Browsing by Author "Priyanka, VGC"

Filter results by typing the first few letters
Now showing 1 - 4 of 4
  • Thumbnail Image
    item: Conference-Abstract
    Cloud images capturing system for solar power level prediction
    Rodrigo, WDAS; Perera, KHE; Priyadharshana, HMS; Priyanka, VGC; Ranasinghe, RARA
    Solar energy has received increasing attention as one of the potential renewable energy sources for power generation in recent past. Introduction of Net Metering and the increment in provision for renewables encouraged the usage of Solar PV systems in Sri Lanka. However, the intermittent nature of solar energy has become one of the barriers for solar energy based power to be integrated to the national power grids. Due to unpredictability solar energy based power plants are non-dispatchable and can cause network instability. With an efficient and reasonably accurate predictable model, a better system balance can be achieved. Shadowing on solar PV modules results in reduction of power produced. Cloud coverage blocking the sun can be identified as the major contributor in shadowing. Identifying and tracking the clouds can be used to finally predict the solar PV output. This paper presents a methodology to obtain cloud image data and an algorithm to process the images which can be used to predict the relationship between the cloud movements and the solar PV output.
  • Thumbnail Image
    item: Conference-Full-text
    Cloud Images Capturing System for Solar Power Level Prediction
    (2015-08-03) Rodrigo, AS; Perera, KHE; Priyadharshana, HMS; Priyanka, VGC; Ranasinghe, RARA
    Solar energy has received increasing attention as one of the potential renewable energy sources for power generation in recent past. Introduction of Net Metering and the increment in provision for renewables encouraged the usage of Solar PV systems in Sri Lanka. However, the intermittent nature of solar energy has become one of the barriers for solar energy based power to be integrated to the national power grids. Due to unpredictability solar energy based power plants are non-dispatchable and can cause network instability. With an efficient and reasonably accurate predictable model, a better system balance can be achieved. Shadowing on solar PV modules results in reduction of power produced. Cloud coverage blocking the sun can be identified as the major contributor in shadowing. Identifying and tracking the clouds can be used to finally predict the solar PV output. This paper presents a methodology to obtain cloud image data and an algorithm to process the images which can be used to predict the relationship between the cloud movements and the solar PV output.
  • Thumbnail Image
    item: Conference-Full-text
    Impact of High Penetration of EV Charging on Harmonics in Distribution Networks
    (IEEE, 2018-05) Rodrigo, AS; Priyanka, VGC; Chathuranga, D
    Electric vehicles (EV) are becoming the most preferred and rapidly growing mode of transportation all around the world. Development of battery technologies and attention on residential scale renewable energy based distribution generation has accelerated the growth of the EV market. Rechargeable batteries are the most common type of energy storage in commercial EVs. A regulated DC current shall be supplied to EV charging and the charging currents are higher compared to conventional loads. Power electronic converters are essential for the AC DC conversion thus a distorted current is fed to the nonlinear load. This will give rise to power quality issues such as voltage unbalance, voltage fluctuations and harmonics in the distribution systems. It is important to study and quantify the power quality impacts to make sure the healthy operation of the distribution system. A commonly available EV charger was modelled in Matlab to study EV chargers in this research and a comprehensive harmonic analysis was carried out in a LV distribution feeder. The research studies impact to the feeder with different EV penetration levels as well as EV charging with different load levels.
  • Thumbnail Image
    item: Thesis-Full-text
    Power quality issues with high penetration of electric vehicle charging in distribution network
    Priyanka, VGC; Rodrigo, AS
    Electric vehicles (EV) are becoming the most preferred and rapidly growing mode of transportation all around the world. Development of battery technologies and attention on residential scale renewable energy based distributed generation has accelerated the growth of the EV market. Commercial EV is equipped with energy storage, where a rechargeable battery is the most common type. EV Chargers are located either on board or off board. These chargers are present in different power levels. A regulated DC current shall be supplied to EV charging and the charging current is higher compared to conventional loads. Power electronic converters are used for the AC DC conversion thus a distorted current is drawn by the nonlinear load. This will give rise to power quality issues such as voltage unbalance, voltage fluctuations and harmonics on distribution systems. This research studies and quantifies the power quality impacts of the EV chargers on the distribution system. A detailed power electronic model of a commonly available EV charger is modelled in Matlab and a comprehensive current harmonic analysis is carried out in a standard IEEE LV distribution test feeder. The research focuses on the impact to the feeder with different EV penetration levels as well as different spatial load distribution. From the analysis it was determined for random EV distribution up to 40% of EV penetration is acceptable to the existing feeder at off peak intervals while only 30% is acceptable under nominal load condition as per IEEE 519 limits. If the EV chargers are clustered together, the current harmonic impact is higher and only 20% of EV penetration will be acceptable prescribed limits. The outcome of the research can be successfully used by distribution grid operators to determine to acceptable limits of EV penetration in the existing system. An algorithm encompassing the results of the study shall be employed in coordinated charging of electric vehicles where the operators shall dispatch the EVs based on the feeder loading and spatial distribution of EVs. Encompassed