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.
Impact of capacitive coupling circuit on online impulse frequency response of a power transformer
- Authors: Zhao, Zhongyong , Yao, Chenguo , Zhao, Xiaozhen , Hashemnia, Naser , Islam, Syed
- Date: 2016
- Type: Text , Journal article
- Relation: IEEE Transactions on Dielectrics and Electrical Insulation Vol. 23, no. 3 (2016), p. 1285-1293
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- Description: Detecting the early signs of mechanical failures of power transformer winding is necessary and is possible with online monitoring techniques. Online impulse frequency response analysis (IFRA) is a promising diagnostic method when a transformer is in service. This paper examines the unrevealed problem existing in the method, namely, the impact of bushing capacitive coupling circuit on online impulse frequency response. An equivalent electrical model of capacitive coupling circuit and transformer winding is established. The frequency response of the capacitive coupling circuit is obtained to study its influence on online impulse frequency response. The parameter variations of capacitive coupling circuit caused by coupling capacitance variation and bushing dielectric breakdown are simulated to investigate their influence on online impulse frequency response signatures. A few experiments are eventually performed to verify the theoretical analysis and simulation results. This paper contributes to the application of online IFRA.
Impact of gearbox oil contamination on the performance of the wind turbine drivetrain
- Authors: Islam, Syed
- Date: 2016
- Type: Text , Conference paper
- Relation: International Conference on Renewable Energies and Power Quality (ICREPQ’16) ; Madrid 4th to 6th May, 2016
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- Description: Wind turbine gearbox is a key component in any wind energy conversion system and online monitoring of the gearbox is essential to maintain system reliability. This paper investigates the impact of gearbox lubrication oil contamination on the performance of wind turbine drivetrain. In this context, vibration signal of the gearbox is measured and analyzed under various contamination levels of the gearbox oil. A thermal camera is used to identify the hot spot location within the gearbox during the investigated case studies. Results show that quality of gearbox oil has a significant impact on the overall performance of the wind energy conversion system.
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.
Online optimal variable charge-rate coordination of plug-in electric vehicles to maximize customer satisfaction and improve grid performance
- Authors: Hajforoosh, Somayeh , Masoum, Mohammad , Islam, Syed
- Date: 2016
- Type: Text , Journal article
- Relation: Electric Power Systems Research Vol. 141, no. (2016), p. 407-420
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- Description: Participation of plug-in electric vehicles (PEVs) is expected to grow in emerging smart grids. A strategy to overcome potential grid overloading caused by large penetrations of PEVs is to optimize their battery charge-rates to fully explore grid capacity and maximize the customer satisfaction for all PEV owners. This paper proposes an online dynamically optimized algorithm for optimal variable charge-rate scheduling of PEVs based on coordinated aggregated particle swarm optimization (CAPSO). The online algorithm is updated at regular intervals of Δt = 5 min to maximize the customers’ satisfactions for all PEV owners based on their requested plug-out times, requested battery state of charges (SOCReq) and willingness to pay the higher charging energy prices. The algorithm also ensures that the distribution transformer is not overloaded while grid losses and node voltage deviations are minimized. Simulation results for uncoordinated PEV charging as well as CAPSO with fixed charge-rate coordination (FCC) and variable charge-rate coordination (VCC) strategies are compared for a 449-node network with different levels of PEV penetrations. The key contributions are optimal VCC of PEVs considering battery modeling, chargers’ efficiencies and customer satisfaction based on requested plug-out times, driving pattern, desired final SOCs and their interest to pay for energy at a higher rate.
Performance analysis of filter sensing board for measuring the battery online impedance
- Authors: Hossain, Kamal , Islam, Syed , Park, Sung-Yeul
- Date: 2016
- Type: Text , Conference proceedings , Conference paper
- Relation: 2016 Asian Conference on Energy, Power and Transportation Electrification, ACEPT 2016; Singapore, Singapore; 25th-27th October 2016 Vol. 2017, p. 1-6
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- Description: This paper presents the performance analysis of filter sensing board for extracting ac ripple information to estimate the battery impedance for the sinusoidal ripple current charging technique. The charging ac ripple content is extracted from the battery voltage and current by filtering the dc component using an op-amp filter circuit while producing a 90° phase angle in order to transform the a-p frame for calculating the battery impedance. The digital signal processor based board has computational burden due to the many transformations and calculation steps with limited ADC sensing range between 0 to 3 V at 12 bit resolution. Additionally, in the software approach it is observed that the gain and phase angle of sensor output is changing with respect to the AC input ripple frequency. In this paper, we propose a filter sensing circuit board to reduce the transformation and computation burdens for measuring the AC impedance. In this proposed method, the impedance is calculated via a dSPACE interface with a ± 10 V ADC sensing range at 16 bit resolution. This paper also verifies the variation of phase delay between the sensor input and output at different frequencies by using the proposed 16-channel analog filter circuit. A prototype ac load is used as an experimental test bed considering the equivalent battery internal impedance model for measuring the accuracy of the filter sensing board. Finally, the performance of this proposed approach is verified by comparing the experimental result with the simulation and the commercial frequency response analyzer results.
