# US 9,751,408 B2 · Motor driving unit

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- Number: US 9,751,408 B2
- Document ID: US9751408B2
- Status: Granted
- Kind: B2
- Application number: 15/173,787
- Filed: 2016-06-06
- Published: 2017-01-05
- Granted: 2017-09-05
- Earliest claimed: 2015-07-03
- Assignees: Kabushiki Kaisha Toyota Jidoshokki
- Applicants: Kabushiki Kaisha Toyota Jidoshokki
- Inventors: Keisuke Kitamura; Yoshinori Shimizu
- Web page: https://patentgrep.com/patent/US9751408B2

## CPC

- B60L 3/003: {relating to inverters}
- B60L 50/51: characterised by AC-motors
- H02P 27/06: using DC to AC converters or inverters (H02P27/05 takes precedence)
- H02P 29/0241: {the fault being an overvoltage}
- Y02T 10/64: Electric machine technologies in electromobility
- Y02T 10/70: Energy storage systems for electromobility, e.g. batteries
- B60L: PROPULSION OF ELECTRICALLY-PROPELLED VEHICLES (arrangements or mounting of electrical propulsion units or of plural diverse prime-movers for mutual or common propulsion in vehicles B60K1/00, B60K6/20; arrangements or mounting of electrical gearing in vehicles B60K17/12, B60K17/14; preventing wheel slip by reducing power in rail vehicles B61C15/08; dynamo-electric machines H02K; control or regulation of electric motors H02P); SUPPLYING ELECTRIC POWER FOR AUXILIARY EQUIPMENT OF ELECTRICALLY-PROPELLED VEHICLES (electric coupling devices combined with mechanical couplings of vehicles B60D1/64; electric heating for vehicles B60H1/00); ELECTRODYNAMIC BRAKE SYSTEMS FOR VEHICLES IN GENERAL (control or regulation of electric motors H02P); MAGNETIC SUSPENSION OR LEVITATION FOR VEHICLES; MONITORING OPERATING VARIABLES OF ELECTRICALLY-PROPELLED VEHICLES; ELECTRIC SAFETY DEVICES FOR ELECTRICALLY-PROPELLED VEHICLES
- H02P: CONTROL OR REGULATION OF ELECTRIC MOTORS, ELECTRIC GENERATORS OR DYNAMO-ELECTRIC CONVERTERS; CONTROLLING TRANSFORMERS, REACTORS OR CHOKE COILS
- Y02T: CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION

## Abstract

A motor driving unit (1) includes a controller (15) that performs driving control of a motor (3) by controlling an inverter (11). During regeneration of the motor (3), the controller (15) performs output stopping control for causing the inverter (11) to stop an output, when an inter-terminal voltage of a capacitor (12) is equal to or greater than a first threshold value. The controller (15) performs output restarting control for causing the inverter (11) to restart the output, when the inter-terminal voltage of the capacitor (12) is equal to or smaller than a second threshold value which is smaller than the first threshold value. The controller (15) performs regenerative braking by allowing the output stopping control and the output restarting control to be repeatedly performed.

## Claims

### Claim 1

A motor driving unit for driving a vehicle driving motor by using a battery as a power source, comprising:
an inverter that converts DC power supplied from the battery into AC power, and that supplies the AC power to the motor;
a controller that performs driving control of the motor by controlling the inverter, based on a rotation frequency of the motor;
a capacitor that is connected in parallel to an input side of the inverter; and
a voltage sensor that detects an inter-terminal voltage of the capacitor,
wherein during regeneration of the motor, the controller performs output stopping control for causing the inverter to stop an output of the AC power, when the inter-terminal voltage of the capacitor which is detected by the voltage sensor is equal to or greater than a first threshold value,
wherein the controller performs output restarting control for causing the inverter to restart the output of the AC power, when the inter-terminal voltage of the capacitor which is detected by the voltage sensor is equal to or smaller than a second threshold value which is smaller than the first threshold value, and
wherein the controller performs regenerative braking by allowing the output stopping control and the output restarting control to be repeatedly performed.

### Claim 2 (depends on 1)

The motor driving unit according to claim 1,
wherein the controller performs the regenerative braking by allowing the output stopping control and the output restarting control to be repeatedly performed, when a variation amount of the inter-terminal voltage of the capacitor falls below a third threshold value during the output stopping control.

### Claim 3 (depends on 2)

The motor driving unit according to claim 2,
wherein the controller increases a count when the variation amount of the inter-terminal voltage of the capacitor does not fall below the third threshold value during the output stopping control, and
wherein the controller continuously performs the output stopping control, and does not allow the output restarting control, when the count reaches a predetermined value.

### Claim 4 (depends on 2)

The motor driving unit according to claim 2,
wherein the controller does not increase a count when the variation amount of the inter-terminal voltage of the capacitor falls below the third threshold value during the output stopping control.

### Claim 5 (depends on 1)

The motor driving unit according to claim 1,
wherein the controller reduces the output of the AC power of the inverter during the output restarting control.