Amirhossein Sajadi

Transient voltage stability of offshore wind farms following faults on the collector system

This work focuses on the analysis of the transient voltage stability at the point of interconnection (POI) of offshore wind farms following faults on the collector system. In particular, this study studies offshore wind farms that use an AC export system to transfer generated power onshore and investigates transient voltage stability under the influence of operating reactive power support equipment such as static VAR compensators (SVC) and active power support units such as battery storage or generation units at the POI. Operation of SVC and active power support such are widely believed to improve the stability and dynamic operation of offshore wind farms. This study, using the Great Lakes Offshore Wind Study models, determines the precise conditions under which SVC and active power support can improve the transient stability of the system following faults on the collector system.

Impact of wind turbine generator type in large-scale offshore wind farms on voltage regulation in distribution feeders

The goal of the U.S. Department of Energy (DOE) roadmap [1] is a 20% penetration of wind energy into the generation mix by 2030. Attaining this objective will help protect the environment and reduce fossil fuel dependency, thus improving energy security and independence. This paper discusses how the technology used in large scale offshore wind farms impacts voltage regulation in distribution feeders. Although the offshore wind farms are integrated into an interconnected power system through transmission lines, the system constraints can cause stability, resiliency and reliability issues. The major types of machine used in offshore wind farms are modeled using a generic model of General Electric (GE) wind machines. The transmission and distribution system models are based on the actual existing regional FirstEnergy/PJM power grid in Midwestern of United State. In addition, the impact of installing Static VAR Compensator (SVC) at Points of Interconnection (POI) on voltage regulation is investigated.

Transient Stability Analysis for Offshore Wind Farm Integration Planning Studies - Part I: Short Term Faults

Power system planning is the process of forecasting load demand and ensuring sufficient generation and reserve capacities over some planning horizon. This process includes investigation of steady-state and dynamic operations of the power system of interest. This paper addresses the transient stability (also known as large-signal stability) analysis of power systems for offshore wind power plant integration planning studies. In particular, this study develops a comprehensive practical methodology to assess the transient stability of power systems, including rotor angle stability, voltage stability, and frequency response for large scale power systems. This methodology considers variability of the offshore wind power plants as well as the type of any faulted systems components present. Additionally, this methodology is applicable to the study of both short-term and long-term faults, though only short-term faults are considered here (long-term faults are treated sequentially in a companion paper). This paper considers the integration of offshore wind power plants into existing power systems and demonstrates the utility of this methodology through the examination of the specific case of integrating 1000 MW of offshore wind power into the FirstEnergy/PJM service territory using a realistic model of 63k-bus test system that represents the U.S. Eastern Interconnection.

Inter-continental school of geometry and topology in soft matter, optics and biological systems: I-CAMP’14’s review