Performance evaluation of a process bus architecture in a zone substation based on IEC 61850-9-2
- Authors: Kumar, Shantanu , Das, Narottam , Islam, Syed
- Date: 2016
- Type: Text , Conference proceedings , Conference paper
- Relation: IEEE PES Asia-Pacific Power and Energy Engineering Conference, APPEEC 2015; Brisbane, Australia; 15th-18th November 2015 Vol. 2016, p. 1-5
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- Description: Ethernet communication has been the back bone of high speed communication in digital substations from protection relaying, control and automation perspective. Major substation manufacturers have been constantly upgrading softwares and adding new features in their Intelligent Electronic Devices (IED's) to carry out multiple functions in process bus devices. This paper presents simulation results with respect to the delay in packets transfer in an Ethernet environment. Understanding the delay in packet transfer of Generic Object Oriented Substation Event (GOOSE) and Sampled Values (SV) shall assist the user in understanding the substation automation, control and protection of substation primary plants such as current transformers (CT's), voltage transformers (VT's), circuit breakers etc. connected in the network during a fault condition Conventional substation uses Merging Units (MU's) to communicate with the IED's featuring IEC 61850-9-2 standard. This standard exhibits transparency and standardization of data communication while addressing issues related to reliability, packet sharing, and maintainability, etc. However, process bus architecture is yet to be widely accepted in the industry and needs further validation due to lack of confidence. This paper evaluates the performance of a digital protection scheme in a zone substation operating at 132kV, featuring IEC 61850-9-2 IED's and using an optimized network engineering tool (OPNET) simulator. Understanding the delay in receiving time critical GOOSE and sampled value SV messages from protection perspective is critical as loss of data could cause malfunction in the protection jeopardizing vital substation plants.
Performance monitoring of a PMU in a microgrid environment based on IEC 61850-90-5
- Authors: Kumar, Shantanu , Das, Narottam , Islam, Syed
- Date: 2016
- Type: Text , Conference proceedings , Conference paper
- Relation: 2016 Australasian Universities Power Engineering Conference, AUPEC 2016; Brisbane, Australia; 25th-28th September 2016 p. 1-5
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- Description: Reliable protection, communication and control are the key features of a digital protection scheme in a utility substation. Microgrid is an alternative solution of installing long Transmission & Distribution lines could be cost prohibitive. There are number of Intelligent Electronic Devices (IEDs) which could find applications in controlling and monitoring of power network in a Microgrid set up and one such device is Phasor Measurement Unit (PMU). It is a microprocessor based intelligent device which gathers high-resolution data, checks the power quality and records disturbances. However, few issues that remains to be addressed such as, interoperability in a multi-vendor equipment and coordination between individual control systems in an integrated scheme. In this paper, an Operational Network Technology (OPNET) software model of a PMU has been designed and tested for its performance in a Microgrid environment based on IEC 61850-90-5 standard.
Reactive power distribution strategy using power factor correction converters for smart home application
- Authors: Islam, Syed , Maxwell, Shawn , Hossain, Kamal , Park, Sung-Yeul , Park, Sungmin
- Date: 2016
- Type: Text , Conference proceedings , Conference paper
- Relation: 2016 IEEE Energy Conversion Congress and Exposition, ECCE 2016; Milwaukee, United States; 18th-22nd September 2016 p. 1-6
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- Description: Multiple unit of PFC converters can be utilized for better power quality in the residential applications. It is important to set proper amount of reactive power contribution from each unit of PFC converter to reduce power loss and increase stability. To set the referenced amount of reactive power contribution for each PFC converter, a dynamic supervisory controller is necessary. In this paper, a wireless based supervisory controller is introduced to mitigate the problem. Multiple unit of unidirectional bridgeless ac-dc boost PFC converters were used as reactive power resources in a smart home application. The supervisory controller is comprised of a discrete Proportional-Integral controller and distributor which sets the reactive power references for each PFC converter. The controller was designed based on the systems identification method. The controller was designed and simulated considering different communication delays. In the ideal condition, the system had no communication delay. However, actual practical system had some reasonable delay. The effect of the use of supervisory controller was observed for dynamic load changing conditions. The simulation was done by using SIMULINK. Reactive power consumption from grid becomes 0VAR within 0.25 second for ideal condition. However, for the actual condition this become 9.35 seconds.
