Electric vehicle and control method of electric vehicle

Patent metadata

Field	Value
Publication number	US-9641106-B2
Application number	US-201514592330-A
Country	US
Kind code	B2
Filing date	Jan 8, 2015
Priority date	Jan 10, 2014
Publication date	May 2, 2017
Grant date	May 2, 2017

Abstract

An electric vehicle driven by a synchronous motor 21 and an induction motor 31 , and braked with a first regenerative torque BT 1 generated by the synchronous motor generator 21 and a second regenerative torque BT 2 generated by the induction motor generator 31 . The ratio of the first regenerative torque BT 1 to the second regenerative torque BT 2 is changed in accordance with a state of charge (SOC) of a battery 11 . In this way, a switching frequency from a regenerative brake to a hydraulic brake is restricted to improve drivability when a state of charge (SOC) of the battery 11 is high.

First claim

What is claimed is:

1. An electric vehicle comprising
a synchronous motor; and
an induction motor;
wherein the electric vehicle is driven by the synchronous motor and the induction motor, and braked with a first regenerative torque generated by the synchronous motor and a second regenerative torque generated by the induction motor;
the electric vehicle further comprises a battery which supplies a drive electric power to the synchronous motor and the induction motor, and receives a regenerative electric power from the synchronous motor and the induction motor; and
a controller which adjusts the first regenerative torque and the second regenerative torque, and the controller includes a torque setting unit which changes a ratio of the first regenerative torque to the second regenerative torque in accordance with a state of charge of the battery.

2. The electric vehicle according to claim 1 , wherein
when the state of charge of the battery is high, the torque ratio setting unit sets the proportion of the second regenerative torque is set higher than when the state of charge of the battery is low.

3. The electric vehicle according to claim 2 , wherein
when the state of charge of the battery exceeds a first threshold, the torque ratio setting unit increases the proportion of the second regenerative torque and decreases the proportion of the first regenerative torque is decreased along with an increase of the state of charge of the battery.

4. The electric vehicle according to claim 3 , wherein
when the state of charge of the battery is equal to or more than a second threshold, the torque ratio setting unit sets the proportion of the second regenerative torque at 100% and sets the proportion of the first regenerative torque at 0%.

5. The electric vehicle according to claim 4 , wherein
the second threshold is the state of charge of the battery at which a limit starts to be applied to a maximum regenerative electric power of the battery, and the first threshold is smaller than the second threshold.

6. An electric vehicle comprising
a synchronous motor; and
an induction motor;
wherein the electric vehicle is driven by the synchronous motor and the induction motor, and braked with a first regenerative torque generated by the synchronous motor and a second regenerative torque generated by the induction motor;
the electric vehicle further comprises
a battery which supplies a drive electric power to the synchronous motor and the induction motor, and receives a regenerative electric power from the synchronous motor and the induction motor; and
a controller including a CPU, and

the CPU of the controller executes a torque ratio setting program which changes a ratio of the first regenerative torque to the second regenerative torque in accordance with a state of charge of the battery.

7. The electric vehicle according to claim 6 , wherein
when the state of charge of the battery is high, the CPU in the controller sets the proportion of the second regenerative torque higher than when the state of charge of the battery is low.

8. The electric vehicle according to claim 7 , wherein when the state of charge of the battery exceeds a first threshold, the CPU in the controller increases the proportion of the second regenerative torque and decreases the proportion of the first regenerative torque along with an increase of the state of charge of the battery.

9. The electric vehicle according to claim 8 , wherein
when the state of charge of the battery is equal to or more than a second threshold, the CPU in the controller sets the proportion of the second regenerative torque at 100% and sets the proportion of the first regenerative torque at 0%.

10. The electric vehicle according to claim 9 , wherein the second threshold is the state of charge of the battery at which a limit starts to be applied to a maximum regenerative electric power of the battery, and the first threshold is smaller than the second threshold.

11. A controlling method of an electric vehicle including:
a synchronous motor;
an induction motor; and
a battery which supplies a drive electric power to the synchronous motor and the induction motor, and receives a regenerative electric power from the synchronous motor and the induction motor,
the controlling method comprising:
driving the electric vehicle by the synchronous motor and the induction motor, and braking with a first regenerative torque generated by the synchronous motor and a second regenerative torque generated by the induction motor; and
changing the ratio of the first regenerative torque to the second regenerative torque in accordance with a state of charge of the battery.

Assignees

• Toyota Motor Co Ltd

Inventors

• Ota Takashi
• Sato Ryoji
• Suhama Masayoshi

Classifications

• B60L7/00

  Electrodynamic brake systems for vehicles in general · CPC title

• H02P3/18 Primary

  for stopping or slowing an AC motor · CPC title

• H02P5/74

  controlling two or more AC dynamo-electric motors (H02P5/46, H02P5/60 take precedence) · CPC title

• B60L7/24

  with additional mechanical or electromagnetic braking · CPC title

• Y02T10/64

  Electric machine technologies in electromobility · CPC title