IoT-Grid: IoT Communication for Smart DC Grids

IoT technology is considered an essential imperative for Smart Grids (SGs). However, IoT devices have inherently limited responsiveness that may not be sufficient for a time critical SG with stringent demands on communication delay. In practice, it remains an outstanding problem to combine IoT technology with existing grids. To facilitate deployment of IoT-based grids in domestic environments, we propose IoT-grid, a programmable, small-scale, direct current (DC) grid, that can be easily implemented with low-power hardware with limited processing capacity. The proposed grid adopts relatively cheap DC-DC converters which not only provide high conversion efficiency but also accommodate existing small-scale DC power systems (e.g. solar panels). We then explore the communication aspects of IoT-grid, namely, control and monitoring functions. We observe that processing delays of IoT devices have large impact on IoT-grid, which cause a chain of control commands to take considerable longer time as the number of commands increases. To mitigate this problem, we propose a mechanism based on sending burst commands with scheduled responses. Our experimental results show that, in the presence of processing delays, this method can significantly reduce the overall response time.