amplitude of a total resultant magnetic flux lower than the amplitude of a field resultant magnetic flux. The total resultant magnetic flux is the resultant of the field resultant magnetic flux and magnetic flux generated by harmonic currents flowing in phase windings of a stator coil. The field resultant magnetic flux is the resultant of magnetic fluxes generated by harmonic currents flowing in the first and second windings.

First claim

What is claimed is:

1. A field coil type rotating electric machine comprising:
a stator including a stator coil that is comprised of a plurality of phase windings;
a field coil including a serially-connected winding pair consisting of a first winding and a second winding that are connected in series with each other; and
a rotor including a rotor core and a plurality of main pole portions that are formed at predetermined intervals in a circumferential direction and each radially protrude from the rotor core,
wherein
each of the first and second windings of the field coil is wound on each of the main pole portions of the rotor,
each of the phase windings of the stator coil is configured to be supplied with harmonic current to induce field current in the field coil,
the field coil type rotating electric machine further comprises a diode and a capacitor,
the diode has its cathode connected to a first-winding-side end of the serially-connected winding pair and its anode connected to a second-winding-side end of the serially-connected winding pair,
the capacitor is connected in parallel with the second winding,
in the field coil type rotating electric machine, there are formed both a series resonant circuit including the first winding and the capacitor and a parallel resonant circuit including the second winding and the capacitor,
the first winding is radially located closer than the second winding to the stator, and
a capacitance of the capacitor and a turn number ratio, which is the ratio of the number of turns of the second winding to the number of turns of the first winding, are set to have an amplitude of a total resultant magnetic flux lower than an amplitude of a field resultant magnetic flux when the harmonic currents are supplied to the phase windings of the stator coil, the total resultant magnetic flux being the resultant of the field resultant magnetic flux and magnetic flux generated by the harmonic currents flowing in the phase windings of the stator coil, the field resultant magnetic flux being the resultant of magnetic flux generated by harmonic current flowing in the first winding and magnetic flux generated by harmonic current flowing in the second winding.

2. The field coil type rotating electric machine as set forth in claim 1 , wherein the turn number ratio is set to be higher than or equal to 0.5 and lower than or equal to 5.2 with the capacitance of the capacitor set to be in a predetermined range under a constraint of keeping a resonance frequency of the series resonant circuit at a predetermined frequency and a turn number sum, which is the sum of the number of turns of the first winding and the number of turns of the second winding, at a predetermined turn number.

3. The field coil type rotating electric machine as set forth in claim 2 , wherein

A

2
⁢

⁢
π
⁢

(

2
×
N
⁢

⁢
2

)

2

·
C

≤
fs
≤

A

2
⁢

⁢
π
⁢

(

0.2
×
N
⁢

⁢
2

)

2

·
C

where A is a predetermined coefficient, N 2 is the number of turns of the second winding, C is the capacitance of the capacitor and fs is a frequency of the harmonic currents supplied to the phase windings of the stator coil.

4. The field coil type rotating electric machine as set forth in claim 2 , wherein the predetermined range is higher than or equal to 20 μF and lower than or equal to 50 μF.

5. The field coil type rotating electric machine as set forth in claim 2 , wherein the turn number ratio is set to be higher than or equal to 0.7 and lower than or equal to 5.2.

6. Afield coil type rotating electric machine ( 30 ) comprising:
a stator ( 50 ) including a stator coil ( 31 ) that is comprised of a plurality of phase windings ( 31 U, 31 V, 31 W);
a field coil ( 70 ) including a serially-connected winding pair consisting of a first winding ( 71 a ) and a second winding ( 71 b ) that are connected in series with each other; and
a rotor ( 60 ) including a rotor core ( 61 ) and a plurality of main pole portions ( 62 ) that are formed at predetermined intervals in a circumferential direction and each radially protrude from the rotor core,
wherein
each of the first and second windings of the field coil is wound on each of the main pole portions of the rotor,
each of the phase windings of the stator coil is configured to be supplied with harmonic current to induce field current in the field coil,
the field coil type rotating electric machine further comprises a diode ( 80 ) and a capacitor ( 100 ),
the diode has its cathode connected to a first-winding-side end of the serially-connected winding pair and its anode connected to a second-winding-side end of the serially-connected winding pair,
the capacitor is connected in parallel with the first winding,
in the field coil type rotating electric machine, there are formed both a series resonant circuit including the second winding and the capacitor and a parallel resonant circuit including the first winding and the capacitor,
the second winding is radially located closer than the first winding to the stator, and
a capacitance (C) of the capacitor and a turn number ratio (N 2 /N 1 ), which is the ratio of the number of turns (N 2 ) of the second winding to the number of turns (N 1 ) of the first winding, are set to have an amplitude of a total resultant magnetic flux (ϕtotal) lower than an amplitude of a field resultant magnetic flux (ϕrt) when the harmonic currents are supplied to the phase windings of the stator coil, the total resultant magnetic flux being the resultant of the field resultant magnetic flux and magnetic flux (ϕs) generated by the harmonic currents flowing in the phase windings of the stator coil, the field resultant magnetic flux being the resultant of magnetic flux (ϕ 1 ) generated by harmonic current flowing in the first winding and magnetic flux (ϕ 2 ) generated by harmonic current flowing in the second winding.

Assignees

• Denso Corp

Inventors

• Seguchi Masahiro

Classifications

• H02K19/26

  characterised by the arrangement of exciting windings · CPC title

• H02P27/08

  with pulse width modulation · CPC title

• H02K2213/03

  Machines characterised by numerical values, ranges, mathematical expressions or similar information · CPC title

• H02P6/17

  and for generating speed information · CPC title

• H02K19/28

  for self-excitation · CPC title