US-12618882-B2 - Communication apparatus, smart meter, and secondary battery

Abstract

A communication apparatus, which is mounted in a smart meter, includes: a secondary battery; a transmitter-receiver circuit that is operable by using electric power supplied from the secondary battery; and an antenna that emits a wireless signal based on a transmission signal, which is output from the transmitter-receiver circuit, to a space, wherein the secondary battery is a lithium-ion battery; and wherein when electric power supplied from outside to the smart meter is cut off, the transmitter-receiver circuit outputs the transmission signal indicating a specified alarm to the antenna by using the electric power supplied from the secondary battery and thereby wirelessly transmits the alarm via the antenna.

Inventors

• Ritsu Tanaka
• Iwao Ohwada
• Takaaki Koizumi

Assignees

• NGK INSULATORS, LTD.

Dates

Publication Date

20260505

Application Date

20240222

Priority Date

20210827

Claims (7)

1. 1 . A communication apparatus mounted in a smart meter, comprising: a secondary battery; a transmitter-receiver circuit that is operable by using electric power supplied from the secondary battery; and an antenna that emits a wireless signal based on a transmission signal, which is output from the transmitter-receiver circuit, to a space, a circuit board on which the transmitter-receiver circuit, the battery and the antenna are mounted on a same side of the circuit board; and wherein the secondary battery is a lithium-ion battery having a thickness of 1 mm or less; wherein when electric power supplied from outside to the smart meter is cut off, the transmitter-receiver circuit outputs the transmission signal indicating a specified alarm to the antenna by using the electric power supplied from the secondary battery and thereby wirelessly transmits the alarm via the antenna; wherein the secondary battery has a first principal plane in contact with the circuit board and a second principal plane opposite the first principal plane: wherein the antenna is formed in a planar shape on the circuit board; wherein the secondary battery is placed so that the first principal plane and the second principal plane respectively become in parallel with the antenna; and wherein the secondary battery does not obstruct the wireless signal emitted from the antenna.
2. 2 . The communication apparatus according to claim 1 , wherein the secondary battery has bending resistance and torsion resistance which satisfy conditions specified in ISO/IEC 14443-1.
3. 3 . The communication apparatus according to claim 1 , comprising an electric charging circuit for electrically charging the secondary battery by using the electric power supplied from outside to the smart meter.
4. 4 . The communication apparatus according to claim 3 , wherein the electric charging circuit electrically charges the secondary battery by means of constant voltage charging.
5. 5 . The communication apparatus according to claim 1 , wherein when the transmitter-receiver circuit receives the alarm, which has been wirelessly transmitted from a communication apparatus mounted in another smart meter, via the antenna, the transmitter-receiver circuit relays and transmits the alarm.
6. 6 . The smart meter in which the communication apparatus according to claim 1 is mounted.
7. 7 . The secondary battery mounted in the communication apparatus according to claim 1 .

Description

INCORPORATION BY REFERENCE The contents of the following priority applications are herein incorporated by reference: Japanese Patent Application No. 2021-139082 filed on Aug. 27, 2021 and International Patent Application No. PCT/JP2022/031739 filed on Aug. 23, 2022. BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a communication apparatus used by being mounted in a smart meter, the smart meter in which the communication apparatus is mounted, and a secondary battery mounted in the communication apparatus. 2. Description of Related Art In recent years, along with a wide spread of distributed power sources which use renewable energy such as solar power generation, the development of next-generation smart meters is underway for the purpose of, for example, stabilization of demands and supplies for electric power and expansion of consumers' interests. One of desired functions of this next-generation smart meter is a Last Gasp function. The Last Gasp function is a function that detects a power outage upon its occurrence and immediately sends an alarm to a power distribution monitoring system. A technology of PTL 1 (Japanese Patent No. 6383007) is known regarding implementation of the Last Gasp function of a smart meter. PTL 1 describes that a communication hub for measuring electric energy used by a smart meter system is equipped with an electric double layer capacitor (a supercapacitor) and the communication hub is made to perform a Last Gasp operation by using the electric power accumulated in the supercapacitor upon the occurrence of a power outage. In PTL 1, a supercapacitor is mounted in order to supply the electric power during the power outage. However, generally with a capacitor including the supercapacitor, an output voltage and an output current change depending on discharge characteristics which are determined according to a time constant of the circuit, so that the supplied electric power fluctuates significantly due to the passing of time during electric discharge. Therefore, the supercapacitor needs to be enlarged in size in order to continue supply the electric power required for the Last Gasp operation for a certain amount of time or longer after the occurrence of the power outage, and there is fear that the size enlargement of the supercapacitor may squeeze a loading space for other equipment and circuits to be mounted in the smart meter and may also lead to the size enlargement of the smart meter. In light of the above-described problem, it is an object of the present invention to provide a communication apparatus which can be mounted in a smart meter in a space-saving manner. SUMMARY OF THE INVENTION A communication apparatus according to the present invention, which is mounted in a smart meter, includes: a secondary battery; a transmitter-receiver circuit that is operable by using electric power supplied from the secondary battery; and an antenna that emits a wireless signal based on a transmission signal, which is output from the transmitter-receiver circuit, to a space, wherein the secondary battery is a lithium-ion battery; and wherein when electric power supplied from outside to the smart meter is cut off, the transmitter-receiver circuit outputs the transmission signal indicating a specified alarm to the antenna by using the electric power supplied from the secondary battery and thereby wirelessly transmits the alarm via the antenna. A smart meter according to the present invention is that in which the above communication apparatus is mounted. A secondary battery according to the present invention is to be mounted in the above communication apparatus. According to the present invention, it is possible to provide the communication apparatus which can be mounted in the smart meter in the space-saving manner. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a schematic configuration diagram of a smart meter according to one embodiment of the present invention. FIGS. 2A and 2B are diagrams illustrating one example of the structure of a communication apparatus mounted in the smart meter according to one embodiment of the present invention. FIGS. 3A and 3B are diagrams illustrating examples of electric discharge characteristics of a battery and a supercapacitor. DESCRIPTION OF PREFERRED EMBODIMENTS FIG. 1 is a schematic configuration diagram of a smart meter according to one embodiment of the present invention. A smart meter 1 illustrated in FIG. 1 is installed and used at, for example, a residence of a consumer who receives the supply of electric power from an electric power provider, such as an ordinary house or each room of a housing complex. The smart meter 1 has an electric power measurement function that measures the electric energy supplied to the consumer, and a communication function that transmits measurement results of the electric energy to the electric power provider. The smart meter 1 is configured, as illustrated in FIG. 1, by including a communi