Granted Patent B2

US 7,560,904 · App. 11/163,036 · Granted Jul 14, 2009

Abstract

Claims (23)

1. A system of managing power distribution in a hybrid electric vehicle having an a number of transistors for controlling energy flow between an alternator, ultracapacitor, battery, and electric motor, the system comprising:

a sufficient number of transistors associated with each of the ultracapacitor and battery to manage separately flowing energy between the alternator and motor, alternator and ultracapacitor, alternator and battery, ultracapacitor and battery, ultracapacitor and motor, battery and ultracapacitor, and battery and motor;

at least one voltage elevator associated with each transistor and configured for boosting an inputted reference voltage (Vref) by a fixed elevator voltage (VEfixed for output as a voltage (VEout) to a gate of the associated transistor, the fixed elevator voltage (VEfixed corresponds with a minimum voltage differential between the gate and a source (Vgs) required to activate the associate transistor; and

a controller for controlling the separate energy flow between the alternator, ultracapacitor, battery, and electric motor by controlling activation of the transistors, wherein the controller controls activation of the transistors by selecting the reference voltage (Vref) inputted to the voltage elevator of each active transistor to correspond with a source voltage (Vs) of the associated transistor.

2. The system of claim 1 wherein three transistors are associated with each of the ultracapacitor and battery to control the separate energy flow between the alternator, ultracapacitor, battery, and electric motor.

3. A system of managing power distribution in a circuit having a number of switches for controlling energy flow between first and second energy storage devices, a power source, and a load, the system comprising:

a sufficient number of switches associated with each of the energy storage devices to manage energy flow between the energy storage devices, power source, and load;

at least one voltage elevator associated with each switch and configured for outputting a voltage (VEout) to activate the associated switch;

a controller for controlling the energy flow between the energy storage devices, power source, and load by controlling activation switches;

wherein the voltage elevators output the voltage (VEout) as a function of an inputted reference voltage (Vref) boosted according to a fixed elevator voltage (VEfixed); and

wherein the fixed voltage (VEfixed) is associated with an activation threshold voltage (Vt) of the switches.

4. The system of claim 3 wherein the fixed voltage (VEfixed) is further associated with a voltage of the associated ultracapacitor (Vcap) or battery (Vbat).

5. The system of claim 3 wherein the switches are transistors and the fixed voltage (VEfixed) corresponds with a desired gate-to-source voltage (Vgs) of the transistors associated with the activation thereof.

6. The system of claim 5 wherein the fixed voltage (VEfixed) equals the desired gate-to-source voltage (Vgs) if the inputted reference voltage (Vref) equals a source voltage (Vs) of the associated transistor.

7. The system of claim 3 wherein three switches are associated with each of the energy storage devices to control the separate energy flow between the energy storage devices, power source, and load.

8. The system of claim 7 wherein the three voltage elevators associated with the switches of the first energy storage device are configured to bias the associated switch as a function of a fixed voltage boost to a reference voltage associated with the first energy storage device and wherein the three voltage elevators associated with the switches of the second energy storage device are configured to bias the associated switch as a function of a fixed voltage boost voltage to a reference voltage associated with the second energy storage device.

9. The system of claim 8 wherein the power source is an alternator and the load is an electric motor and the first and second storage devices are passive energy storage devices.

10. A method of managing power distribution in a hybrid electric vehicle having an a number of switches for controlling energy flow between an alternator, ultracapacitor, battery, and electric motor, the method comprising:

associating a sufficient number of switches with each of the ultracapacitor and battery to manage separately flowing energy between the alternator and motor, alternator and ultracapacitor, alternator and battery, ultracapacitor and battery, ultracapacitor and motor, battery and ultracapacitor, and battery and motor;

associating at least one voltage elevator with each switch and configuring each voltage elevator for boosting an inputted reference voltage (Vref) by a fixed elevator voltage (VEfixed) for output as a voltage (VEout) sufficient to activate the associated switch;

selecting the fixed elevator voltage (VEfixed) used to boost the inputted reference voltage (Vref) of each switch to correspond with a minimum voltage differential between the voltage (VEout) received from the voltage elevator and an output of the switch; and

controlling the separate energy flow between the alternator, ultracapacitor, battery, and electric motor by controlling activation of the switches, including selecting the inputted reference voltages (Vref) inputted to the voltage elevator for each activated switch to correspond with a voltage at the output of the associated switch.

11. The method of claim 10 wherein the switches are transistors and the method includes fixing the fixed voltage (VEfixed) to corresponds with a desired gate-to-source voltage (Vgs) of the transistors associated with the activation thereof such that the fixed voltage (VEfixed) equals the desired gate-to-source voltage (Vgs) if the inputted reference voltage (Vref) equals a source voltage (Vs) of the associated transistor.

Assignments (9)