Solar energy is going to be a major component of global energy generation. Loss due to dust depos... more Solar energy is going to be a major component of global energy generation. Loss due to dust deposition has raised a great concern to the investors in this field. Pre-estimation of this reduced generation and hence the economic loss will help the operators’ readiness for efficient and enhanced economic energy management of the system. In an earlier article, a physics–based model is proposed for assessment of dust accumulation under various climatic conditions which is validated by data of a single location. In this paper, the universality of this model is established and is used to demonstrate the effect of generation loss due to dust deposition and of cleaning. Variation in the soiling pattern due to climatic covariates has also been studied. Generation loss is calculated for Solar Photovoltaic power plants of different capacities at various locations in India. Finally this model has also been extended to predict the generation accounting for the soiling loss in Photovoltaic system....
Colloidal suspension of free standing silicon/silicon oxide core/shell nanoparticles has been syn... more Colloidal suspension of free standing silicon/silicon oxide core/shell nanoparticles has been synthesized using a mechanochemical top-down approach. Quasi-mono-dispersed core size distribution of synthesized nanoparticles has been confirmed using different structural, morphological, and optoelectronic characterizations. Raman, continuous wave photoluminescence and time-resolved photoluminescence studies have been performed on synthesized colloidal nanoparticles in ethanol medium. Asymmetric broadening of the Raman peak (red shifted with respect to that of bulk silicon) has been observed. Intensities and positions of photoluminescence emission peaks are prominently dependent on excitation photon energy. Moreover, the photoluminescence decay time varies from sub-nanoseconds to tens of nanoseconds. The decay time also exhibits a strong dependence on the excitation wavelength, while the emission wavelength is kept unaltered. The abovementioned observations indicate the slow relaxation o...
TENCON 2019 - 2019 IEEE Region 10 Conference (TENCON)
Microgrids effectively integrate the various distributed renewable energy sources such as solar, ... more Microgrids effectively integrate the various distributed renewable energy sources such as solar, wind, biomass and storage batteries. However, the control, scheduling, and clustering of traditional AC microgrids are affected by various factors like reactive power mismatch, synchronization to the main grid, effect of harmonics, etc. This affects the reliability and quality of power fed into the grid and the demand-supply gap and also includes multiple stages of electricity conversion, introducing losses at each stage. The DC microgrids help in mitigating some of these difficulties faced by the AC microgrids and are mainly modelled with several DC-DC converters connected in parallel to a dc link or dc bus. This work considers a stack of two similar high power DC-DC boost converters connected to a dc bus voltage of 400V working as controlled current sources instead of traditional voltage sources as in droop control schemes. The modelling and control of the high voltage (HV) DC-DC boost converter for DC microgrid have been done on LTSpice platform. The modelled converters work for a wide range of input voltage (200V-400V) catering to the wide range of output voltages of different sources connected to a microgrid. The major focus of this paper is to study and analyze the power-sharing between the current controlled HV DC-DC converters depending on the variable load demand. LTSpice being used for real-time circuit analysis, the proposed simulated model for high voltage application can be implemented in hardware in the future.
International Journal of Renewable Energy Research, 2018
This paper presents the design and development of a novel highly efficient synchronous buck conve... more This paper presents the design and development of a novel highly efficient synchronous buck converter operating both as a battery charge controller with five stage charging method and also as improved Maximum Power Point Tracker (MPPT) for operation in Solar Photovoltaic (PV) Systems. The algorithm regulates the duty cycle of the switching devices of the converter following a variable step size perturb and observe (P&O) MPPT technique. At the same time it provides precise control on the battery charging voltage and current according to five charging stages which is desirable for protection of battery health and maximizing charging rate. Thus the algorithm developed provides a combined solution for maximizing the transfer of solar electricity generated by the PV module(s) and also ensuring a long battery lifetime. Both these aspects, which are generally investigated separately earlier, are treated in an integrated fashion in this work. The work analyses in detail about the converte...
