Nano-structured photovoltaic cell design for high conversion efficiency by optimizing various parameters
- Authors: Shelat, Niraj , Das, Narottam , Khan, Masud , Islam, Syed
- Date: 2019
- Type: Text , Conference proceedings , Conference paper
- Relation: 2019 29th Australasian Universities Power Engineering Conference; Momi Bay, Fiji; 26th-29th November 2019
- Full Text: false
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- Description: This paper investigates the effect of different types of nano-grating structures embossed on top of the substrate of solar photovoltaic (PV) cell for high conversion efficiency. The simulation results for light reflection are obtained by using Opti-wave finite difference time-domain (Opti-FDTD) software. These nano-grating structures have different shapes, such as triangular, trapezoidal, pillar and parabolic. These nano-grating profiles work as a multilayer anti-reflective coating for GaAs solar cells and reduce the light reflection from the surface of the panel and increase the light trapping capacity inside the solar cell. These structures allow the gradual change in refractive index and provide a high transmission and less reflection of light that confirms excellent anti-reflective coating and increased light trapping capacity inside the cell substrate. For this simulation, different periodic shaped arrangements were made to obtain the higher conversion efficiency, the factors considered while develop the design are the aspect ratio (AR), thickness of the nano-grating structure and duty cycles. The simulation result shows that the light reflection loss in pillar shaped nano-grating structures having 150 nm of height and a 50% period (i.e., duty cycle) is ~0.5% only, which is the lowest reflection loss obtained, when compared with the triangular and trapezoidal shaped nano-grating structures, it is approximately 38% more efficient in trapping the incident light.
- Description: This research is supported by the School of Engineering and Technology, Melbourne, Victoria; Centre for Intelligent Systems, Brisbane, QLD, Central Queensland University, Australia.
Verification of latency and delays related to a digital topology based on IEC 61850
- Authors: Kumar, Shantanu , Das, Narottam , Islam, Syed , Abu-Siada, Ahmed
- Date: 2019
- Type: Text , Conference proceedings , Conference paper
- Relation: 2019 29th Australasian Universities Power Engineering Conference (AUPEC2019); Momi Bay, Fiji; 26th-29th November 2019
- Full Text: false
- Reviewed:
- Description: Digital Communication systems have matured to a point of acceptance in the last decade enormously based on IEC 61850 guidelines from Substation Automation System (SAS) perspective. However, these networks have issues related to latency, data clogging delays, errors etc. in the digital protection system. Measuring propagation delays and assessing the performance of IED's and other peripherals in an Ethernet topology play a critical role in relay coordination setting. This paper discusses issues associated with a digital network and addresses the problems that could mitigate spurious tripping or compromise the protection of the assets in the feeders leading to a reliable operation of the protection system. The discussion in this paper is carried out based on a case study related to a digital star topology using Optimized Network Engineering Tool (OPNET) software of a 132/22-kV zone substation. We report the practical case of measuring delay time during frame exchanges of Generic Object Oriented Substation Event (GOOSE) and Sampled Value (SV) messages amongst the IED' and peripherals.
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.
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
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
High performance communication redundancy in a digital substation based on IEC 62439-3 with a station bus configuration
- Authors: Kumar, Shantanu , Das, Narottam , 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: High speed communication is critical in a digital substation from protection, control and automation perspectives. Although International Electro-Technical Commission (IEC) 61850 standard has proven to be a reliable guide for the substation automation and communication systems, yet it has few shortcomings in offering redundancies in the protection architecture, which has been addressed better in IEC 62439-3 standard encompassing Parallel Redundancy Protocol (PRP) and High-Availability Seamless Redundancy (HSR). Due to single port failure, data losses and interoperability issues related to multi-vendor equipment, IEC working committee had to look beyond IEC 61850 standard. The enhanced features in a Doubly Attached Node components based on IEC 62439-3 provides redundancy in protection having two active frames circulating data packets in the ring. These frames send out copies in the ring and should one of the frame is lost, the other copy manages to reach the destination node via an alternate path, ensuring flawless data transfer at a significant faster speed using multi-vendor equipment and fault resilient circuits. The PRP and HSR topologies provides higher performance in a digitally protected substation and promise better future over the IEC 61850 standard due to its faster processing capabilities, increased availability and minimum delay in data packet transfer and wireless communication in the network. This paper exhibits the performance of PRP and HSR topologies focusing on the redundancy achievement within the network and at the end nodes of a station bus ring architecture, based on IEC 62439-3.
