Ibrahim abdulhadi - Academia.edu (original) (raw)

Papers by Ibrahim abdulhadi

CIRED - Open Access Proceedings Journal, 2017

The rising penetration of intermittent energy resources is increasing the need for more diverse e... more The rising penetration of intermittent energy resources is increasing the need for more diverse electrical energy resources that are able to support ancillary services. Demand side management (DSM) has a significant potential to fulfil this role but several challenges are still impeding the wide-scale integration of DSM. One of the major challenges is ensuring the performance of the networks that enable communications between control centres and the end DSM resources. This paper presents an analysis of all communications networks that typically participate in the activation of DSM, and provides an estimate for the overall latency that these networks incur. The most significant sources of delay from each of the components of the communications network are identified which allows the most critical aspects to be determined. This analysis therefore offers a detailed evaluation of the performance of DSM resources in the scope of providing real-time ancillary services. It is shown that, using available communications technologies, DSM can be used to provide primary frequency support services. In some cases, Neighbourhood Area Networks (NANs) may add significant delay, requiring careful choice of the technologies deployed.

A hardware level study, performed at the Power Networks Demonstration Centre (PNDC), testing seve... more A hardware level study, performed at the Power Networks Demonstration Centre (PNDC), testing seven off-the-shelf PV inverters is introduced in this paper. The objective of this work is to characterise the connection stability limits of the small scale grid-tied PV inverters under a variety of network disturbances represented by step changes in voltage magnitude and phase angle (referred to as Vector Shift - VS) applied on the LV AC terminals of the inverter. Such conditions, often caused by faults in the transmission network, can compromise the connection stability of the PV inverters and potentially exacerbate the network instability if large loss of PV generation ensues. The results presented in this paper reflect a future grid dominated by inverter connected generation with a wide range of inverters behaviours observed under the imposed testing scenarios.

An MV fault location technique based exclusively on low voltage measurements in the distribution ... more An MV fault location technique based exclusively on low voltage measurements in the distribution network is presented in this paper. The technique is based on sequence component analysis of the voltage measurements in order to characterise the LV voltage during MV faults. The accuracy of the technique is evaluated using a DigSILENT PowerFactory model where various fault conditions have been studied including the impact of distributed generation connection on the network voltage profile. The model represents the Power Networks Demonstration Centre’s (PNDC) MV and LV test network. This is to facilitate the validation of the model in the future implementing physical fault testing and measurements using the PNDC network.

This paper is a precursor to a number of HubNet position papers identifying research challenges a... more This paper is a precursor to a number of HubNet position papers identifying research challenges and directions associated with developing a UK smart grid blueprint that effectively integrates smart control and protection functions with the aid of a robust communications infrastructure.

IEEE Transactions on Smart Grid, 2020

This paper presents the design and validation of a Wide Area Monitoring and Control (WAMC) system... more This paper presents the design and validation of a Wide Area Monitoring and Control (WAMC) system for Fast Frequency Response (FFR) to address the challenges associated with reduced and non-uniformly distributed inertia in power systems. The WAMC system, designed for the power system in Great Britain, is termed "Enhanced Frequency Control Capability (EFCC)". It uses real time measurements from Phasor Measurement Units (PMUs) to monitor the system state in order to rapidly detect frequency disturbances and evaluate the magnitude of power imbalances. The impact of the disturbances on different parts of the network is considered to subsequently allocate the required response for different regions of the network, all within less than one second from the initiating event. The capabilities and characteristics of different resources (e.g. wind, energy storage, demand, etc.) are also evaluated and taken into account to achieve a suitable, optimized and coordinated response. Case studies using highly realistic hardware-in-the-loop setups are presented and these demonstrate that the proposed system is capable of detecting frequency events and deploying appropriate and coordinated responses in a timely fashion even with degraded communication conditions, thereby effectively enhancing the frequency control in future low-inertia systems and permitting higher penetrations of low-carbon and low-inertia energy sources. Index Terms-Frequency control, low inertia, PMU, wide-area monitoring and control. Rn Frequency measured by i th PMU in Region n θ Rn Regional equivalent angle in Region n θ i Rn Angle measured by i th PMU in Region n W i Rn