Software implementation of two seamless redundant topologies in a digital protection system based on IEC 62439-3
- Authors: Kumar, Shantanu , Das, Narottam , Islam, Syed
- Date: 2016
- Type: Text , Conference proceedings , Conference paper
- Relation: 2016 Australasian Universities Power Engineering Conference, AUPEC 2016; Brisbane, Australia; 25th-28th September 2016 p. 1-5
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- Description: Substations are the junctions of any transmission and distribution network in utilities. They carry bulk power to the customers using transmission network involving high voltage (HV) apparatus. Protection of HV equipment during a fault is the primary concern of an operator. Advancement in design and manufacturing of Intelligent Electronic Devices (IEDs) and IEC 61850 are finding increased application in utilities from automation and communication perspective, which addresses few shortcomings that couldn't be resolved in a conventional system. However there are few challenges in the digital scheme such as end to end delays in the packet transfer and interoperability of devices. Utilities are able to perceive these benefits by leveraging on IEC 62439-3 which has two important topologies i.e. Parallel Redundancy Protocol (PRP) and High-availability Seamless Redundancy (HSR). It offers seamless redundancy in digital protection network without compromising the availability and downtime cost. In this paper, an Optimized Network Engineering Tool (OPNET) is used to simulate and compare the performance of these topologies with respect to delay time.
- Description: Proceedings of the 2016 Australasian Universities Power Engineering Conference, AUPEC 2016
Stochastic modeling of the output power of photovoltaic generators in various weather conditions
- Authors: Batool, Munira , Islam, Syed , Shahnia, Farhad
- Date: 2016
- Type: Text , Conference proceedings , Conference paper
- Relation: 2016 Australasian Universities Power Engineering Conference, AUPEC 2016; Brisbane, Australia; 25th-28th September 2016 p. 1-5
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- Description: The intermittency of solar-powered energy sources prompt the uncertainty of load management. The influence of shading (whatever the reason may be) directly diminishes the feasible output power of the photovoltaic (PV) generators. The major causes of shading are the weather condition changes like the clouds, storms, and rains. Thereby, the dispatchable power for a distinct weather condition at an explicit time frame needs to be quantified. The stochastic modeling of a practical PV system has been performed in this paper. A step-by-step MATLAB-based algorithm is developed for tracking of dispatchable power limit using the Monte Carlo Principle. The proposed algorithm describes the weather condition as a function of cloud presence. The prescribed characteristics consist of the solar irradiance and the ambient temperature. The impact of weather changes on the output power of a PV system is evaluated by this algorithm. The results of this research are concluded by realistic data analysis taken from the Australian bureau of meteorology.
Understanding online frequency response signatures for transformer winding deformation: Axial displacement simulation
- Authors: Zhao, Zhongyong , Islam, Syed , Hashemnia, Naser , Hu, Di , Yao, Chenguo
- Date: 2016
- Type: Text , Conference proceedings , Conference paper
- Relation: 2016 International Conference on Condition Monitoring and Diagnosis, CMD 2016; Xi'an, China; 25th-28th September 2016 p. 404-407
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- Description: The power transformer is considered as the most critical and expensive device in substation, however, the irreversible transformer winding mechanical deformation can eventually develop into catastrophic failure if no further steps are taken in a proper way, which would cause the outage of transformer and the significant economic losses. Online frequency response analysis (FRA) has been proven to be a promising tool for condition monitoring and diagnosing of winding deformation. Online FRA relies on graphic comparison of signatures, but up to now, there is no standard and practical interpretation code for signatures classification and quantification. This paper particularly studies the characteristic of online FRA signatures under the winding axial displacement mode, in which the 3D finite element electromagnetic analysis and online transformer equivalent high frequency electrical model are established as auxiliary tools to precisely emulate winding axial displacement. Results of this simulation will provide guidance on understanding online frequency response signatures.
Voltage profile modification in harmonically affected power networks
- Authors: Yengejeh, Hadi , Islam, Syed , Galvani, Sadjad
- Date: 2016
- Type: Text , Conference proceedings , Conference paper
- Relation: 17th International Conference on Harmonics and Quality of Power, ICHQP 2016; Minas Gerais, Brazil; 16th-19th October 2016 Vol. 2016, p. 652-656
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- Description: Considering importance of power quality in power systems especially in distribution systems and daily increasing application of electronic devices which are more sensitivity to quality of supplied power, improvement of quality of power is a must. Hence, in this paper voltage profile in distribution systems has been paid attention and improvement of voltage profile by various type of capacitor placement has been investigated. The effects of applying these methods on networks voltage profile have been scrutinized. These methods have been compared to each other and the best method has been selected for this affair. To achieve precise result, harmonic load flow is performed on case study that is IEEE 37 node test feeder.