Stellenbosch, a hometown to wineries in the west of South Africa, hosted the sixth annual Inter-Continental Advanced Materials for Photonics (I-CAMP) in June 2014. This town is located 50 kilometres east of Cape Town and surrounded by Drakenstein and Stellenbosch mountains. Stellenbosch has been named after its founder, Simon van der Stel, the last Commander and first Governor of the Cape Colony, the Dutch settlement at the Cape of Good Hope in South Africa. Stellenbosch University (Universiteit van Stellenbosch and Universiteit Stellenbosch in Afrikaans), a world-class public university located in Stellenbosch, was the venue for the I-CAMP’14, from 15 to 29 June. This university has had numerous notable alumni such as Friedel Sellschop, pioneer in the field of nuclear applied physics, and Uys Krige, famous writer, poet and playwright. The I-CAMP is an annual school that brings together both prominent and junior scientists and allows them to combine advanced education with learning about different cultures worldwide. This summer it mainly welcomed scientists, researchers and professors working in materials science, energy, optics, photonics, biophysics, nanoscience and related fields. Although the I-CAMP’14 took place during the winter in South Africa, the excitement of FIFA World Cup alongwithmoderate temperature allowed attendees to have a great time during this school. The Jonkershoek Nature Reserve and Hottentots-Holland Mountain are incredible places to hike. And Stellenbosch University Botanical Garden is a great example of sightseeing destinations in this town. The social life in Stellenbosch gathers mostly in the city centre, where people enjoy walking, sitting and socialising (Figure 1). The school provided accommodation for attendees at Dagbreek, the largest and second oldest hall of residency of the University of Stellenbosch. The most distinctive element in this hall of residency was its Eiffel Tower (or Die Eiffel), which residents found quite comparable with the French version. The I-CAMP’14, similarly to previous I-CAMPs, was financially sponsored by the International Institute for Complex Adaptive Matter (ICAM-I2CAM), National Science Foundation (NSF) and University of Colorado Boulder (CU-Boulder). Because of scientific contributions from various highly regarded universities and research centres from different countries across the world, it has established itself as one of the worlds best summer schools in terms of technology and scientific techniques. In addition to the aforementioned sponsors, local sponsors contribute support as well. These have in previous years included the National Renewable Energy Laboratory (NREL), the only federal laboratory dedicated to the research, development, commercialisation and deployment of renewable energy and energy efficiency, in 2012, and Isaac Newton Institute of University of Cambridge, a very well-known international research institute for mathematics and theoretical physics, in 2013. This year, the African Institute for Mathematical Sciences (AIMS), a tertiary education and research institute in Muizenberg, South Africa, sponsored and hosted this event for the last 2 days. In 2014, the I-CAMP convened more than 40 undergraduate and graduate students, postdoc fellows and lecturers, from all across the world (Figure 2). The typical educational background of the students was physics; however, chemists, engineers and a few mathematicians attended this event. Although the registration fee was reasonably affordable, thanks to the bountiful support of the sponsors, a considerable number of the participants also received fellowships that included the lodging with complementary breakfast meals as well as conference receptions and school tours for the entire duration of the I-CAMP. Technological advances in the education system are a remarkable characteristic of I-CAMP. The realtime webcast of the lectures gave the opportunity to follow the summer school online for those who could not attend in person. Moreover, the records of the presentations are now archived; thus, they can be watched and downloaded, anytime of the year, from any part of the world. This archive is available online at http://spot.colorado.edu/~smalyukh/icamp2014/ ICAMP2014_Program.html. Liquid Crystals Today, 2015 Vol. 24, No. 1, 15–24, http://dx.doi.org/10.1080/1358314X.2014.973262

Smart homes in Poland: Challenges and opportunities

Poland, the 34th most populous country in the world and 6th among members of the European Union, generated 142.9 TWh net electricity, of which households consumed more than 30% in 2010. This work provides an insight into the potential of smart buildings in Poland. The essential contribution of this work is the consideration of the experiences of the national electrical system operator, existing building technologies, feasible solutions, and opportunities for smart homes in Poland.

Inter-continental summer school of liquid crystal physics, mathematics, photonics, electro-optics, and optomechanics: I-CAMP’13’s overview

Cambridge is a famous city in Cambridgeshire, England, located in East Anglia, on the River Cam, north of London. The charming architecture of this historical city, the surrounding heritage villages, towns, and ancient monuments, such as Ely, Peterborough, and Grantchester, draw attention to the city from visitors. The city’s tourist attractions aside, one could hardly find a place in the world that is more pervaded by the spirit of education and science than University of Cambridge. The name of this school is associated with many famous alumni and academics such as Sir Isaac Newton, Henry Cavendish, James Clerk Maxwell, J.J. Thomson, Ernest Rutherford, Charles Darwin, Francis Crick and James D. Watson attended. In the summer of 2013, this prestigious institution and the second-oldest university in English-speaking world, hosted ‘The 5th Inter-Continental Advanced Materials for Photonics (I-CAMP’13)’ summer school, from 26 June to 6 July. The I-CAMP is an annual school that brings together both prominent and junior scientists and will allow them to combine advanced education with learning about different cultures worldwide. This summer it mainly welcomed scientists, researchers, and professors working in materials science, optics, photonics, biophysics, nanoscience, and related fields. The beautiful historical environment and the memories of great discoveries that occurred in Cambridge created an incredibly inspiring atmosphere that provided a perfect set-up for the I-CAMP’13. The architecture of Cambridge, a harmonious blend of ancient and modern styles, attracts architecture fans. St John’s College, King’s College, Queens’ College, Trinity College, and Homerton College are great examples of sightseeing destinations in this city. The social life in Cambridge gathers mostly along River Cam, where visitors enjoy walking, sitting, and socialising. The fascinating atmosphere along the river makes these simple activities to be indispensable. Punting is of course one of the best activities to get the flavour of the river. King’s College Chapel, the Mathematical Bridge, Wren Library at Trinity College, and the Bridge of Sighs are some of the attractive views during these punting tours (Figure 1).