# US 10,770,577 B2 · Rectifier and rotating electric machine including rectifier

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 10,770,577 B2
- Document ID: US10770577B2
- Status: Granted
- Kind: B2
- Application number: 16/250,367
- Filed: 2019-01-17
- Published: 2019-08-01
- Granted: 2020-09-08
- Earliest claimed: 2018-01-26
- Assignees: Denso Corporation
- Applicants: Denso Corporation
- Inventors: Toshinori Maruyama
- Web page: https://patentgrep.com/patent/US10770577B2

## CPC

- H10D 84/148: {the built-in components being breakdown diodes, e.g. Zener diodes}
- H02K 11/05: Rectifiers associated with casings, enclosures or brackets
- H02K 19/36: Structural association of synchronous generators with auxiliary electric devices influencing the characteristic of the generator or controlling the generator, e.g. with impedances or switches
- H02M 1/08: Circuits specially adapted for the generation of control voltages for semiconductor devices incorporated in static converters
- H02M 1/083: {for the ignition at the zero crossing of the voltage or the current}
- H02M 1/32: Means for protecting converters other than automatic disconnection
- H02M 7/2195: {the switches being synchronously commutated at the same frequency of the AC input voltage}
- H10D 8/25: Zener diodes
- H10D 8/60: Schottky-barrier diodes
- H10D 30/668: {having trench gate electrodes, e.g. UMOS transistors}
- H10D 84/146: {the built-in components being Schottky barrier diodes}
- H10D 84/811: {Combinations of field-effect devices and one or more diodes, capacitors or resistors}
- H10D 84/86: of Schottky-barrier gate FETs
- H10D 89/611: {using diodes as protective elements}
- H02K 9/06: with fans or impellers driven by the machine shaft
- H10D 12/481: {having gate structures on slanted surfaces, on vertical surfaces, or in grooves, e.g. trench gate IGBTs}
- H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})
- H02M: APPARATUS FOR CONVERSION BETWEEN AC AND AC, BETWEEN AC AND DC, OR BETWEEN DC AND DC, AND FOR USE WITH MAINS OR SIMILAR POWER SUPPLY SYSTEMS; CONVERSION OF DC OR AC INPUT POWER INTO SURGE OUTPUT POWER; CONTROL OR REGULATION THEREOF (transformers H01F; dynamo-electric converters H02K47/00; controlling transformers, reactors or choke coils, control or regulation of electric motors, generators or dynamo-electric converters H02P)

## Abstract

A rectifier has a rectification circuit configured to rectify multi-phase alternating current generated by a rotating electric machine into direct current. The rectifier includes upper-arm semiconductor switching elements included in an upper arm of the rectification circuit, upper-arm protection diodes included in the upper arm and each being electrically connected in parallel with one of the upper-arm semiconductor switching elements, lower-arm semiconductor switching elements included in a lower arm of the rectification circuit, and lower-arm protection diodes included in the lower arm and each being electrically connected in parallel with one of the lower-arm semiconductor switching elements. Each of the upper-arm and lower-arm protection diodes is configured to have, when a reverse voltage higher than a breakdown voltage of the protection diode is applied to the protection diode, an operating resistance that is higher than three times an operating resistance of any of the upper-arm and lower-arm semiconductor switching elements.

## Claims

### Claim 1

A rectifier for a rotating electric machine, the rotating electric machine comprising a rotating shaft, a rotor fixed on the rotating shaft to rotate together with the rotating shaft, and a stator configured to generate multi-phase alternating current therein with rotation of the rotor,
the rectifier having a rectification circuit formed therein, the rectification circuit being configured as a multi-phase bridge circuit, which has an upper arm and a lower arm, to rectify the multi-phase alternating current generated in the stator into direct current,
the rectifier comprising:
a plurality of upper-arm semiconductor switching elements for respective phases included in the upper arm of the rectification circuit;
a plurality of upper-arm protection diodes for respective phases included in the upper arm of the rectification circuit, each of the upper-arm protection diodes being electrically connected in parallel with one of the upper-arm semiconductor switching elements which is of the same phase as the upper-arm protection diode;
a plurality of lower-arm semiconductor switching elements for respective phases included in the lower arm of the rectification circuit; and
a plurality of lower-arm protection diodes for respective phases included in the lower arm of the rectification circuit, each of the lower-arm protection diodes being electrically connected in parallel with one of the lower-arm semiconductor switching elements which is of the same phase as the lower-arm protection diode,
wherein each of the upper-arm and lower-arm protection diodes is configured to have, when a reverse voltage higher than a breakdown voltage of the protection diode is applied to the protection diode, an operating resistance that is higher than three times an operating resistance of any of the upper-arm and lower-arm semiconductor switching elements.

### Claim 2 (depends on 1)

The rectifier as set forth in claim 1, wherein the operating resistance of each of the upper-arm and lower-arm protection diodes is higher than 6 mΩ.

### Claim 3 (depends on 1)

The rectifier as set forth in claim 1, wherein the operating resistance of each of the upper-arm and lower-arm protection diodes is lower than 50 mΩ.

### Claim 4 (depends on 1)

The rectifier as set forth in claim 1, wherein each of the upper-arm and lower-arm semiconductor switching elements is a MOSFET, and
a withstand voltage of the MOSFET against a reverse voltage applied between a drain and a source of the MOSFET is higher than the breakdown voltage of each of the upper-arm and lower-arm protection diodes.

### Claim 5 (depends on 4)

The rectifier as set forth in claim 4, further comprising a controller that controls switching of the MOSFET based on a voltage between the drain and the source of the MOSFET, wherein
the controller is electrically connected between the drain and the source of the MOSFET in parallel with the MOSFET, and
a withstand voltage of the controller against the reverse voltage applied between the drain and the source of the MOSFET is higher than the withstand voltage of the MOSFET against the reverse voltage.

### Claim 6 (depends on 1)

The rectifier as set forth in claim 1, wherein each of the upper-arm and lower-arm protection diodes is formed of a semiconductor wafer having a first thickness, each of the upper-arm and lower-arm semiconductor switching elements is formed of a semiconductor wafer having a second thickness, and
the first thickness is greater than three times the second thickness.

### Claim 7 (depends on 1)

The rectifier as set forth in claim 1, wherein each of the upper-arm and lower-arm protection diodes is a Zener diode, and
the upper-arm and lower-arm protection diodes are integrally formed with the upper-arm and lower-arm semiconductor switching elements on a same semiconductor wafer.

### Claim 8 (depends on 7)

The rectifier as set forth in claim 7, wherein each of the upper-arm and lower-arm semiconductor switching elements is a MOSFET with a trench structure, and the upper-arm and lower-arm protection diodes are separated from one another by the trench structure.

### Claim 9 (depends on 1)

The rectifier as set forth in claim 1, wherein each of the upper-arm and lower-arm protection diodes is a Schottky diode,
each of the upper-arm and lower-arm semiconductor switching elements is a MOSFET, and
the upper-arm and lower-arm protection diodes are integrally formed with the upper-arm and lower-arm semiconductor switching elements on a same semiconductor wafer.

### Claim 10 (depends on 9)

The rectifier as set forth in claim 9, wherein each of the upper-arm and lower-arm semiconductor switching elements is a MOSFET with a trench structure, and the upper-arm and lower-arm protection diodes are separated from one another by the trench structure.

### Claim 11 (depends on 1)

A rotating electric machine including the rectifier as set forth in claim 1.

### Claim 12 (depends on 1)

The rectifier as set forth in claim 1, wherein when a surge current is generated in the stator and flows through the rectifier, the surge current is distributed to the upper arm and the lower arm.