Peak load reduction of multiple water heaters: Respecting consumer comfort and money savings

Demand Response programs can allow residential electricity consumers to cut their energy bills. However, in case of contingencies in the energy system when the guaranteed peak load reduction is needed, comfort of consumers can be significantly deteriorated and they can choose to opt out. This paper investigates the possibility of peak load reduction and yet highly respecting consumers' comfort by coordinating a group of electric tank water heaters. The proposed peak shaving mechanism accounts for interests of both utility companies and their customers. It employs two optimization models tailored to the needs of both sides to optimally schedule individual water heaters. The suggested Simulation results show the potential of the proposed mechanism to provide the guaranteed peak load reduction thus contributing to the stability of the electrical grid, while transparent balancing between comfort-money and comfort-energy incorporated in the control scheme is of interest and use to green consumers

Switch based high cardinality node detection

The detection of supernodes with high cardinality is of interest for network monitoring and security. Existing schemes for supernode detection rely on data structures that are independent of the switching functions. This means that for each packet that traverses the switch, both the switching table and the supernode detection structure have to be checked which requires significant memory bandwidth. This can create a bottleneck and reduce the speed of the switch, especially for software implementations. In this letter, a scheme that performs supernode detection as part of Ethernet switching and does not require additional memory accesses nor separated data structures is presented. The scheme has been implemented and compared with the existing methods. The results show that the proposed scheme can reliably identify supernodes while providing a speed up of more than 15% when compared with the existing solutions.This work was supported in part by the Higher Education Commission (HEC) Pakistan and the Ministry of Planning, Development and Special Initiatives under National Centre for Cyber Security; in part by the ACHILLES Project PID2019-104207RB-I00 and the Go2Edge network RED2018-102585-T funded by the Spanish Ministry of Science and Innovation; and in part by the Madrid Community Research Project TAPIR-CM under Grant P2018/TCS4496

SALSA: A Formal Hierarchical Optimization Framework for Smart Grid

The smart grid, by the integration of advanced control and optimization technologies, provides the traditional grid with an indisputable opportunity to deliver and utilize the electricity more efficiently. Building smart grid applications is a challenging task, which requires a formal modeling, integration, and validation framework for various smart grid domains. The design flow of such applications must adapt to the grid requirements and ensure the security of supply and demand. This dissertation, by proposing a formal framework for customers and operations domains in the smart grid, aims at delivering a smooth way for: i) formalizing their interactions and functionalities, ii) upgrading their components independently, and iii) evaluating their performance quantitatively and qualitatively.The framework follows an event-driven demand response program taking no historical data and forecasting service into account. A scalable neighborhood of prosumers (inside the customers domain), which are equipped with smart appliances, photovoltaics, and battery energy storage systems, are considered. They individually schedule their appliances and sell/purchase their surplus/demand to/from the grid with the purposes of maximizing their comfort and profit at each instant of time. To orchestrate such trade relations, a bilateral multi-issue negotiation approach between a virtual power plant (on behalf of prosumers) and an aggregator (inside the operations domain) in a non-cooperative environment is employed. The aggregator, with the objectives of maximizing its profit and minimizing the grid purchase, intends to match prosumers' supply with demand. As a result, this framework particularly addresses the challenges of: i) scalable and hierarchical load demand scheduling, and ii) the match between the large penetration of renewable energy sources being produced and consumed. It is comprised of two generic multi-objective mixed integer nonlinear programming models for prosumers and the aggregator. These models support different scheduling mechanisms and electricity consumption threshold policies.The effectiveness of the framework is evaluated through various case studies based on economic and environmental assessment metrics. An interactive web service for the framework has also been developed and demonstrated

Relay-aided Slotted Aloha for Optical Wireless Communications

We consider a relay-aided Slotted ALOHA solution for uplink random access for an Optical Wireless Communications (OWC)-based Internet of Things (IoT). The first phase of uplink, the one between IoT devices and the relays, is realized using indoor OWC, while the second phase, between the relays and a base station, represents the long-range RF transmission based on low-power wide area network such as LoRaWAN and occurs outdoors. The throughput performance dependence on the OWC and RF channel conditions is observed. The behavior of the performance gain due to adding relays is highlighted and investigated under different channel and traffic conditions.Comment: Published in: 2020 12th International Symposium on Communication Systems, Networks and Digital Signal Processing (CSNDSP

An IC architecture for RF Energy Harvesting systems

In this work we present an IC architecture for RF energy harvesting. The system has been designed with a 0.18μm CMOS SMIC technology and optimized at 900MHz. Simulation results have confirmed that the integrated system handles an incoming power typically ranging from -25 dBm to 20 dBm by rectifying the variable input signals into a DC voltage source with an overall efficiency up to 50%. The chip area estimation for the proposed system is as low as 3x3mm2