International Journal of Electrical Power & Energy Systems, 2020

A medium voltage (MV) faulted section location technique depending solely on unsynchronized low v... more A medium voltage (MV) faulted section location technique depending solely on unsynchronized low voltage (LV) measurements in distribution systems is introduced in this paper. The proposed method identifies the faulted MV feeder segment when an unsymmetrical MV fault occurs. It exploits parameters including voltage magnitude, angle and sequence components captured via distributed non-synchronized monitoring devices connected at secondary substations. In this study, the characterization of a system's LV profile during MV faults was achieved throughout both software simulations and physical testing. The latter was conducted in the 11 kV and LV distribution network of the Power Networks Demonstration Centre (PNDC) of the University of Strathclyde. The tests were performed for both 11 kV radial and ring network configurations. Modelling and simulations implemented using the DigSILENT PowerFactory package, complemented the hardware level testing and provided the opportunity for further examinations, such as the impact of MV laterals connection, distributed energy resources on both MV and LV side as well as the presence of unbalanced loads. Finally, the paper evaluates the effectiveness of the proposed faulted section location technique under various physical and simulated fault scenarios, loss of communications and noise interference.

IEEE Transactions on Industrial Electronics, 2019

The Journal of Engineering, 2018

The increasing penetration of renewable generation has led to the decrease of power systems' over... more The increasing penetration of renewable generation has led to the decrease of power systems' overall inertia, which introduces significant challenges to frequency stability. In this paper, the potential of using Fast Frequency Response (FFR) to enhance frequency control in power systems with low inertia is investigated in detail. A Generic System Frequency Response (GSFR) model taking into account of the penetration level of Non-Synchronous Generation (NSG) and FFR has been developed and used to investigate the impact of reduced inertia on frequency control and demonstrate that the amount of reserve power to be scheduled can be significantly reduced with the deployment of FFR. The impact of the different FFR resources' characteristics (e.g. response delay, ramp rate, etc.) on the effectiveness of frequency control is also investigated, based on which the desirable specifications for FFR schemes are summarised. These desirable properties of FFR schemes are taken into account in the design of a wide-area monitoring and control system termed "Enhanced Frequency Control Capability (EFCC)", which is proposed for the delivery of FFR in the future Great Britain transmission system. The design and operation of the EFCC scheme are presented, along with a case study demonstrating its effectiveness in enhancing the frequency control.

CIRED - Open Access Proceedings Journal, 2017

This paper presents the experimental testing of commercial LV-connected PV inverters to character... more This paper presents the experimental testing of commercial LV-connected PV inverters to characterise their behaviour during fault conditions. Understanding this behaviour is critical for the proper design and operation of distribution networks with a large amount of inverter-connected generation. Hardware test results for a number of different inverters are discussed and compared. The challenges for modelling, particularly with respect to fault conditions, are discussed with an example simulation.

CIRED - Open Access Proceedings Journal, 2017

With the increasing penetration of distributed renewable generation being connected, a number of ... more With the increasing penetration of distributed renewable generation being connected, a number of solutions have been developed to avoid network overloads. A number of the already implemented schemes are based on generation curtailment during times of high generation and low demand. The ACCESS (Assisting Communities to Connect to Electric Sustainable Sources) system implements a more sophisticated predictive based solution. In the ACCESS system the generation resource and electrical demand is predicted and the storage heating resource is managed, providing a demand side management instead of a generation curtailment solution. The ACCESS system was installed, tested and demonstrated in the Power Network Demonstration Centre (PNDC), a research facility that enables realistic testing of novel hardware and network operation schemes in a controlled environment, in 2015. Following the testing at the PNDC, the ACCESS system was deployed in the Isle of Mull, in 2016. This paper reports on the outcome of the testing of the demand response features of the ACCESS system at the PNDC prior to its deployment on the Isle of Mull. This paper reports on: the different components of the system in detail (i.e. what it is designed to do and why); the test regime undertaken at the PNDC; the results of the testing (i.e. how effectively it achieves its design objectives); and the updates to the ACCESS system based on the testing with regards to the solutions employed and the benefits achieved.