Analysis of power system communication architectures between substations using IEC 61850
- Authors: Das, Narottam , Islam, Syed
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 5th Brunei International Conference on Engineering and Technology, BICET 2014; Bandar Seri Begawan, Brunei Darussalam; 1st-3rd November 2014 Vol. 2014, p. 1-6
- Full Text: false
- Reviewed:
- Description: Interoperability among multi-vendor substations automation devices, is now achievable due to the introduction of IEC 61850 standard, which allows power system communication between substations. This standard does not mandatorily demands for redundancy in any type of substation neither does it mentions a specific type of substation design application. Ethernet based communication protocols for substation automation systems (SASs) are specified in IEC 61850 standard. The standards include Ethernet based process-level connections between switchyards and control rooms. However, their in-service performance is not well known. Moreover, IEC 61850 demands for a communication topology which is zero point failure proof and provides worthy data transmission rates, without pursuing any delays. In order to achieve these norms, Ethernet architectures must be modelled and analysed in detail. The performance of individual architecture must be analysed in terms of their reliability, availability and efficiency of data transfer. This paper presents the reliability and availability using the reliability block diagrams, along with OPNET network real-time simulations, which shows the efficiency of individual architecture along with comparing and synthesizing the most effective communication topology for the SASs.
Investigation on architectures for power system communications between substations using IEC 61850
- Authors: Das, Narottam , Modi, Hitesh , Islam, Syed
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 24th Australasian Universities Power Engineering Conference, AUPEC 2014; Perth, Australia; 28th September-1st October 2014 p. 1-6
- Full Text: false
- Reviewed:
- Description: This paper investigates the communication network architectures for power systems between substations using IEC 61850. Optimized Network Engineering Tools (OPNET) is used for the simulations. The simulation results show the performance of individual architectures power system communications (PSC) for substation automation systems (SASs). Nowadays, interoperability among multi-vendor substations automation devices is achievable using IEC 61850 standard which allows the PSC between substations. Ethernet based communication protocols for the SASs are specified in IEC 61850 standard. These standards include Ethernet based process-level connections between switchyards and control rooms. However, their in-service performance is not well known yet. The IEC 61850 demands for a communication topology which is zero point failure proof and provides worthy data transmission rates, without pursuing any delays. In order to achieve these norms, Ethernet architectures are modeled and analyzed in detail. The performance of individual architecture also analyzed in terms of their reliability, availability and efficiency of data transfer. The hybrid, star-ring and redundant ring network architectures are the most efficient in terms of data transmission, delay times, reliability and availability between the SASs for data transmission.
Modelling and analysis of multi-junction solar cells to improve the conversion efficiency of photovoltaic systems
- Authors: Das, Narottam , Al Ghadeer, Abdulmohsen , Islam, Syed
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 24th Australasian Universities Power Engineering Conference, AUPEC 2014; Perth, Australia; 28th September-1st October 2014 p. 1-5
- Full Text: false
- Reviewed:
- Description: This paper presents modelling and analysis of multi-junction solar cells to improve the conversion efficiency of photovoltaic (PV) power generation systems. For this modelling, Matlab/Simulink tool is used to obtain the simulation results. The modelling of a single junction solar cell can be performed by single or double diode models. From the simulation results, it was found that the double diode model is more accurate than the single diode model. Hence, the double diode model is used to simulate dual and triple junction solar cells. The simulations were performed under varying the critical factors, such as temperature and solar irradiance. The effect of these factors was clearly demonstrated on the I-V and P-V characteristics of the solar cells. It was found that the temperature increases, short circuit current increases slightly and open circuit voltage drops significantly. Consequently, the PV power generation decreases considerably. However, when the irradiance increases, the short circuit current increases slightly and the open circuit voltage increases significantly. Consequently, the power generation increases considerably and the conversion efficiency increases of the PV systems.
Performance analysis of substation automation systems architecture based on IEC 61850
- Authors: Kumar, Shantanu , Das, Narottam , Islam, Syed
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 24th Australasian Universities Power Engineering Conference, AUPEC 2014; Perth, Australia; 28th September-1st October 2014 p. 1-6
- Full Text: false
- Reviewed:
- Description: Digital Communications amongst multi-vendor intelligent electronic devices (IED's) is an important feature of a substation automation system (SAS). Measuring the propagation delays and assessing the interoperability performance of IED's in an Ethernet architecture play a critical role in the protection of important substation assets. Early detection of the loss of data packets in a star connected Ethernet architecture is an important step towards identification of delay in message transfer issue. This identification of the problem could lead to reliable operation of protection system and better understanding of the issues of interoperability which may improve the protection system from safety and availability point of view. This paper focuses on a star connected architecture using Optimized Network Engineering Tool (OPNET) software for a 132/22kV zone substation. It shares a practical case for measuring delay time in exchanging Generic Object Oriented Substation Event (GOOSE) messages amongst the IED's.
