As solar energy costs continue to drop, the number of large-scale deployment projects increases, ... more As solar energy costs continue to drop, the number of large-scale deployment projects increases, and the need for different analysis models for photovoltaic (PV) modules in both academia and industry rises. This paper proposes a modified equivalent-circuit model for PV modules. A PV module comprises several series-connected PV cells, to generate more electrical power, where each PV cell has an internal shunt resistance. Our proposed model simplifies the standard one-diode equivalent-circuit (SEC) model by removing the shunt resistance and including its effect on the diode part of the circuit, while retaining the original model accuracy. Our proposed equivalent circuit, called here a modified SEC (MSEC), has less number of circuit elements. All of the PV cells are assumed operating under the same ambient conditions where they share the same electric voltage and current values. To ensure the simplification did not come at a reduction in the accuracy of the SEC model, we validate our M...
Photovoltaic (PV) modules comprise bypass diodes to limit hotspot formation. However, they suffer... more Photovoltaic (PV) modules comprise bypass diodes to limit hotspot formation. However, they suffer from performance reduction in the presence of partial shading. This paper proposes external circuitry to control the connection type (series/parallel) of the PV cells through a pair of on/off switches resulting in three different operation modes. Mode 1 represents the typical 36 series-connected cells, while mode 2 represents two parallel-connected strings, and mode 3 maximizes the output current where the four strings are connected in parallel. The added values of the approach are that (1) the output current of the PV module can be increased without the need for a buck-boost converter and (2) the partial shading has less impact on the output power than the adoption of bypass diodes. This work shows that simulating three monocrystalline PV modules (120 W, 200 W, and 241 W), consisting of 36, 60, and 72 series-connected cells, lose about 74% when one cell has 80% shading in the absence o...
This paper proposes a system model for optimal dispatch of the energy and reserve capacity consid... more This paper proposes a system model for optimal dispatch of the energy and reserve capacity considering uncertain load demand and unsteady power generation. This implicates uncertainty in managing the power demand along with the consideration of utility, user and environmental objectives. The model takes into consideration a day-ahead electricity market that involves the varying power demand bids and generates a required amount of energy in addition with reserve capacity. The lost opportunity cost is also considered and incorporated within the context of expected load not served. Then, the effects of combined and separate dispatching the energy and reserve are investigated. The nonlinear cost curves have been addressed by optimizing the objective function using robust optimization technique. Finally, various cases in accordance with underlying parameters have been considered in order to conduct and evaluate numerical results. Simulation results show the effectiveness of proposed sche...
2013 48th International Universities' Power Engineering Conference (UPEC), 2013
ABSTRACT This paper recommends improving the traditional grounding practice by focusing on the de... more ABSTRACT This paper recommends improving the traditional grounding practice by focusing on the design and implementation of a portable grounding system used for different electrical equipment and portable machines. It involves experimental work to find earth resistance of portable and compact grounding system. The experimental results obtained have been used to develop a desired grounding system. The main contribution is based on a practical designing of portable grounding system to make it transportable, reusable, cost efficient, compact, semi prepared and easy to install. A number of grounding blocks have been prepared and attached together to obtain the desired value of earth resistance. Experiments have been performed for different combination of blocks having different sizes and results have been obtained. Variations in resistance with volume of water for this portable grounding system is also calculated from a series of experiments conducted in three days.
Gesture Vocalizer is a large scale multi-microcontroller based system being designed to facilitat... more Gesture Vocalizer is a large scale multi-microcontroller based system being designed to facilitate the communication among the dumb, deaf and blind communities and their communication with the normal people. This system can be dynamically reconfigured to work as a "smart ...
Personal computers draw non-sinusoidal current with odd harmonics more significantly. Power Quali... more Personal computers draw non-sinusoidal current with odd harmonics more significantly. Power Quality of distribution networks is severely affected due to the flow of these generated harmonics during the operation of electronic loads. In this paper, mathematical modeling of odd harmonics in current like 3rd, 5th, 7th and 9th influencing the power quality has been presented. Live signals have been captured with the help of power quality analyzer for analysis purpose. The interesting feature is that Total Harmonic Distortion (THD) in current decreases with the increase of nonlinear loads has been verified theoretically. The results obtained using mathematical expressions have been compared with the practical results and exciting results have been found.
ABSTRACT This paper focuses on the use of flexible loads for providing emergency reserve to manag... more ABSTRACT This paper focuses on the use of flexible loads for providing emergency reserve to manage wind variability in an island power system. It involves experimental work to assess the thermal storage capability of domestic heating arrangements by the use of electrically operated heat pumps coupled to underfloor heating, under different operating conditions. The Irish power system has been scheduled with varying amount of reserve from loads. Final results suggest that DSM, in the form of heat pumps, can enable the demand shape to be modified, the ramping duty of conventional generation to be reduced and the reserve burden to be improved.