IEEE Transactions on Systems, Man, and Cybernetics: Systems, 2017

Prognostics predictions estimate the remaining useful life of assets. This information enables th... more Prognostics predictions estimate the remaining useful life of assets. This information enables the implementation of condition-based maintenance strategies by scheduling intervention when failure is imminent. Circuit breakers are key assets for the correct operation of the power network, fulfilling both a protection and a network reconfiguration role. Certain breakers will perform switching on a deterministic schedule, while operating stochastically in response to network faults. Both types of operation increase wear on the main contact, with high fault currents leading to more rapid ageing. This paper presents a hybrid approach for prognostics of circuit breakers, which integrates deterministic and stochastic operation through Piecewise Deterministic Markov Processes. The main contributions of this paper are (i) the integration of hybrid prognostics models with dynamic reliability concepts for a more accurate remaining useful life forecasting and (ii) the uncertain failure threshold modelling to integrate and propagate uncertain failure evaluation levels in the prognostics estimation process. Results show the effect of dynamic operation conditions on prognostics predictions and confirm the potential for its use within a condition-based maintenance strategy.

10th IET International Conference on Developments in Power System Protection (DPSP 2010). Managing the Change, 2010

This paper presents an assessment of the performance of distance protection for transmission line... more This paper presents an assessment of the performance of distance protection for transmission lines in the presence of Quadrature Booster Transformers (QBs). The use of QBs in the UK transmission grid is increasing to maximise the utility of existing infrastructure as well as enabling rapid network modifications as dictated by operational requirements. An analysis is performed with the aid of a real time digital simulator (RTDS) to quantify the extent of error which may lead to the mal-operation of distance protection on transmission lines with QBs installed and operating under different scenarios. Using QBs in the future for more active constraint management may cause further complications that stretch existing protection schemes' capability. These issues are also considered. Furthermore the scope for an adaptive relaying solution is defined with focus on a wider scale coordination of protection for networks with QBs installed.

The date palm (Phoenix dactylifera L) is the most important crop of the Gulf region in the Middle... more The date palm (Phoenix dactylifera L) is the most important crop of the Gulf region in the Middle-East. The Kingdom of Saudi Arabia with an estimated 25 million date palms produces nearly a million tones of dates annually with a good potential for exporting the surplus produce. In order to standardize quality norms of major date cultivars in the Kingdom, studies were taken up at the National Date Palm Research Centre, Al Hassa, Saudi Arabia to ascertain fruit characteristics of dates (Tamar stage) in the cultivars Khalas, Sheshi and Reziz with respect to fruit weight (g) , size of fruit (length and breath), number of fruits /500g, fruit moisture, colour and texture. Khalas recorded the maximum fruit length in all the three categories of large, medium and small sized fruits. With regard to the breath of fruits, the cultivar Sheshi registered the highest values. Further, Sheshi recorded the highest fruit weight values, which in turn influenced the number of fruits per unit weight, with Sheshi recording the least number of fruits per 500g. The cultivar Khalas had the least fruit moisture and the highest mean ∆E for colour indicating light colour (yellow) fruits. We also studied four texture parameters viz, hardness, springiness, cohesiveness and resilience of Khalas, Sheshi and Reziz date cultivars. Findings of this investigation will strengthen the data base of fruit quality norms in major Saudi Arabian date cultivars and boost export of dates from the Kingdom, besides protecting the identity of the cultivars studied.

Date palm (Phoenix dactylifera L.) is cultivated in the Kingdom of Saudi since prehistoric times ... more Date palm (Phoenix dactylifera L.) is cultivated in the Kingdom of Saudi since prehistoric times and is the most important fruit crop of the Kingdom. High soil salinity is a major abiotic stress that is impacting on the productivity of date palm in the Arabian Peninsula. Trials conducted at the National Date Palm Research Centre, Al Hassa, Saudi Arabia to determine the effect of NaCl induced salinity on photosynthesis and chlorophyll in the three date palm cultivars viz. Khalas, Madjool and Barhy revealed that increasing soil salinity levels (0, 50, 100, 200 and 400 mM NaCl) resulted in progressive decrease of K + , K + /Na + ratio and N content, along with increase in Na + levels in all the three tested cultivars. Increasing salinity levels also decreased the net photosynthesis and chlorophyll levels in these cultivars. However, Saudi Arabia's premier date cultivar 'Khalas' was able to withstand increasing salinity levels as compared to Majdol and Barhi.

mainly from the Zulfi and Riyadh regions were found to meet the required standards with potential... more mainly from the Zulfi and Riyadh regions were found to meet the required standards with potential for commercial date farming. Among these, fruits of Adbah had the highest total sugars of 72.9% followed by Duhiba with a total sugar content of 71.9%. Fruit length was maximum (49.1 mm) in the variety Aliah, while the fruits of the variety Hussan recorded the maximum weight of 19.5 g. Furthermore, it is pertinent to mention that fruit size of the 12 selected cultivars was generally large and comparable to Majdool, a well-known date palm cultivar of North Africa. The fruits of the selected cultivars were also tasty and can be stored separately.

