Badrul H. Chowdhury

Initial review of methods for cascading failure analysis in electric power transmission systems IEEE PES CAMS task force on understanding, prediction, mitigation and restoration of cascading failures

Large blackouts are typically caused by cascading failure propagating through a power system by means of a variety of processes. Because of the wide range of time scales, multiple interacting processes, and the huge number of possible interactions, the simulation and analysis of cascading blackouts is extremely complicated. This paper defines cascading failure for blackouts and gives an initial review of the current understanding, industrial tools, and the challenges and emerging methods of analysis and simulation.

Risk Assessment of Cascading Outages: Methodologies and Challenges

Cascading outages can cause large blackouts, and a variety of methods are emerging to study this challenging topic. The Task Force on Understanding, Prediction, Mitigation, and Restoration of Cascading Failures, under the IEEE PES Computer Analytical Methods Subcommittee (CAMS), seeks to consolidate and review the progress of the field towards methods and tools of assessing the risk of cascading failure. This paper discusses the challenges of cascading failure and summarizes a variety of state-of-the-art analysis and simulation methods, including analyzing observed data, and simulations relying on various probabilistic, deterministic, approximate, and heuristic approaches. Limitations to the interpretation and application of analytical results are highlighted, and directions and challenges for future developments are discussed.

Vulnerability assessment for cascading failures in electric power systems

Cascading failures present severe threats to power grid security, and thus vulnerability assessment of power grids is of significant importance. Focusing on analytic methods, this paper reviews the state of the art of vulnerability assessment methods in the context of cascading failures. These methods are based on steady-state power grid modeling or high-level probabilistic modeling. The impact of emerging technologies including phasor technology, high-performance computing techniques, and visualization techniques on the vulnerability assessment of cascading failures is then addressed, and future research directions are presented.

Power education at the crossroads

To meet the demands of designing and running far more complex and highly integrated electricity systems, a new kind of power engineer is needed. In this paper, the author describes how, though students tend to favor higher-tech and more lucrative fields than power engineering, reports of the disciplines demise are exaggerated.

Pricing and Control in the Next Generation Power Distribution System

Smart grid technologies are gaining acceptance and are being integrated into power distribution systems as a result of public and private investment and funding. However, costs of these technologies appear to be a clear obstacle in the widespread integration and maximal use of these technologies. In this paper, the utilization of dollar pricing signals is proposed and illustrated for power distribution engineering. A signal modeled after locational marginal pricing from transmission engineering is proposed to provide pricing data locally in distribution systems. The calculation, utilization, advantages, and shortcomings of the concept are presented. A main conclusion is that the use of a distribution locational marginal price signal fits well with an electronically controlled power distribution system.

Microgrids — A review of modeling, control, protection, simulation and future potential

Results of a literature survey done on microgrids from conception to installation is presented. The purpose is to evaluate the current status, major obstacles and existing research efforts directed toward establishing functional microgrids within utility systems. This review paper covers technical issues associated with frequency control and re-synchronization associated with typical distributed energy sources. Also evaluated are regulatory and policy issues associated with ownership, maintenance, availability, coordinated equipment control, obligation to provide adequate power quality, etc. associated with operating an islanded microgrid within a utility companys service territory. Actual microgrids in operation today are described. Benchmark test systems for steady state and dynamic simulations are also discussed.

Power flow and stability models for induction generators used in wind turbines

Model initialization of the induction generator for the wind power generation is investigated. Incorrect initialization may lead to numerical instability problems, not to mention erroneous result from dynamic simulation. The machine model is studied from the perspective of slip and reactive power calculation and tested for various cases. The dynamic reactive power calculation in well-know software package is discussed and the deviation of dynamic reactive power from the steady state reactive power is highlighted

Simulation of photovoltaic power systems and their performance prediction

A number of photovoltaic (PV) performance-analysis models are tested for their ability to estimate the AC power output and validated against historical observations from a PV test facility. A method to estimate meteorological parameters is developed for use in PV performance models for predicting future AC power output from a PV test site. Twelve such PV performance models are examined, and the PVFORM system analysis program and lifetime cost and performance models are extensively tested. These two models are tested using the typical meteorological year and the VPI model-generated estimates of long-term data. Performance prediction results are compared against actual observations at a 4 kW PV test facility. Results show that the VPI model-generated data, when used with the PVFORM model, provide the best predictions for AC power output from this 4 kW PV test facility. >

Superconducting Magnetic Energy Storage System (SMES) for Improved Dynamic System Performance

A Superconducting Magnetic Energy Storage System (SMES) consists of a high inductance coil emulating a constant current source. Such a SMES system, when connected to a power system, is able to inject/absorb active and reactive power into or from a system. The active power injected into the system is controlled by varying the duty cycle of the switches in the dc-dc chopper while the SMES coil is discharging into the system. The reactive power is controlled by the magnitude of the converter output voltage. The storage setup is tested on a WSCC 3 machine 9 bus system. The behavior of the system is tested for a three phase fault on the network at different locations. The transient behavior of the system is observed with and without the SMES unit. The SMES unit is able to damp out the post-fault oscillations within a short time.

Risk assessment of cascading outages: Part I — Overview of methodologies

This paper is a result of ongoing activity carried out by Understanding, Prediction, Mitigation and Restoration of Cascading Failures Task Force under IEEE Computer Analytical Methods Subcommittee (CAMS). The task forces previous papers are focused on general aspects of cascading outages such as understanding, prediction, prevention and restoration from cascading failures. This is the first of two new papers, which extend this previous work to summarize the state of the art in cascading failure risk analysis methodologies and modeling tools. This paper is intended to be a reference document to summarize the state of the art in the methodologies for performing risk assessment of cascading outages caused by some initiating event(s). A risk assessment should cover the entire potential chain of cascades starting with the initiating event(s) and ending with some final condition(s). However, this is a difficult task and heuristic approaches and approximations have been suggested. This paper discusses different approaches to this and suggests directions for future development of methodologies. The second paper summarizes the state of the art in modeling tools for risk assessment of cascading outages.