阅读说明：本技术 一种传感器响应时间测量方法 (Sensor response time measuring method ) 是由 周二孟 赵立东 马仕洪 金跃明 居法立 王超 何飞军 于 2019-10-08 设计创作，主要内容包括：本发明涉及传感器响应时间测试技术领域,尤其涉及一种传感器响应时间测量方法。包括：采集传感器输出的噪声信号；在频域分析所述噪声信号的频域延时,在时域分析所述噪声信号的时域延时；将所述频域延时和所述时域延迟中的最大值作为传感器的响应时间；其中,所述噪声信号满足正态分布。上述技术方案采用频域分析方法和时域分析方法两种独立的方式对传感器的噪声信号进行分析,通过比较时域和频域响应时间的结果确定最终的响应时间。可有效地定期检查传感器的实际性能,提前识别潜在的传感器性能降级,避免因传感器性能降级导致的安全系统误动作/拒动作,从而保证核电厂关键参数的测量准确可靠,系统安全、经济运行。(The invention relates to the technical field of sensor response time testing, in particular to a sensor response time measuring method. The method comprises the following steps: collecting a noise signal output by a sensor; analyzing the frequency domain delay of the noise signal in a frequency domain, and analyzing the time domain delay of the noise signal in a time domain; taking the maximum value of the frequency domain delay and the time domain delay as the response time of the sensor; wherein the noise signal satisfies a normal distribution. According to the technical scheme, the noise signals of the sensor are analyzed in two independent modes, namely a frequency domain analysis method and a time domain analysis method, and the final response time is determined by comparing the results of time domain response time and frequency domain response time. The actual performance of the sensor can be effectively checked regularly, potential sensor performance degradation is identified in advance, and misoperation/refusal action of the safety system caused by the sensor performance degradation is avoided, so that the accurate and reliable measurement of key parameters of the nuclear power plant is ensured, and the system is operated safely and economically.)

1. A sensor response time measurement method, comprising:

collecting a noise signal output by a sensor;

analyzing the frequency domain delay of the noise signal in a frequency domain, and analyzing the time domain delay of the noise signal in a time domain;

taking the maximum value of the frequency domain delay and the time domain delay as the response time of the sensor;

wherein the noise signal satisfies a normal distribution.

2. A sensor response time measurement method according to claim 1, characterized by:

and in the process of collecting the noise signals output by the sensor, the sampling frequency is greater than 200 Hz.

3. A method of sensor response time measurement according to claim 2, wherein said acquiring a noise signal output by a sensor comprises:

firstly, the direct current component in the sensor output signal is filtered, and secondly, the irrelevant noise component in the sensor output signal is eliminated through low-pass filtering.

4. A sensor response time measurement method according to claim 3, characterized in that:

and in the step of filtering the direct-current component in the output signal of the sensor, a high-pass filter or a direct-current offset meter is adopted to filter the direct-current component in the output signal of the sensor.

5. A sensor response time measurement method according to claim 1, characterized by:

the frequency spectrum of the noise signal comprises an unattenuated portion, a turning point portion and an attenuated transition portion.

6. The method of claim 1, wherein analyzing the frequency domain delay of the noise signal in the frequency domain comprises:

fourier transforming the noise signal to obtain a power spectral density curve Y (f) of the noise signal;

fitting and obtaining a frequency domain transfer function H (f) based on the power spectral density curve Y (f);

obtaining a frequency domain ramp response based on the frequency domain transfer function h (f);

and taking the maximum time delay in a certain time period of the frequency domain slope response as the frequency domain time delay of the noise signal.

7. The method of claim 6, wherein the Fourier transforming the noise signal to obtain the power spectral density curve Y (f) of the noise signal comprises:

and calculating a power density curve Y (f) of the noise signal by using a periodogram method and Fourier transform.

8. The method of claim 6, wherein the fitting of the frequency domain transfer function H (f) based on the power spectral density curve Y (f) comprises:

using fitting functions

9. A method of measuring sensor response time according to claim 1, wherein said analyzing the time domain delay of said noise signal in the time domain comprises:

calculating a power spectral density PSD using a power spectral density AR model for the noise signal;

acquiring a time domain transfer function H (z) based on the calculated power spectral density PSD;

obtaining a time-domain ramp response based on the time-domain transfer function h (z);

and taking the maximum time delay in a certain time period of the time domain slope response as the time domain time delay of the noise signal.

10. The method of claim 1, wherein the obtaining the time-domain transfer function h (z) based on the calculated PSD of the power spectral density is:

power universal density based on calculationDetermining parameter p and parameter a in formula_kA value of (d);

based on the parameters p and a_kDetermining a transfer function

Technical Field

The invention relates to the technical field of sensor response time testing, in particular to a sensor response time measuring method.

Background

Control systems and safety systems of nuclear power plants rely primarily on process instrumentation to provide reliable information for confirming plant safety and efficiency. Therefore, there is a need to verify the performance of such instruments at predetermined intervals over the life of the plant. Therefore, it is desirable to measure the response time of sensing devices in the nuclear plant control system and safety system at predetermined time intervals.

