Fundamentals of power systems
- Authors: Banerjee, Binayak , Jayaweera, Dilan , Islam, Syed
- Date: 2016
- Type: Text , Book chapter
- Relation: Smart Power Systems and Renewable Energy System Integration (part of the Studies in Systems, Decision and Control book series) Chapter 1 p. 1-13
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- Description: The chapter describes the history, evolution, and fundamental analysis frameworks of a power system. Power systems started modestly as small scale DC systems. As the dependence on electricity has increased, the complexities and demands placed on electricity have also been increased. The chapter begins with a description of the history of power systems and then describes major events that have shaped the modern power system industry. A description of the basic power system components are presented along with analysis techniques of load flow, optimal power dispatch, and transient stability. The chapter fundamentals will aid in a better understanding of the remaining chapters.
Grid integration of renewable energy systems
- Authors: Banerjee, Binayak , Jayaweera, Dilan , Islam, Syed
- Date: 2016
- Type: Text , Book chapter
- Relation: Smart Power Systems and Renewable Energy System Integration (part of the Studies in Systems, Decision and Control book series) Chapter 5 p. 75-97
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- Description: The percentage of renewable power demand met by renewable power generators is increasing rapidly. This growth is driven by environmental concerns, government policies and decreasing cost of technologies. However, as the penetration of renewable power sources increases, new challenges in system planning and operation are becoming evident. There are short term operational challenges as well as long term planning challenges due to the intermittent nature of renewable power generation primarily from wind and solar photovoltaics. The study of grid integration of renewables is concerned with determining the optimal technical and regulatory framework that can effectively manage the short term and long term challenges of large scale renewable power penetration. Operational challenges of this chapter include maintaining frequency and voltage stability due to intermittency as well as network congestion. Planning challenges include allocating long term capacity credits of wind and solar power generation. Currently, the cost of a number of balancing technologies is expected to play a major role in overall viability of renewable power generation. This includes energy storage, demand side management, and dynamic ratings of assets. Smart grids are expected to provide the platform for utilizing the full potential of renewable power generation as well as balancing the technologies.
Micro grid planning and operation
- Authors: Banerjee, Binayak , Jayaweera, Dilan , Islam, Syed
- Date: 2016
- Type: Text , Book chapter
- Relation: Smart Power Systems and Renewable Energy System Integration (part of the Studies in Systems, Decision and Control book series) Chapter 3 p. 29-47
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- Description: Increasing penetrations of renewable power as well as deregulation of electricity markets have seen a rise around the world. A Micro Grid is a smaller entity that can intelligently control and coordinate distributed energy resources with the support of intelligent controllers and other necessary architecture. However, achieving such objectives that lead to a smart operation require significant advances to planning and operation of the Micro Grid as the collective operation of Micro Grids can potentially provide business cases. Roles of Micro Grids include improving reliability, resilience and security at the normal and emergency operating conditions of the power grid. Each mode of operation presents challenges such as frequency control in islanded mode and voltage control in grid connect mode. Micro Grid control strategies may be classified into grid following and grid forming and further into interactive or non-interactive. Most control hierarchies combine centralised as well as decentralised control. This chapter investigates specific challenges in a Micro Grid, planning and operation, control strategies as well as realistic studies of micro grids.
Modelling and simulation of power systems
- Authors: Banerjee, Binayak , Jayaweera, Dilan , Islam, Syed
- Date: 2016
- Type: Text , Book chapter
- Relation: Smart Power Systems and Renewable Energy System Integration (part of the Studies in Systems, Decision and Control book series) 2 p. 15-28
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- Description: This chapter presents major modelling and simulation techniques applied in power systems research. As the smart grids will be a journey through the modern power system environment, it is vital to know how these models and techniques are applied in a traditional power grid environment and how they can make advances to realize smart grid objectives. The chapter describes optimization techniques applied in power systems research and then extended to incorporate stochastic elements. The chapter ends with a brief exploration into the Monte Carlo simulation based research.
