Saugata S. Biswas

Real-Time Implementation of Intelligent Reconfiguration Algorithm for Microgrid

Microgrids with renewable distributed generation and energy storage offer sustainable energy solutions. To maintain the availability of energy to the connected loads, considering priority and to interrupt the smallest portion of the microgrid under any abnormal conditions, reconfiguration is critical to restore service to a section or to meet some operational requirements of dropping minimum loads. Reconfiguration is the process of modifying the microgrids topological structure by changing the status (open/close) of the circuit breakers or switches. In this work, constraints are the power balance equation and power generation limits, and we assumed that the system is designed with the entire planning and operational control criterion to meet the voltage violation and line overloading constraints. This paper offers novel real-time implementation of intelligent algorithm for microgrid reconfiguration. Intelligent algorithm is based on the genetic algorithms and has been tested on two test systems including shipboard power system and modified Consortium for Electric Reliability Technology Solutions (CERTS) microgrid. Real-time test bed utilizes real-time digital simulator and commercial real-time controllers from Schweitzer Engineering Lab. Reconfiguration algorithm has been implemented in the real time using real-time test bed, e.g., microgrid system, and satisfactory results were obtained.

Analyzing the Cyber-Physical Impact of Cyber Events on the Power Grid

With ongoing smart grid activities, advancements in information and communication technology coupled with development of sensors are utilized for better situational awareness, decision support, and control of the power grid. However, it is critical to understand the complex interdependencies between cyber and power domains, and also the potential impacts of cyber events on the power grid. In this paper, the impact of three different possible cyber events on physical power grid have been analyzed using an integrated cyber-power modeling and simulation testbed. Real-time modeling of end-to-end cyber-power systems have been developed with hardware-in-the-loop capabilities. Real-time digital simulator, synchrophasor devices, DeterLab, and network simulator-3 are utilized in this developed testbed with a wide-area control algorithm and associated closed-loop control. DeterLab can be used to model real-life cyber events in the developed cyber-physical testbed. Man-in-the-middle and denial-of-service attacks have been modeled as specific cases for the IEEE standard test cases. Additionally, communication failure impact on the power grid has been analyzed using the testbed.

A Real-Time Data-Driven Algorithm for Health Diagnosis and Prognosis of a Circuit Breaker Trip Assembly

With ongoing efforts to make the power grid smarter, there is a large emphasis on the automation and data analytics. Substation automation is a key enabling technology for online monitoring, diagnosis, and prediction for the health condition of the substation assets. Circuit breakers (CBs) are one of the most vital components in a substation for the tripping action required during fault occurrence, line isolation, and other similar actions. It is critical to ensure that the CB is in healthy state and can operate as expected. Enhanced automation and availability of various CB measurements make it possible to continuously monitor the health of all the components within a CB, including the trip coil assembly (TCA). This paper presents the development of a new real-time diagnosis algorithm that runs at a substation and continuously monitors the health condition of a CB TCA and suggests maintenance actions, if necessary. The developed algorithm detects the abnormalities, finds their root causes, and predicts the possibility of potential health problems for the CB TCA. Additionally, the monitoring architecture also allows remote access of data for engineering access. Finally, the results obtained by the online implementation of the proposed algorithm using industry-grade CB and substation data have been presented.

Development of a smart grid test bed and applications in PMU and PDC testing

The electric power system is moving towards the smart grid development for improved reliable, secure and economic operation. Many researchers are now concentrating their research that is aimed at upgrading the power system by using state-of-the-art computer based online monitoring and control tools along with advanced communication facilities. Implementation of such a system requires enhanced testing and validation of smart grid technologies as well as development of new approaches to fully utilize the capabilities of these technologies. This paper is a modest attempt to present the summary of the effort to model a smart power grid in real time by developing a “smart grid test bed”. Additionally, some of the applications of the developed test bed have been briefly described, with special emphasis on testing of synchrophasor devices like PMUs and PDCs.

Real Time Modeling and Simulation of Cyber-Power System

Ongoing smart grid activities have resulted in proliferation of intelligent devices and associated Information and Communication Technologies (ICT) to enable enhanced system monitoring and control. Integration of ICT has led to an increase in the number of cyber assets and requires cyber-physical study for system analysis. In order to realize the vision of a smarter grid, it is necessary to understand the complex relationship between cyber and physical domains, and potential impacts on the power grid due to successful cyber-physical attacks. In order to understand this coupling, cyber physical test bed can help to model and simulate the smart grid with sufficient level of detail. In this chapter, an introduction to the smart electric grid and the challenges associated with the development of cyber-power test bed is presented. The integration of Real Time Digital Simulator (RTDS) and Network Simulator 3 (NS3) to realize a real time cyber-power test bed is discussed with the implementation of an example application.

