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This paper proposes a market framework to approach economic dispatch as a subproblem in smart distribution systems. Four subproblems are associated with four different submarkets (SMs) in the presented framework. Market participants are eligible to bid in different submarkets based on the type of their distributed generation (DG) unit. To effectively tackle the conflicts among objective functions of different submarkets, the corresponding formulated subproblems are assigned to two different agents, namely distribution system operator (DSO) and a green bank agent (GBA). A communication mechanism is designed within the proposed framework such that DSO and GBA compromise their solutions and find a tradeoff to reasonably address the concerns of the four subproblems within SMs 1-4. The effectiveness of the proposed market framework is validated on a well-known 136-bus distribution system, which is modified to contain wind turbine DG aggregators, photovoltaic DG aggregators, and diesel-engine DG aggregators. [ABSTRACT FROM AUTHOR]

Deployment of photovoltaic generation in smart grids has introduced overvoltage problems. Cyberattackers can take advantage of this situation and cause intentional overvoltages in distribution systems using stealthy false data injections (FDIs). To protect distribution grids from these FDIs, the first step is to model cyberattacks that can cause overvoltages. An accurate nonlinear optimization model is developed for stealthy FDI cyberattacks that can result in overvoltages on targeted nodes in distribution grids without being detected by bad data detection algorithms. Compared to the existing research, which mainly focused on dc state estimation for transmission systems, the proposed model formulates cyberattacks that cause overvoltages using ac state estimation in distribution grids. The proposed nonlinear model is then approximated to a convex optimization model using second-order cone programming relaxation formulation to guarantee that a global optimum exists for the model. Several case studies are considered to validate the effectiveness of the proposed attack model. It is shown that by limiting the FDIs on targeted buses to 20% of their nominal load, multiple buses can experience severe overvoltages in a distribution grid. [ABSTRACT FROM AUTHOR]

This article proposes a remedial action scheme (RAS) based on thyristor-controlled series capacitors (TCSCs) to cope with false data injection (FDI) cyberattacks leading to tie-line congestions in transmission systems. To develop such a RAS, a three-level framework is designed. The first level of the framework is associated with the planning phase, where strategic locations of TCSCs are determined. The second level, which is related to the operation phase, challenges the upgraded system via FDI attacks, resulting in tie-line congestions. This necessitates the third level of the framework, where system operator takes advantage of a RAS based on the preinstalled TCSCs to rapidly alleviate the congestions caused by FDIs. The effectiveness of the developed framework is verified on two IEEE test systems, where it is assumed that a higher budget is spent on securing remote terminal units of TCSCs; hence, phasor measurement units are more prone to cyberattacks. [ABSTRACT FROM AUTHOR]

This article proposes a framework as a remedial action scheme (RAS) for close to real-time system operation when system operator becomes aware of possibility of decentralized outages due to simultaneous attacks on several market retailers. The upper level of the framework is an offline RAS where system operator immediately implements a customized reconfiguration preventing the decentralized outages. Due to immediate implementation of upper-level reaction, it is possible to face decentralized congestions in the new topology having minimum reliance on the attacked market retailers. Since severity of congestions is less than that of outages, the lower level of the framework is implemented as an online RAS. In this level, eligible nonattacked market retailers are invited into a secondary market to compete for generation/consumption redispatch and contribute into alleviation of congestions with the purpose of increasing their income. The effectiveness of the proposed framework is validated on a well-known 136-bus distribution system. [ABSTRACT FROM AUTHOR]

Energy, building, and water networks are three interlinked critical infrastructures that need to be operated cooperatively to maximize the smart grid’s economic benefits. In this paper, a mixed-integer linear programming (MILP) formulation is proposed to approach the economic dispatch (ED) problem for smart grids embedded with interdependent water and energy networks. Energy management of various building applications is considered by intelligently controlling the indoor temperature during occupied and unoccupied hours. To optimize the demand of water distribution system, pump’s nonlinear scheduling and hydraulic factors and daily water usage of buildings are added to the proposed model. Piecewise linear approximation of univariate and bivariate nonlinear functions is used to convert the nonlinear problem to an MILP formulation. Several case studies were conducted to examine the impact of indoor temperature settings of the buildings, speed of pumps, battery efficiency, and end of day (EoD) battery and tank constraints on economic dispatch of the microgrid system. [ABSTRACT FROM AUTHOR]

The technology of supercapacitor is vastly examined by researchers to cope with a lower power density of battery. It is validated that a hybrid battery-supercapacitor storage (HBSS) framework can improve the overall efficiency due to taking advantage of battery's higher energy density and supercapacitor's higher power density. Despite the extensive investigations on this hybrid storage scheme in the electric vehicle (EV) industry, its experimental implementation in the power grid to cope with non-dispatchable nature of wind and solar energy is still in its initial stages. As a result, this paper concentrates on analysis of its experimental implementation on a lab-scale hybrid microgrid located at Southern Illinois University, Carbondale, IL, USA containing two wind turbines and two photovoltaic (PV) modules. The objective of this work is to promote the utilization of the experimentally validated lab-scale HBSS in power industry. [ABSTRACT FROM AUTHOR]