A new technique to measure interfacial tension of transformer oil using UV-Vis spectroscopy
- Authors: Abu Bakar, Norazhar , Abu-Siada, Ahmed , Islam, Syed , El-Naggar, Mohammed
- Date: 2015
- Type: Text , Journal article
- Relation: IEEE Transactions on Dielectrics and Electrical Insulation Vol. 22, no. 2 (2015), p. 1275-1282
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- Description: Interfacial tension (IFT) and acid numbers of insulating oil are correlated with the number of years that a transformer has been in service and are used as a signal for transformer oil reclamation. Oil sampling for IFT measurement calls for extra precautions due to its high sensitivity to various oil parameters and environmental conditions. The current used technique to measure IFT of transformer oil is relatively expensive, requires an expert to conduct the test and it takes long time since the extraction of oil sample, sending it to external laboratory and getting the results back. This paper introduces a new technique to estimate the IFT of transformer oil using ultraviolet-to-visible (UV-Vis) spectroscopy. UV-Vis spectral response of transformer oil can be measured instantly with relatively cheap equipment, does not need an expert person to conduct the test and has the potential to be implemented online. Results show that there is a good correlation between oil spectral response and its IFT value. Artificial neural network (ANN) approach is proposed to model this correlation.
Analysis of end-to-end delay characteristics for various packets in IEC 61850 substation communications system
- Authors: Das, Narottam , Ma, Wu , Islam, Syed
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: 25th Australasian Universities Power Engineering Conference, AUPEC 2015, Wollongong, Australia; 27th-30th September 2015 p. 1-5
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- Description: Substation plays an important role in power system communications for safe and reliable operation of entire power networks. Substation communication networks are connected with various substation intelligent electronic devices (IEDs), which is substation systems lifeblood and the system availability is decided by its real-Time performance. International Electro-Technical Commission (IEC) has been developed the standards based on object-oriented technologies for substation automation. IEC 61850 protocol has been applied widely in substation communication applications. It presents new challenges to realtime performance simulation and testing of protective relays. In this paper, an optimized network engineering tool (OPNET) or Riverbed modeler simulation tool/ software has been used for the modeling of IED in substation level network. Based on the simulation results, different types of data stream have been discussed, such as, periodic data stream, random data stream and burst data steam. The typical studies using these models, to construct substation automation system (SAS) network on the OPNET modeler or Riverbed modeler was made to reveal the impact of each affecting parameter or factor to the real-Time performance of substation communications system, which is also incorporated in this report.
- Description: 2015 Australasian Universities Power Engineering Conference: Challenges for Future Grids, AUPEC 2015
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.
Detection of power transformer bushing faults and oil degradation using frequency response analysis
- Authors: Hashemnia, Naser , Abu-Siada, Ahmed , Islam, Syed
- Date: 2015
- Type: Text , Journal article
- Relation: IEEE Transactions on Dielectrics and Electrical Insulation Vol. 23, no. 1 (2015), p. 222-229
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- Description: Frequency response analysis (FRA) has been globally accepted as a reliable tool to detect mechanical deformation within power transformers. However, because of its reliance on graphical analysis, interpretation of FRA signature is still a challenging area that calls for skilled personnel, as so far, there is no widely accepted reliable standard code for FRA signature identification and quantification. While several papers investigating the impact of various mechanical winding deformations on the transformer FRA signature can be found in the literature, no attention was given to investigate the impact of various bushing faults and transformer oil degradation on the FRA signature. This paper introduces a detailed simulation and practical analyses to elaborate the impact of bushing faults as well as transformer oil degradation on the transformer FRA signature. In this regard, the physical geometrical dimension of a three phase power transformer is simulated using 3D finite element analysis to emulate the real transformer operation. Various bushing faults have been emulated on the studied model and oil degradation is implemented through changing oil permittivity. Practical FRA test is conducted on a three phase 132kV, 35MVA power transformer to validate the simulation results. Results show that bushing faults and oil degradation can be visibly detected through FRA signature.
Disconnection time and sequence of rooftop PVs under short-circuit faults in low voltage networks
- Authors: Yengejeh, Hadi , Shahnia, Farhad , Islam, Syed
- Date: 2015
- Type: Text , Conference proceedings , Conference paper
- Relation: North American Power Symposium, NAPS 2015; Charlotte, United States; 4th-6th October 2015 p. 1-6
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- Description: This paper presents an analysis on the disconnection time of single-phase rooftop PVs, located in a three-phase four-wire low voltage distribution feeder after a line-to-ground short-circuit fault on the low voltage feeder. The paper aims to evaluate and discuss the disconnection time and sequence of PVs in a network with 100% PV penetration level. The impact of different parameters such as the location of the fault, impedance of the fault and the ratio of PVs generation capacity to the load demand are considered. Furthermore, the effect of the system earthing in the form of multiple earthed neutral and non-effectively grounded systems are evaluated on the PVs disconnection time. The analyses intend to figure out the conditions under which the PVs in the feeder may fail to disconnect after a line-to-ground fault and keep feeding the fault. The analyses are carried out in PSCAD/EMTDC software.