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A Novel Temperature Sensor with Low Temperature Delay

IP.com Disclosure Number: IPCOM000248293D
Publication Date: 2016-Nov-15
Document File: 7 page(s) / 279K

Publishing Venue

The IP.com Prior Art Database

Abstract

This paper describes a method to reduce the temperature delay between the target and the sensor. The temperature sensor described herein reduces thermal resistance between the target and the sensor coming from the variable air gap, the rough surface and the medium. On the other hand, in this design, a large thermal resistance between the sensor and the surroundings in maintained in order to hold more thermal energy, which will help to achieve quicker transient response. This temperature sensor design is uniquely suitable to solve the temperature delay between the sensor and the cable conductor of high voltage power line.

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A Novel Temperature Sensor with Low Temperature Delay

This paper describes a method to reduce the temperature delay between the target and the sensor. The temperature sensor described herein reduces thermal resistance between the target and the sensor coming from the variable air gap, the rough surface and the medium. On the other hand, in this design, a large thermal resistance between the sensor and the surroundings in maintained in order to hold more thermal energy, which will help to achieve quicker transient response. This temperature sensor design is uniquely suitable to solve the temperature delay between the sensor and the cable conductor of high voltage power line.

Background

With the rapid economic development in China, high voltage cable will be more and more used in city based on its advantages such as, safety and small form factor. At the end of the service life, the cable conductor temperature may increase as the current increases.

More than this, cable splices are used to connect cables and function as electrical connection and insulation. But cable splices are usually installed in the field. In order to guarantee the safety and maximal utilize the cable system, detecting cable conductor temperature appears to be more and more important these days.

The passive and wireless temperature monitoring and transmitting system for high-voltage cable splices is developed to monitor the accrual temperature of cable conductor, see Fig. 2. The implementation of this (30) which is inside of high voltage splice; this capacitor is connected with a coil (22), which forms a L-C loop (20), see Fig. 1. When the temperature of cable (30) conductor (31) changes, the temperature-sensitive capacitor's (21) capacitance changes too, then the resonant frequency of the L-C circuit (20) changes.

On the outside of the rubber-made high-voltage splice (11), there is a transceiver coil (40) connected with controller unit (50). When the resonant frequency of the L-C loop (20) changes, the controller unit (50) can detect the change by emitting a frequency sweeping signal to the transceiver coil (40) outside the splice (11), then controller unit (50) will convert the detected frequency data to the temperature value. This method is used to detect the cable conductor's (30) temperature (please see Fig. 2)

Fig 1: Temperature measuring L-C loop

As shown in Fig.1, for the L-C loop, the capacitance is changed depending on temperature.

20

21

22



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50

40

11

60

30

10

Fig. 2: Temperature detecting system

  As illustrated in Fig.2, the controller unit (50) is connected to the transceiver coil (40). And the temperature data is collected, converted and transmitted by the controller unit (50). The current transformer (60) provides the required power source for controller unit (50). The current transformer (60) is installed on the outside of high-voltage cable
(30), when a current flows through the cable (30), the current transformer (60) will output a stab...