Intelligent station zone recognition instrument with voice device and recognition method

Abstract

The invention relates to an intelligent transformer area recognition instrument with a voice apparatus and a recognition method to solve the problems of common signal crosstalk and short transmission distance of current transformer area recognition instruments and the problem of inconvenient and unsafe usage of the instruments. The recognition instrument comprises that an audio unit which is connected with a microphone and a loudspeaker is connected with a carrier main processing unit, the carrier main processing unit is connected with an analog front end transceiving unit, the analog front end transceiving unit is connected with a line driving unit, and the line driving unit is connected with a crosstalk suppression unit which is connected with a line safe coupling unit. A USB port is connected with a charging and discharging management unit and an interface conversion unit, and accordingly, charging and file updating can be performed. According to the recognition instrument, main and auxiliary machines can perform conversation and recognize line belonging through voice intelligibility. The recognition instrument is accurate in recognition, safe to use, simple to operate, capable of not being powered in site, small in size, convenient to carry and low in cost.

Description

technical field [0001] The invention relates to a device for determining the phase correspondence between a distribution transformer and a user's electric meter, in particular to an intelligent station area identification device and an identification method in the field of electric power marketing. Background technique [0002] The station area identification instrument is a special instrument for the power marketing department. In the past, the grid construction in suburban areas and rural areas was chaotic, the wires were pulled randomly, and the account was not clear. Therefore, this instrument is needed to determine the corresponding relationship between distribution transformers and user meters. [0003] Due to the inherent characteristics of the FSK carrier communication principle, the station area identification device based on FSK carrier communication technology has its defects mainly in the following two aspects: First, the uncertainty of the identification distance...

AI Technical Summary

Problems solved by technology

The shortcoming of this invention is that the discrimination accuracy rate is very low, because the signal strength collected by the hand-held detector has a great relationship with the distance between the hand-held collector and the cable to a large extent. The cable is routed in the air, either in the cable trench or along the wall. It is difficult to test the cable with a hand-held detector. When multiple cables are placed side by side, the signal strengths measured by several cables are basically the same, and it is difficult to distinguish the cable. It is because the communication circuit design does not address the problem of signal crosstalk in the case of common high voltage, common ground, parallel wiring and common cable trench. The pulse mode will produce obvious narrow-band interference noise and burst noise, and will affect a wide bandwidth, so It is more likely to cause signal crosstalk; the third is that the design of the electromagnetic induction antenna in the handheld pulse detector is difficult. If the sensitivity is too low, the signal cannot be received, and if the sensitivity is too high, it will be difficult to distinguish multiple signals received. For filter amplification design, it is expensive to make a handheld detector that meets the requirements of the index; fourth, it is inconvenient to use, and it takes time to track and determine the direction of the cable with a handheld detector

The disadvantage of this invention is that the operation is difficult to implement. The power company has strict safety regulations for power outages. The power company will never allow multiple power outages in the same area in order to identify the station. The second is that the design of the communication circuit does not address the problem of signal crosstalk in the case of common high voltage common ground parallel wiring and common cable trench;

[0015] The Fsk modulation method is suitable for communication methods with low transmission rates and short transmission distances, which have poor anti-interference and are prone to self-interference.

[0016] The disadvantage of the zero-crossing detection modulation method is that it is necessary to convert the sine wave into a square wave, and then perform zero-crossing detection. During the waveform conversion process, due to factors such as signal instability and noise, jitter will occur near the zero point, so it is easy to convert these The jitter is misjudged as zero, thus causing an error and affecting the subsequent circuit

[0017] The pulse method is easy to generate narrow-band interference noise and burst noise in a wide frequency band. The power line itself has a pulse generated by a 50Hz power frequency signal from the peak to zero. At the same time, the random connection and disconnection of electrical equipment on the line also produces The broadband characteristics of pulse signal pulse interference make it more likely to cause triple interference

The high-frequency voltage pulse signal has a large dv / di, di / dt, forming strong electromagnetic interference, the frequency can range from a few KHZ to tens of MHZ, and the pulse interference will seriously affect the communication quality. The maximum intensity of pulse interference can reach 40DB Therefore, there is a security risk

[0018] What needs special explanation is that the FSK plus pulse current method is adopted as a mature technology by most station area identifier manufacturers. In actual use, multiple receiving ends can receive pulse signals. To determine the corresponding relationship of attribution, this method is prone to misjudgment when the line is long or even aging

[0019] The communication environment of the power carrier channel is harsh, the impedance changes greatly, the time variation is strong, there is a large frequency selective attenuation, and there are many interferences (including steady-state background noise, narrow-band interference noise, burst noise, periodic pulse noise, etc.), so the communication used in the above patent The modulation method is not enough to deal with the harsh power carrier channel environment. The signal is seriously distorted during the transmission process. When the line load is heavy, the transmission distance is only a few hundred meters.

Images