Systems and methods for monitoring temperature of electrical conductor

• US 10,378,965 B2
• Filed: 09/11/2013
• Issued: 08/13/2019
• Est. Priority Date: 09/11/2013
• Status: Active Grant

• Current Assignee: 3M Innovative Properties Company (3M Company)
• Original Assignee: 3M Innovative Properties Company (3M Company)
• Inventors: Wen, Zhiguo, Huang, Zheng, Yuan, Sihua, Yu, Xuetao, Zhang, Ming
• Primary Examiner(s): Caputo, Lisa M
• Assistant Examiner(s): Ahmed, Nasir U.
• Application Number:
  US15/021,290
• Publication Number:
  US 20160223406A1
• Time in Patent Office: 2,162 Days
• CPC Class Codes: G01K 1/024 for remote indication
• CPC Class Codes: G01K 2215/00 Details concerning sensor power supply
• CPC Class Codes: G01K 7/00 Measuring temperature based on the use of electric or magnetic elements directly sensitive to heat giving results other than momentary value of temperature G01K3/00 ; Power supply therefor, e.g. using thermoelectric elements

Abstract

A system (100) for monitoring a temperature of an electrical conductor of an electrical cable and including a temperature sensor unit (100a) and a transceiver unit (100b). The temperature sensor unit (100a) is located inside the first (semi)conductive layer and includes a micro-controller (120), a temperature sensor (110), an energy harvest sub-unit (140) and a wireless transmitter layer (130). The temperature sensor (110) is adapted to detect a first signal (S1) representing temperature of the electrical conductor and to supply the first signal (S1) to the micro-controller (120). The transceiver unit (100b) is located outside the first (semi)conductive layer and includes an energy transmitter (160) and a wireless receiver (150). The energy harvest sub-unit (140) is adapted to harvest electromagnetic power from the energy transmitter (160) and to provide electrical power to the micro-controller (120). The wireless transmitter (130) is adapted to being engaged with the wireless receiver (150) under the control of the micro-controller (120) to transmit a second signal (S2) converted from the first signal (S1) to the wireless receiver (150). The energy harvest sub-unit (140) and the wireless transmitter (130) are designed to have different working frequency.

Claims

1. A system for monitoring temperature of an electrical conductor enclosed in at least a first semi-conductive layer, the system comprising:

a temperature sensor unit located inside the first semi-conductive layer, and comprising a micro-controller, a temperature sensor, an energy harvest sub-unit and a wireless transmitter, and the temperature sensor adapted to detect a first signal representing temperature of the electrical conductor and to supply the first signal to the micro-controller; and

a transceiver unit located outside the first semi-conductive layer and comprising an energy transmitter and a wireless receiver;

wherein, the energy harvest sub-unit is adapted to harvest electromagnetic power from the energy transmitter and to provide electrical power to the micro-controller;

the wireless transmitter is adapted to being engaged with the wireless receiver under the control of the micro-controller to transmit a second signal converted from the first signal to the wireless receiver; and

the energy harvest sub-unit and the wireless transmitter are designed to have different working frequency, wherein a ratio of the working frequency of the wireless transmitter to that of the energy harvest sub-unit is larger than 100, wherein the energy harvest sub-unit has a working frequency in a range from 10 KHz to 990 KHz, and wherein the wireless transmitter has a working frequency in a range from 10 MHz to 10 GHz.

2. The system according to claim 1, wherein the energy harvest sub-unit comprises a LC resonant circuit adapted to generate an AC power after triggered by the energy transmitter.

3. The system according to claim 2, wherein the energy harvest sub-unit comprises a rectifier circuit adapted to convert the AC power to DC power.

4. The system according to claim 1, wherein the temperature sensor is in direct contact or in thermal contact with the electrical conductor.

5. The system according to claim 1, wherein the first semi-conductive layer is enclosed by a second semi-conductive layer, the energy transmitter is located between the first semi-conductive layer and the second semi-conductive layer.

6. The system according to claim 5, wherein the transceiver unit comprises a micro-controller located outside the second semi-conductive layer and connected with the energy transmitter via a wire.

7. The system according to claim 6, wherein the wireless receiver is adapted to be located outside the second semi-conductive layer and to communicate with the micro-controller of the transceiver unit.

8. The system according to claim 7, wherein the micro-controller of the transceiver unit is configured to determine the temperature of the electrical conductor based on the received second signal.

9. A method of monitoring temperature of an electrical conductor enclosed in at least a first semi-conductive layer, comprising the steps of:

harvesting electrical power and providing the electrical power to a first micro-controller by an energy harvest sub-unit working on a first working frequency, the first micro-controller and the energy harvest sub-unit located inside the first (semi)conductive layer;

detecting a first signal representing temperature of the electrical conductor by a temperature sensor unit located inside the first semi-conductive layer;

converting the first signal by the first micro-controller into a second signal applicable of being transmitted via a wireless way; and

transmitting the second signal by a wireless transmitter to a wireless receiver located outside the first semi-conductive layer, the wireless transmitter located inside the first semi-conductive layer and working on a second working frequency different from the first working frequency, wherein a ratio of the second working frequency to the first working frequency is larger than 100, wherein the energy harvest sub-unit has a working frequency in a range from 10 KHz to 990 KHz, and wherein the wireless transmitter has a working frequency in a range from 10 MHz to 10 GHz.

10. The method according to claim 9, wherein the harvesting step includes a sub-step of emitting a trigger signal by an energy transmitter located outside the first semi-conductive layer to trigger the energy harvest sub-unit to oscillate to generate AC power.

11. The method according to claim 9, comprising the step of determining the temperature of the electrical conductor based on the second signal by a second micro-controller located outside the first semi-conductive layer.