Damian Flynn | University College Dublin (original) (raw)
Papers by Damian Flynn
In Northern Ireland, wind generation is mainly located in the west of the country, being connecte... more In Northern Ireland, wind generation is mainly located in the west of the country, being connected to the major loads in the east through the transmission and distribution network. With the expansion of wind generation in the west it is envisaged that during wind intensive periods power flow through the limited network capacity, in times of contingency outages and low demand, will see overhead lines breaching their thermal limits. On the Northern Ireland Electricity (NIE) network, dynamic line ratings (i.e. ratings which are dependent on actual weather conditions, as opposed to static line ratings which are based on assumed weather conditions) of overhead lines are being investigated as an interim measure to accommodate distributed generation, as network reinforcement is commissioned. This paper presents analysis from two physical models based on the IEEE and CIGRE standards. Comparison of the modelling techniques is made, with both models used to predict conductor temperatures utilising data gathered from the NIE network and laboratory data from wind tunnel tests.
Iet Generation Transmission & Distribution, 2009
A graphical method is presented for determining the capability of individual system nodes to acco... more A graphical method is presented for determining the capability of individual system nodes to accommodate wind power generation. The method is based upon constructing a capability chart for each node at which a wind farm is to be connected. The capability chart defines the domain of allowable power injections at the candidate node, subject to constraints imposed by voltage limits, voltage stability and equipment capability limits being satisfied. The chart is first derived for a two-bus model, before being extended to a multi-node power system. The graphical method is employed to derive the chart for a twonode system, as well as its application to a multi-node power system, considering the IEEE 30-bus test system as a case study. Although the proposed method is derived with the intention of determining the wind farm capacity to be connected at a specific node, it can be used for the analysis of a PQ bus loading as well as generation.
This paper describes different assumptions and methods utilized to calculate the amount of differ... more This paper describes different assumptions and methods utilized to calculate the amount of different types of reserves carried, and how these methods have evolved as more studies have been performed.
IEEE Transactions on Power Systems, 2000
As power systems evolve to incorporate greater penetrations of variable renewables, the demand fo... more As power systems evolve to incorporate greater penetrations of variable renewables, the demand for flexibility within the system is increased. Combined-cycle gas turbines are traditionally considered as relatively inflexible units, but those which incorporate a steam bypass stack are capable of opencycle operation. Facilitating these units to also operate in opencycle mode can benefit the power system via improved system reliability, while reducing the production needed from dedicated peaking units. The utilization of the multi-mode functionality is shown to be dependent on the flexibility inherent in the system and the manner in which the system is operated.
IEEE PES General Meeting, 2010
As variable generation integration continues to grow rapidly in power systems globally, system pl... more As variable generation integration continues to grow rapidly in power systems globally, system planners are seeking new tools to understand the role of variable output generators and the challenges experienced with their integration. The North American Electric Reliability Corporation (NERC) has established a task force to examine the integration of variable generation. This paper details the achievements to date and outlines ongoing efforts from Task 1.2 on the capacity value of variable generation and from Task 1.4 on the concept of flexibility in power systems and options for its definition. Arising from international collaboration with the International Energy Agency, a discussion on the definition of flexible resources is presented. A potential metric for flexibility offered by conventional plant is developed and applied to a test system.
IEEE PES General Meeting, 2010
Printed on paper containing at least 50% wastepaper, including 10% post consumer waste.
IEEE Transactions on Power Systems, 2000
ABSTRACT Increased competition in the electricity sector and the integration of variable renewabl... more ABSTRACT Increased competition in the electricity sector and the integration of variable renewable energy sources is resulting in more frequent cycling of thermal plant. Thus, the wear-and-tear to generator components and the related costs are a growing concern for plant owners and system operators alike. This paper presents a formulation that can be implemented in a MIP dispatch model to dynamically model cycling costs based on unit operation. When implemented for a test system, the results show that dynamically modeling cycling costs reduces cycling operation and tends to change the merit order over time. This leads to the burden of cycling operation being more evenly distributed over the plant portfolio and reduces the total system costs relative to the case when cycling costs are not modeled.
IEEE Transactions on Sustainable Energy, 2000
ABSTRACT Power systems with high wind penetration experience increased variability and uncertaint... more ABSTRACT Power systems with high wind penetration experience increased variability and uncertainty, such that determination of the required additional operating reserve is attracting a significant amount of attention and research. This paper presents methods used in recent wind integration analyses and operating practice, with key results that compare different methods or data. Wind integration analysis over the past several years has shown that wind variability need not be seen as a contingency event. The impact of wind will be seen in the reserves for nonevent operation (normal operation dealing with deviations from schedules). Wind power will also result in some events of larger variability and large forecast errors that could be categorized as slow events. The level of operating reserve that is induced by wind is not constant during all hours of the year, so that dynamic allocation of reserves will reduce the amount of reserves needed in the system for most hours. The paper concludes with recent emerging trends.
