Power distribution network industrial frequency communicating method and system

Abstract

The invention relates to a power frequency communication method for a distribution network and a system using the method, firstly, installing a master-slave type communication system which comprises a master station device, a power distribution network and a plurality of user end transceivers, carries modulated information by using weak distortion of waveforms of current and voltage near a zero-crossing point of a power frequency of an electric network, takes the modulated information as part of sine wave of alternating current, takes middle and low voltage distribution network as a medium of information transmission, and uses a mode of half duplex for a both-way communication, so that the master-slave type communication system can penetrate a transformer with power frequency wave with low consumption to achieve a communication over distribution transformers without relaying, has the characteristics of far transmission distance, strong capability of anti-interference, simple device and small investment, and solves the problem that the prior signal of a power line carrier communication is hard to penetrate the distribution transformer to transmit over distribution transformers. The method and the system can be widely used in fields, such as remote meter reading of data of a water meter, an electricity meter and a gas meter, electric power load controlling, electric energy remote collecting, etc.

Description

technical field [0001] The invention relates to a communication method and system, in particular to a distribution network power frequency communication method and system which utilizes a medium and low voltage distribution network to transmit data. Background technique [0002] The distribution network is an important part of the power grid. It is located at the end of the power grid and mainly completes the transmission and distribution of electric energy. It has a wide distribution. like figure 1 As shown, in this power distribution network system, high-voltage lines refer to power lines above 10kV, medium-voltage lines are typically 10kV lines in my country, and low-voltage lines refer to single-phase 220V lines. It is undoubtedly a very convenient and economical way to use the existing distribution network to transmit data information while distributing electric energy, such as water, electricity, gas meter reading data and power load control. For the transmission net...

AI Technical Summary

Problems solved by technology

Different from the transmission network, the distribution network has many branches, complex load types, variable network topology, and large noise interference, so it is not an ideal communication environment.

The existing medium and low-voltage distribution network carrier communication at home and abroad generally has poor reliability and short effective transmission distance. The main reason is that the frequency of the carrier signal is in the high frequency band (40kHz-500kHz), and the power grid has a large attenuation of the carrier signal transmission. , the transmission distance is short, and long-distance transmission requires intermediate devices, such as repeaters; Can be transmitted within the same voltage level range

The existing audio pulsating carrier and ultra-narrow-band carrier that can be transmitted through distribution transformers, the carrier signal spectrum is in the low-frequency band below 2kHz, these two technologies can only realize one-way transmission of downlink and uplink, and cannot communicate bidirectionally. The carrier of information is still a low-frequency or very low-frequency carrier signal superimposed on the power line

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