The authors propose, design, and implement a low-cost universal smart energy meter (USEM) with demand-side load management. The meter can be used in the postpaid and prepaid modes with flexible tariff plans such as time of use, block rate tariff, and their combination. The smart meter comprises of a potential transformer, current transformer, and microcontroller unit with an embedded communication module. The connectivity among the utility authority, the smart meter, and consumer is established by authority identification number, meter identification number, and user identification number using the cellular network. The load management option of the meter controls electrical loads and provides emergency power during the power shortage. The USEM can be configured and reconfigured remotely simply by short message service without changing hardware. Besides, energy consumption status, meter tampering, and fault at the distribution end can be monitored with the proposed metering system. Here, a prototype of the smart meter is presented, and its effectiveness, flexibility, and versatility are experimentally demonstrated. 1 Introduction Smart energy metering system is highly demanded as it offers quick revenue collection, remote monitoring, and control of power distribution system. Since smart metering requires more features than what standard electromechanical or electronic metering system offers [1], automatic meter reading (AMR) system was introduced by combining the communication infrastructure with the electronic metering system. This combination expedites collecting meter information and hence provides a reliable and effective solution remotely [2]. However, the AMR-based metering system is not an efficient and affordable solution; while it replaces manual meter reading, it requires huge financial involvement to establish communication infrastructure. In recent years, prepaid energy metering system has become very attractive to both consumer and power distribution authority as it is efficient, cost effective, and it enhances system accountability [3]. However, some challenging issues limit the attractiveness of prepaid energy metering, e.g. establishing vending station and network connectivity, handheld equipment for tariff plan setting and system upgradations, lack of interoperability and demand-side load management (DSLM), and incompatibility with micro-generation. Advanced metering infrastructure (AMI)-based smart energy metering system with control devices, and a bi-directional communication link became quite popular as it solves several problems inherent in the old metering system [4]. The attractive features of the AMI-based metering system are DSLM, remote tariff plan setting, pricing, billing information, remote connection and disconnection, fault detection, tampering protection etc. AMI comprises of smart meter, user gateways, bi-directional communication system, and meter data management system [5]. The communication system of a smart meter is a crucial part as all functionalities are dependent on its qu...
