Granted Patent B2

US 7,068,017 · App. 10/655,787 · Granted Jun 27, 2006

Abstract

Claims (24)

1. In a system for supplying electrical energy to a load from a direct electrical energy converter, an arrangement for optimizing converter power generation efficiency comprising:

an impedance transformation circuit coupled between the energy converter and load including a power switch operative in a first state to conduct current from the energy converter to the load and operative in a second state to inhibit energy converter current from reaching the load;

an energy converter output current sensor coupled to the energy converter;

an energy converter output voltage sensor coupled to the energy converter;

a load current sensor coupled to the load;

a load voltage sensor coupled to the load; and

a controller coupled to each of the sensors and the power switch, the controller operative to place the power switch in its first and second state in accordance with a desired duty cycle based on a signal from each of the sensors so as to maximize power delivered to the load, and wherein a polarity of the energy converter current delivered to the load is dependent on a product of energy efficiency of the energy converter and power transfer efficiency from the energy converter.

2. The arrangement of claim 1 further comprising:

a load voltage regulator coupled between an output of the impedance transformation circuit and the load.

3. The arrangement of claim 2 wherein the load voltage regulator comprises a DC/DC converter.

4. The arrangement of claim 2 further comprising:

a load balancing energy storage device coupled across the output of the impedance transformation circuit and an input of the load voltage regulator.

5. The arrangement of claim 4 wherein the load balancing energy storage device comprises a battery.

6. The arrangement of claim 4 wherein the load balancing energy storage device comprises an ultra-capacitor.

7. The arrangement of claim 1 wherein the energy converter is selected from the group consisting of: fuel cell, thermoelectric or thermoionic device, electrochemical battery, solar cell or photovoltaic converter, thermophotovoltaic system, plasma power generator, ferroelectric device, piezoelectric device, electrohydrodynamic generator.

8. A method of optimizing power generation efficiency of a direct electrical energy converter applying electrical current to a load, the method comprising:

monitoring output current and output voltage of the direct electrical energy converter;

monitoring current through and voltage across the load;

placing an impedance transformation circuit between the direct electrical energy converter and the load; and

altering a duty cycle of the impedance transformation circuit so as to allow the impedance transformation circuit to operate in a first state to deliver the energy converter current to the load and operating in a second state to inhibit energy converter current from reaching the load so as to maximize power delivered to the load, and wherein a polarity of the energy converter current delivered to the load is dependent on a product of energy efficiency of the energy converter and power transfer efficiency from the energy converter.

9. The method of claim 8 wherein the polarity of the predetermined amount is reversed whenever the product has not changed.

10. The method of claim 8 wherein the polarity of the predetermined amount is reversed whenever the product changes positively and a present polarity of the predetermined amount is positive.

11. The method of claim 8 wherein the polarity of the predetermined amount is reversed whenever the product changes negatively and a present polarity of the predetermined amount is negative.

12. The method of claim 8 wherein the polarity of the predetermined amount is unchanged whenever the product changes in a direction opposite to the present polarity of the predetermined amount.

Assignments (20)