Distributed voltage regulation using permissioned blockchains and extended contract net protocol

Distributed voltage regulation schemes within active distribution networks (ADNs) are receiving plenty of attention because they reduce latency bottlenecks. However, previous schemes often employ a trusted moderator to govern agent communication, thereby exposing potential trust issues that may affect agent performance. Blockchain technology can avoid the need for intermediaries, since it is a fully decentralized network that is governed by agents using distributed consensus mechanisms. Thus, this paper proposes a blockchain-based system for voltage regulation in ADNs that provides a competitive marketplace wherein agents can rationally bid for voltage regulation services. The proposed system utilizes a smart contract that i) enables asynchronous negotiation between agents to mitigate multiple violations simultaneously using the extended contract net protocol (ECNP), and ii) maintains a credit score that reflects the trustworthiness of an agent in resolving voltage violations. The proposed system also develops a bidding and pricing scheme for voltage regulation services that considers both active and reactive power contributions. A permissioned blockchain implementation is used to ensure that only known agents are permitted to access the system. The proposed system is implemented on the Hyperledger Fabric platform, where simulations executed on a 69 bus system demonstrate the system's ability to mitigate multiple voltage violations simultaneously. As demonstrated by the simulation results, the highlight of the main contribution of the paper is the ability of the proposed system to mitigate multiple voltage violations simultaneously via the ECNP, thereby utilizing less bidding cycles to resolve voltage violations as compared to the original contract net protocol.