2020 IEEE Power & Energy Society General Meeting (PESGM)
This manuscript provides an analytical sensitivity framework to assess the impacts of individual ... more This manuscript provides an analytical sensitivity framework to assess the impacts of individual weather parameters on conductor temperature and to determine the weather parameters that have greater potential to impact power networks and hence power system studies, which can be applied to any region around the globe. Application to weather parameter ranges possible across all of New Zealand (NZ) shows that the conductor temperature and hence the power network is most sensitive to the wind speed followed by the wind angle, and the solar irradiance, when paired with the ambient temperature. The sensitivity analysis framework is expected to aid utilities in assessing the region-specific impact of weather parameters on their network and hence improving their planning, operation, and analysis.
We present an improved electrical microgrid design paradigm that exclusively incorporates all fiv... more We present an improved electrical microgrid design paradigm that exclusively incorporates all five sustainable indices (socio-technical-economical-environmental-political) in a single comprehensive framework.
TENCON 2021 - 2021 IEEE Region 10 Conference (TENCON), 2021
Matauranga MÄori is the knowledge of MÄori in New Zealand. It can influence engineering by provid... more Matauranga MÄori is the knowledge of MÄori in New Zealand. It can influence engineering by providing an alternative viewpoint and value system for consideration during initial planning and design such that projects are in line with the local sustainability goals. The goal of this research is to investigate and current and past works on MÄtauranga MÄori and how it can influence / interface with power engineering project design towards a carbon neutral and sustainable future. Currently there is no clear guidelines and interface, making conflict resolution between power companies and iwi challenging if a situation arises. If MÄori ideas of spirituality and environmentalism can be quantified, communication between engineers / academics and iwi can be refined thereby making the design process more environmentally sustainable.
2018 International Conference and Utility Exhibition on Green Energy for Sustainable Development (ICUE), 2018
A safe and reliable grounding system plays a critical role in the design of an effective lightnin... more A safe and reliable grounding system plays a critical role in the design of an effective lightning protection system of a wind turbine generator. An accurate design of grounding electrodes is required to achieve the necessary low impedance of a wind turbine generator earthing system. IEC 61400-24 provides guidelines for selecting the minimum length of an earth electrode, however, this standard cannot be utilized for all types of electrode shapes and buried depths. Moreover, it is important to address the frequency dependency of soil resistivity for the selection of electrode length. This paper proposes a novel method enhancing the IEC 61400-24 standard method. Also, a thorough analysis of existing method with suitable recommendations for the selection of electrode length for various dimension and buried depth to address the frequency dependency issue has been provided. Finally, guidelines for the selection of electrode length for the wind turbine grounding design from the lightning protection view point are proposed.
2018 International Conference and Utility Exhibition on Green Energy for Sustainable Development (ICUE), 2018
A reliable and robust earthing system design is critical for the lightning protection system of a... more A reliable and robust earthing system design is critical for the lightning protection system of a wind turbine. This paper presents an analysis of the wind turbine earthing impedance and potential rise for a horizontal multi-layer soil model in the event of a direct lightning strike on the wind turbine generator. The influence of soil resistivity and lightning current wave shapes on the wind turbine grounding impedance are analysed. The results show that the wind turbine earthing system is more vulnerable to high frequency components of the lightning strikes. The other findings highlight the impact of soil resistivity values and frequencies over the impedance and potential distribution of the wind turbine generator earthing system.
The IEEE Std 1283TM-2013 details the adverse effects of high conductor temperatures, which emphas... more The IEEE Std 1283TM-2013 details the adverse effects of high conductor temperatures, which emphasises the need to model and analyse dynamic conductor temperatures in a power network. Conductor temperatures are dependent on the power flows (due to load current), the resistive losses, and the weather conditions surrounding the conductor. Conventional power system analysis does not take into account changing weather and its impacts and as a result, studies conducted are erroneous due to absence of such realistic assumptions of the weather impacts. In this manuscript, a dynamic conductor temperature model is presented and utilised to study and thermally profile the conductor temperatures in a distribution network. The proposed approach is decoupled i.e. the power flow and the conductor heat balance model are solved separately to obtain the thermal profile network conductors in operation. In comparison to the existing approach suggested in the literature, the proposed approach is computational light and can be easily scaled to larger networks. Simulations were carried out for two cases with different load and weather conditions. The changing weather conditions and their impact on the network and thermal profile was understood by utilising the proposed technique. The simulation results presented show the advantages of using dynamic conductor temperature modelling in power system studies for better analysis of power networks.
2016 IEEE Innovative Smart Grid Technologies - Asia (ISGT-Asia), 2016
One of the value attributes of photovoltaic distributed generation (PV-DG) is the offset of feede... more One of the value attributes of photovoltaic distributed generation (PV-DG) is the offset of feeder currents which in turn reduces the overall feeder loading. In addition, for remote nodes at the end of the distribution network with high voltage unbalance tendency, PV-DG can be used to reduce this unbalance factor and its associated adverse impacts. This paper discusses the impact of distributed PVs on the equipment loading and voltage unbalance factor of the distribution network. Impact analysis has been carried out on the IEEE-13 distribution bus at different penetration levels using the Open-source Distribution System Simulator (OpenDSS). The results showed that for such highly loaded distribution network, PV-DG can be used to offset feeder current, active power demand, equipment loading and voltage unbalance. In addition, we use typical localized average temperature, solar irradiance and load demand profiles in this interconnection study.