2012 IEEE International Workshop on Applied Measurements for Power Systems (AMPS) Proceedings, 2012

The new standard C37.118.1 lays down strict performance limits for phasor measurement units (PMUs... more The new standard C37.118.1 lays down strict performance limits for phasor measurement units (PMUs) under steady-state and dynamic conditions. Reference algorithms are also presented for the P (performance) and M (measurement) class PMUs. In this paper, the performance of the Reference M class filter is analysed. Similarly to the Reference P class filter, the M class filter is found to have a relatively poor performance when the power system frequency is off-nominal. A different architecture for an M class Phasor Measurement Unit (PMU) algorithm is presented, and in particular a completely different design of M class filter. This is shown to have much improved rejection of unwanted harmonic and inter-harmonic components. This allows consistent accuracy to be maintained across a ±33% frequency range. ROCOF (Rate of Change of Frequency) errors can be reduced by factors of >100.

2011 2nd IEEE PES International Conference and Exhibition on Innovative Smart Grid Technologies, 2011

Unique and varied power system conditions are already being experienced as a result of the deploy... more Unique and varied power system conditions are already being experienced as a result of the deployment of novel control strategies and new generation and distribution related technologies driven by the smart grid. A particular challenge is related to ensuring the correct and reliable operation of protection schemes. Implementing smarter protection in the form of adaptive setting selection is one way of tackling some of the protection performance issues. However, introducing such new approaches especially to safety critical systems such as protection carries an element of risk. Furthermore, integrating new secondary systems into the substation is a complex and costly procedure. To this end, this paper proposes an adaptive protection architecture that facilitates the integration of such schemes into modern digital substations which are a staple of smart grids. Functional features of the architecture also offer powerful means of de-risking schemes and flexible implementation through self-contained modules that are suitable for reuse. An example adaptive distance protection scheme is presented and tested to demonstrate how the architecture can be implemented and to highlight the architecture's novel features.

12th IET International Conference on Developments in Power System Protection (DPSP 2014), 2014

This paper describes the current progress of the project developing a satellite based Loss-of-Mai... more This paper describes the current progress of the project developing a satellite based Loss-of-Mains (LOM) protection based on accumulated voltage phase angle difference (VPAD). In the initial stage of the laboratory trial, relay prototype in Opal-RT/RT-lab, test network modelled in RTDS/RSCAD and a commercial SEL-PMU are interconnected to establish a hardware-in-the-loop test platform. With a series of tests carefully designed for stability and sensitivity assessment, considering various generator control and load representations, the new protection scheme has been proved to have both enhanced stability and sensitivity over the existing passive LOM methods.

IET Conference on Power in Unity: a Whole System Approach, 2013

Presents a collection of slides covering the following topics: smart grid control; smart grid fun... more Presents a collection of slides covering the following topics: smart grid control; smart grid functional interoperability; and HubNet.

2008 43rd International Universities Power Engineering Conference, 2008

This paper introduces the concept of dynamic modelling for wide area and adaptive power system pr... more This paper introduces the concept of dynamic modelling for wide area and adaptive power system protection. Although not limited to these types of protection schemes, these were chosen due to their potential role in solving a multitude of protection challenges facing future power systems. The dynamic modelling will be implemented using a bespoke simulation environment. This tool allows for a fully integrated testing methodology which enables the validation of protection solutions prior to their operational deployment. Furthermore the paper suggests a distributed protection architecture, which when applied to existing and future protection schemes, has the potential to enhance their functionality and avoid mal-operation given that safety and reliability of power systems are paramount. This architecture also provides a means to better understand the underlying dynamics of the aforementioned protection schemes and will be rigorously validated using the modelling environment.

