Plug-and-Play Model Predictive Control for Load Shaping and Voltage Control in Smart Grids

TL;DR

This paper introduces a hierarchical model predictive control scheme for smart grid load shaping and voltage regulation, effectively managing plug-and-play electric vehicle charging and flexible loads while maintaining system constraints.

Contribution

It proposes a novel hierarchical MPC approach for load management and voltage control in smart grids with plug-and-play loads, ensuring feasibility and user satisfaction.

Findings

Controller maintains voltage within limits during load variations.

Method achieves load shaping while satisfying user demands.

Scheme demonstrated on a 55-bus distribution network.

Abstract

This paper presents a predictive controller for handling plug-and-play (P&P) charging requests of flexible loads in a distribution system. We define two types of flexible loads: (i) deferrable loads that have a fixed power profile but can be deferred in time and (ii) shapeable loads that have flexible power profiles but fixed energy requests, such as Plug-in Electric Vehicles (PEVs). The proposed method uses a hierarchical control scheme based on a model predictive control (MPC) formulation for minimizing the global system cost. The first stage computes a reachable reference that trades off deviation from the nominal voltage with the required generation control. The second stage uses a price-based objective to aggregate flexible loads and provide load shaping services, while satisfying system constraints and users' preferences at all times. It is shown that the proposed controller is recursively feasible under specific conditions, i.e. the flexible load demands are satisfied and bus voltages remain within the desired limits. Finally, the proposed scheme is illustrated on a 55 bus radial distribution network.