VEHICLE STEP-UP CONVERTER CIRCUIT

• US 20100289330A1
• Filed: 07/29/2008
• Published: 11/18/2010
• Est. Priority Date: 08/27/2007
• Status: Abandoned Application

• Current Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Original Assignee: Toyota Jidosha Kabushiki Kaisha (Toyota Motor Corporation)
• Inventors: Uchida, Kenji
• Application Number:
  US12/669,875
• Publication Number:
  US 20100289330A1
• Time in Patent Office: Days
• US Class Current: 307/9.1
• CPC Class Codes: B60R 16/03 for supply of electrical power to vehicle subsystems or for circuit arrangements for charging batteries H02J7/00
• CPC Class Codes: H02M 3/158 including plural semiconductor devices as final control devices for a single load

Abstract

A vehicle step-up converter circuit capable of preventing an excessive current from flowing in electric components and quickly regulating the step-up voltage. The vehicle step-up converter circuit comprises a battery; an inductor, one terminal of which is connected to one terminal of the battery; a first switch connected between the other terminal of the inductor and the other terminal of the battery; a second switch, one terminal of which is connected to the other terminal of the inductor; a capacitor connected between the other terminal of the second switch and the other terminal of the battery; and a switch control unit that controls the first and second switches; wherein the first and second switches are controlled, thereby charging the capacitor to output the voltage held by the capacitor. The switch control unit controls the second switch on and off at a predetermined duty ratio, thereby regulating the output voltage.

Claims

1. A vehicle step-up converter circuit comprising:

a battery for supplying power to a vehicle drive motor;

an inductor of which one terminal is connected to one terminal of the battery;

a first switch connected between the other terminal of the inductor and the other terminal of the battery;

a second switch of which one terminal is connected to the other terminal of the inductor;

a capacitor connected between the other terminal of the second switch and the other terminal of the battery; and

a switch control unit for controlling the first switch and the second switch;

due to control of the first switch and the second switch, a voltage, which is an induced electromotive force of the inductor added to the terminal voltage of the battery, is applied to the capacitor and a voltage, which is retained by the capacitor, is output as an output voltage;

due to control of the first switch and the second switch in accordance with travel control of a vehicle, the output voltage is regulated;

wherein the switch control unit regulates the output voltage by controlling the second switch on and off at a predetermined duty ratio.

2. A vehicle step-up converter circuit according to claim 1 further comprising a table storage unit for storing a duty ratio table where a duty ratio corresponds to a difference between the battery voltage and the output voltage;

the switch control unit selects one of a plurality of duty ratios included the duty ratio table on the basis of the difference between the battery voltage and the output voltage and controls the second switch according to the selected duty ratio.

3. A vehicle step-up converter circuit according to claim 1 further comprising a table storage unit for storing a duty ratio time variable table where a duty ratio corresponds to an elapsed time from control start;

the switch control unit selects one of a plurality of duty ratios included in the duty ratio time variable table on the basis of elapsed time from control start and controls the second switch according to the selected duty ratio.

4. A vehicle step-up converter according to claim 1, wherein the first switch and the second switch respectively comprise a transistor;

the switch control unit controls a base-emitter voltage of the respective transistor in the first switch and the second switch.