# US 2013/0278192 A1 · Control apparatus reducing noise coming from rotary electric machine

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- Number: US 2013/0278192 A1
- Document ID: US20130278192A1
- Status: Published application
- Kind: A1
- Application number: 13/868,430
- Filed: 2013-04-23
- Published: 2013-10-24
- Earliest claimed: 2012-04-23
- Assignees: Denso Corporation
- Applicants: Denso Corporation
- Inventors: Junichi SEMURA; Tomohiro SUDOH; Masanori MORIKAWA
- Web page: https://patentgrep.com/patent/US20130278192A1

## CPC

- H02P 6/10: Arrangements for controlling torque ripple, e.g. providing reduced torque ripple
- H02P 6/15: Controlling commutation time
- H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS

## Abstract

A control apparatus for a rotary electric machine includes: operating unit for operating a DC-AC conversion circuit including a switching element so as to control a controlled variable of the rotary electric machine, the switching element selectively connects positive and negative terminals of a DC power source to respective terminals of the rotary electric machine and conduction period setting unit, in response to a rotational speed of the rotary electric machine, for setting a conduction period during which the respective terminals of the rotary electric machine, and the positive and negative terminals of the DC power source are allowed to be electrically connected therebetween via the switching element. The conduction period setting unit set the conduction period as a manipulated variable so as to reduce electromagnetic force distortion at a frequency corresponding to a resonant frequency of the rotary electric machine.

## Claims

### Claim 1

A control apparatus that controls a rotary electric machine, comprising:
operating means for operating a DC-AC conversion circuit including a switching element so as to control a controlled variable of the rotary electric machine, the switching element selectively connecting a positive terminal and a negative terminal of a DC power source to respective terminals of the rotary electric machine; and
conduction period setting means included in the operating means for setting, in response to a rotational speed of the rotary electric machine, a conduction period during which the respective terminals of the rotary electric machine, and the positive terminal and the negative terminal of the DC power source are allowed to be electrically connected therebetween via the switching element,
wherein the conduction period setting means is configured to set the conduction period as a manipulated variable so as to reduce electromagnetic-force distortion having a frequency component corresponding to a resonant frequency of the rotary electric machine.

### Claim 2 (depends on 1)

The control apparatus according to claim 1, wherein
the rotary electric machine has a circular mode specified by a plurality of degrees, the circular mode being defined by variations of periodical change in shape of the rotary electric machine as an elastic body, the resonant frequency corresponding to own frequency inherent to the degree of the circular mode.

### Claim 3 (depends on 2)

The control apparatus according to claim 2, wherein
the degree of the circular mode corresponds to a number of regions including an increasing angle of a repulsive force in a mechanical angle region, which is generated during one mechanical angle corresponding to one rotation of the rotary electric machine, the mechanical angle region being divided by an increasing angle of a suction force produced by current flowing to generate a rotational flux in the rotary electric machine.

### Claim 4 (depends on 1)

The control apparatus according to claim 1,
wherein the conduction period setting means is configured to control the conduction period such that the higher the rotational speed of the rotary electric machine, the lower the conduction period.

### Claim 5 (depends on 1)

The control apparatus according to claim 1, wherein the conduction period setting means is configured to set the conduction period to be changed with respect to the rotational speed in an available rotational speed range, to have an increasing region in which the conduction period is increased while the rotational speed is increasing and a decreasing region in which the conduction period is decreased while the rotational speed is increasing.

### Claim 6 (depends on 1)

The control apparatus according to claim 1, wherein the conduction period setting means is configured to change the conduction period continuously in response to the rotational speed.

### Claim 7 (depends on 1)

The control apparatus according to claim 1, wherein operating means includes a feedback control means that controls either a duty value of the switching element in the conduction period set by the conduction period setting means or a phase of the conduction period so as to control the controlled variable including a torque or a rotational speed of the rotary electric machine.