Performance evaluation of data transmission in a single and double bus network within the utility substation based on IEC 61850
- Authors: Kumar, Shantanu , Das, Narottam , Muigai, John , Islam, Syed
- Date: 2014
- Type: Text , Conference proceedings , Conference paper
- Relation: 2014 IEEE Power and Energy Society General Meeting; National Harbor, United States; 27th-31st July 2014 Vol. 2014, p. 1-5
- Full Text: false
- Reviewed:
- Description: Communication between intelligent electronic devices (IED's) is an important feature of a utility substation automation system based on IEC 61850. Time critical information related to fault and overcurrent, under frequency messages for substation automation system (SAS) and the use of IED's from multiple vendors, has opened up issues related to a reliable protection system within the high voltage substation. Early detection of the delay in data transmission over a Generic Object Oriented Substation Event (GOOSE) network is an important step towards identification of problems associated with the dynamic protection system. It is observed that non critical messages adds up the queuing time and delays in the delivery of the messages which could be an issue in the reliable operation of a protection system. In this paper an Optimized Network Engineering Tool (OPNET) model is created, tested and analysed for a single and double bus configuration in detail for the delay encountered in data transfer within a typical zone substation. In order to understand the delay in transmission of packets, a 132/22kV zone substation model is analysed and results are discussed based on GOOSE communication in an IEC 61850 environment. Further, the delay in communication is compared and analysed between a single and double bus system of a 132/22kV substation to determine the best alternative technique available from protection point of view in a SAS network.
Analysis of IEC 61850 for a Reliable Communication System between Substations
- Authors: Yang, Xin , Das, Narottam , Islam, Syed
- Date: 2013
- Type: Text , Conference proceedings , Conference paper
- Relation: 2013 Australasian Universities Power Engineering Conference, AUPEC 2013; Hobart, Australia; 29th September-3rd October 2013 p. 1-6
- Full Text: false
- Reviewed:
- Description: IEC 61850 Standard was introduced to address the challenge presented by existence of the multiple protocols in substation communications, which include many proprietary protocols; and to address the challenge introduced by legacy complicated substation from both cost and complicity. In this paper, the simulation results of different types of IEC 61850 network system configurations using OPNET Modeler simulation software were presented and the influence on data rate and delay characteristics of these system configurations were evaluated. The simulated results confirm that the ring configured system suitable for higher loading characteristics and higher system reliability.
Analysis of incident light angles on nan-grating structure for minimizing reflection losses in GaAs solar cells
- Authors: Das, Narottam , Charoenpitaks, Korawat , Islam, Syed
- Date: 2013
- Type: Text , Conference proceedings , Conference paper
- Relation: 2013 Australasian Universities Power Engineering Conference, AUPEC 2013; Hobart, Australia; 29th September-3rd October 2013 p. 1-6
- Full Text: false
- Reviewed:
- Description: Subwavelength grating (SWG) structures make an excellent alternative antireflective (AR) coating due to its capacity to reduce the reflection losses in GaAs solar cells. The SWG structures allow the gradual change in refractive index that confirms an excellent AR coating and the light trapping properties when compare with planar thin film structures. Finite-difference time domain (FDTD) method is used to simulate the reflection losses of the SWG structure in GaAs solar cells. The FDTD simulation results show that the slightly change of incident angle affect the reflection losses of all nano-grating structure. The simulation results also confirmed that the reflection loss of nano-grating structure maintained optimum within ~±5° of incident angle tolerance for the grating height over 300-nm for minimizing the reflection losses in GaAs solar cells.
Impact of buckling deformation on the FRA signature of power transformer
- Authors: Amini, Arman , Das, Narottam , Islam, Syed
- Date: 2013
- Type: Text , Conference proceedings , Conference paper
- Relation: 2013 Australasian Universities Power Engineering Conference, AUPEC 2013; Hobart, Australia; 29th September-3rd October 2013 p. 1-4
- Full Text: false
- Reviewed:
- Description: Power transformer is an important asset within the electrical power system network. Frequency Response Analysis (FRA) has been developing in popularity in recent years as a tool to detect mechanical deformation of power transformers winding. Since the FRA has been relying on graphical analysis, it calls for an expert person to analyze the results to detect the type of the fault and its location. There are no reliable guidelines for FRA signature in the event that a failure occurs in service and the impact can be far reaching. The concept of FRA has been successfully used as a diagnostic technique to detect the winding deformation, core and clamping structure for the power transformers. This paper investigated the impact of the forced and free winding buckling based on the variation of the electrical parameters to show how these faults vary the FRA signature.
