Vehicle-mounted power supply system
First Claim
1. A power supply system mounted on a vehicle, comprising:
- a first storage battery;
an automotive generator for generating a voltage and charging said first storage battery with the generated voltage;
a second storage battery connected to an electrical load;
power conversion circuitry having a power converter including a semiconducting switching device connected between said first storage battery and said second storage battery, said power conversion circuitry being operable in a first mode in which a voltage at said second storage battery is maintained at a substantially constant level and in a second mode in which the voltage at said second storage battery varies with a voltage at said first storage battery;
control circuitry for controlling a power transistor according to the voltage at said second storage battery when said power conversion circuitry is operating in said first mode and continuously setting said semiconducting switching device in a conducting state when said power conversion circuitry is operating in said second mode; and
a controller for operating said power conversion circuitry in said first mode when power consumption of said electrical load is lower than a specified value and controlling said generator so that the generated voltage undergoes a transition at a first rate, and operating said power conversion circuitry in said second mode when power consumption of said electrical load is higher than said specified value and controlling said generator so that said generated voltage undergoes a transition at a second rate lower than said first rate.
1 Assignment
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Accused Products
Abstract
In a vehicle-mounted power supply system, the automotive generator generates a voltage for charging a first battery. Power conversion circuitry is connected between the first battery and a second battery that is connected to an electrical load to operate in a first mode or in a second mode when power consumption of the load is lower or higher than a specified value, respectively. In the first mode, the power conversion circuitry maintains the voltage at the second battery at a substantially constant level and in the second mode, the voltage at the second battery varies with the voltage at the first battery. In response to a vehicle speed variation, the automotive generator is controlled so that its output voltage is varied at a first rate when power conversion is performed in the first mode and varied at a second rate lower than the first rate when power conversion is performed in the second mode.
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Citations
12 Claims
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1. A power supply system mounted on a vehicle, comprising:
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a first storage battery; an automotive generator for generating a voltage and charging said first storage battery with the generated voltage; a second storage battery connected to an electrical load; power conversion circuitry having a power converter including a semiconducting switching device connected between said first storage battery and said second storage battery, said power conversion circuitry being operable in a first mode in which a voltage at said second storage battery is maintained at a substantially constant level and in a second mode in which the voltage at said second storage battery varies with a voltage at said first storage battery; control circuitry for controlling a power transistor according to the voltage at said second storage battery when said power conversion circuitry is operating in said first mode and continuously setting said semiconducting switching device in a conducting state when said power conversion circuitry is operating in said second mode; and a controller for operating said power conversion circuitry in said first mode when power consumption of said electrical load is lower than a specified value and controlling said generator so that the generated voltage undergoes a transition at a first rate, and operating said power conversion circuitry in said second mode when power consumption of said electrical load is higher than said specified value and controlling said generator so that said generated voltage undergoes a transition at a second rate lower than said first rate. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. A method of operating a power supply system mounted on a vehicle, wherein the system comprises a first storage battery, an automotive generator for generating a voltage for charging said first storage battery, a second storage battery connected to an electrical load and power conversion circuitry connected between said first storage battery and said second storage battery, the method comprising the steps of:
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a) operating said power conversion circuitry in a first mode when power consumption of said electrical load is lower than a specified value so that a voltage at said second storage battery is substantially maintained at a constant level and operating the power conversion circuitry in a second mode when said power consumption is higher than said specified value so that said voltage at said second storage battery varies with a voltage at said first storage battery; b) controlling said automotive generator so that the generated voltage undergoes a transition at a first rate when said power conversion circuitry is operating in said first mode and undergoes a transition at a second rate lower than said first rate when said power conversion circuitry is operating in said second mode, wherein when the power conversion circuitry is operating in said first mode, step (b) further comprises the steps of; controlling said generator so that the generated voltage is set at a lower target level when said vehicle is under acceleration; controlling said generator so that the generated voltage is set at a higher target level when said vehicle is under deceleration; and controlling said generator so that the generated voltage is set at a medium target level between said higher and lower target levels when said vehicle changes speed either from acceleration or deceleration to cruising, and wherein, when the power conversion circuitry is operating in said second mode, step (b) comprises the steps of; controlling said generator so that the generated voltage gradually decreases until it reaches said lower target level when said vehicle is under acceleration; controlling said generator so that the generated voltage gradually increases until it reaches said higher target level when said vehicle is under deceleration; and controlling said generator so that the generated voltage gradually varies until it reaches said medium target level when said vehicle changes speed either from acceleration or deceleration to cruising.
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Specification