Kelvin Anoh

The increasing integration of prosumers and smart metering devices into the energy distribution network, is transforming the traditional energy market to a community energy trading that requires peer-to-peer (P2P) interactions. Such P2P interactions result in complex data exchanges among prosumers, utility grid, and market operators. This inevitably introduces control complexity, security, and privacy challenges in the existing power system. The application of distributed ledger technology (DLT) has seen an increase in solving security challenges in the power network, specifically, in P2P energy exchanges. Thus, this study explores different DLT structures including blockchain and IOTA usage in energy P2P trading. A smart contract for managing trust and transactions is designed and implemented on IBM hyperledger fabric platform. In addition, we evaluated the performance of interconnected internet of things devices for energy transactions with IOTA protocol, which uses the directed acyclic graph as its DLT structure, against the Ethereum-based blockchain structure. It is shown that the end-to-end transaction delay with the IOTA DLT is lower than the Ethereum-based DLT implementation.

As the evolving communication standards would leverage on high data rates and low power consumption, future communication systems must be able to demonstrate these strengths. Space-time block codes (STBC) and quasi-orthogonal STBC (QO-STBC) including beamforming are multiple-input multiple output (MIMO) system design techniques used to improve data rates and reduce bit error ratio (BER). STBCs for larger antenna configurations use QO-STBC schemes which suffer from self-interference problems. The self-interference in QO-STBC systems diminishes the data rates and worsen the BER. In this study, we present three (3) methods of overcoming the self-interference problems in QO-STBC systems. We implement the interference-free QO-STBC systems with directional beamforming to improve the data rates and also reduce the BER. The results show significantly improved BER performance when the interferences are eliminated. An additional 3dB gain is achieved at 10(-4) BER when the interference-free QO-STBCs are operated with directional beamforming. In terms of data rates, up to 6 bits/s at reasonably low power consumption are realized when the Hadamard-based QO-STBC is operated with directional beamforming.

In residential homes, domestic energy storage in batteries have been proposed by many to support the grid. To foster its integration into the grid, virtual power plant (VPP) technology is used. In this paper, we evaluate Peukert condition of domestic battery storage within a given distribution level market. An evolutionary algorithm is applied to optimize the social welfare of stakeholders in a community VPP at different levels of Peukert conditions. The dynamic load performance of the VPP with respect to the grid requirements for demand-side management (DSM) is also presented to evaluate the impact of the Peukert effect on DSM. The results show that the social welfare of the VPP stakeholders decreases as Peukert effects increase.

Orthogonal frequency-division multiplexing (OFDM) is a popular multi-carrier technique used in many digital communication systems such as wireless fidelity (Wi-Fi), long term evolution (LTE) and power line communication systems. It can be designed using fast Fourier transform (FFT) or wavelet transform (WT). The major drawback in using WT is that it is computationally inefficient. In this study, we introduce a simple and computationally efficient WT, harmonic wavelet transform, for OFDM signal processing. The new WT uses the orthogonal basis functions of conventional FFT-OFDM except that it involves translation and dilation of the input signal; the new wavelets is referred to as harmonic wavelets (HW). When compared with pilot-assisted OFDM system in terms of reduction in the peak-to-average power ratio, the results show that HW-OFDM outperforms FFT-OFDM by 3 dB at 10(-4) CCDF (complementary cumulative distribution function). Over Rayleigh fading channel with additive white Gaussian noise (AWGN), the bit error ratio of both FFT-OFDM and HW-OFDM perfectly matched, showing that the proposed HW-OFDM is better in terms of peak-to-average power ratio reduction.

Smart Grid is expected to support a variety of services for energy prosumers - entities that are able both to produce and consume energy. Enabling cooperation among such prosumers in the form of energy trading may be highly beneficial for all actors in Smart Grid. However, in order to provide energy trading capabilities, a communication infrastructure that will be able to offer energy trading service to a massive number of energy traders dispersed over a large geographic area is needed. In this paper, we argue that a 4G/5G cellular network that offers cellular Internet of Things (IoT) services and provides mobile edge computing (MEC) capabilities is ideally suited for future widespread energy trading. We discuss architecture of such a system, identify and present analytic models for each of its parts that also account for stochastic aspects, and propose an overall energy trading system model. By doing so, we obtain a novel optimization problem formulation of the energy trading, that is capable of handling uncertainties in price changes. Our results and discussion provides initial insights towards the design of energy trading services via emerging IoT/MEC-enabled mobile cellular networks.