# Analysis of AMI Communication Methods in Various Field Environments
###### Abstract
A data concentration unit (DCU) is installed below a pole-mounted transformer or inside a pad-mounted transformer cabinet to collect electrical data, such as the effective powers, energies, power factors, voltages, and currents, from the smart meters of customers and to set the smart meter management variables. AMI modems can be installed inside or outside near the smart meters to transmit those electrical data to DCU. The smart meter of the customer is configured in a form that one or a plurality of adjacent smart meters is clustered according to the customer structure. A low-voltage consumer modem can be built into a meter or installed as an external modem separate from the meters. Smart meters clustered within a short distance can be connected to an AMI modem through a separate wired communication method such as ISO485, so that electrical data of multiple smart meters can be collected using one modem. The types of low-voltage customers in the Republic of Korea can be characterized according to residential, rural, commercial, and factory areas. The types can also be characterized according to the wiring method that supplies electricity to the low-voltage customer as overhead and underground power lines as shown in Figure 1.  
For AMI in Korea, HS PLC as a broadband PLC method, and ZigBee and Wi-SUN as wireless communication methods are currently being used. In this paper, we first experimentally measured and compared their communication performances with each other according to the types of low-voltage customers of AMI. Here, the employed broadband PLC can meet the requirements of KEPCO's AMI communication technology in terms of high communication success rates, fast meter data reading periods of at least 15 min, time-of-use (TOU) tables, and large data transmissions such as the firmware update. However, narrowband PLC methods are excluded from the field measurement of the AMI communication method targeting low-voltage customers because these methods cannot meet the KEPCO requirements. For field environment analyses under AMI, we select practical sites according to the customer type, and measured the communication performances at each measurement point (MP), from the utility pole where the transformer is mounted, to the smart meter of the customer. Here, we use the signal and noise powers, signal-to-noise ratio (SNR), and packet error rate (PER) in evaluating the communication performances. For the TOU billing, which requires the most frequent data transmission, the power usage data only needs to be collected within a fairly long period of 15 min. The maximum size of data transmitted by each meter is only 128 bytes. Due to these AMI operating environment characteristics, latency and channel bandwidth performances are not considered. The most important consideration for power companies to design an AMI field network is the meter reading success rate which depends on the channel packet error rate (PER), which greatly depends on the distance between the DCU and the meter. Thus, in order to efficiently assign MPs, we use New Distribution Information System (NDIS), which can graphically provide distribution information and has been used by KEPCO since 1997 for distribution planning, management, and operation. In this paper, through extensive experiments for  
Figure 1: Low-voltage distribution configurations at KEPCO, Republic of Korea. (**a**) Low-voltage power system using overhead power lines. (**b**) Low-voltage power system using underground power lines. (**c**) Mixed type of the overhead and underground power lines. Figure 2: Advanced metering infrastructure (AMI) system configuration of Korea Electric Power Corporation (KEPCO), Republic of Korea. practical AMI field environments and their regression analyses, we construct communication models for each communication method. From the constructed communication models with NDIS, we can consider an appropriate communication method and plan a methodology for constructing an AMI network based on the selected communication method.