This paper investigates the design and analysis of a robust nonlinear controller for voltage source converters (VSCs) connected to weak AC grids. Feedback linearization method is used to develop the control inputs that regulate the active power and output voltage of the grid-connected converter. The frequency-domain model of an LCL filter in $dq$ -frame is used to develop the nonlinear control blocks for small-signal stability analysis. Impact of phase-locked loop (PLL) is added to the control block through feedforward loops. It is shown that unlike vector controlled converters, the proposed controller is not negatively affected by the PLL gains and a broader range of operation is achieved. In addition, the designed controller is robust against sudden active power commands from 0 to 1 p.u., and is capable of fault ride through when AC grid is very weak. The robustness of the proposed controller is evaluated using eigenvalue analysis of the linearized closed-loop model and time-domain simulations of a grid-connected VSC in various cases. [ABSTRACT FROM AUTHOR]

This article proposes a novel approach to efficiently distribute braking force of an electric vehicle (EV) between friction and regenerative braking with an ultimate goal of maximizing harvested energy during braking. The regenerative braking performance of an EV depends on various factors influenced by the driver behavior and driving conditions, which are challenging to measure or predict in real-time. In the proposed method, the performance map of the traction motor (TM) and its controller is used to define a boundary in which blending of regenerative and friction braking is performed with the goal of maximizing recaptured energy through the regenerative braking process. The performance, effectiveness, and robustness of the proposed strategy are validated through a hardware-in-the-loop (HIL) experimental testbed for a predetermined drive cycle of Urban Dynamometer Driving Schedule (UDDS). It is shown that using the proposed method, the amount of recaptured energy through the regenerative braking process can significantly increase compared to constant or variable boundary methods using a weight factor for brake distribution. [ABSTRACT FROM AUTHOR]

This article proposes a distributed consensus-based demand response control for permanent magnet synchronous generator (PMSG)-based wind turbines using standalone distributed battery energy storage systems (BESSs). The proposed controller cooperatively regulates the output power of individual wind turbines and BESSs in a wind farm to deliver active and reactive powers to the load in varying wind speed conditions. Capability curves of the wind turbines and BESSs are considered in the design. In addition, a virtual leader is designed to regulate the voltage and frequency of the combined PMSG-BESS units at the point of common coupling. Simulations on modified IEEE 14-bus power system are performed to validate the proposed design. [ABSTRACT FROM AUTHOR]

Coordinated energy management plays a main role in increasing the performance and economic benefits of future smart homes. This article focuses on the energy management of a smart home equipped with a plug-in electric vehicle (PEV), household battery storage, and photovoltaics (PV), and it proposes an energy price tag (EPT) for all energy storage devices connected to the smart home system. A hybrid approach that consists of optimization and a rule-based prioritization is presented. The proposed algorithm establishes a priority order between the PEV, the household battery, and the imported power from the grid based on the EPT of energy sources. The proposed energy management algorithm seeks for the minimum overall energy cost for the smart home and PEV owner while satisfying household power demand and charging requirements of the storage devices. The performance of the energy management algorithm is examined on a typical smart home over a 24-h period based on time-varying grid electricity price. [ABSTRACT FROM AUTHOR]

This paper proposes a day-ahead market framework for congestion management in smart distribution networks. The presented scheme provides a platform for collaboration between distribution-level market operator (DMO) and data traffic operator (DTO) to alleviate congested feeders such that data transmission traffic between market participants is effectively managed in a smart grid. In addition, a decentralized mechanism is developed for collaboration of electric vehicle (EV) aggregators with common clients to take advantage of EVs not only as flexible loads but also as mobile distributed storage (MDS) for congestion management. Moreover, the proposed framework outlines an administrative action for distribution system operator (DSO) to support the market when the decentralized competitions among distributed generation (DG) aggregators and EV aggregators do not fully relieve a serious congestion. The proposed day-ahead congestion management scheme is validated on an unbalanced 136-bus distribution system massively integrated with wind turbine DGs (WTDGs), photovoltaic DGs (PVDGs), diesel-engine DGs (DEDGs), and EVs. [ABSTRACT FROM AUTHOR]

Voltage source converter (VSC) based high-voltage direct current (HVDC) system is an emerging technology in high-power applications. Previous research has shown that VSCs, with commonly used vector current control (VCC) technique, cannot transmit more than 0.4 p.u. of active power when connected to a very weak ac grid. This paper presents a virtual synchronous generator (VSG) control strategy integrated with VCC to allow stable power transfer for very weak ac grid integration. Impedance analysis is used to analyze the designed controller in various scenarios. In addition, sensitivity analysis is performed to study the effect of virtual inertia gains on system stability. Time-domain simulation results using MATLAB/Simscape Power System toolbox show the effectiveness of the developed controller in very weak ac grid integration of VSC-HVDC systems. [ABSTRACT FROM AUTHOR]