Assessment of post-contingency congestion risk of wind power with asset dynamic ratings
- Authors: Banerjee, Binayak , Jayaweera, Dilan , Islam, Syed
- Date: 2015
- Type: Text , Journal article
- Relation: International Journal of Electrical Power and Energy Systems Vol. 69, no. (2015), p. 295-303
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- Description: Large scale integration of wind power can be deterred by congestion following an outage that results in constrained network capacity. Post outage congestion can be mitigated by the application of event control strategies; however they may not always benefit large wind farms. This paper investigates this problem in detail and proposes an advanced mathematical framework to model network congestion as functions of stochastic limits of network assets to capture post contingency risk of network congestion resulting through the constrained network capacity that limits high penetration of wind. The benefit of this approach is that it can limit the generation to be curtailed or re-dispatched by dynamically enhancing the network latent capacity in the event of outages or as per the need. The uniqueness of the proposed mathematical model is that it converts conventional thermal constraints to dynamic constraints by using a discretized stochastic penalty function with quadratic approximation of constraint relaxation penalty. The case study results with large and small network models suggest that the following an outage, wind utilization under dynamic line rating can be increased considerably if the wind power producers maintain around a 15% margin of operation.
Risk constrained short-term scheduling with dynamic line ratings for increased penetration of wind power
- Authors: Banerjee, Binayak , Jayaweera, Dilan , Islam, Syed
- Date: 2015
- Type: Text , Journal article
- Relation: Renewable Energy Vol. 83, no. (2015), p. 1139-1146
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- Description: Limited transmission capacity may lead to network congestion which results in wind curtailment during periods of high availability of wind. Conventional congestion management techniques usually involve generation management which may not always benefit large wind farms. This paper investigates the problem in detail and presents an improved methodology to quantify the latent scheduling capacity of a power system taking into account stochastic variation in line-thermal rating, intermittency of wind, and mitigating the risk of network congestion associated with high penetration of wind. The mathematical model converts conventional thermal constraints to dynamic constraints by using a discretized stochastic penalty function with quadratic approximation of constraint relaxation risk. The uniqueness of the approach is that it can limit the generation to be curtailed or re-dispatch by dynamically enhancing the network latent capacity as per the need. The approach is aimed at strategic planning of power systems in the context of power systems with short to medium length lines with a priori known unit commitment decisions and uses stochastic optimization with a two stage recourse action. Results suggest that a considerable level of wind penetration is possible with dynamic line ratings, without adversely affecting the risk of network congestion.
Alleviating post-contingency congestion risk of wind integrated systems with dynamic line ratings
- Authors: Banerjee, Binayak , Jayaweera, Dilan , Islam, Syed
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 24th Australasian Universities Power Engineering Conference, AUPEC 2014; Perth, Australia; 28th September-1st October 2014 p. 1-6
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- Description: One of the factors hindering the large scale integration of wind power is the post contingency congestion of a network due to limited availability of network capacity and auxiliary constraints. Under such conditions, the network operators can potentially request a curtailment of wind farm output if the remedial strategies fail. The paper investigates this problem in detail and proposes a mathematical framework to capture the post contingency spare capacity of network assets that is required to limit the wind curtailment. The proposed approach incorporates stochastic variation in asset thermal rating; models network congestion, and quantifies the risk of congestion using an extended version of conic-quadratic programming based optimization. The uniqueness of the proposed mathematical model is that it converts conventional thermal constraints to dynamic constraints by using a discretized stochastic penalty function with quadratic approximation of constraint relaxation penalty. The results suggest that the wind utilization can be maximized if the networks are operated 30-50% less than the nominal rating of the assets.
Optimal scheduling with dynamic line ratings and intermittent wind power
- Authors: Banerjee, Binayak , Jayaweera, Dilan , Islam, Syed
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 2014 IEEE Power and Energy Society General Meeting; National Harbor, United States; 27th-31st July 2014 Vol. 2014, p. 1-5
- Full Text: false
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- Description: Limited transmission capacity may lead to wind curtailment during periods of high availability of wind. This paper presents an improved methodology to quantify the latent scheduling capacity of a power system taking into account stochastic variation in line-thermal rating, intermittency of wind, and mitigating the risk of network congestion associated with high penetration of wind. The approach is aimed at strategic planning of power systems in the context of power systems with short to medium length lines with a priori known unit commitment decisions and uses stochastic optimization with a two stage recourse action. Results suggest that a considerable level of wind penetration is possible with dynamic line ratings, without adversely affecting the risk of network congestion.