2020 IEEE Power & Energy Society General Meeting (PESGM)
This manuscript provides an analytical sensitivity framework to assess the impacts of individual ... more This manuscript provides an analytical sensitivity framework to assess the impacts of individual weather parameters on conductor temperature and to determine the weather parameters that have greater potential to impact power networks and hence power system studies, which can be applied to any region around the globe. Application to weather parameter ranges possible across all of New Zealand (NZ) shows that the conductor temperature and hence the power network is most sensitive to the wind speed followed by the wind angle, and the solar irradiance, when paired with the ambient temperature. The sensitivity analysis framework is expected to aid utilities in assessing the region-specific impact of weather parameters on their network and hence improving their planning, operation, and analysis.
We present an improved electrical microgrid design paradigm that exclusively incorporates all fiv... more We present an improved electrical microgrid design paradigm that exclusively incorporates all five sustainable indices (socio-technical-economical-environmental-political) in a single comprehensive framework.
TENCON 2021 - 2021 IEEE Region 10 Conference (TENCON), 2021
Matauranga MÄori is the knowledge of MÄori in New Zealand. It can influence engineering by provid... more Matauranga MÄori is the knowledge of MÄori in New Zealand. It can influence engineering by providing an alternative viewpoint and value system for consideration during initial planning and design such that projects are in line with the local sustainability goals. The goal of this research is to investigate and current and past works on MÄtauranga MÄori and how it can influence / interface with power engineering project design towards a carbon neutral and sustainable future. Currently there is no clear guidelines and interface, making conflict resolution between power companies and iwi challenging if a situation arises. If MÄori ideas of spirituality and environmentalism can be quantified, communication between engineers / academics and iwi can be refined thereby making the design process more environmentally sustainable.
2018 International Conference and Utility Exhibition on Green Energy for Sustainable Development (ICUE), 2018
A safe and reliable grounding system plays a critical role in the design of an effective lightnin... more A safe and reliable grounding system plays a critical role in the design of an effective lightning protection system of a wind turbine generator. An accurate design of grounding electrodes is required to achieve the necessary low impedance of a wind turbine generator earthing system. IEC 61400-24 provides guidelines for selecting the minimum length of an earth electrode, however, this standard cannot be utilized for all types of electrode shapes and buried depths. Moreover, it is important to address the frequency dependency of soil resistivity for the selection of electrode length. This paper proposes a novel method enhancing the IEC 61400-24 standard method. Also, a thorough analysis of existing method with suitable recommendations for the selection of electrode length for various dimension and buried depth to address the frequency dependency issue has been provided. Finally, guidelines for the selection of electrode length for the wind turbine grounding design from the lightning protection view point are proposed.
2018 International Conference and Utility Exhibition on Green Energy for Sustainable Development (ICUE), 2018
A reliable and robust earthing system design is critical for the lightning protection system of a... more A reliable and robust earthing system design is critical for the lightning protection system of a wind turbine. This paper presents an analysis of the wind turbine earthing impedance and potential rise for a horizontal multi-layer soil model in the event of a direct lightning strike on the wind turbine generator. The influence of soil resistivity and lightning current wave shapes on the wind turbine grounding impedance are analysed. The results show that the wind turbine earthing system is more vulnerable to high frequency components of the lightning strikes. The other findings highlight the impact of soil resistivity values and frequencies over the impedance and potential distribution of the wind turbine generator earthing system.
The IEEE Std 1283TM-2013 details the adverse effects of high conductor temperatures, which emphas... more The IEEE Std 1283TM-2013 details the adverse effects of high conductor temperatures, which emphasises the need to model and analyse dynamic conductor temperatures in a power network. Conductor temperatures are dependent on the power flows (due to load current), the resistive losses, and the weather conditions surrounding the conductor. Conventional power system analysis does not take into account changing weather and its impacts and as a result, studies conducted are erroneous due to absence of such realistic assumptions of the weather impacts. In this manuscript, a dynamic conductor temperature model is presented and utilised to study and thermally profile the conductor temperatures in a distribution network. The proposed approach is decoupled i.e. the power flow and the conductor heat balance model are solved separately to obtain the thermal profile network conductors in operation. In comparison to the existing approach suggested in the literature, the proposed approach is computational light and can be easily scaled to larger networks. Simulations were carried out for two cases with different load and weather conditions. The changing weather conditions and their impact on the network and thermal profile was understood by utilising the proposed technique. The simulation results presented show the advantages of using dynamic conductor temperature modelling in power system studies for better analysis of power networks.
2016 IEEE Innovative Smart Grid Technologies - Asia (ISGT-Asia), 2016
One of the value attributes of photovoltaic distributed generation (PV-DG) is the offset of feede... more One of the value attributes of photovoltaic distributed generation (PV-DG) is the offset of feeder currents which in turn reduces the overall feeder loading. In addition, for remote nodes at the end of the distribution network with high voltage unbalance tendency, PV-DG can be used to reduce this unbalance factor and its associated adverse impacts. This paper discusses the impact of distributed PVs on the equipment loading and voltage unbalance factor of the distribution network. Impact analysis has been carried out on the IEEE-13 distribution bus at different penetration levels using the Open-source Distribution System Simulator (OpenDSS). The results showed that for such highly loaded distribution network, PV-DG can be used to offset feeder current, active power demand, equipment loading and voltage unbalance. In addition, we use typical localized average temperature, solar irradiance and load demand profiles in this interconnection study.
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Papers by Ramesh Rayudu