Disclosure of Invention

The present invention provides a method for measuring the response time of a sensor to solve the above technical problems.

A sensor response time measurement method, comprising:

collecting a noise signal output by a sensor;

analyzing the frequency domain delay of the noise signal in a frequency domain, and analyzing the time domain delay of the noise signal in a time domain;

taking the maximum value of the frequency domain delay and the time domain delay as the response time of the sensor;

wherein the noise signal satisfies a normal distribution.

According to the technical scheme, the noise signals of the sensor are analyzed in two independent modes, namely a frequency domain analysis method and a time domain analysis method, and the final response time is determined by comparing the results of time domain response time and frequency domain response time. The actual performance of the sensor can be effectively checked regularly, potential sensor performance degradation is identified in advance, and misoperation/refusal action of the safety system caused by the sensor performance degradation is avoided, so that the accurate and reliable measurement of key parameters of the nuclear power plant is ensured, and the system is operated safely and economically.

Preferably, in the process of acquiring the noise signal output by the sensor, the sampling frequency is greater than 200 Hz.

Preferably, the acquiring the noise signal output by the sensor includes: firstly, the direct current component in the sensor output signal is filtered, and secondly, the irrelevant noise component in the sensor output signal is eliminated through low-pass filtering.

Preferably, in filtering out the dc component in the sensor output signal, a high pass filter or a dc offset meter is used to filter out the dc component in the sensor output signal.

Preferably, the frequency spectrum of the noise signal comprises an unattenuated portion, a turning point portion and an attenuated transition portion.

Preferably, the analyzing the frequency domain delay of the noise signal in the frequency domain includes: fourier transforming the noise signal to obtain a power spectral density curve Y (f) of the noise signal; fitting and obtaining a frequency domain transfer function H (f) based on the power spectral density curve Y (f); obtaining a frequency domain ramp response based on the frequency domain transfer function h (f); and taking the maximum time delay in a certain time period of the frequency domain slope response as the frequency domain time delay of the noise signal.

Preferably, in the fourier transform of the noise signal to obtain the power spectral density curve y (f) of the noise signal: and calculating a power density curve Y (f) of the noise signal by using a periodogram method and Fourier transform.

Preferably, in the process of fitting the frequency domain transfer function h (f) based on the power spectral density curve y (f): using fitting functions

And (6) fitting.

Preferably, the analyzing the time-domain delay of the noise signal in the time domain includes: calculating a power spectral density PSD using a power spectral density AR model for the noise signal; acquiring a time domain transfer function H (z) based on the calculated power spectral density PSD; obtaining a time-domain ramp response based on the time-domain transfer function h (z); and taking the maximum time delay in a certain time period of the time domain slope response as the time domain time delay of the noise signal.

Preferably, the obtaining of the time-domain transfer function h (z) based on the calculated power spectral density PSD is: power universal density based on calculation

Determining parameter p and parameter a in formula_kA value of (d); based on the parameters p and a_kDetermining a transfer function

。

The invention has the following beneficial effects:

the noise signals of the sensor are analyzed in two independent modes, namely a frequency domain analysis method and a time domain analysis method, and the final response time is determined by comparing the results of the time domain response time and the frequency domain response time. The frequency domain analysis method and the time domain analysis method have differences, the data analysis and calculation processes are completely independent, but the power spectral densities calculated by the two methods are almost consistent, and the calculation accuracy of the frequency domain power spectral densities and the time domain power spectral densities is ensured.

Drawings

Fig. 1 is a flowchart of a method for measuring a response time of a sensor according to a first embodiment of the present invention.

Fig. 2 is a schematic diagram of a system for generating a noise signal according to a first embodiment of the present invention.

Fig. 3 is a frequency domain slope response curve according to a first embodiment of the invention.

Fig. 4 is a time-domain ramp response curve according to a first embodiment of the present invention.

Detailed Description

The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. Unless otherwise defined, all terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that the conventional terms should be interpreted as having a meaning that is consistent with their meaning in the relevant art and this disclosure. The present disclosure is to be considered as an example of the invention and is not intended to limit the invention to the particular embodiments.

Noise analysis techniques monitor the response of sensors, such as level transmitters, to natural disturbances (noise) present in the water/steam system while the nuclear power plant is in operation. These fluctuations are typically produced by system currents, pump turbulence, random core heat transfer, and other naturally occurring phenomena. The noise analysis technique can also be used for response time experiments of sensors such as thermocouples, neutron detectors and the like, and the response time measurement method of the sensor is described below by taking the response time measurement method of the liquid level transmitter as an example. The noise analysis method of the invention mainly comprises the following technical points: collecting noise signals meeting normal distribution; analysis in the time domain by an Autoregressive (AR) model of power spectral density; the power spectral density is calculated in the frequency domain by Fast Fourier Transform (FFT) of the discrete signal for analysis, and the noise analysis flow is detailed in fig. 1. The following embodiment will describe the implementation of the method of the present invention in detail by taking the response time measurement method of a level transmitter as an example.