- Description: IEEE Power and Energy Society General Meeting
Risk of supply insecurity with weather condition-based operation of plug in hybrid electric vehicles
- Authors: Jayaweera, Dilan , Islam, Syed
- Date: 2014
- Type: Text , Journal article
- Relation: IET Generation, Transmission & Distribution Vol. 8, no. 12 (2014), p. 2153-2162
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- Description: Plug in hybrid electric vehicles (PHEVs) can be a strategic source to mitigate risk of supply insecurity in an active distribution network. This study proposes a new methodology to quantify the risk of supply insecurity with weather condition based operation of PHEVs in an active distribution network. The approach divides operating characteristics of PHEVs into charging, discharging and null. Operation of PHEVs with change in weather conditions, intermittent characteristics of distributed generation, sector customer demand characteristics and random outages of components are modelled on Markov-chain Monte Carlo simulation. A set of case studies are performed considering distributed operation of PHEVs as oppose to central operation of conventional units. Results suggest that distributed operation of PHEVs can potentially mitigate risk of supply insecurity of moderately stressed networks. Highly stressed networks, which are operated with PHEVs, need supplementary supports from conventional units to mitigate risk of supply insecurity.
Security assessment in active distribution networks with change in weather patterns
- Authors: Jayaweera, Dilan , Islam, Syed
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 2014 International Conference on Probabilistic Methods Applied to Power Systems, PMAPS 2014; Durham, United Kingdom; 7th-10th July 2014 p. 1-6
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- Description: Security of supply of an active distribution network is constrained with increased presence of intermittent distributed generation, component outages, network constraints, change in weather patterns, and resource availability. Long term predictions of weather patterns are challenging, however, potential vulnerability of networks into change in weather patterns can be modeled with uncertainties distributing along the time frame of study. This paper investigates this problem in detail and proposes an improved approach to model the change in weather patterns and to assess the security of supply in an active distribution network. The approach incorporates Monte Carlo simulation and captures weather patterns in three modes dynamically. A case study is performed on a 24 bus active distribution network model, and the results suggest that the security of supply can be significantly affected with change in weather patterns. Change in weather patterns by 50% of the nominal weather can result in impacts on security of supply up to three times the nominal impacts.
Security of energy supply with change in weather conditions and dynamic thermal limits
- Authors: Jayaweera, Dilan , Islam, Syed
- Date: 2014
- Type: Text , Journal article
- Relation: IEEE Transactions on Smart Grid Vol. 5, no. 5 (2014), p. 2246-2254
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- Description: Aging network assets, significant variations in weather conditions, increased accommodation of intermittent distributed generation, and the network operating patterns deviate actual thermal limits of assets from deterministic thermal limits. In that context, the paper proposes a model integrated innovative approach to assess the security of energy supply in an active distribution network. The approach integrates models of dynamic thermal limits, stochastic variations in weather conditions, random outages, intermittent generation outputs, and random load fluctuations into Monte Carlo simulation and quantifies the level of insecurity. The effectiveness of the approach is demonstrated by a case study. The results suggest that costs of outages can be significantly affected by combinatorial effects of weather patterns and dynamic thermal limits. Changes in weather patterns contribute more to the costs of the outages than dynamic variations in thermal limits. Latent capacities of assets do not necessarily reduce insecurity of energy supply. The paper also argues that assets in stressed distribution networks should be modeled with dynamic thermal limits for the quantification of true impacts.