2015 IEEE Eindhoven PowerTech, 2015
IEEE PES Innovative Smart Grid Technologies, Europe, 2014
ABSTRACT Modern doubly-fed induction generator (DFIG) wind turbines have significant reactive pow... more ABSTRACT Modern doubly-fed induction generator (DFIG) wind turbines have significant reactive power control capability, even during low wind speed conditions. This can improve system security by providing terminal voltage control at buses in the system. Generally, such control employs the full range of reactive power production from the turbine which can lead to increased system losses. By utilizing optimal power flow analysis, and limiting the range of reactive power production at certain wind farms, system losses can be minimized. If the reactive power of the wind farms are optimized to achieve the minimum system losses this may adversely affect the voltage security of the system. However, by proper allocation of reactive power control strategies across the wind farms in the system voltage security can be preserved while reducing the system losses in the network.
Aupec 2011, 2011
Abstract─ Frequency stability is the paramount concern for secure and reliable operation of a pow... more Abstract─ Frequency stability is the paramount concern for secure and reliable operation of a power system. High wind penetration levels are reported in power systems with high thermal generation, and hence its likely to result high wind and combined-cycle gas turbine (CCGT) penetrations during system operation since CCGTs are the most preferable choice for the thermal generation. The doubly-fed induction generators (DFIGs) do not provide any inertial response while the CCGTs have unique frequency response during the system frequency disturbances. Therefore, CCGT turbine response characteristics and the zero inertial response may influence on frequency dynamics of a power network. The main objective of this study is to analyze the frequency dynamics during generator outages and three-phase short-circuit faults in a power network with high CCGT and wind penetrations. A test network model was developed based on the Northern-Ireland network in DIgSILENT Power Factory software package. It has shown that frequency stability may be threatened when three-phase short circuit faults occur in power networks during high CCGT and wind penetrations which may lead to CCGT combustor leanblowout and ultimately results large frequency excursions in the network.
... Page 7. Wind Power Integration Connection and system operational aspects Brendan Fox, DamianF... more ... Page 7. Wind Power Integration Connection and system operational aspects Brendan Fox, DamianFlynn, Leslie Bryans, Nick Jenkins, David Mi I borrow, Mark O'Malley, Richard Watson and Olimpo Anaya-Lara The Institution of Engineering and Technology Page 8. ...
ABSTRACT The rapid growth of wind generation in many European countries is pushing power systems ... more ABSTRACT The rapid growth of wind generation in many European countries is pushing power systems into uncharted territory. As additional wind generators are installed, the changing generation mix may impact on power system stability. This paper adopts the New England 39 bus system as a test system for transient stability analysis. Thermal generator models are based on a likely future plant mix for existing systems, while varying capacities of fixed-speed induction generators (FSIG) and doubly-fed induction generators (DFIG) are considered. The main emphasis here has been placed on the impact of wind technology mix on inter-area oscillations following transient grid disturbances. In addition, both rotor angle stability and transient voltage stability are examined, and results are compared with current grid code requirements and standards. Results have shown that FSIGs can reduce tie-line oscillations and improve damping following a transient disturbance, but they also cause voltage stability and rotor angle stability problems at high wind penetrations. In contrast, DFIGs can improve both voltage and rotor angle stability, but their power output noticeably oscillates during disturbances.
The increasing complexity of electric power systems, coupled with the demands of economic and ope... more The increasing complexity of electric power systems, coupled with the demands of economic and operational requirements, drives the need for continuing improvements in power plant performance and control. Accurate plant modelling and subsequent controller design is paramount to attaining the required performance and to seeking future improvements in design and operating procedures.
Transactions of the Institute of Measurement and Control
... simulation and on a laboratory micromachine system. Keywords: Self-tuning control; expert sys... more ... simulation and on a laboratory micromachine system. Keywords: Self-tuning control; expert systems; power system control; transputer applications ...
Advances in the development of electric vehicles, along with policy incentives, will see a wider ... more Advances in the development of electric vehicles, along with policy incentives, will see a wider uptake of this technology in the transport sector in future years. However, large penetrations of EVs could lead to adverse effects on power system networks, especially at the residential distribution network level. These effects could include excessive voltage drop and thermal loading of network components. A stochastic method is developed to take account of the uncertainties associated with EV charging and the technique is implemented on a residential test network using power system simulation software. The results show how voltage levels, component loading network losses are impacted from EV charging, taking into account the probabilistic behaviour of the EV owners.
