CN204989403U - Portable cable partial discharge takes electric detection means - Google Patents

Abstract

The utility model discloses a portable cable partial discharge charged detection device, which comprises a high-frequency partial discharge sensor capable of collecting partial discharge information of the cable to be tested, a current transformer capable of collecting partial charge information of the cable to be tested, and a device capable of collecting partial charge information based on the measured cable. The signal processor for processing the partial discharge information of the cable to be tested collected by the high frequency partial discharge sensor and the local electrification information of the cable to be tested collected by the current transformer. The portable cable partial discharge charged detection device of the utility model can overcome the defects of poor timeliness, poor accuracy and difficult maintenance in the prior art, so as to realize the advantages of good timeliness, good accuracy and low maintenance difficulty.

Description

A Portable Cable Partial Discharge Live Detecting Device

technical field

The utility model relates to the technical field of electric cable insulation detection, in particular to a portable electric cable partial discharge live detection device.

Background technique

In recent years, there have been more and more insulation breakdown accidents caused by partial discharge of power cables in urban power grids. Cable partial discharge (referred to as partial discharge) is the most important cause of cable insulation breakdown accidents.

At present, the mainstream partial discharge detection equipment for cables can only complete the measurement and analysis of relatively elementary partial discharge spectrograms, and cannot further distinguish and identify partial discharge pulse waveforms. At the same time, the sampling rate of the acquisition equipment and the processing bandwidth of analog signals are not high. very high.

According to the current measurement technical conditions, it is difficult to detect hidden dangers of cable insulation in a timely and accurate manner, and it is difficult to complete the maintenance tasks of cable equipment. Therefore, in view of the partial discharge live detection requirements of cable accessories, better partial discharge detection and The positioning device has important significance and economic value.

In the process of realizing the utility model, the inventor of the utility model has found that there are at least defects in the prior art such as poor timeliness, poor accuracy and high maintenance difficulty.

Utility model content

The purpose of this utility model is to propose a portable cable partial discharge charged detection device to achieve the advantages of good timeliness, good accuracy and low maintenance difficulty in view of the above problems.

In order to achieve the above purpose, the technical solution adopted by the utility model is: a portable cable partial discharge electrification detection device, including a high-frequency partial discharge sensor capable of collecting partial discharge information of the cable to be tested, and capable of collecting partial electrification information of the cable to be tested A current transformer, and a signal processor capable of processing based on the partial discharge information of the cable to be tested collected by the high-frequency partial discharge sensor and the local electrification information of the cable to be tested collected by the current transformer.

Further, the portable cable partial discharge charging detection device also includes a user terminal capable of outputting the processing result of the signal processor.

Further, the signal processor includes a signal conditioning module respectively connected to the high-frequency partial discharge sensor and the current transformer, and a power management module and a signal acquisition module respectively connected to the signal conditioning module.

The portable cable partial discharge charged detection device of each embodiment of the utility model includes a high-frequency partial discharge sensor capable of collecting partial discharge information of the cable to be measured, a current transformer capable of collecting partial charge information of the cable to be measured, and a device based on A signal processor that processes the partial discharge information of the cable under test collected by the high-frequency partial discharge sensor and the local live information of the cable under test collected by the current transformer; thus it can overcome the defects of poor timeliness, poor accuracy and difficult maintenance in the prior art , in order to achieve the advantages of good timeliness, good accuracy and low maintenance difficulty.

Other features and advantages of the present invention will be set forth in the following description, and, in part, will be apparent from the description, or can be learned by practicing the present invention.

The technical solutions of the present utility model will be further described in detail through the drawings and embodiments below.

Description of drawings

The accompanying drawings are used to provide a further understanding of the utility model, and constitute a part of the description, and are used to explain the utility model together with the embodiments of the utility model, and do not constitute a limitation to the utility model. In the attached picture:

Fig. 1 is the structure schematic diagram of the utility model portable cable partial discharge charged detection device;

Fig. 2 is the working flow diagram of the utility model portable cable partial discharge charged detection device;

Fig. 3 is a schematic flow chart of the partial discharge test module in the present invention.

detailed description

The preferred embodiments of the present utility model are described below in conjunction with the accompanying drawings. It should be understood that the preferred embodiments described here are only used to illustrate and explain the present utility model, and are not intended to limit the present utility model.

According to an embodiment of the present invention, as shown in FIGS. 1-3 , a portable cable partial discharge charging detection device is provided.

The portable cable partial discharge live detection device according to the technical solution of the utility model includes a housing, a high-frequency partial discharge sensor, a current transformer, a signal conditioning module, a signal acquisition module, a power management module and a notebook computer (including a partial discharge test module) . The model of the high-frequency partial discharge sensor is HFCT-Ⅱ, the model of the current transformer is BY-CT, the model of the signal conditioning module is TPE, the model of the power management module is BY-PM, and the model of the signal acquisition module is BY-DAQ.

The portable cable partial discharge live detection device of the above embodiment may further include a partial discharge test module; the partial discharge test module has the functions of wavelet noise reduction analysis, discharge pattern recognition, and defect location.

