Toyota Jidosha Kabushiki Kaisha

Hidenori Yokoyama

Nobuyuki Okabe

Shoji Abo

Shuuichi Nagata

Yoshinori Okazaki

Kousuke Suzui

An abnormality detection apparatus for a power supply circuit associated with an internal combustion engine detects an abnormality that may occur in a power supply circuit, and controls the automatic stop and the automatic start of the engine based on the state of the power supply circuit. The state of charge/discharge of a battery determined based on the electric potential of a terminal located between the battery and a generator-motor or a load is compared with the current through the battery detected by an ammeter. If there is a contradiction therebetween, it is determined that an abnormality has occurred somewhere in the power supply circuit including the battery. When it is determined that the power supply circuit has an abnormality, the apparatus performs such a control as to prevent the automatic stop/start control in which the engine is automatically stopped if a predetermined condition is met, and in which the engine is automatically restarted when the condition is unmet after being met.

Abnormality detection apparatus for power supply circuit

A refresh charge control device which counts a time after achieving a fully charged condition of a battery by last refresh charge and an accumulative value of a charge and discharge electric current. Plural relationship between the time and the accumulative value is determined as conditions for carrying out the refresh charge of the battery. When either one of those relationship is established, the refresh charge of the battery is performed for fully charging the battery. It is judged whether a condition that a vehicle speed is equal to or faster than a predetermined vehicle speed continues for a predetermined time. Even the condition that the vehicle speed is equal to or faster than the predetermined vehicle speed continues for the predetermined time, the refresh charge of the battery is performed for fully charging the battery irrespective of the relationship between the time and the accumulative value.

Refresh charge control device and method

The invention provides a circuit for supplying electric power to a load using a high voltage battery, the circuit supplying a dark current when the load is not being operated. A high voltage load and a low voltage load are attached to a battery and electric power is supplied to the low voltage load through a main DC-DC converter and a sub DC-DC converter. When an ignition switch is OFF, only the sub converter supplies the dark current to the low voltage load and the main DC-DC converter is turned OFF. When the ignition switch is ON, the main DC-DC converter supplies required electric power. Since a low-capacity sub DC-DC converter supplies the dark current, the battery discharge can be prevented.

Control apparatus for a power supply circuit including plural converter

In a power supply system in which a load is connected to a battery, the battery is efficiently charged without degrading the characteristics of the load. When a load that deteriorates in characteristics if a voltage exceeding the rated voltage of the load is applied thereto is connected to the battery (during an on-state of the load), the battery is charged with the rated voltage even if there is a need to charge the battery with a charging voltage higher than the rated voltage. Alternatively, the battery may be charged for a predetermined time at a voltage above the rated voltage and then at or below the rated voltage, or the voltage seen by the load may be converted to a voltage at or below the rated voltage while the battery is being charged at a voltage above the rated voltage. When the load is off, the battery is charged with a voltage higher than the rated voltage.

Power supply system and control method for the system

A device for determining a state of charge of a battery with high precision regardless of deterioration of the battery. After fully charging the battery, the device sets the battery to an arbitrary state of charge. The device then detects the charging voltage and the charging current occurring at that time. Based on the detected charging voltage and the detected charging current, the device corrects a pre-stored relationship among the charging voltage, the charging current, and the state of charge. After that, based on the corrected relationship, the device determines a state of charge of the battery.

Growing community of inventors

Toyota, Japan

Hidenori Yokoyama