Entity

Time filter

Source Type

Sydney, Australia

Czibula O.G.,Ausgrid | Czibula O.G.,University of Technology, Sydney | Gu H.,University of Technology, Sydney | Zinder Y.,University of Technology, Sydney
Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics) | Year: 2016

The paper is concerned with the planning of training sessions in large organisations requiring periodic retraining of their staff. The allocation of students must take into account student preferences as well as the desired composition of study groups. The paper presents a bicriteria Quadratic Multiple Knapsack formulation of the considered practical problem, and a novel solution procedure based on Lagrangian relaxation. The paper presents the results of computational experiments aimed at testing the optimisation procedure on real world data originating from Australia’s largest electricity distributor. Results are compared and validated against a Genetic Algorithm based matheuristic. © Springer International Publishing Switzerland 2016.


Wind turbines can be seen behind electricity wires at the Infigen Energy wind farm located on the hills surrounding Lake George, near the Australian capital city of Canberra, Australia, in this May 13, 2013 file photo. Sheep graze in front of wind turbines that are part of the Infigen Energy's Capital Windfarm located on the hills surrounding Lake George, near the Australian capital city of Canberra, Australia, in this July 17, 2015 file photo. With six to eight state-owned enterprises already involved in or looking closely at Australian energy assets, Melbourne-based financial advisors SILC Group said more deals were on the cards, with so-called green power coming under particular focus. They would follow State Power Investment Corp's (SPIC) [CNPOW.UL] A$300 million ($230 million) buyout of a wind farm in New South Wales last week, as well as its $2.5 billion purchase in December of Pacific Hydro, a company which has wind farms in Australia, Brazil and Chile. "There was always interest, but now there's increased interest from the Chinese," said Peter Munns, an executive director at SILC, which works with China state-backed firms. "Chinese companies always like our rule of law, our currency risk and stable economy. They like renewables, they also like poles and wires because the revenue is underpinned by regulation." After coming to power last year, the government led by Prime Minister Malcolm Turnbull in December reversed a decision by the previous administration banning the country's clean energy fund from investing in wind power projects, opening the door to more deals in the sector. Former prime minister Tony Abbott had described wind farms as "ugly" and "noisy". Munns told Reuters in an interview last week that Chinese firms were looking for projects with long term offtake agreements that would get them a foot in the door in Australian markets, as well as local expertise that would help them grow. "They don't just want to have one wind farm here, they want to have a portfolio," said Munns. "Most want to do solar as well. But they probably think that's a couple of years down the track before it's as economic and as viable as wind is." A unit of China Shenhua is already part operator of several wind farms in Tasmania, while Beijing Jingneng Power has a stake in the Gullen Range wind farm in New South Wales. Other Chinese state-owned companies that have said they are looking at Australian energy assets include Shanghai Electric Power Co Ltd and Cecep Wind-power Corp. Wind farms are Australia's No. 2 renewable energy source, behind hydropower but ahead of solar, providing around 4 percent of its total energy demand. Meanwhile, a tender for New South Wales poles and wire firm Ausgrid, to be decided by mid-2016, has attracted the attention of China State Grid [STGRD.UL] and Southern Power [CNPOW.UL]. State Grid already has a 41 percent stake in South Australia's electricity grid.