The portable cable partial discharge live detection device of the above embodiment may further include an extended cable partial discharge analysis module; the extended cable partial discharge analysis module has the functions of wavelet noise reduction analysis, discharge pattern recognition, and defect location. The cable partial discharge analysis module can save real-time waveform data and accumulated spectrogram data during the PD measurement process. The former waveform data can be used for wavelet noise reduction analysis, and the latter spectrogram data can be used for discharge pattern recognition; The pulse signal can be used for insulation defect location after anti-interference processing.

In the above embodiments, the signal conditioning module, the signal acquisition module and the power management module are placed inside the casing, and the high-frequency partial discharge sensor and the current transformer are placed outside the casing; the signal conditioning module receives signals from the high-frequency partial discharge sensor and the current transformer The signal is sent, and the signal is processed and sent to the signal acquisition module; the signal acquisition module is connected to the notebook computer, and the partial discharge test module is installed in the notebook computer, and the partial discharge test module is used to save the real-time waveform during the partial discharge measurement process data and cumulative spectral data. The signal acquisition module is triggered by a power frequency synchronous voltage signal to realize dual-channel partial discharge signal acquisition and measurement.

Here, the real-time waveform data is the partial discharge pulse waveform data obtained by programming and controlling the signal acquisition module by partial discharge; Spectral features derived from cumulative statistics can be used to reflect the characteristic attributes of partial discharges.

In the above embodiments, the power management module includes a lithium battery and a power protection circuit, and both ends of the power management module are respectively connected to the signal conditioning module and the signal acquisition module. The power management module can also be powered by other types of batteries, and there is no limitation here. The power management module has a +5V double-terminal output, which adds functions such as power protection, energy-saving control, and power display.

Here, the power protection circuit uses the high-performance, low-power ATmega16L microcontroller as the detection and control core, and uses the DC/DC conversion control circuit composed of MC34063 to provide a regulated power supply for the entire protection circuit, supplemented by LM60 temperature measurement, MOS tube IRF530N is used as a charge and discharge control switch to monitor and protect the status of the entire battery pack and a single battery. It has five power protection functions: short circuit, overcharge, overdischarge, overcurrent and voltage regulation.

In the above embodiments, the partial discharge sensor is preferably a high-frequency sensor, and the high-frequency partial discharge sensor is used to couple the partial discharge signal on the ground line of the cable accessory, and at the same time, in order to realize the insulation isolation between the partial discharge measurement device and the high-voltage equipment to be measured, Therefore, non-metallic insulating injection molding is used for the sensor surface. The surface of the high-frequency partial discharge sensor is made of non-metallic insulating injection molding, and it is installed inside the cross-connection box to obtain partial discharge pulse signals; the function of the cross-connection box is to cancel the induced current of the cable core wire current to the shielding layer. The current transformer is used to couple the power frequency synchronous voltage signal from the live cable to trigger the measurement of partial discharge; the current transformer can also be replaced by other current transformers, such as the power frequency current mutual induction coil.

In the above embodiment, the signal conditioning module includes: an amplifier, a filter, a digital-to-analog converter, an impedance matching balun, and an anti-aliasing filter; the signal conditioning module is used for synchronizing two channels of partial discharge pulse signals and one channel of power frequency The voltage signal is processed by an analog circuit.

Here, the specific setting method for two partial discharge pulse signals is as follows: configure two test channels, both of which are coupling signals from partial discharge sensors, but these two configurations are not necessary, because both the signal conditioning module and the signal acquisition module have two The synchronous parallel processing capability of the two channels, and the test performance of the two channels are exactly the same.

In the above embodiment, the signal acquisition module is triggered by the power frequency synchronous voltage signal to realize the acquisition of dual-channel partial discharge pulse signals (that is, two channels of partial discharge pulse signals). The shell is powered by the power management module, the shell size is 300cm (length) x 260cm (width) x 150cm (height), and the weight is 1.8kg.

The portable cable partial discharge electrification detection device of the above-mentioned embodiment can measure the partial discharge pulse signal which can cover the wide-band partial discharge signal of DC~30MHz, and has more accurate pulse waveform resolution ability; the said device should also include partial discharge The analysis module expands the functions of wavelet noise reduction analysis, discharge pattern recognition, and defect location, and can be used as a special detection device for partial discharge of cable accessories.

In the above embodiment, the signal conditioning module integrates the gain adjustable amplifier, the frequency adjustable filter, the digital-to-analog conversion, the impedance matching balun, and the anti-aliasing filter. A power frequency synchronous voltage signal is processed by an analog circuit. The analog bandwidth of the signal conditioning module reaches the high-frequency (HF) frequency band of DC~30MHz, and integrates multiple selectable bandwidth limits (such as 5MHz, 10MHz, 20MHz, etc.), and the sampling rate of the signal acquisition module can reach up to 500MS/s. The resolution is as high as 16 bits, and the dual-channel synchronous pulse acquisition can realize precise positioning by the traveling wave method.

