A saw sensing method based on the combination of code division multiple access and ofc coding

Abstract

The invention provides an SAW sensing method based on the combination of code division multiple access and OFC coding. The method includes the steps that a reader transmits an inquiry signal to an acoustic surface wave sensor through a broadband antenna, the acoustic surface wave sensor receives an OFC signal by means of a single interdigital transducer according to triggering of the inquiry signal and converts the OFC signal into an acoustic surface wave signal, the acoustic surface wave signal is reflected by a frequency orthogonal reflecting grating chip set and forms an echo signal through the single interdigital transducer, the reader receives the echo signal through the broadband antenna, the reader carries out lower linear frequency modulation on the echo signal, and the reader carries out temperature monitoring according to the echo signal after lower linear frequency modulation. According to the long-distance, multi-point-connection and anti-interference acoustic surface wave wireless sensor method based on the combination of orthogonal frequency and code division multiplexing coding, the near-far effect of a passive sensor system of code division multiplexing coding is eliminated, and requirements of an intelligent power grid for power equipment temperature wireless monitoring can be met.

Description

technical field [0001] The invention relates to the field of temperature monitoring of power equipment, in particular to a SAW sensing method based on the combination of code division multiple access and OFC coding. Background technique [0002] Among the many monitoring quantities of power equipment status monitoring, temperature is one of the most critical detection quantities. Through temperature monitoring, the operating status and fault information of power equipment can be understood in a timely and accurate manner. Monitoring the operating temperature of power equipment, such as the oil temperature of transformers, and the conductor temperature of transmission lines (overhead lines and power cables) can be used to calculate the load limit capacity and equipment aging degree, thereby providing a basis for dynamic capacity increase or maintenance of power equipment. Monitor the temperature of the stator and rotor of the generator, high-voltage switchgear, busbar joints...

AI Technical Summary

Problems solved by technology

[0005] However, the currently developed SAW wireless sensor array cannot fully meet the temperature monitoring requirements in smart grid and UHV applications, and the problems mainly include:

[0006] Problem 1: The working distance is not enough

[0007] Problem 2: The number of temperature points detected at the same time is not enough

[0008] Question 3: The anti-interference performance of the sensor needs to be improved

However, due to the limitation of the applicable wireless bandwidth and the length of the SAW substrate material, it is difficult to realize 8 types of piezoelectric substrates on a 10 mm long piezoelectric substrate (which is the limit, and the SAW propagation loss and diffraction loss will be unacceptably large any longer). The above sensor types

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