CN204330901U - A kind of innovative noise sensor - Google Patents

Abstract

The utility model discloses a kind of innovative noise sensor, it comprises the antenna, front port, wave filter, amplifier, A/D converter, signal processing unit and the rear port that are electrically connected successively; Described antenna adopts helical antenna; Described amplifier adopts end of oppisite phase input proportional amplifier; Described wave filter adopts RC filtering circuit.Adopt noise transducer of the present utility model can realize dynamic barrier noise interferences, greatly reduce signal transacting amount, drastically increase the data processing speed of Partial discharge detector.And antenna, amplifier and wave filter all take squelch measure, greatly improve the antijamming capability of Partial discharge detector, have a good application prospect.And according to the size automatic control high frequency current sensor detection threshold switch of ambient noise, the signal to noise ratio (S/N ratio) of detection signal can be not only increased, and reduce the distortion of waveform, maintain the waveform character of discharge pulse preferably.

Description

A kind of innovative noise sensor

Technical field

The utility model relates to detection field, is specifically related to the noise transducer of detected noise signal.

Background technology

Anti-noise signal interference is one of matter of utmost importance of shelf depreciation on-line checkingi always, and noise signal drastically influence the sensitivity of test and the reliability of detection, and survey crew usually can be made to produce understanding and the judgement of mistake.Simultaneously, due to the existence of much noise signal, cause detection data various, these detect data and are recorded one by one by the input passage of the High Frequency Current Sensor of Partial discharge detector, Partial discharge detector is caused to need to process a lot of data, have a strong impact on data processing speed, be easy to cause instrument to crash.

But traditional shelf depreciation anti-noise jamming technology often calculates loaded down with trivial details, reaction is comparatively slow, the development of serious restriction Partial Discharge Detecting Technology.Therefore, in the urgent need to taking certain effective means to shield noise signal, farthest extracting useful local discharge signal, obtaining best signal to noise ratio (S/N ratio), guarantee the accuracy of Partial Discharge Detection, the data processing speed of Partial discharge detector can be improved again simultaneously.

The process of current power equipment Partial Discharge Detection high-frequency signal and some employing fixed signal threshold value of disturbance ecology technology, cannot carry out dynamic barrier to noise interferences; Some needs the threshold values manually adjusting High Frequency Current Sensor according to on-the-spot high-frequency signal size, or uses wavelet analysis method burbling noise, calculates loaded down with trivial details, and reaction is comparatively slow, affects the detection speed of Partial discharge detector's entirety.

Utility model content

The purpose of this utility model is to provide a kind of innovative noise sensor, and it is dynamic shielding noise interferences in shelf depreciation on-line checkingi, greatly reduces signal transacting amount, drastically increases the data processing speed of Partial discharge detector.

To achieve these goals, the utility model adopts following technical scheme:

A kind of innovative noise sensor, comprises the antenna, front port, wave filter, amplifier, A/D converter, signal processing unit and the rear port that are electrically connected successively; Described antenna adopts helical antenna; Described amplifier adopts end of oppisite phase input proportional amplifier; Described wave filter adopts RC filtering circuit;

Described antenna is in order to receive HF noise signal, described front port is in order to send described HF noise signal into described wave filter, described wave filter is in order to carry out filtering to described HF noise signal, described amplifier is in order to carry out signal amplification to filtered described HF noise signal, described A/D converter is in order to carry out A/D conversion to the HF noise signal after amplification, the noise gate and the passage lock that are set with noise transducer in described signal processing unit are fixed time, described signal processing unit is in order to compare judgement to the HF noise signal after A/D conversion, if the peak value of described HF noise signal is higher than the described noise gate set, then export a lock control signal to High Frequency Current Sensor input passage by described rear port, High Frequency Current Sensor input passage is locked, enter the described passage lock set to fix time, any signal that High Frequency Current Sensor detects is the end until described passage lock is fixed time by conductively-closed.

The centre frequency of described helical antenna is 900Hz, and length is 15cm, and diameter is 1cm.

After adopting such scheme, the utility model has following beneficial effect:

1, adopt noise transducer of the present utility model can realize dynamic barrier noise interferences, greatly reduce signal transacting amount, drastically increase the data processing speed of Partial discharge detector.

2, noise transducer of the present utility model adopts antenna, amplifier and wave filter all take squelch measure, greatly improve the antijamming capability of Partial discharge detector, have a good application prospect.

3, noise transducer of the present utility model is adopted can to control High Frequency Current Sensor input channel switch in real time, if the peak value of a certain moment HF noise signal is higher than the noise transducer noise gate set, High Frequency Current Sensor input passage will be locked, enter the noise transducer passage lock set to fix time, any signal that High Frequency Current Sensor detects is the end until passage lock is fixed time by conductively-closed.According to the size automatic control high frequency current sensor detection threshold switch of ambient noise, not only increase the signal to noise ratio (S/N ratio) of detection signal, and reduce the distortion of waveform, maintain the waveform character of discharge pulse preferably.

Accompanying drawing explanation

Fig. 1 is schematic block circuit diagram of the present utility model;

Fig. 2 is the structural representation of antenna in Fig. 1;

Fig. 3 is the structural representation of Fig. 1 median filter;

Fig. 4 is the structural representation of amplifier in Fig. 1.