As solar energy costs continue to drop, the number of large-scale deployment projects increases, ... more As solar energy costs continue to drop, the number of large-scale deployment projects increases, and the need for different analysis models for photovoltaic (PV) modules in both academia and industry rises. This paper proposes a modified equivalent-circuit model for PV modules. A PV module comprises several series-connected PV cells, to generate more electrical power, where each PV cell has an internal shunt resistance. Our proposed model simplifies the standard one-diode equivalent-circuit (SEC) model by removing the shunt resistance and including its effect on the diode part of the circuit, while retaining the original model accuracy. Our proposed equivalent circuit, called here a modified SEC (MSEC), has less number of circuit elements. All of the PV cells are assumed operating under the same ambient conditions where they share the same electric voltage and current values. To ensure the simplification did not come at a reduction in the accuracy of the SEC model, we validate our M...
Photovoltaic (PV) modules comprise bypass diodes to limit hotspot formation. However, they suffer... more Photovoltaic (PV) modules comprise bypass diodes to limit hotspot formation. However, they suffer from performance reduction in the presence of partial shading. This paper proposes external circuitry to control the connection type (series/parallel) of the PV cells through a pair of on/off switches resulting in three different operation modes. Mode 1 represents the typical 36 series-connected cells, while mode 2 represents two parallel-connected strings, and mode 3 maximizes the output current where the four strings are connected in parallel. The added values of the approach are that (1) the output current of the PV module can be increased without the need for a buck-boost converter and (2) the partial shading has less impact on the output power than the adoption of bypass diodes. This work shows that simulating three monocrystalline PV modules (120 W, 200 W, and 241 W), consisting of 36, 60, and 72 series-connected cells, lose about 74% when one cell has 80% shading in the absence o...
This paper proposes a system model for optimal dispatch of the energy and reserve capacity consid... more This paper proposes a system model for optimal dispatch of the energy and reserve capacity considering uncertain load demand and unsteady power generation. This implicates uncertainty in managing the power demand along with the consideration of utility, user and environmental objectives. The model takes into consideration a day-ahead electricity market that involves the varying power demand bids and generates a required amount of energy in addition with reserve capacity. The lost opportunity cost is also considered and incorporated within the context of expected load not served. Then, the effects of combined and separate dispatching the energy and reserve are investigated. The nonlinear cost curves have been addressed by optimizing the objective function using robust optimization technique. Finally, various cases in accordance with underlying parameters have been considered in order to conduct and evaluate numerical results. Simulation results show the effectiveness of proposed sche...
2013 48th International Universities' Power Engineering Conference (UPEC), 2013
ABSTRACT This paper recommends improving the traditional grounding practice by focusing on the de... more ABSTRACT This paper recommends improving the traditional grounding practice by focusing on the design and implementation of a portable grounding system used for different electrical equipment and portable machines. It involves experimental work to find earth resistance of portable and compact grounding system. The experimental results obtained have been used to develop a desired grounding system. The main contribution is based on a practical designing of portable grounding system to make it transportable, reusable, cost efficient, compact, semi prepared and easy to install. A number of grounding blocks have been prepared and attached together to obtain the desired value of earth resistance. Experiments have been performed for different combination of blocks having different sizes and results have been obtained. Variations in resistance with volume of water for this portable grounding system is also calculated from a series of experiments conducted in three days.
Gesture Vocalizer is a large scale multi-microcontroller based system being designed to facilitat... more Gesture Vocalizer is a large scale multi-microcontroller based system being designed to facilitate the communication among the dumb, deaf and blind communities and their communication with the normal people. This system can be dynamically reconfigured to work as a "smart ...
Personal computers draw non-sinusoidal current with odd harmonics more significantly. Power Quali... more Personal computers draw non-sinusoidal current with odd harmonics more significantly. Power Quality of distribution networks is severely affected due to the flow of these generated harmonics during the operation of electronic loads. In this paper, mathematical modeling of odd harmonics in current like 3rd, 5th, 7th and 9th influencing the power quality has been presented. Live signals have been captured with the help of power quality analyzer for analysis purpose. The interesting feature is that Total Harmonic Distortion (THD) in current decreases with the increase of nonlinear loads has been verified theoretically. The results obtained using mathematical expressions have been compared with the practical results and exciting results have been found.
ABSTRACT This paper focuses on the use of flexible loads for providing emergency reserve to manag... more ABSTRACT This paper focuses on the use of flexible loads for providing emergency reserve to manage wind variability in an island power system. It involves experimental work to assess the thermal storage capability of domestic heating arrangements by the use of electrically operated heat pumps coupled to underfloor heating, under different operating conditions. The Irish power system has been scheduled with varying amount of reserve from loads. Final results suggest that DSM, in the form of heat pumps, can enable the demand shape to be modified, the ramping duty of conventional generation to be reduced and the reserve burden to be improved.
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