CIRED - Open Access Proceedings Journal, 2017

The rising penetration of intermittent energy resources is increasing the need for more diverse e... more The rising penetration of intermittent energy resources is increasing the need for more diverse electrical energy resources that are able to support ancillary services. Demand side management (DSM) has a significant potential to fulfil this role but several challenges are still impeding the wide-scale integration of DSM. One of the major challenges is ensuring the performance of the networks that enable communications between control centres and the end DSM resources. This paper presents an analysis of all communications networks that typically participate in the activation of DSM, and provides an estimate for the overall latency that these networks incur. The most significant sources of delay from each of the components of the communications network are identified which allows the most critical aspects to be determined. This analysis therefore offers a detailed evaluation of the performance of DSM resources in the scope of providing real-time ancillary services. It is shown that, using available communications technologies, DSM can be used to provide primary frequency support services. In some cases, Neighbourhood Area Networks (NANs) may add significant delay, requiring careful choice of the technologies deployed.

A hardware level study, performed at the Power Networks Demonstration Centre (PNDC), testing seve... more A hardware level study, performed at the Power Networks Demonstration Centre (PNDC), testing seven off-the-shelf PV inverters is introduced in this paper. The objective of this work is to characterise the connection stability limits of the small scale grid-tied PV inverters under a variety of network disturbances represented by step changes in voltage magnitude and phase angle (referred to as Vector Shift - VS) applied on the LV AC terminals of the inverter. Such conditions, often caused by faults in the transmission network, can compromise the connection stability of the PV inverters and potentially exacerbate the network instability if large loss of PV generation ensues. The results presented in this paper reflect a future grid dominated by inverter connected generation with a wide range of inverters behaviours observed under the imposed testing scenarios.

An MV fault location technique based exclusively on low voltage measurements in the distribution ... more An MV fault location technique based exclusively on low voltage measurements in the distribution network is presented in this paper. The technique is based on sequence component analysis of the voltage measurements in order to characterise the LV voltage during MV faults. The accuracy of the technique is evaluated using a DigSILENT PowerFactory model where various fault conditions have been studied including the impact of distributed generation connection on the network voltage profile. The model represents the Power Networks Demonstration Centre’s (PNDC) MV and LV test network. This is to facilitate the validation of the model in the future implementing physical fault testing and measurements using the PNDC network.

This paper is a precursor to a number of HubNet position papers identifying research challenges a... more This paper is a precursor to a number of HubNet position papers identifying research challenges and directions associated with developing a UK smart grid blueprint that effectively integrates smart control and protection functions with the aid of a robust communications infrastructure.

IEEE Transactions on Smart Grid, 2020

This paper presents the design and validation of a Wide Area Monitoring and Control (WAMC) system... more This paper presents the design and validation of a Wide Area Monitoring and Control (WAMC) system for Fast Frequency Response (FFR) to address the challenges associated with reduced and non-uniformly distributed inertia in power systems. The WAMC system, designed for the power system in Great Britain, is termed "Enhanced Frequency Control Capability (EFCC)". It uses real time measurements from Phasor Measurement Units (PMUs) to monitor the system state in order to rapidly detect frequency disturbances and evaluate the magnitude of power imbalances. The impact of the disturbances on different parts of the network is considered to subsequently allocate the required response for different regions of the network, all within less than one second from the initiating event. The capabilities and characteristics of different resources (e.g. wind, energy storage, demand, etc.) are also evaluated and taken into account to achieve a suitable, optimized and coordinated response. Case studies using highly realistic hardware-in-the-loop setups are presented and these demonstrate that the proposed system is capable of detecting frequency events and deploying appropriate and coordinated responses in a timely fashion even with degraded communication conditions, thereby effectively enhancing the frequency control in future low-inertia systems and permitting higher penetrations of low-carbon and low-inertia energy sources. Index Terms-Frequency control, low inertia, PMU, wide-area monitoring and control. Rn Frequency measured by i th PMU in Region n θ Rn Regional equivalent angle in Region n θ i Rn Angle measured by i th PMU in Region n W i Rn

