System and method for driving an electric vehicle

• US 6,963,145 B2
• Filed: 02/06/2002
• Issued: 11/08/2005
• Est. Priority Date: 02/06/2001
• Status: Expired due to Term

• Current Assignee: Invacare Corporation
• Original Assignee: Invacare Corporation
• Inventors: Richey, Joseph B. II
• Primary Examiner(s): Deberadinis, Robert L.
• Application Number:
  US10/068,391
• Publication Number:
  US 20040195984A1
• Time in Patent Office: 1,371 Days
• Field of Search: 307/87, 307/43, 307/71, 307/45, 307/46, 307/54, 307/86, 307/9.1, 307/10.1, 180/65.3
• US Class Current: 307/9.1
• CPC Class Codes: B60L 50/00 Electric propulsion with power supplied within the vehicle with power supply from force of nature, e.g. sun or wind, B60L8/00; for monorail vehicles, suspension vehicles or rack railways B60L13/00
• CPC Class Codes: H02P 2201/07 DC-DC step-up or step-down converter inserted between the power supply and the inverter supplying the motor, e.g. to control voltage source fluctuations, to vary the motor speed
• CPC Class Codes: H02P 2201/09 Boost converter, i.e. DC-DC step up converter increasing the voltage between the supply and the inverter driving the motor
• CPC Class Codes: H02P 2201/11 Buck converter, i.e. DC-DC step down converter decreasing the voltage between the supply and the inverter driving the motor
• CPC Class Codes: Y02T 10/64 Electric machine technologies in electromobility

Abstract

A system and method for driving an electric vehicle is provided. The system has, for example, a power source generating a voltage, a voltage converter, a control system, and one or more motors for driving or propelling the vehicle. The voltage converter is configured to accept an input voltage and generate an output voltage, which is different from the input voltage. The power source provides the input voltage to the voltage converter. A switch is further provided to switch the delivery of power to the control system between a power source voltage and an increased voltage derived from the voltage converter.

Claims

1. A system for driving an electric vehicle comprising:

(a) power source;

(b) a voltage booster circuit in circuit communication with the power source, wherein the voltage booster circuit comprises a voltage converter, wherein said voltage converter comprises an input and an output and wherein the output is configured to provide a lesser voltage than the input;

(c) a control circuit in circuit communication with the power source and voltage booster circuit, the control circuit comprising;

a drive circuit in circuit communication with at least one motor; and

(d) a switch in circuit communication with the power source, voltage booster circuit, and control circuit, the switch comprising a first state for connecting the power source to the control circuit and a second state for connecting the voltage booster circuit to the control circuit;

(e) wherein the power source comprises a positive terminal having a voltage and a negative terminal and wherein the voltage converter output comprises a positive terminal and a negative terminal and wherein the voltage converter'"'"'s negative terminal comprises a voltage approximately equal to the voltage of the positive terminal of the power source.

2. The system of claim 1 wherein the control circuit further comprises a logic for switching the switch between the first and second states.

3. A system for driving an electric vehicle comprising:

(a) a voltage booster circuit in circuit communication with a power source, said voltage booster circuit comprising a voltage converter, wherein the voltage converter comprises an input and an output and wherein the output is configured to provide a lesser voltage than the input;

(b) a control circuit in circuit communication with the power source and voltage booster circuit, the control circuit comprising;

drive output signal and a drive circuit in circuit communication with at least one motor;

(c) a switch in circuit communication with the power source, voltage booster circuit, and control circuit, the switch comprising selectively activatable first and second states, the first state connecting the power source to the control circuit and the second state connecting the voltage booster circuit to the control circuit; and

(d) logic for controlling the state of the switch based on the drive output signal;

(e) wherein the power source comprises a positive terminal having a voltage and a negative terminal and wherein the voltage converter output comprises a positive terminal and a negative terminal and wherein the voltage converter'"'"'s negative terminal comprises a voltage approximately equal to the voltage of the positive terminal of the power source.

4. The system of claim 3 wherein the logic for controlling the state of the switch based on the drive output signal comprises logic for placing the switch in the second state when the drive signal is above a predetermined threshold level.

5. The system of claim 3 wherein the logic for controlling the state of the switch based on the drive output signal comprises logic for placing the switch in the first state when the drive signal is below a predetermined threshold level.