Autonomous power supply system

Patent metadata

Field	Value
Publication number	US-9590451-B2
Application number	US-201414323694-A
Country	US
Kind code	B2
Filing date	Jul 3, 2014
Priority date	Jul 5, 2013
Publication date	Mar 7, 2017
Grant date	Mar 7, 2017

Abstract

An autonomous power supply system includes a generation control circuit which controls power generation efficiency of a power generation element, a group of storage elements for charging electric power generated by the power generation element, and a charging control circuit which controls a charging operation and a discharging operation of the storage element group. The storage element group includes a primary storage element for supplying electric power to the generation control circuit and the charging control circuit, and secondary storage elements for supplying electric power to a loading device. The electric power generated by the power generation element charges the primary storage element preferentially, and the secondary storage elements subsequent to the primary storage element. A capacity value of the primary storage element is set to be smaller than a capacity value of the secondary storage elements.

First claim

What is claimed is:

1. An autonomous power supply system for supplying electric power generated by a power generation element to a loading device, comprising:
a generation control circuit which controls power generation efficiency of the power generation element;
a storage element group which charges the electric power generated by the power generation element; and
a charging control circuit which controls a charging operation and a discharging operation of the storage element group,
wherein the storage element group includes a primary storage element for supplying electric power to the generation control circuit and the charging control circuit, and a secondary storage element for supplying electric power to the loading device; and
the primary storage element is first charged with the electric power generated by the power generation element until a voltage of the primary storage element reaches a first predetermined threshold value, and when the first predetermined threshold value is reached, the secondary storage element is subsequently charged by charge supplied from the primary storage element until the voltage of the primary storage element reaches a second predetermined threshold value.

2. The autonomous power supply system according to claim 1 , wherein a capacity value of the primary storage element is smaller than a capacity value of the secondary storage element.

3. The autonomous power supply system according to claim 2 , wherein the secondary storage element includes a plurality of storage elements for supplying electric power to a plurality of loading blocks of the loading device.

4. The autonomous power supply system according to claim 3 , wherein a priority is given to the plurality of storage elements in accordance with a priority order of the plurality of loading blocks.

5. The autonomous power supply system according to claim 2 ,
wherein the storage element group further includes a tertiary storage element which is charged subsequent to the primary storage element after charging of the primary and the secondary storage elements; and
when electric power is not generated by the power generation element, the tertiary storage element supplies electric power to the primary and the secondary storage elements.

6. The autonomous power supply system according to claim 2 , wherein the charging control device judges whether or not it is possible to discharge the storage elements by comparing each voltage of the storage elements with a one or more of the first and second predetermined threshold values, and executes charging of the storage element when it is judged that it is impossible to discharge in accordance with a preset priority order of the respective storage elements.

7. The autonomous power supply system according to claim 3 , wherein charge is not performed among the plurality of storage elements included in the secondary storage element.

8. The autonomous power supply system according to claim 1 , wherein the power generation element collects at least one kind of environmental energy including environmental light, vibration, heat and electric wave, and converts the environmental energy into electric energy.

Assignees

• Hitachi Ltd

Inventors

• Fujimori Tsukasa
• Goto Yasushi
• Kurata Hideaki
• Takano Hideaki

Classifications

• H02J50/001

  Energy harvesting or scavenging · CPC title

• H02J7/345 Primary

  using capacitors as storage or buffering devices · CPC title

• H02J2207/40

  adapted for charging from various sources, e.g. AC, DC or multivoltage · CPC title

• H02J7/34 Primary

  Parallel operation in networks using both storage and other DC sources, e.g. providing buffering (H02J7/14 takes precedence) · CPC title

• H02J7/35

  with light sensitive cells · CPC title