The centralized remote transcription system studied and developed in our country is a district centralized remote transcription system with single distribution transformer. Its typical network topology is as follows:
Subarea Data Acquisition Unit of User Electric Energy Meter Business Station Receiver Host of Distribution Transformer Concentrator
Generally, a family building unit has 14 to 18 low-voltage watt-hour meters. The unit sub-area data collector is responsible for collecting the watt-hour meter data of its subordinates, and the distribution transformer concentrator is responsible for collecting all the data of the sub-area collector of the unit under the distribution transformer. From the point of view of data transmission, the networking modes include two-stage pure dedicated line networking mode, two-stage hybrid networking mode and two-stage carrier networking mode.
From the point of view of network topology, as long as special channel communication is used in user watt-hour meter, unit sub-area collector and distribution transformer concentrator, the cable engineering quantity of remote automatic meter reading system is very large, and the maintenance of cable dedicated channel is also difficult. In view of this situation, each scientific research unit and manufacturer are trying to cancel the unit sub-area collector and realize the direct low-voltage power line carrier communication between the user watt-hour meter and the distribution concentrator, which greatly reduces the amount of cable engineering, and the network topology of data remote transmission is consistent with the low-voltage distribution network, which is conducive to the operation and maintenance of the system and the modular expansion of the number of users. 。 This topology requires a user terminal to realize not only energy metering, but also data information coding, decoding, carrier transceiver and other functions. It can form the network topology of the main business station of the distribution and transformer concentrator of the carrier watt-hour meter based on the low-voltage power line channel. Practice has proved that it is difficult to ensure reliable transmission of power or control data for low-voltage carrier meter and distribution concentrator with narrowband modulation which have been developed in the market at present. The main reason is that the characteristics of low-voltage power line carrier channel are random, time-varying and very unstable. Therefore, low-voltage power line carrier technology is the bottleneck of further popularization and application of remote meter reading system directly through power line network.
This paper is devoted to the development of the spread spectrum carrier user terminal with independent intellectual property rights. Once the development is successful, the transcription system can use the simple and clear network topology of the user terminal distribution unit business station to transcribe the main station, and will become the mainstream network topology of the transcription system in China.
Zhejiang Chint Instrument & Meter Co., Ltd
Wenzhou Production Base: Wenzhou Bridge Industrial Zone, Yueqing, Zhejiang, PR.China
Headquarter: No.560, Yueming Road, Binjiang District, Hangzhou, Zhejiang, China