With the application of computers in power integrated systems, automatic meter reading systems have increasingly become the mainstream meter reading systems in the power industry. Among the mainstream applications of automatic meter reading systems, the 485 bus automatic meter reading system and the carrier wave meter reading system are the two main applications. Below, we will briefly analyze the principles and pros and cons of these two major meter reading systems.
First, we need to analyze the composition of an automatic meter reading system. Generally, an automatic meter reading system consists of electric energy meters, collectors, concentrators, data transmission channels, and a master station system. During operation, the collector collects data from the electric energy meter, then communicates with the concentrator to send commands to freeze the energy data and receive data from the collector. The collected data enters the master station system through the data transmission channel. After the master station system is connected to the power supply bureau network, it can perform functions such as electricity bill calculation, bill printing, statistical reports, and actual electricity fee collection for residential and commercial electricity use.
485 bus automatic meter reading system: The 485 bus automatic meter reading system mainly consists of electric energy meters, collectors, concentrators, data channel machines, and a master computer. This system is generally used in densely populated areas such as residential communities. The main channels use the public telephone network, and the data communication channel between the concentrator and the collector uses shielded twisted pair cables. However, the communication length between the collector and the concentrator should not exceed 1.2 km.
The advantages of the 485 bus meter reading system are simple technology and low cost. The disadvantages are the large workload of construction and wiring, and the difficulty in finding fault points.
Carrier wave meter reading system: The carrier wave meter reading system is mainly used in areas with harsh environments. Generally, most carrier wave collection modules are based on FSK modulation technology, and some manufacturers use spread spectrum technology. In order to adapt to the actual requirements of different power grid structures, different residential areas, and rapidly changing loads at different times, whether it is FSK modulation or spread spectrum modulation power line carrier systems, it is necessary to take measures such as relaying or increasing power (within the allowable range) according to specific situations to extend the propagation distance and improve transmission reliability, so as to achieve all-weather reliable meter data collection.
The advantages of the carrier wave meter reading system are low construction and wiring difficulty and small workload. The disadvantages are that it is susceptible to interference and the system stability is not good.