Impact of conducting materials on furan-spectral correlation of transformer oil
- Authors: Das, Narottam , Abu-Siada, Ahmed , Islam, Syed
- Date: 2013
- Type: Text , Conference proceedings , Conference paper
- Relation: 2013 Australasian Universities Power Engineering Conference, AUPEC 2013; Hobart, Australia; 29th September-3rd October 2013 p. 1-4
- Full Text: false
- Reviewed:
- Description: This paper investigates the impact of conducting materials on the correlation of furan concentration in transformer oil and its spectral response characteristics. The presence of furan derivatives in aged-transformer oil has been one of the key indicators for solid dielectric deterioration. Identification and quantification of furan derivatives are currently performed using high performance liquid chromatography or gas chromatography-mass spectrometry based on ASTM D5837 standard. Although these techniques are well established, they need an expert personal to conduct the test and to analyse its results. Moreover, the test is relatively expensive and the analysis of oil sample may take days as most utilities sending transformer oil samples to external laboratories to be tested. Recently, it has been proven that furan concentration in transformer oil has a strong correlation to the oil spectral response. This paper is to validate this finding and to investigate the impact of conducting materials within transformer oil on this correlation. In this context, extensive experimental tests are conducted to assess the impact of various concentration of conducting materials (e.g., copper dust) dissolved in transformer oil samples of different furan contents on its absorption and transmission spectra. The measured experimental results show that, the impact of such small amount ofdissolved conducting materials on the oil spectral response is minimal.
Photovoltaic cell modeling for maximum power point tracking using MATLAB/Simulink to improve the conversion efficiency
- Authors: Das, Narottam , Wongsodihardjo, Hendy , Islam, Syed
- Date: 2013
- Type: Text , Conference proceedings , Conference paper
- Relation: 2013 IEEE Power and Energy Society General Meeting, PES 2013; Vancouver, Canada; 21st-25th July 2013 p. 1-5
- Full Text: false
- Reviewed:
- Description: This paper focuses on the behavior of maximum power point tracking (MPPT) on photovoltaic (PV) cell systems using MATLAB/Simulink software. The PV cells can offer better simulation results when a double-exponential type, i.e., double-diode model is used. The reason, it is more accurate with the real testing condition even though the efficiency is a bit less. This confirms that theoretical single-diode model still require more improvements. In addition, multijunction solar cell also investigated to obtain its maximum performance compared with the conventional silicon PV cell. The obtained results show that the tandem (or multijunction) cell can provide almost 3-times maximum power compared to the conventional PV cell. Therefore, the multijunction/ tandem PV cells can produce higher power throughout the sunny day due to the higher MPPT capacity. Furthermore, perturb and observe method seems to be very useful because of its simplicity despite the unresolved algorithm for different methods, such as constant voltage tracking technique.
Power transformer winding fault analysis using transfer function
- Authors: Kalpana, Patel , Das, Narottam , Abu Siada, Ahmed , Islam, Syed
- Date: 2013
- Type: Text , Conference proceedings , Conference paper
- Relation: 2013 Australasian Universities Power Engineering Conference, AUPEC 2013; Hobart, Australia; 29th September-3rd October 2013 p. 1-3
- Full Text: false
- Reviewed:
- Description: Condition monitoring of power transformers is essential to maintain the reliability of electricity grid. Frequency response analysis (FRA) is a useful tool for the detection of incipient mechanical faults within power transformers. There are various methods of evaluating the frequency spectrum for fault classification and quantification. This paper presents a useful method to detect and to identify various winding faults of a power transformer based on its FRA signature. Simulation results show that location of resonance frequencies which are the key parameters in identifying various winding deformations are uniquely altered due to different faults.
Process-to-bay level peer-to-peer network delay in IEC 61850 substation communication systems
- Authors: Das, Narottam , Aung, Tin Tun , Islam, Syed
- Date: 2013
- Type: Text , Conference proceedings , Conference paper
- Relation: 2013 Australasian Universities Power Engineering Conference, AUPEC 2013; Hobart, Australia; 29th September-3rd October 2013 p. 1-6
- Full Text: false
- Reviewed:
- Description: This paper presents the application of IEC 61850 protocol in electrical power engineering industry for data communication systems between substations. This IEC 61850 protocol presents new challenges for real-time communication performance between Intelligent Electronic Devices (IEDs) within substation because of the Generic Object Oriented Substation Event (GOOSE) messages. The analyses of substation Ethernet communication delay, its impact factors, various methods and different network topologies which can improve the real-time performance are discussed. For basic analysis of data flow within a substation, the Optimized Network Engineering Tool (OPNET) software is used. The process to bay level network simulation model is performed by using the OPNET software. The Ethernet delay performance of the process to bay level network simulation results are analyzed which is based on switched, shared Ethernet network or Peer to Peer network.