Energy

State Estimation for an Electrochemical Model of Multiple-Material Lithium-Ion Batteries

Camacho-Solorio, Leobardo
Krstic, Miroslav
Klein, Reinhardt
Mirtabatabaei, Anahita
Moura, Scott
2017

This paper presents state estimation for a system of diffusion equations coupled in the boundary appearing in reduced electrochemical models of lithium-ion batteries with multiple active materials in single electrodes. The observer is synthesized from a single particle model and is based on the backstepping method for partial differential equations. The observer is suitable for state of charge estimation in battery management systems and is an extension of existing backstepping observers which were derived only for cells with electrodes of single active materials. Observer gains still can...

Observer Design for Boundary Coupled PDEs: Application to Thermostatically Controlled Loads in Smart Grids

Moura, Scott
Bendtsen, Jan
Ruiz, Victor
2013

This paper develops methods for state estimation of aggregated thermostatically controlled loads (TCLs) in smart grids, via partial differential equation (PDE) techniques. TCLs include on/off controlled devices, such as heat pumps, HVAC systems, and deep freezers. Control of aggregated TCLs provides a promising opportunity to mitigate the mismatch between power generation and demand, thus enhancing grid reliability and enabling renewable energy penetration. However, persistent communication between thousands of TCLs to a central server can be prohibitive. To this end, this paper focuses on...

Analytic Modeling and Integral Control of Heterogeneous Thermostatically Controlled Load Populations

Ghaffari, Azad
Moura, Scott
Krstic, Miroslav
2014

Thermostatically controlled loads (TCLs) account for approximately 50% of U.S. electricity consumption. Various techniques have been developed to model TCL populations. A High-fidelity analytical model of heterogeneous TCL populations facilitates the aggregate synthesis of power control in power networks. Such a model assists the utility manager to increase the stability margin of the network. The model, also, assists the customer to schedule his/her tasks in order to reduce his/her energy cost. We present a deterministic hybrid partial differential equation (PDE) model which accounts for...

Empirical Regret Bounds for Control in Spatiotemporally Varying Environments: A Case Study in Airborne Wind Energy

Haydon, Ben
Cole, Jack
Dunn, Laurel
Keyantuo, Patrick
Chow, Tina
Moura, Scott
Vermillion, Chris
2019

Abstract. This paper focuses on the empirical derivation of regret bounds for mobile systems that can vary their locations within a spatiotemporally varying environment in order to maximize performance. In particular, the paper focuses on an airborne wind energy system, where the replacement of towers with tethers and a lifting body allows the system to adjust its altitude continuously, with the goal of operating at the altitude that maximizes net power production. While prior publications have proposed control strategies for this problem, often with favorable results based on simulations...

Integrated Optimization of Battery Sizing, Charging, and Power Management in Plug-In Hybrid Electric Vehicles

Hu, Xiaosong
Moura, Scott J.
Murgovski, Nikolce
Egardt, Bo
Cao, Dongpu
2016

This brief presents an integrated optimization framework for battery sizing, charging, and on-road power management in plug-in hybrid electric vehicles. This framework utilizes convex programming to assess interactions between the three optimal design/control tasks. The objective is to minimize carbon dioxide (CO2) emissions, from the on-board internal combustion engine and grid generation plants providing electrical recharge power. The impacts of varying daily grid CO2 trajectories on both the optimal battery size and charging/power management algorithms are analyzed. We find that the...

Model Predictive Control of Residential Baseboard Heaters with Distributed System Architecture

Burger, Eric M.
Perez, Hector E.
Moura, Scott J.
2014

Typical residential HVAC systems employ mechanical or hard-coded deadband control behaviors that are unresponsive to changing energy costs and weather conditions. In this paper, we investigate the potential of electric baseboard heaters to maintain a comfortable temperature while optimizing electricity consumption given weather forecasts and price data. We first propose a distributed system architecture that utilizes mobile application platforms. We then develop, assemble, and deploy a sensor network and Internet server to collect real-time temperature data from an apartment. With these...

Parameter Identification of Aggregated Thermostatically Controlled Loads for Smart Grids Using PDE Techniques

Moura, Scott
Bendtsen, Jan
Ruiz, Victor
2014

This paper develops methods for model identification of aggregated thermostatically controlled loads (TCLs) in smart grids, via partial differential equation (PDE) techniques. Control of aggregated TCLs provides a promising opportunity to mitigate the mismatch between power generation and demand, thus enhancing grid reliability and enabling renewable energy penetration. To this end, this paper focuses on developing parameter identification algorithms for a PDE-based model of aggregated TCLs. First, a two-state boundary-coupled hyperbolic PDE model for homogenous TCL populations is derived...

Fast Charging Batteries via Electrochemical Model-based Control

Moura, Scott J.
2014

Title: Fast Charging Batteries via ElectroChemical Model-Based Control In telecommunications, there were 5.2B active mobile handsets and over 1.7B mobile phone sales worldwide for 2012. Mobile phones are also a powerful tool for solving poverty and financial inequity in third world countries. In electrified transportation, there were 53,000 were plug-in electric vehicles sold in the U.S. for 2012. Despite growing sales, range anxiety is considered the largest inhibitor of electrified transportation. Significant reduction in charge times, e.g. comparable to filling a gas tank, would...

Better Batteries Through Electrochemistry

Moura, Scott J.
Perez, Hector E.
2014

This article introduces key concepts in Electrochemical-based Control (ECC) systems for batteries, and highlights the fundamentals of battery electrochemistry, state-of-charge/state-of-health (SOC/SOH) estimation, and constrained control. Research on battery SOC/SOH estimation has experienced considerable growth, and can be categorized under equivalent circuit models (ECM) or EChem model-based algorithms. EChem models capture the spatiotemporal dynamics of lithium-ion concentration, electric potential, and intercalation kinetics. The most fundamental reduced EChem model is the single-...

Comparison of Velocity Forecasting Strategies for Predictive Control in HEVs

Sun, Chao
Hu, Xiaosong
Moura, Scott J.
Sun, Fengchun
2014

The performance of model predictive control (MPC) for energy management in hybrid electric vehicles (HEVS) is strongly dependent on the projected future driving profile. This paper proposes a novel velocity forecasting method based on artificial neural networks (ANN). The objective is to improve the fuel economy of a power-split HEV in a nonlinear MPC framework. In this study, no telemetry or on-board sensor information is required. A comparative study is conducted between the ANN-based method and two other velocity predictors: generalized exponentially varying and Markov-chain models. The...