ENERGY HARVESTING APPARATUS AND A METHOD FOR OPERATING AN ENERGY HARVESTING APPARATUS

• US 20140071722A1
• Filed: 09/09/2013
• Published: 03/13/2014
• Est. Priority Date: 09/07/2012
• Status: Active Grant

• Current Assignee: Agency For Science Technology and Research
• Original Assignee: Agency For Science Technology and Research
• Inventors: Gao, Yuan, Je, Minkyu, Darmayuda, I Made, Cheng, San Jeow, Heng, Chun Huat
• Granted Patent: US 10,050,557 B2
• Time in Patent Office: Days
• US Class Current: 363/80
• CPC Class Codes: H02M 3/1582 Buck-boost converters H02M3/1584 takes precedence
• CPC Class Codes: H02M 7/2176 comprising a passive stage to generate a rectified sinusoidal voltage and a controlled switching element in series between such stage and the output
• CPC Class Codes: H02M 7/219 in a bridge configuration

Abstract

In various embodiments of the present disclosure, there is provided an energy harvesting apparatus, including: an energy harvester for generating electric power from an ambient source; a power conditioning circuit coupled to the output of the energy harvester; including: a boost converter module; a buck-boost converter module; and a power modification control module; wherein the power modification control module is configured to initialize the energy harvesting apparatus from inactivity to a normal energy harvesting state by operating the boost converter module, and operating the buck-boost converter when an output voltage of the power conditioning circuit rises to a predetermined value. A corresponding method of operating an energy harvesting apparatus is provided.

Claims

1. An energy harvesting apparatus, comprising:

an energy harvester for generating electric power from an ambient source;

a power conditioning circuit coupled to the output of the energy harvester;

comprising;

a boost converter module;

a buck-boost converter module; and

a power modification control module;

wherein the power modification control module is configured to initialize the energy harvesting apparatus from inactivity to a normal energy harvesting state by operating the boost converter module, and operating the buck-boost converter when an output voltage of the power conditioning circuit rises to a predetermined value.

2. The energy harvesting apparatus of claim 1, wherein the power modification control module comprises a voltage driver module further comprising a voltage divider coupled to a semiconductor switch.

3. The energy harvesting apparatus according to claim 2, wherein the voltage divider comprises a pair of resistors arranged to activate the semiconductor switch when the output voltage rises to the predetermined value.

4. The energy harvesting apparatus according to claim 2, further comprising a converter control module configured to receive a driving signal from the voltage driver module and manipulate semiconductor switches for operating any one of the boost converter module and the buck-boost converter module.

5. The energy harvesting apparatus according to claim 2, further comprising an oscillator module configured to provide a waveform variation for operating any one of the boost converter module and the buck-boost converter module.

6. The energy harvesting apparatus according to claim 1, wherein the power conditioning module comprises a combined boost/buck-boost converter arrangement configured to operate as any one of the boost converter module and the buck-boost converter module at any time.

7. The energy harvesting apparatus according to claim 1, further comprising:

a rectifier coupled to the energy harvester, the rectifier comprising a plurality of semiconductor switches; and

a body bias control module configured to lower a threshold voltage of at least one of the plurality of semiconductor switches.

8. The energy harvesting apparatus according to claim 7, wherein the plurality of semiconductor switches comprises any one of P-type semiconductor switches and N-type semiconductor switches, and the body bias control module is configured to connect a body of the P-type semiconductor switches to electrical ground, and to connect a body of the N-type semiconductor switches to a reference voltage.

9. The energy harvesting apparatus according to claim 8, wherein the body bias control module comprises a comparator configured to compare the output voltage of the power conditioning circuit to a bandgap voltage.

10. The energy harvesting apparatus according to claim 9, wherein the body bias control module connects the body of the P-type semiconductor switches to the reference voltage, and connects the body of the N-type semiconductor switches to electrical ground, when the output voltage of the power conditioning circuit is larger than the bandgap voltage.

11. A method for operating an energy harvesting apparatus, the energy generating apparatus comprising an energy harvester for generating electric power from an ambient source, the energy harvester coupled to a power conditioning circuit, comprising:

initializing the energy harvesting apparatus from inactivity to a normal generation state, comprising;

carrying out a boost converter function with the power conditioning module; and

monitoring an output voltage of the power conditioning circuit; and

switching from the boost converter function to a buck-boost converter function with the power conditioning module when the output voltage rises to a predetermined value.

12. The method according to claim 11, comprising monitoring the output voltage and switching from the boost converter function to a buck-boost converter function with a voltage driver module comprising a voltage divider coupled to a semiconductor switch.

13. The method according to claim 12, comprising activating the semiconductor switch when a voltage drop across a resistor in the voltage divider rises to the predetermined value.

14. The method according to claim 12, further comprising receiving a driving signal from the voltage driver module and manipulating semiconductor switches for operating any one of the boost converter function and the buck-boost converter function.

15. The method according to claim 12, further comprising providing a waveform variation for operating any one of the boost converter function and the buck-boost converter function with an oscillator module.

16. The method according to claim 11, comprising manipulating a combined boost/buck-boost converter arrangement to operate any one of the boost converter function and the buck-boost converter function with an oscillator module.

17. The method according to claim 11, wherein the energy harvesting apparatus comprises a rectifier coupled to the energy harvester, the rectifier comprising a plurality of semiconductor switches, the method comprising:

lowering a threshold voltage of at least one of the plurality of semiconductor switches with a body bias control module.

18. The method according to claim 17, wherein the plurality of semiconductor switches comprises any one of P-type semiconductor switches and N-type semiconductor switches, the method comprising:

connecting a body of the P-type semiconductor switches to electrical ground; and

connecting a body of the N-type semiconductor switches to a reference voltage.

19. The method according to claim 18, further comprising comparing the output voltage of the power conditioning circuit to a bandgap voltage.

20. The method according to claim 19, further comprising:

determining when the output voltage of the power conditioning circuit is larger than the bandgap voltage;

connecting the body of the P-type semiconductor switches to the reference voltage; and

connecting the body of the N-type semiconductor switches to electrical ground.