International Journal of Electrical Power & Energy Systems, 2020

A medium voltage (MV) faulted section location technique depending solely on unsynchronized low v... more A medium voltage (MV) faulted section location technique depending solely on unsynchronized low voltage (LV) measurements in distribution systems is introduced in this paper. The proposed method identifies the faulted MV feeder segment when an unsymmetrical MV fault occurs. It exploits parameters including voltage magnitude, angle and sequence components captured via distributed non-synchronized monitoring devices connected at secondary substations. In this study, the characterization of a system's LV profile during MV faults was achieved throughout both software simulations and physical testing. The latter was conducted in the 11 kV and LV distribution network of the Power Networks Demonstration Centre (PNDC) of the University of Strathclyde. The tests were performed for both 11 kV radial and ring network configurations. Modelling and simulations implemented using the DigSILENT PowerFactory package, complemented the hardware level testing and provided the opportunity for further examinations, such as the impact of MV laterals connection, distributed energy resources on both MV and LV side as well as the presence of unbalanced loads. Finally, the paper evaluates the effectiveness of the proposed faulted section location technique under various physical and simulated fault scenarios, loss of communications and noise interference.

IEEE Transactions on Industrial Electronics, 2019

The Journal of Engineering, 2018

The increasing penetration of renewable generation has led to the decrease of power systems' over... more The increasing penetration of renewable generation has led to the decrease of power systems' overall inertia, which introduces significant challenges to frequency stability. In this paper, the potential of using Fast Frequency Response (FFR) to enhance frequency control in power systems with low inertia is investigated in detail. A Generic System Frequency Response (GSFR) model taking into account of the penetration level of Non-Synchronous Generation (NSG) and FFR has been developed and used to investigate the impact of reduced inertia on frequency control and demonstrate that the amount of reserve power to be scheduled can be significantly reduced with the deployment of FFR. The impact of the different FFR resources' characteristics (e.g. response delay, ramp rate, etc.) on the effectiveness of frequency control is also investigated, based on which the desirable specifications for FFR schemes are summarised. These desirable properties of FFR schemes are taken into account in the design of a wide-area monitoring and control system termed "Enhanced Frequency Control Capability (EFCC)", which is proposed for the delivery of FFR in the future Great Britain transmission system. The design and operation of the EFCC scheme are presented, along with a case study demonstrating its effectiveness in enhancing the frequency control.

CIRED - Open Access Proceedings Journal, 2017

This paper presents the experimental testing of commercial LV-connected PV inverters to character... more This paper presents the experimental testing of commercial LV-connected PV inverters to characterise their behaviour during fault conditions. Understanding this behaviour is critical for the proper design and operation of distribution networks with a large amount of inverter-connected generation. Hardware test results for a number of different inverters are discussed and compared. The challenges for modelling, particularly with respect to fault conditions, are discussed with an example simulation.

CIRED - Open Access Proceedings Journal, 2017

With the increasing penetration of distributed renewable generation being connected, a number of ... more With the increasing penetration of distributed renewable generation being connected, a number of solutions have been developed to avoid network overloads. A number of the already implemented schemes are based on generation curtailment during times of high generation and low demand. The ACCESS (Assisting Communities to Connect to Electric Sustainable Sources) system implements a more sophisticated predictive based solution. In the ACCESS system the generation resource and electrical demand is predicted and the storage heating resource is managed, providing a demand side management instead of a generation curtailment solution. The ACCESS system was installed, tested and demonstrated in the Power Network Demonstration Centre (PNDC), a research facility that enables realistic testing of novel hardware and network operation schemes in a controlled environment, in 2015. Following the testing at the PNDC, the ACCESS system was deployed in the Isle of Mull, in 2016. This paper reports on the outcome of the testing of the demand response features of the ACCESS system at the PNDC prior to its deployment on the Isle of Mull. This paper reports on: the different components of the system in detail (i.e. what it is designed to do and why); the test regime undertaken at the PNDC; the results of the testing (i.e. how effectively it achieves its design objectives); and the updates to the ACCESS system based on the testing with regards to the solutions employed and the benefits achieved.