In Northern Ireland, wind generation is mainly located in the west of the country, being connecte... more In Northern Ireland, wind generation is mainly located in the west of the country, being connected to the major loads in the east through the transmission and distribution network. With the expansion of wind generation in the west it is envisaged that during wind intensive periods power flow through the limited network capacity, in times of contingency outages and low demand, will see overhead lines breaching their thermal limits. On the Northern Ireland Electricity (NIE) network, dynamic line ratings (i.e. ratings which are dependent on actual weather conditions, as opposed to static line ratings which are based on assumed weather conditions) of overhead lines are being investigated as an interim measure to accommodate distributed generation, as network reinforcement is commissioned. This paper presents analysis from two physical models based on the IEEE and CIGRE standards. Comparison of the modelling techniques is made, with both models used to predict conductor temperatures utilising data gathered from the NIE network and laboratory data from wind tunnel tests.
Iet Generation Transmission & Distribution, 2009
A graphical method is presented for determining the capability of individual system nodes to acco... more A graphical method is presented for determining the capability of individual system nodes to accommodate wind power generation. The method is based upon constructing a capability chart for each node at which a wind farm is to be connected. The capability chart defines the domain of allowable power injections at the candidate node, subject to constraints imposed by voltage limits, voltage stability and equipment capability limits being satisfied. The chart is first derived for a two-bus model, before being extended to a multi-node power system. The graphical method is employed to derive the chart for a twonode system, as well as its application to a multi-node power system, considering the IEEE 30-bus test system as a case study. Although the proposed method is derived with the intention of determining the wind farm capacity to be connected at a specific node, it can be used for the analysis of a PQ bus loading as well as generation.
This paper describes different assumptions and methods utilized to calculate the amount of differ... more This paper describes different assumptions and methods utilized to calculate the amount of different types of reserves carried, and how these methods have evolved as more studies have been performed.
IEEE Transactions on Power Systems, 2000
As power systems evolve to incorporate greater penetrations of variable renewables, the demand fo... more As power systems evolve to incorporate greater penetrations of variable renewables, the demand for flexibility within the system is increased. Combined-cycle gas turbines are traditionally considered as relatively inflexible units, but those which incorporate a steam bypass stack are capable of opencycle operation. Facilitating these units to also operate in opencycle mode can benefit the power system via improved system reliability, while reducing the production needed from dedicated peaking units. The utilization of the multi-mode functionality is shown to be dependent on the flexibility inherent in the system and the manner in which the system is operated.
IEEE PES General Meeting, 2010
As variable generation integration continues to grow rapidly in power systems globally, system pl... more As variable generation integration continues to grow rapidly in power systems globally, system planners are seeking new tools to understand the role of variable output generators and the challenges experienced with their integration. The North American Electric Reliability Corporation (NERC) has established a task force to examine the integration of variable generation. This paper details the achievements to date and outlines ongoing efforts from Task 1.2 on the capacity value of variable generation and from Task 1.4 on the concept of flexibility in power systems and options for its definition. Arising from international collaboration with the International Energy Agency, a discussion on the definition of flexible resources is presented. A potential metric for flexibility offered by conventional plant is developed and applied to a test system.
IEEE PES General Meeting, 2010
Printed on paper containing at least 50% wastepaper, including 10% post consumer waste.
IEEE Transactions on Power Systems, 2000
ABSTRACT Increased competition in the electricity sector and the integration of variable renewabl... more ABSTRACT Increased competition in the electricity sector and the integration of variable renewable energy sources is resulting in more frequent cycling of thermal plant. Thus, the wear-and-tear to generator components and the related costs are a growing concern for plant owners and system operators alike. This paper presents a formulation that can be implemented in a MIP dispatch model to dynamically model cycling costs based on unit operation. When implemented for a test system, the results show that dynamically modeling cycling costs reduces cycling operation and tends to change the merit order over time. This leads to the burden of cycling operation being more evenly distributed over the plant portfolio and reduces the total system costs relative to the case when cycling costs are not modeled.
IEEE Transactions on Sustainable Energy, 2000
ABSTRACT Power systems with high wind penetration experience increased variability and uncertaint... more ABSTRACT Power systems with high wind penetration experience increased variability and uncertainty, such that determination of the required additional operating reserve is attracting a significant amount of attention and research. This paper presents methods used in recent wind integration analyses and operating practice, with key results that compare different methods or data. Wind integration analysis over the past several years has shown that wind variability need not be seen as a contingency event. The impact of wind will be seen in the reserves for nonevent operation (normal operation dealing with deviations from schedules). Wind power will also result in some events of larger variability and large forecast errors that could be categorized as slow events. The level of operating reserve that is induced by wind is not constant during all hours of the year, so that dynamic allocation of reserves will reduce the amount of reserves needed in the system for most hours. The paper concludes with recent emerging trends.