Steady-state security in distribution networks with large wind farms
- Authors: Jayaweera, Dilan , Islam, Syed
- Date: 2014
- Type: Text , Journal article
- Relation: Journal of Modern Power Systems and Clean Energy Vol. 2, no. 2 (2014), p. 134-142
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- Description: Aging network assets, forced and unforced outages, and the way the networks are operated in a deregulated market are of significant concerns to integrate large wind farms in a distribution network. In many cases, the constrained network capacity is a potential barrier to the large-scale integration of wind power. This paper probabilistically assesses the steady-state security in a distribution network in the presence of large wind farms. The approach incorporates active distribution network operating conditions, including intermittent power outputs, random outages, demand fluctuations, and dynamic interactions and exchanges, and then assesses the steady state security using Monte Carlo simulation. A case study is performed by integrating large wind farms into a distribution network. The results suggest that intermittent outputs of large wind farms in a distribution network can impact the steady-state security considerably. However, the level of impact of wind farms does not necessarily correlate with the installed capacity of them.
Assessment of distributed generation capacity mixture for hybrid benefits
- Authors: Jayaweera, Dilan , Islam, Syed , Neduvelil, Sandeep
- Date: 2013
- Type: Text , Conference proceedings , Conference paper
- Relation: 22nd International Conference and Exhibition on Electricity Distribution, CIRED 2013; Stockholm, Sweden; 10th-13th June 2013 Vol. 2013, p. 1-4
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- Description: The distributed generation (DG) mixture in an active distribution network can provide different levels of network benefits and benefits external to the network. This paper investigates this problem in detail and proposes an approach to assess the DG mixture for hybrid benefits through the sequential simulation of optimized samples. A case study is performed incorporating Wind and PV generation as intermittent DG, diesels, their life-cycle costs (LCCs), and contribution to greenhouse-gas (GHG) abatement. Results suggest that specific operating conditions in a network can dominate the DG mixture and deliver the combined benefits. Wind and diesel hybrid operation can be the most beneficial DG mixture in an active distribution network compared to any other DG combination with current costing structure.
Security enhancement with nodal criticality based integration of PHEV micro grids
- Authors: Jayaweera, Dilan , Islam, Syed
- Date: 2013
- Type: Text , Conference proceedings , Conference paper
- Relation: 2013 Australasian Universities Power Engineering Conference, AUPEC 2013; Hobart, Australia; 29th September-3rd October 2013 p. 1-6
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- Description: Modern distribution networks are increasingly vulnerable to disturbances and improving the security of supply to customers are complex and challenging with the traditional approach. This paper presents a new approach to enhance the security of power supply in an active distribution network by integrating PHEV (Plug-in Hybrid Electric Vehicle) based micro grids on the basis of the nodal criticality. The nodal criticality is assessed by integrating operational uncertainties of events into samples of Monte Carlo simulation and classifying load interruptions on the basis of their magnitudes and frequencies. Criticality of the system stress that results nodal loads shedding is classified into arrays of clusters based on the magnitudes of interrupted loads at samples. The critical clusters that represent largest disturbances to the respective nodal loads are served with PHEV micro grids. Case studies are performed, and the results suggest that the security of distribution networks can be significantly improved with the proposed approach.
Two-stage approach for the assessment of distributed generation capacity mixture in active distribution networks
- Authors: Jayaweera, Dilan , Islam, Syed , Neduvelil, Sandeep
- Date: 2013
- Type: Text , Journal article
- Relation: Journal of Renewable and Sustainable Energy Vol. 5, no. 5 (2013), p.
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- Description: Distribution networks are limited with spare capacities to integrate increased volumes of distributed generation (DG). Network constraints and congestion, dynamic thermal limits, intermittent outputs, and the need for reduction in greenhouse gas emission increase the complexity of capturing optimal DG mixture that can safely permit the optimal operation. This paper investigates this problem in detail and proposes a two-stage approach for the quantification of optimal DG capacity mixture in an active distribution network. The approach is aimed at operational planning and takes into account dynamic thermal limits, network internal benefit, and network external benefit and then optimizes samples of DG mixtures through sequential simulation. A case study is performed incorporating wind and photovoltaic generation as intermittent DG and diesel units as standing reserve units. Results suggest that specific operating conditions in an active distribution network can dominate the optimal DG mixture. Wind and diesel hybrid operation can be the most beneficial DG mixture compared to any other DG combination. Dynamic thermal limits of assets can potentially control the type of DG of the optimized mixture.