IEEE Transactions on Systems, Man, and Cybernetics: Systems, 2017

Prognostics predictions estimate the remaining useful life of assets. This information enables th... more Prognostics predictions estimate the remaining useful life of assets. This information enables the implementation of condition-based maintenance strategies by scheduling intervention when failure is imminent. Circuit breakers are key assets for the correct operation of the power network, fulfilling both a protection and a network reconfiguration role. Certain breakers will perform switching on a deterministic schedule, while operating stochastically in response to network faults. Both types of operation increase wear on the main contact, with high fault currents leading to more rapid ageing. This paper presents a hybrid approach for prognostics of circuit breakers, which integrates deterministic and stochastic operation through Piecewise Deterministic Markov Processes. The main contributions of this paper are (i) the integration of hybrid prognostics models with dynamic reliability concepts for a more accurate remaining useful life forecasting and (ii) the uncertain failure threshold modelling to integrate and propagate uncertain failure evaluation levels in the prognostics estimation process. Results show the effect of dynamic operation conditions on prognostics predictions and confirm the potential for its use within a condition-based maintenance strategy.

10th IET International Conference on Developments in Power System Protection (DPSP 2010). Managing the Change, 2010

This paper presents an assessment of the performance of distance protection for transmission line... more This paper presents an assessment of the performance of distance protection for transmission lines in the presence of Quadrature Booster Transformers (QBs). The use of QBs in the UK transmission grid is increasing to maximise the utility of existing infrastructure as well as enabling rapid network modifications as dictated by operational requirements. An analysis is performed with the aid of a real time digital simulator (RTDS) to quantify the extent of error which may lead to the mal-operation of distance protection on transmission lines with QBs installed and operating under different scenarios. Using QBs in the future for more active constraint management may cause further complications that stretch existing protection schemes' capability. These issues are also considered. Furthermore the scope for an adaptive relaying solution is defined with focus on a wider scale coordination of protection for networks with QBs installed.

The date palm (Phoenix dactylifera L) is the most important crop of the Gulf region in the Middle... more The date palm (Phoenix dactylifera L) is the most important crop of the Gulf region in the Middle-East. The Kingdom of Saudi Arabia with an estimated 25 million date palms produces nearly a million tones of dates annually with a good potential for exporting the surplus produce. In order to standardize quality norms of major date cultivars in the Kingdom, studies were taken up at the National Date Palm Research Centre, Al Hassa, Saudi Arabia to ascertain fruit characteristics of dates (Tamar stage) in the cultivars Khalas, Sheshi and Reziz with respect to fruit weight (g) , size of fruit (length and breath), number of fruits /500g, fruit moisture, colour and texture. Khalas recorded the maximum fruit length in all the three categories of large, medium and small sized fruits. With regard to the breath of fruits, the cultivar Sheshi registered the highest values. Further, Sheshi recorded the highest fruit weight values, which in turn influenced the number of fruits per unit weight, with Sheshi recording the least number of fruits per 500g. The cultivar Khalas had the least fruit moisture and the highest mean ∆E for colour indicating light colour (yellow) fruits. We also studied four texture parameters viz, hardness, springiness, cohesiveness and resilience of Khalas, Sheshi and Reziz date cultivars. Findings of this investigation will strengthen the data base of fruit quality norms in major Saudi Arabian date cultivars and boost export of dates from the Kingdom, besides protecting the identity of the cultivars studied.

Date palm (Phoenix dactylifera L.) is cultivated in the Kingdom of Saudi since prehistoric times ... more Date palm (Phoenix dactylifera L.) is cultivated in the Kingdom of Saudi since prehistoric times and is the most important fruit crop of the Kingdom. High soil salinity is a major abiotic stress that is impacting on the productivity of date palm in the Arabian Peninsula. Trials conducted at the National Date Palm Research Centre, Al Hassa, Saudi Arabia to determine the effect of NaCl induced salinity on photosynthesis and chlorophyll in the three date palm cultivars viz. Khalas, Madjool and Barhy revealed that increasing soil salinity levels (0, 50, 100, 200 and 400 mM NaCl) resulted in progressive decrease of K + , K + /Na + ratio and N content, along with increase in Na + levels in all the three tested cultivars. Increasing salinity levels also decreased the net photosynthesis and chlorophyll levels in these cultivars. However, Saudi Arabia's premier date cultivar 'Khalas' was able to withstand increasing salinity levels as compared to Majdol and Barhi.

mainly from the Zulfi and Riyadh regions were found to meet the required standards with potential... more mainly from the Zulfi and Riyadh regions were found to meet the required standards with potential for commercial date farming. Among these, fruits of Adbah had the highest total sugars of 72.9% followed by Duhiba with a total sugar content of 71.9%. Fruit length was maximum (49.1 mm) in the variety Aliah, while the fruits of the variety Hussan recorded the maximum weight of 19.5 g. Furthermore, it is pertinent to mention that fruit size of the 12 selected cultivars was generally large and comparable to Majdool, a well-known date palm cultivar of North Africa. The fruits of the selected cultivars were also tasty and can be stored separately.

