The Alberta Electric System Operator, (AESO), is a not-for-profit entity responsible for the planning and operation of the Alberta Interconnected Electric System (AIES) in a "safe, reliable, and economical" manner. It is mandated by provincial legislation to act in the public interest and cannot own any transmission, distribution or generation assets.The key duties and responsibilities of the AESO are dictated by the Province of Alberta's Electric Utilities Act (EUA) and the Transmission Regulation (T-Reg) and include, without limitation, the following:The AESO operates a market for the exchange of electric energy in Alberta and attempts to uphold the principles of market fairness, openness, and efficiency. To this end the AESO "contracts with transmission facility owners to provide generators access to the electric grid."One of AESO's responsibilities is to manage system load in the case where shortfalls in supply or excessive demand for electricity threaten the integrity of the power grid. In this case AESO can direct power companies to shed load temporarily through measures such as rolling blackouts. In July 2012, six power generators were shut down during a major heat wave that resulted in high demand on the power grid, Edmonton, Calgary, Red Deer and Lethbridge were hit by rolling blackouts. AESO directed utilities to reduce their customer load. AESO's Doug Simpson explained that this had not happened since 2006.According to their homepage, AESO operates "independently of any industry affiliations and owns no transmission or market assets.
One of the challenges resulting from the adoption of machine-based distributed energy resources lies within the intersection of protection and performance grounding. These are strongly interrelated and conflicting subjects that dictate the occurrence of ground fault overvoltage and the effectiveness of ground overcurrent protection. Currently, there remains a gap in the distribution planning of most jurisdictions in formulating these aspects and adopting simple and practical measures to balance these subjects. This letter introduces a simulation-based method to develop a set of practical charts intended to be used as a sizing guideline for neutral grounding elements, which are to be employed in the associated step-up transformers. This solution became pivotal to the electrical utility conducting the research and has allowed planning engineers to simplify design and streamline cooperation between the utility and large-scale DER developers.
The circuit analysis approach based on geometric algebra and M , the power definition based on the geometric product between the voltage and the current multivectors, are used here to demonstrate the shortcomings of the traditional definition of the non-sinusoidal apparent power S . The shortcomings of S are illustrated in three ways. Firstly, by showing an example of how the norm of M contains S . Secondly, through six experiments that involve compliance with: Kirchhoff’s circuit laws, Tellegen’s theorem, the principle of conservation of energy, the equivalency of two terminal networks and the concept of reactive power compensation. Lastly, by showing how the use of S leads the current’s physical component power theory astray. The experiments show contradictions between the aforementioned circuit theory fundamentals and the results attained with S but a compelling harmony with the results attained with M . The evidence reveals two unprecedented discoveries: (1) that mathematical models aimed at explaining energy flow in non-sinusoidal circuits shouldn’t be based on the decomposition of S —as traditionally done— and, (2) the inappropriateness of extrapolating definitions from sinusoidal conditions to non-sinusoidal settings.
This paper proposes a dynamic wind-thermal generation scheduling (DWTGS) framework to minimize system generation costs and pollutant emissions. To deal with wind power uncertainty, a new probabilistic wind cost function is introduced, which decomposes wind power uncertainty into several components with varying frequencies. This model not only allows for the use of a more accurate wind power prediction technique in system scheduling, but it also enables the system operator to schedule different thermal units with distinct characteristics to compensate for specific components of uncertainty. This paper also proposes a straightforward procedure for dynamic load dispatch based on power flow, taking into account system constraints and requirements, thereby obtaining more realistic results compared to a large number of previous works in this area. To make the optimization algorithm able to deal with such a complex and high-dimensional optimization problem, a novel heuristic technique is suggested, which is also capable to be readily adapted to other population-based optimization algorithms to improve accuracy. The proposed DWTGS framework is implemented on the IEEE-30 bus test system for performance evaluation. Beneficial information is extracted from the obtained results, and the efficacy of each of the proposed techniques in the optimization procedure is investigated meticulously.
The currents' physical component power theory (CPC-PT) is used here to show the improperness of extrapolating definitions of the power phenomena in sinusoidal conditions to non-sinusoidal settings. We prove, through seven examples, that the fundamentals of circuit theory are sine qua non for assessing: 1) the acceptability of a power theory (PT), 2) the appropriates of power quantities such as the reactive power and 3) the reason PTs fail. We show how the Geometric Algebra-based PT overcomes the contradictions found with the CPC-PT and unveils the reason PTs fail. Finally, we show that once the appropriate definition of the reactive power is obtained, the definition of $S$ based on the geometric addition of the active and non-active powers is a more reliable that the definition of $S$ based on the product of the root mean square values of the voltage and the current.
The increased adoption of inverter-based distributed energy resources in the form of the mass deployment of renewable generation systems has been a focal goal of many jurisdictions worldwide. Actions taken by local governments have included adapted regulations, financial subsidies, and a variety of grants. This has spurred the proliferation of solar generation among residential customers in virtually all provinces of the United States and Canada. Needless to say, these small generators are interfaced with DC–AC inverters, which have evolved tremendously since the formation of working groups targeting the impact of inverter-based generation on the grid. Among the first rules and standards are California’s ISO Rule 21 and the UL1741 SA, which were published in September 2017. IEEE followed suit in 2018 with the revision of IEEE 1547, inspiring virtually all jurisdictions to either adopt these standards or adapt them as their own variants. Among many features, these standards mandate inverters to be fitted with autonomous performance functions, including the constant power factor, voltage-reactive power (Volt-VAR), voltage-active power (Volt-Watt), and grid support functions, as well as provisions for compatibility with control centers. These functions have been demonstrated to increase the nameplate hosting capacity. At the same time, grid modernization strategies have become more prevalent, one of which is the use of conservation voltage reduction. This grid modernization initiative has a great impact on the hosting capacity. Conversely, the increased penetration of distributed energy resources has a negative effect on the conservation voltage reduction, but surprisingly to only a limited extent. The characterization of these impacts is addressed in this paper, with a focus on a case with very high DER penetration and with very long daily sunlight hours.