Sheep graze in front of wind turbines that are part of the Infigen Energy's Capital Windfarm located on the hills surrounding Lake George, near the Australian capital city of Canberra, Australia, in this July 17, 2015 file photo. REUTERS/David Gray/Files More MELBOURNE (Reuters) - Chinese state-owned companies are expected to boost their investment in Australia's expanding renewable energy sector, attracted by a national leadership that is more favorable to the industry than its forerunner. With six to eight state-owned enterprises already involved in or looking closely at Australian energy assets, Melbourne-based financial advisors SILC Group said more deals were on the cards, with so-called green power coming under particular focus. They would follow State Power Investment Corp's (SPIC) [CNPOW.UL] A$300 million ($230 million) buyout of a wind farm in New South Wales last week, as well as its $2.5 billion purchase in December of Pacific Hydro, a company which has wind farms in Australia, Brazil and Chile. "There was always interest, but now there's increased interest from the Chinese," said Peter Munns, an executive director at SILC, which works with China state-backed firms. "Chinese companies always like our rule of law, our currency risk and stable economy. They like renewables, they also like poles and wires because the revenue is underpinned by regulation." After coming to power last year, the government led by Prime Minister Malcolm Turnbull in December reversed a decision by the previous administration banning the country's clean energy fund from investing in wind power projects, opening the door to more deals in the sector. Former prime minister Tony Abbott had described wind farms as "ugly" and "noisy". Munns told Reuters in an interview last week that Chinese firms were looking for projects with long term offtake agreements that would get them a foot in the door in Australian markets, as well as local expertise that would help them grow. "They don't just want to have one wind farm here, they want to have a portfolio," said Munns. "Most want to do solar as well. But they probably think that's a couple of years down the track before it's as economic and as viable as wind is." A unit of China Shenhua is already part operator of several wind farms in Tasmania, while Beijing Jingneng Power has a stake in the Gullen Range wind farm in New South Wales. Other Chinese state-owned companies that have said they are looking at Australian energy assets include Shanghai Electric Power Co Ltd and Cecep Wind-power Corp. Wind farms are Australia's No. 2 renewable energy source, behind hydropower but ahead of solar, providing around 4 percent of its total energy demand. Meanwhile, a tender for New South Wales poles and wire firm Ausgrid, to be decided by mid-2016, has attracted the attention of China State Grid [STGRD.UL] and Southern Power [CNPOW.UL]. State Grid already has a 41 percent stake in South Australia's electricity grid.


Stanbury M.,Ausgrid | Djekic Z.,Ausgrid
IEEE Transactions on Power Delivery | Year: 2015

Current-transformer (CT) saturation has a major impact on the operation of differential protection schemes. Transformer differential protection must maintain security during CT saturation for external faults while preserving high sensitivity and speed of operation for lower magnitude internal faults. Relay manufacturers provide very little information or direction for protection engineers to set relays adequately to achieve these goals. If an engineer lacks a deep understanding of relay behavior during CT saturation, he or she could make setting implementation mistakes that may lead to spurious trips or failures to trip with catastrophic consequences. This work investigated the impact of CT saturation on transformer differential relays in order to provide guidance on scheme behavior. It was discovered that harmonic blocking is triggered by CT saturation - a significant effect which is not described in the literature or relay manuals. This effect was modeled and the model's accuracy was verified with CT simulations, relay secondary injections, and high current primary injections. It is demonstrated that harmonic blocking provides effective security against nuisance trips caused by CT saturation. It is also shown that the traditional use of a high slope 2 is mostly redundant wherever harmonic blocking is enabled. © 1986-2012 IEEE.


Smith R.,Ausgrid | Meng K.,University of Newcastle | Dong Z.,University of Newcastle | Simpson R.,Ausgrid
Journal of Modern Power Systems and Clean Energy | Year: 2013

Rapid growth in electricity network peak demand is increasing pressure for new investment which may be used for only a few hours a year. Residential air-conditioning is widely believed to be the prime cause of the rise in peak demand but, in the absence of detailed residential demand research, there is no bottom-up empirical evidence to support this supposition or to estimate its impact. This paper first examines the developments in network peak demand, at a national, network distribution, and local distribution feeder level to show recent trends in peak demand. Secondly, this paper applies analytics to the half-hourly consumption data of a sample of Ausgrid’s interval metered customers, combined with local weather data, to develop an algorithm which can recognize air-conditioner use and can identify consumption patterns and peak load. This estimate is then compared to system peaks to determine residential air-conditioning’s impact on overall demand. Finally, this paper considers the future impacts of air-conditioning load on peak demand as penetration rates reaches saturation levels and new minimum energy performance standards take effect reducing new units peak impacts. © 2013, The Author(s).

Discover hidden collaborations