2012 IEEE International Workshop on Applied Measurements for Power Systems (AMPS) Proceedings, 2012

The new standard C37.118.1 lays down strict performance limits for phasor measurement units (PMUs... more The new standard C37.118.1 lays down strict performance limits for phasor measurement units (PMUs) under steady-state and dynamic conditions. Reference algorithms are also presented for the P (performance) and M (measurement) class PMUs. In this paper, the performance of the Reference M class filter is analysed. Similarly to the Reference P class filter, the M class filter is found to have a relatively poor performance when the power system frequency is off-nominal. A different architecture for an M class Phasor Measurement Unit (PMU) algorithm is presented, and in particular a completely different design of M class filter. This is shown to have much improved rejection of unwanted harmonic and inter-harmonic components. This allows consistent accuracy to be maintained across a ±33% frequency range. ROCOF (Rate of Change of Frequency) errors can be reduced by factors of >100.

2011 2nd IEEE PES International Conference and Exhibition on Innovative Smart Grid Technologies, 2011

Unique and varied power system conditions are already being experienced as a result of the deploy... more Unique and varied power system conditions are already being experienced as a result of the deployment of novel control strategies and new generation and distribution related technologies driven by the smart grid. A particular challenge is related to ensuring the correct and reliable operation of protection schemes. Implementing smarter protection in the form of adaptive setting selection is one way of tackling some of the protection performance issues. However, introducing such new approaches especially to safety critical systems such as protection carries an element of risk. Furthermore, integrating new secondary systems into the substation is a complex and costly procedure. To this end, this paper proposes an adaptive protection architecture that facilitates the integration of such schemes into modern digital substations which are a staple of smart grids. Functional features of the architecture also offer powerful means of de-risking schemes and flexible implementation through self-contained modules that are suitable for reuse. An example adaptive distance protection scheme is presented and tested to demonstrate how the architecture can be implemented and to highlight the architecture's novel features.

12th IET International Conference on Developments in Power System Protection (DPSP 2014), 2014

This paper describes the current progress of the project developing a satellite based Loss-of-Mai... more This paper describes the current progress of the project developing a satellite based Loss-of-Mains (LOM) protection based on accumulated voltage phase angle difference (VPAD). In the initial stage of the laboratory trial, relay prototype in Opal-RT/RT-lab, test network modelled in RTDS/RSCAD and a commercial SEL-PMU are interconnected to establish a hardware-in-the-loop test platform. With a series of tests carefully designed for stability and sensitivity assessment, considering various generator control and load representations, the new protection scheme has been proved to have both enhanced stability and sensitivity over the existing passive LOM methods.

IET Conference on Power in Unity: a Whole System Approach, 2013

Presents a collection of slides covering the following topics: smart grid control; smart grid fun... more Presents a collection of slides covering the following topics: smart grid control; smart grid functional interoperability; and HubNet.

2008 43rd International Universities Power Engineering Conference, 2008

This paper introduces the concept of dynamic modelling for wide area and adaptive power system pr... more This paper introduces the concept of dynamic modelling for wide area and adaptive power system protection. Although not limited to these types of protection schemes, these were chosen due to their potential role in solving a multitude of protection challenges facing future power systems. The dynamic modelling will be implemented using a bespoke simulation environment. This tool allows for a fully integrated testing methodology which enables the validation of protection solutions prior to their operational deployment. Furthermore the paper suggests a distributed protection architecture, which when applied to existing and future protection schemes, has the potential to enhance their functionality and avoid mal-operation given that safety and reliability of power systems are paramount. This architecture also provides a means to better understand the underlying dynamics of the aforementioned protection schemes and will be rigorously validated using the modelling environment.