Sarika Khushalani Solanki

Coordinated Predictive Control of a Wind/Battery Microgrid System

This paper presents the operation and controller design of a microgrid consisting of a direct drive wind generator and a battery storage system. A model predictive control strategy for the ac-dc-ac converter of wind system is derived and implemented to capture the maximum wind energy as well as provide desired reactive power. A novel supervisory controller is presented and employed to coordinate the operation of wind farm and battery system in the microgrid for grid-connected and islanded operations. The proposed coordinated controller can mitigate both active and reactive power disturbances that are caused by the intermittency of wind speed and load change. Moreover, the control strategy ensures the maximum power extraction capability of wind turbine while regulating the point of common coupling bus voltage within acceptable range in both grid-connected and islanded operations. The designed concept is verified through various simulation studies in EMTDC/PSCAD, and the results are presented and discussed.

Demand response using multi-agent system

Smart grid has been a significant development trend of power system. Within smart grid, microgrids share the burden of traditional grids and reduce energy consumption cost. In a microgrid, consumers are the integral part with varying demand throughout a day. Furthermore, the penetration of Plug-in-Hybrid Vehicles (PHEVs) is overloading the existing residential network and calls for dynamic strategy. This paper proposes a dynamic Demand Response (DR) approach in the context of isolated smart microgrid for a residential community. A multi-agent system is proposed for optimizing the demand response by updating the grid generation resources and controlling the customer load. The multi-agent system can switch customer load and controls the charging of PHEVs depending on their Battery State of Charge (BSOC) to reduce cost and avoid overload during peak hours. Simulation and numerical results show the effectiveness of using multi-agent system on reducing the energy consumption cost of the residential customers and also allowing electric vehicles charging during the peak hours.

Demand response model and its effects on voltage profile of a distribution system

This paper develops a model for Demand Response (DR) by utilizing consumer behavior modeling considering different scenarios and levels of consumer rationality. Consumer behavior modeling has been done by developing extensive demand-price elasticity matrices for different types of consumers. These Price Elasticity Matrices (PEMs) are utilized to calculate the level of demand response for a given consumer. DR thus obtained is applied to a real world distribution network considering a day-ahead real time pricing scenario to study the effects of demand reduction on system voltage. Results show considerable boost in system voltage that paves way for further demand curtailment through demand side management techniques like Volt/Var Control (VVC).

Market optimization for microgrid with Demand Response model

This paper develops a market optimization model for a microgrid with Demand Side Bidding (DSB) and Demand Response (DR) by residential consumers. Demand Response (DR) models have been developed by utilizing consumer behavior modeling by Price Elasticity Matrices (PEMs) considering different scenarios and levels of consumer rationality. These PEMs are utilized to calculate the levels of demand response for different consumer types and utilized in the bidding mechanism for the double sided microgrid market. The proposed method is tested for different scenarios on a microgrid system with Independent Power Producers (IPPs) and Load Serving Entities (LSEs) for optimized generation and demand response levels so as to minimize cost.

Steady state analysis of high penetration PV on utility distribution feeder

The current deregulation trend in the electric power industry has led to the utilities trying to adapt Distributed Generation (DG) into their existing infrastructure. In this paper, 12.47 kV distribution feeders of American Electric Power (AEP) are modeled in OpenDSS to investigate the impacts of PV integration. With increasing PV penetration reverse power may flow on the grid which is associated with voltage rise that may lead to violation of integration standards. The impact on voltage profiles and losses depends upon the size and location of the PV system. Voltages of the feeder, voltage regulation and feeder losses under various locations and levels of PV penetration are analyzed for the utility feeder utilizing unbalanced power flow solution.

Multi-agent-based reconfiguration for restoration of distribution systems with distributed generators

Restoration involves supplying the loads that lose power in the process of fault isolation. This process entails the development of a plan consisting of opening or closing of switches, the process called reconfiguration. Existing methods, based on centralized restoration schemes, which require a powerful central computer, may lead to a single point of failure. This paper proposes a decentralized scheme based on agents. The large-scale introduction of Distributed Generation (DG) in distribution systems has made it increasingly necessary to develop restoration schemes that consider DG. When a portion of the system isolated from the utility is fed by DGs, an island occurs. Load shedding may be the only option to maintain the island when conditions are so severe they require correction by restoration schemes. In this paper, a fast and efficient service restoration with load shedding method has been designed for land-based and ship systems, considering priority of customers. The load-shedding algorithm with the service restoration algorithm performs load shedding and restores the loads for systems with and without DG.

Coordination of Demand Response and Volt/Var Control algorithm using Multi Agent System

In this paper the smart grid features of Demand Response (DR) and Volt/Var Control (VVC) are integrated in a distribution system. A coordination scheme for DR and VVC is developed and simulated on American Electric Powers 12.47 KV distribution feeders. Multi Agent System (MAS) is used to establish the coordination scheme by the exchange of distribution network model in real time. Varying levels of DR and VVC for the AEP feeder with different load types show that integration of DR and VVC in real time can yield considerable demand reduction by the combined effects of bus voltage reduction, demand curtailment and demand redistribution over time.

Steady state analysis of three phase unbalanced distribution systems with interconnection of photovoltaic cells

With the deregulation of the electric power industry and the advancement of new technologies, the attention of the utilities has been drawn towards adapting Distributed Generation (DG) into their existing infrastructure. In this paper photovoltaic (PV) systems are modeled to study the effects of their interconnection in a distribution system. The system is a combination of the PV array, DC-DC boost converter with Maximum Power Point Tracking (MPPT) control and DC-AC inverter. With increasing penetration of PV, reverse power may flow on the grid which is associated with voltage rise that may lead to violation of various standards. The impact depends upon the size and location of the PV system. Studies are conducted on the real time data obtained from DTE Energy utility. Voltages of the feeder, two way flow of power and the voltage regulation under various levels of PV penetration are analyzed for an IEEE test system utilizing unbalanced power flow solution.

Study of unified control of STATCOM to resolve the Power quality issues of a grid-connected three phase PV system

The challenges from intermittent solar generation are twofold: system stability and power quality. System stability depends on solar penetration level, fault ride through ability, and reactive power support, for which an average model or controllable voltage source representation can be utilized. Power quality is more about consumer-driven issues and dynamic performance, for which a detailed model is needed. This paper analyzes the power quality issues of voltage flicker, harmonics and transient voltage variation for a three phase photovoltaic (PV) system. Control strategies are proposed for STATCOM to mitigate issues of power quality, and tested in a grid-connected PV system using PSCAD/ EMTDC software. Simulation results show the effectiveness of the proposed strategies.

Application of PHEV in load frequency problem of a hybrid microgrid

Microgrids are low voltage distribution networks comprising distributed generations (DGs), storage devices, Plug-In Hybrid Electric Vehicles (PHEVs) and responsive loads that can operate either interconnected to the main grid or in an island mode. With the large penetration of distributed generation like Wind and large load variations there are issues of frequency stability of the microgrid. This paper develops load frequency control for a microgrid system with significant wind penetration and PHEVs. Particle swarm optimization is used to determine control parameters. Case studies are presented to demonstrate the effectiveness of the controller and examine the role of PHEVs in frequency stabilization.