The external connection of the portable cable partial discharge live detection device in the above embodiment: the output end of the high frequency partial discharge sensor is connected to the "HFCT-I" or "HFCT-II" interface on the front panel of the portable cable partial discharge live detection device through a shielded cable connection; the output end of the current transformer is connected to the "SYNC" interface on the front panel of the portable cable partial discharge live detection device; the notebook computer uses two "USB" ports to connect with the portable cable partial discharge live detection through the USB shielded connection line The "DATA" and "SPI" interfaces on the front panel of the device are connected separately.

The internal connection of the portable cable partial discharge live detection device of the above-mentioned embodiment: two "DC+5V" output ports of the power management module, one of which is connected to the "DC+5VIN" interface of the signal conditioning module, and one of them is connected to the signal conditioning module. Connect to the "DC+5VIN" interface of the acquisition module. Two "OUT-A" and "OUT-B" signal output ports of the signal conditioning module and "SYNC-OUT" synchronization output port and "CH-A" and "CH-B" two-channel signal input of the signal acquisition module The ports and the "EXT" trigger port are connected separately using shielded cables.

The connection between the interior of the portable cable partial discharge live detection device and the front panel: the two "IN-A" and "IN-B" signal input ports of the signal conditioning module use shielded cables to connect with the front panel of the portable cable partial discharge live detection device The "HFCT-I" and "HFCT-II" interfaces on the device are respectively connected; the "SYNC-IN" synchronous input port of the signal conditioning module uses a shielded cable to connect to the "SYNC" interface on the front panel of the portable cable partial discharge charged detection device Connection; the "USB-B" data interface of the signal conditioning module is connected to the "SPI" interface on the front panel of the device through a USB shielded cable; the "USB-B" data interface of the signal acquisition module is connected through a USB shield The cable is connected to the "DATA" interface on the front panel of the portable cable partial discharge live detection device.

Referring to Fig. 3, the flow process of partial discharge in the technical solution of the utility model is as follows:

⑴Before the test, it is recommended to carry out the electrification correction link first. After correction, the partial discharge test result can be expressed as the discharge capacity pC.

⑵Waveform acquisition is the driver programming of the signal acquisition module, using the producer-consumer programming mode, and using the queue to buffer data, and should have the storage function of waveform data, which is divided into two types: waveform file format and screenshot image format.

(3) Carry out the two algorithms of "peak detection" and "synchronous phase" on the collected waveform data to calculate the data source required for the cumulative partial discharge spectrum. Similarly, spectrogram data should also have a storage function, which is divided into spectrogram file format, screenshot image format and database storage table.

⑷ More comprehensive and in-depth partial discharge analysis functions in the form of additional module toolkits, including "wavelet noise reduction analysis", "discharge pattern recognition", "discharge defect location", "database management query" and other toolkits.

The portable cable partial discharge charged detection device of the technical solution of the utility model is mainly composed of a sensor, a current transformer, a power management module, a signal conditioning module, a signal acquisition module, and a notebook computer (with a partial discharge test module). Compared with the existing partial discharge detection technology, the portable cable partial discharge live detection device can measure the partial discharge pulse signal and can cover the wide frequency band partial discharge signal of DC~30MHz, and has more accurate pulse waveform resolution capability, and the partial discharge test The module expands the functions of wavelet noise reduction analysis, discharge pattern recognition, and defect location, and can be used as a special detection device for partial discharge of cable accessories.

Compared with the prior art, the technical solution of the utility model can at least achieve beneficial effects: due to the use of a high-sampling rate and high-resolution data acquisition device, and the ability to process signals up to high-frequency bands, the The portable cable partial discharge live detection device can complete the cable partial discharge live detection task and high-precision fault location function; the portable cable partial discharge live detection device is powered by a built-in lithium battery, which meets the portability requirements at the cable test site and improves the cable safety. Work efficiency of partial discharge detection.

Finally, it should be noted that: the above is only a preferred embodiment of the utility model, and is not intended to limit the utility model, although the utility model has been described in detail with reference to the foregoing embodiments, for those skilled in the art , it is still possible to modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements for some of the technical features. Any modification, equivalent replacement, improvement, etc. made within the spirit and principles of the present utility model shall be included in the protection scope of the present utility model.

Claims (3)

1. A portable cable partial discharge electrification detection device, is characterized in that, comprises the high-frequency partial discharge sensor that can gather the partial discharge information of the cable to be tested, the current transformer that can gather the partial electrification information of the cable to be tested, and can be based on A signal processor for processing the partial discharge information of the cable under test collected by the high-frequency partial discharge sensor and the partial electrification information of the cable under test collected by the current transformer. 2. The portable cable partial discharge live detection device according to claim 1, characterized in that the portable cable partial discharge live detection device further comprises a user terminal capable of outputting the processing results of the signal processor. 3. The portable cable partial discharge live detection device according to claim 1 or 2, wherein the signal processor includes a signal conditioning module connected to the high-frequency partial discharge sensor and the current transformer respectively, and A power management module and a signal acquisition module respectively connected to the signal conditioning module.