Embodiment

A kind of innovative noise sensor of the present utility model, as shown in Figure 1, comprises the antenna 1, front port 2, wave filter 3, amplifier 4, A/D converter 5, signal processing unit 6 and the rear port 7 that are electrically connected successively.

Helical antenna makes with the metal that electric conductivity is good, because helical antenna has the advantages such as circular polarisation, beam angle be wide, so helical antenna selected by antenna 1 in the utility model, for receiving HF noise signal.As shown in Figure 2, D is the diameter of helical antenna to the structure of antenna 1, and ρ is pitch, and L is the length of helical antenna, and I, II is corresponding 2 points on helix.In the utility model, antenna 1 is mainly used in the noise signal gathering low-frequency range, finds that the frequency range of this partial noise signal mainly concentrates near 900Hz, so the centre frequency f choosing antenna 1 is 900Hz by research, choose antenna length L=15cm, antenna diameter D=1cm.

When antenna 1 works in certain centre frequency, its required around coil number N meet following formula: $N=\frac{30}{\mathrm{fD}}{\left(\frac{L}{D}\right)}^{\frac{1}{5}},$ Pitch $\mathrm{\ρ}=\frac{L}{N}.$

Can be obtained by above-mentioned formula:

(1) detour number of turns N=9;

(2) pitch ρ=1.6cm.

In sum, the parameter of antenna 1 is: length L=15cm, diameter D=1cm, and detour number of turns N=9, pitch ρ=1.6cm.

Because RC filtering circuit Filtering Efficacy is higher, so the utility model median filter 3 selects RC filtering circuit.The structure of wave filter 3 as shown in Figure 3, is made up of the resistance of a 5k Ω and the electric capacity of a 10pF.

Noise transducer only has the level of millivolt level to export, and such signal has to pass through amplifying circuit to carry out amplifying the requirement that could meet embody rule.Because the common-mode rejection ratio of see-saw circuit to amplifier does not have particular/special requirement, so amplifier 4 adopts end of oppisite phase to input proportional amplifier in the utility model.The structure of amplifier 4 as shown in Figure 4.

Antenna 1 is in order to receive HF noise signal; Front port 2 is in order to send described HF noise signal into wave filter 3; Wave filter 3 is in order to carry out filtering, with filtering interference signals to HF noise signal; Amplifier 4 is in order to carry out signal amplification to filtered HF noise signal; A/D converter 5 is in order to carry out A/D conversion to the HF noise signal after amplification; The noise gate and the passage lock that are set with noise transducer in signal processing unit 6 are fixed time, signal processing unit 6 is in order to compare judgement to the HF noise signal after A/D conversion, and export according to comparative result or do not export lock control signal to rear port 7, rear port 7 transfers to High Frequency Current Sensor in order to the lock control signal exported by signal processing unit 6.

During work, the HF noise signal received is sent into wave filter 3 by front port 2 by antenna 1, by wave filter 3, filtering is carried out to this high-frequency discharge signal, with filtering interference signals, filtered high-frequency discharge signal carries out signal through amplifier 4 and is amplified into A/D converter 5 and carries out A/D conversion, high-frequency discharge signal after A/D conversion sends into signal processing unit 6, if the peak value of the high-frequency discharge signal after A/D conversion is higher than the noise gate of setting, then export a lock control signal to High Frequency Current Sensor input passage by rear port 7, High Frequency Current Sensor input passage is locked, the passage lock entering setting is fixed time, in this passage lock is fixed time, any one signal that High Frequency Current Sensor detects all will be considered to a noise signal, High Frequency Current Sensor input passage will not record these information, and then shield large noise signal, simultaneously can not occupying system resources, improve the processing speed of instrument detection data.When this passage lock is fixed time end, it is again open-minded that noise transducer controls High Frequency Current Sensor input passage, until the HF noise signal of peak value higher than the noise gate of setting again detected, High Frequency Current Sensor input passage then admission passage locking time again, so circulate.

Claims (2)

1. an innovative noise sensor, is characterized in that: comprise the antenna, front port, wave filter, amplifier, A/D converter, signal processing unit and the rear port that are electrically connected successively; Described antenna adopts helical antenna; Described amplifier adopts end of oppisite phase input proportional amplifier; Described wave filter adopts RC filtering circuit;

Described antenna is in order to receive HF noise signal, described front port is in order to send described HF noise signal into described wave filter, described wave filter is in order to carry out filtering to described HF noise signal, described amplifier is in order to carry out signal amplification to filtered described HF noise signal, described A/D converter is in order to carry out A/D conversion to the HF noise signal after amplification, the noise gate and the passage lock that are set with noise transducer in described signal processing unit are fixed time, described signal processing unit is in order to compare judgement to the HF noise signal after A/D conversion, if the peak value of described HF noise signal is higher than the described noise gate set, then export a lock control signal to High Frequency Current Sensor input passage by described rear port, High Frequency Current Sensor input passage is locked, enter the described passage lock set to fix time, any signal that High Frequency Current Sensor detects is the end until described passage lock is fixed time by conductively-closed.

2. a kind of innovative noise sensor according to claim 1, is characterized in that: the centre frequency of described helical antenna is 900Hz, and length is 15cm, and diameter is 1cm.