Real time testing and validation of Smart Grid devices and algorithms

With ongoing efforts to upgrade the traditional electric power system into a smart grid, emphasis is on the integration of state-of-the-art computer based online monitoring and control tools along with advanced communication technology. However, testing and validation of these devices and algorithms are required before implementation in a physical grid. New testing and validation method needs to be developed in a simulated environment in a lab. This paper discusses some of the applications of the “smart grid test bed” developed at the “Smart Grid Development and Research Investigation Lab (SGDRIL)” at Washington State University. The specific applications discussed in this paper include synchrophasor device testing, microgrid reconfiguration, voltage stability and vulnerability analysis.

Development and real time implementation of a synchrophasor based fast voltage stability monitoring algorithm with consideration of load models

With ongoing smart electric grid development, several algorithms have been developed that make use of synchrophasor technology for online wide area voltage stability monitoring. Most of these algorithms have several advantages, but at the same time also have some limitations. Measurement based algorithms are generally based on iterative approach to estimate system parameters to compute proximity to voltage stability margin. There is a need for fast and robust online voltage stability algorithm utilizing synchrophasor measurements. This paper discusses briefly about limitations of few existing online voltage stability algorithms and presents a new real time algorithm for voltage stability monitoring based on local measurements only, which also considers detailed load models. Developed algorithm has been tested offline and online on different IEEE standard test cases under different scenarios. Simulation results show satisfactory performance.

Real time implementation of intelligent reconfiguration algorithm for microgrid

Microgrids with renewable distributed generation and energy storage offer sustainable energy solutions. To maintain the availability of energy to the connected loads, considering priority and to interrupt the smallest portion of the microgrid under any abnormal conditions, reconfiguration is critical to restore service to a section or to meet some operational requirements of dropping minimum loads. Reconfiguration is the process of modifying the microgrids topological structure by changing the status (open/close) of the circuit breakers or switches. In this work, constraints are the power balance equation and power generation limits, and we assumed that the system is designed with the entire planning and operational control criterion to meet the voltage violation and line overloading constraints. This paper offers novel real-time implementation of intelligent algorithm for microgrid reconfiguration. Intelligent algorithm is based on the genetic algorithms and has been tested on two test systems including shipboard power system and modified Consortium for Electric Reliability Technology Solutions (CERTS) microgrid. Real-time test bed utilizes real-time digital simulator and commercial real-time controllers from Schweitzer Engineering Lab. Reconfiguration algorithm has been implemented in the real time using real-time test bed, e.g., microgrid system, and satisfactory results were obtained.

Development and Application of a Real-Time Test Bed for Cyber–Physical System

Enhanced integration of information and communication technologies in the smart grid has led to an increase in the number of cyber assets and has also opened up the possibility of a cyberattack. It is necessary to understand the complex relationship between the cyber and physical domains, and its potential impact on the power grid because of a successful cyber–physical attack. A cyber–physical test bed that can model and simulate the smart grid is necessary to test and validate algorithms and devices. This paper presents the development of an end-to-end, real-time cyber–physical test bed using Real-Time Digital Simulator and Network Simulator 3 (ns-3). A methodology for integrating the hardware phasor measurement unit and the phasor data concentrator in the test bed is presented along with the detailed modeling of the communication network for the power system. The developed test bed is validated and used to demonstrate the impact of different cyberattacks on the power system and tested algorithms.

A comparative study of model and measurement based voltage stability approaches

With the increasing complexity and advancements in the power system, several algorithms and tools have been developed to assess the voltage stability using synchrophasor measurements or system model or both. Several new algorithms have been proposed by researchers and some of them have been converted into commercial tools. Most of these algorithms have several advantages, but at the same time also have some limitations. Local synchrophasor measurement based algorithms are generally based on window based approach to estimate system parameters to compute proximity to voltage stability margin. Model based approach is suitable for offline and planning studies but may not be suitable for online real-time implementation. There are limited number of hybrid algorithms using measurements and model both, but more work need to be done to meet the accuracy and time-line requirements. This paper discusses about limitations of the existing online voltage stability algorithms in detail and the reasons for a need of fast and robust online voltage stability algorithm. A number of operating conditions have been modeled and simulated for standard IEEE test systems.