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Dai R.,Alstom | Davis Hwang M.,University of Texas at Austin | Qiu W.,Alstom | Wang W.,Alberta Electrical System Operator | And 2 more authors.
IEEE Power and Energy Society General Meeting | Year: 2015

Line-Commutated Converter (LCC) based HVDC lines are widely used to transmit electric power and interconnect asynchronous AC systems. Due to the characteristic of LCC-based HVDC, large amount of reactive power consumed by HVDC potentially deteriorates system voltage stability. Reactive power control is crucial to alleviate adverse impacts of HVDC reactive power consumption from AC network and secure voltage stability of AC system. In this paper, a special reactive power control (RPC) approach is presented and implemented in EMS at system control center. Reactive power resources at HVDC converter substations are controlled collaboratively to satisfy the reliability criteria and voltage stability constraints. Numerical studies on Alberta power grid at different HVDC MW transfer levels have demonstrated that the RPC approach is effective in controlling reactive power to support the connected HVDC system. The net exchange of reactive power between the HVDC and the AC system can be minimized at levels close to neutral in most real-time operation conditions. © 2015 IEEE.


Hajian M.,AltaLink | Schwartz J.,AltaLink | Cui R.,AltaLink | Kshatriya N.,Alberta Electrical System Operator
IEEE Power and Energy Society General Meeting | Year: 2014

In this paper, a summary of a proposed method to optimize transmission losses in Alberta using HVDC links is presented. The proposed method is based on a linear relationship between HVDC power orders and transmission line active power flows. Simulation results show the proposed method can accurately calculate HVDC power orders which lead to lowest transmission losses in the system. © 2014 IEEE.


Leschert D.,WorleyParsons Group Inc | McLean P.,Alberta Electrical System Operator
2015 IEEE/IAS 51st Industrial and Commercial Power Systems Technical Conference, I and CPS 2015 | Year: 2015

A model of a power system is a representation of that system. The value of that model depends on both the degree to which the model correctly represents the power system, and the analyses for which that model will be used. The documentation of the data used in a model is the provenance of that data. This paper discusses the provenance of data which appears in a power system model. While model data provenance is important for any model, data provenance is especially important when a model is to be maintained and used repeatedly for the life of a facility. © 2015 IEEE.


Kiani Bejestani A.,Alberta Electrical System Operator | Annaswamy A.,Massachusetts Institute of Technology
IEEE Transactions on Smart Grid | Year: 2014

In this paper, a dynamic model of the wholesale energy market that captures the effect of uncertainties of renewable energy sources and real-time pricing with demand response is derived. Beginning with a framework that includes real-time pricing as an underlying state, an attempt is made in this model to capture the dynamic interactions between generation, demand, locational marginal price (LMP), and congestion price near the equilibrium of the optimal dispatch. Conditions under which stability of the market can be guaranteed are derived. Modeling the effect of renewable energy resources (RERs) and demand response as perturbations, robust stability of the energy market model in the presence of such perturbations is discussed. Numerical studies of an IEEE 30-bus are reported to illustrate the effect of transmission lines constraints on the wholesale market stability in the presence of wind power. © 2014 IEEE.


Kiani A.,Alberta Electrical System Operator | Annaswamy A.,Massachusetts Institute of Technology
IEEE Transactions on Smart Grid | Year: 2014

One of the main challenges in the emerging smart grid is the integration of renewable energy resources (RER). The latter introduces both intermittency and uncertainty into the grid, both of which can affect the underlying energy market. An interesting concept that is being explored for mitigating the integration cost of RERs is demand response (DR). Beginning with an overall model of the major market participants with RER and DR, together with the constraints of transmission and generation, we analyze the energy market in this paper and derive conditions for existence and uniqueness of the competitive market equilibrium using standard Karush-Kuhn-Tucker (KKT) criteria. The effect of wind uncertainty on the competitive market equilibrium is then quantified. Perturbation analysis methods are used to compare the equilibria in the nominal and perturbed markets. This analysis is used to quantify the effect of RERs uncertainty and its possible mitigation using DR. Finally numerical studies are reported using an IEEE 30-bus to validate the theoretical results. © 2013 IEEE.


Kishimoto R.R.,Alberta Electrical System Operator | Yao Z.,BC Hydro | Vinnakota V.R.,BC Hydro
IEEE Power and Energy Society General Meeting | Year: 2012

During the summer 2011, two forced outages occurred on power lines in British Columbia (BC) Hydro system. Market conditions and generation pattern stressed the power network in operations and additional generation shedding was required. Contingency Analysis tool in SCADA (Supervisory Control And Data Acquisition)/EMS (Energy Management System) system was used in order to determine the additional generation shedding and it provided security to the parallel paths to mitigate overload impacts for next contingencies. The purpose of this paper is to share BC Hydro experience during this scenario and how Contingency Analysis in SCADA/EMS system supported the operation. © 2012 IEEE.


Wang Y.,University of Alberta | Xu W.,University of Alberta | Shen J.,Alberta Electrical System Operator
IEEE Transactions on Power Delivery | Year: 2016

Series impedance and shunt admittance parameters of transmission lines are fundamental data for various online and offline power system studies. This paper shows that the active power, reactive power, and voltage magnitude (P, Q, V) data measured at the two ends of a transmission line are sufficient to determine the positive-sequence line parameters. The phase-angle information is not essential. Since the P, Q, and V data are readily available from the supervisory control and data-acquisition systems, the proposed method can be easily implemented in existing control centers. Algorithms, characteristics, performances, and potential applications of the proposed method are presented in this paper. Simulation study and field test results show that the proposed technique can be a useful addition to the energy-management systems of utility companies. © 2015 IEEE.


Wai C.H.,Alberta Electrical System Operator | Beaudin M.,University of Calgary | Zareipour H.,University of Calgary | Schellenberg A.,University of Calgary | Lu N.,North Carolina State University
IEEE Transactions on Smart Grid | Year: 2015

Demand response plays an important role in the development of the smart grid, which can effectively manage society's energy consumption. Cooling devices, such as refrigerators and freezers, are ideal devices for demand-response programs because their energy states can be controlled without reducing the lifestyle and comfort of the residents. Conversely, managing air conditioning and space heating would affect a resident's comfort level. Direct compressor control and thermostat control methods have been proposed in the past for controlling cooling devices but they are never studied concurrently. This paper proposes a new control mechanism and compares the effectiveness of the three control mechanisms for cooling devices in demand response. In addition, this paper illustrates the need for a damping strategy to mitigate demand oscillations that occur from synchronous fleet control. © 2014 IEEE.


Liang X.,University of Alberta | Xu W.,University of Alberta | Chung C.Y.,Hong Kong Polytechnic University | Freitas W.,University of Campinas | Xiong K.,Alberta Electrical System Operator
IEEE Transactions on Power Systems | Year: 2012

This paper presents a new method to construct dynamic models for large industrial and commercial facilities commonly connected to power transmission systems. These facilities typically draw large amounts of power and have complex dynamic responses to power system disturbances. Traditional load modeling approaches such as those based on load composition or site measurement are not adequate to produce dynamic models for such facilities. In this paper, a facility template-based load modeling technique along with template scaling/equivalence algorithms is proposed to solve the facility modeling problem. Oil refinery facilities are used as an example to illustrate the proposed modeling technique. The technique requires minimal user input and can be implemented in a database program. © 2006 IEEE.

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