Hybrid vehicle

• US 6,422,331 B1
• Filed: 08/28/2000
• Issued: 07/23/2002
• Est. Priority Date: 08/30/1999
• Status: Expired due to Term

• Current Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Original Assignee: Honda Giken Kogyo Kabushiki Kaisha (Honda Motor Company)
• Inventors: Yoshikawa, Shinji, Ochiai, Shinobu
• Primary Examiner(s): Mai, Lanna
• Assistant Examiner(s): RESTIFO, JEFFREY J
• Application Number:
  US09/648,749
• Time in Patent Office: 694 Days
• Field of Search: 180/65.2, 180/65.3, 180/65.4, 180/65.1, 180/65.8, 701/22, 318/430, 318/432, 318/433, 318/434, 318/471
• US Class Current: 180/65.25
• CPC Class Codes: B60K 6/48 Parallel type
• CPC Class Codes: B60L 2240/36 Temperature of vehicle components or parts
• CPC Class Codes: B60L 2250/10 by alarm
• CPC Class Codes: B60L 3/003 relating to inverters
• CPC Class Codes: B60L 3/0038 relating to sensors
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/0069 relating to the isolation, e.g. ground fault or leak current
• CPC Class Codes: B60L 3/0092 with use of redundant elements for safety purposes
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/18 of two or more battery modules
• CPC Class Codes: B60L 58/26 by cooling
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 10/08 including control of electric propulsion units, e.g. motors or generators
• CPC Class Codes: B60W 10/26 for electrical energy, e.g. batteries or capacitors
• CPC Class Codes: B60W 20/00 Control systems specially adapted for hybrid vehicles hybrid vehicle design, B60K6/00; electric vehicles B60L
• CPC Class Codes: B60W 20/13 in order to stay within battery power input or output limits; in order to prevent overcharging or battery depletion
• CPC Class Codes: Y02T 10/62 Hybrid vehicles
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y10S 903/903 : having energy storing means, e.g. battery, capacitor

Abstract

A hybrid vehicle includes a power drive unit which is quickly stopped without increasing the load on a motor control apparatus should a short develop inside the power drive unit. The power drive unit contains a self-protection circuit, which shuts off the control signals to the switching elements for a given interval, when the temperature of the switching elements reaches a certain temperature value or when the current flowing in the power drive unit reaches a certain current value. The self-protection circuit outputs a shorting signal to indicate the state of the self-protection caused by the shut off. The motor control apparatus detects shorting signals from the self-protection circuit, and responds by stopping the output of control signals, when the self-protection state is reported, is greater than a predetermined number of times or the cumulative time in the self-protection state reaches a predetermined time.

Claims

1. A hybrid vehicle comprising:

an engine;

a motor which operates with electrical energy;

a power drive unit having switching elements to control the flow of current to operate said motor; and

a control apparatus for generating control signals to operate said switching elements;

wherein

said power drive unit is further provided with a self-protection circuit to interrupt the supply of said current to said switching elements temporarily for a specified interval when a temperature of at least one of said switching elements is higher than a specific temperature value or the value of current flowing through said power drive unit is greater than a specific current value, and to output a signal indicating that said power drive unit is in a self-protection state caused by a current flow interruption; and

said control apparatus receives said signal from said self-protection circuit indicating that said power drive unit is in the self-protection state, and if a number of times said self-protection state is greater than a predetermined number or if the cumulative time in said self-protection state is greater than a predetermined time, said control apparatus prohibits said control signal from operating said switching elements.

2. A hybrid vehicle according to claim 1, wherein said control apparatus prohibits said control signals when said control apparatus sequentially detects, at a predetermined duration, a condition that either a number of times said signal is received is greater than a predetermined number or the cumulative time in said self-protection state is greater than a predetermined time.

3. A hybrid vehicle according to claim 1, wherein said vehicle is further provided with a battery to supply driving power to at least said self-protection circuit and said control apparatus;

and said control apparatus stops receiving said signal sent from said self-protection circuit when a detected voltage of said battery is lower than a specified voltage value.

4. A hybrid vehicle according to claim 3, wherein said control apparatus decides that said battery is in a voltage-low state when a state, in which said detected voltage of said battery is lower than said specified voltage value, continues for a specified voltage-low determination interval, and responds by lowering an existing value of the motor torque to zero or by prohibiting said control signals depending on the operating conditions of said motor.

5. A hybrid vehicle according to claim 4, wherein said control apparatus determines that said battery that had been in a voltage-low state is now in a voltage-recovery state when a state, in which said detected voltage of said battery is higher than a specified threshold value, continues for a specified voltage-recovery determination interval, and responds by outputting a control signal to operate said motor so as to adjust an existing value of the motor torque to match a demanded value of the motor torque.