2015 IEEE Eindhoven PowerTech, 2015
IEEE PES Innovative Smart Grid Technologies, Europe, 2014
ABSTRACT Modern doubly-fed induction generator (DFIG) wind turbines have significant reactive pow... more ABSTRACT Modern doubly-fed induction generator (DFIG) wind turbines have significant reactive power control capability, even during low wind speed conditions. This can improve system security by providing terminal voltage control at buses in the system. Generally, such control employs the full range of reactive power production from the turbine which can lead to increased system losses. By utilizing optimal power flow analysis, and limiting the range of reactive power production at certain wind farms, system losses can be minimized. If the reactive power of the wind farms are optimized to achieve the minimum system losses this may adversely affect the voltage security of the system. However, by proper allocation of reactive power control strategies across the wind farms in the system voltage security can be preserved while reducing the system losses in the network.
Aupec 2011, 2011
Abstract─ Frequency stability is the paramount concern for secure and reliable operation of a pow... more Abstract─ Frequency stability is the paramount concern for secure and reliable operation of a power system. High wind penetration levels are reported in power systems with high thermal generation, and hence its likely to result high wind and combined-cycle gas turbine (CCGT) penetrations during system operation since CCGTs are the most preferable choice for the thermal generation. The doubly-fed induction generators (DFIGs) do not provide any inertial response while the CCGTs have unique frequency response during the system frequency disturbances. Therefore, CCGT turbine response characteristics and the zero inertial response may influence on frequency dynamics of a power network. The main objective of this study is to analyze the frequency dynamics during generator outages and three-phase short-circuit faults in a power network with high CCGT and wind penetrations. A test network model was developed based on the Northern-Ireland network in DIgSILENT Power Factory software package. It has shown that frequency stability may be threatened when three-phase short circuit faults occur in power networks during high CCGT and wind penetrations which may lead to CCGT combustor leanblowout and ultimately results large frequency excursions in the network.
... Page 7. Wind Power Integration Connection and system operational aspects Brendan Fox, DamianF... more ... Page 7. Wind Power Integration Connection and system operational aspects Brendan Fox, DamianFlynn, Leslie Bryans, Nick Jenkins, David Mi I borrow, Mark O'Malley, Richard Watson and Olimpo Anaya-Lara The Institution of Engineering and Technology Page 8. ...
ABSTRACT The rapid growth of wind generation in many European countries is pushing power systems ... more ABSTRACT The rapid growth of wind generation in many European countries is pushing power systems into uncharted territory. As additional wind generators are installed, the changing generation mix may impact on power system stability. This paper adopts the New England 39 bus system as a test system for transient stability analysis. Thermal generator models are based on a likely future plant mix for existing systems, while varying capacities of fixed-speed induction generators (FSIG) and doubly-fed induction generators (DFIG) are considered. The main emphasis here has been placed on the impact of wind technology mix on inter-area oscillations following transient grid disturbances. In addition, both rotor angle stability and transient voltage stability are examined, and results are compared with current grid code requirements and standards. Results have shown that FSIGs can reduce tie-line oscillations and improve damping following a transient disturbance, but they also cause voltage stability and rotor angle stability problems at high wind penetrations. In contrast, DFIGs can improve both voltage and rotor angle stability, but their power output noticeably oscillates during disturbances.
The increasing complexity of electric power systems, coupled with the demands of economic and ope... more The increasing complexity of electric power systems, coupled with the demands of economic and operational requirements, drives the need for continuing improvements in power plant performance and control. Accurate plant modelling and subsequent controller design is paramount to attaining the required performance and to seeking future improvements in design and operating procedures.
Transactions of the Institute of Measurement and Control
... simulation and on a laboratory micromachine system. Keywords: Self-tuning control; expert sys... more ... simulation and on a laboratory micromachine system. Keywords: Self-tuning control; expert systems; power system control; transputer applications ...
Advances in the development of electric vehicles, along with policy incentives, will see a wider ... more Advances in the development of electric vehicles, along with policy incentives, will see a wider uptake of this technology in the transport sector in future years. However, large penetrations of EVs could lead to adverse effects on power system networks, especially at the residential distribution network level. These effects could include excessive voltage drop and thermal loading of network components. A stochastic method is developed to take account of the uncertainties associated with EV charging and the technique is implemented on a residential test network using power system simulation software. The results show how voltage levels, component loading network losses are impacted from EV charging, taking into account the probabilistic behaviour of the EV owners.