This paper demonstrates a smart energy management scheme for solar photovoltaic-biomass integrate... more This paper demonstrates a smart energy management scheme for solar photovoltaic-biomass integrated grid-interactive microgrid cluster system. Three interconnected microgrids were chosen as a cluster of microgrids for validation of the proposed community energy management scheme. In this work, a Global System for Mobile (GSM)-based bidirectional communication technique was adopted for real-time coordination among the renewable energy sources and loads. To realize the common phenomenon of local grid outage in rural distribution networks, a practical case study is designed in this work. The optimized scheduling of the energy sources and loadsof different microgrids and the distribution grid were implemented to ensure zero loss of power supply probability (LPSP) for dynamic load profiles. The laboratory-scale prototype of the proposed microgrid clustering was first developed in this work by establishing real-time communication among multiple energy sources and loads through different en...
International Journal on Smart Sensing and Intelligent Systems, 2014
A digital moisture measuring instrument based on phase angle measuring technique with porous sili... more A digital moisture measuring instrument based on phase angle measuring technique with porous silicon (PSi) or porous alumina (PA) as capacitive moisture sensor is proposed. The proposed technique can measure digitally the phase angle change of capacitive impedance of porous silicon or porous alumina sensor due to change in moisture concentration in terms of clock pulses. Analysis shows that the proposed circuit leads to higher precision by minimizing the errors caused by parasitic earth capacitance as well as offset voltage in the circuit. Simulation and experimental results are reported to confirm the effectiveness of the technique.
Solar energy is going to be a major component of global energy generation. Loss due to dust depos... more Solar energy is going to be a major component of global energy generation. Loss due to dust deposition has raised a great concern to the investors in this field. Pre-estimation of this reduced generation and hence the economic loss will help the operators’ readiness for efficient and enhanced economic energy management of the system. In an earlier article, a physics–based model is proposed for assessment of dust accumulation under various climatic conditions which is validated by data of a single location. In this paper, the universality of this model is established and is used to demonstrate the effect of generation loss due to dust deposition and of cleaning. Variation in the soiling pattern due to climatic covariates has also been studied. Generation loss is calculated for Solar Photovoltaic power plants of different capacities at various locations in India. Finally this model has also been extended to predict the generation accounting for the soiling loss in Photovoltaic system....
Colloidal suspension of free standing silicon/silicon oxide core/shell nanoparticles has been syn... more Colloidal suspension of free standing silicon/silicon oxide core/shell nanoparticles has been synthesized using a mechanochemical top-down approach. Quasi-mono-dispersed core size distribution of synthesized nanoparticles has been confirmed using different structural, morphological, and optoelectronic characterizations. Raman, continuous wave photoluminescence and time-resolved photoluminescence studies have been performed on synthesized colloidal nanoparticles in ethanol medium. Asymmetric broadening of the Raman peak (red shifted with respect to that of bulk silicon) has been observed. Intensities and positions of photoluminescence emission peaks are prominently dependent on excitation photon energy. Moreover, the photoluminescence decay time varies from sub-nanoseconds to tens of nanoseconds. The decay time also exhibits a strong dependence on the excitation wavelength, while the emission wavelength is kept unaltered. The abovementioned observations indicate the slow relaxation o...
TENCON 2019 - 2019 IEEE Region 10 Conference (TENCON)
Microgrids effectively integrate the various distributed renewable energy sources such as solar, ... more Microgrids effectively integrate the various distributed renewable energy sources such as solar, wind, biomass and storage batteries. However, the control, scheduling, and clustering of traditional AC microgrids are affected by various factors like reactive power mismatch, synchronization to the main grid, effect of harmonics, etc. This affects the reliability and quality of power fed into the grid and the demand-supply gap and also includes multiple stages of electricity conversion, introducing losses at each stage. The DC microgrids help in mitigating some of these difficulties faced by the AC microgrids and are mainly modelled with several DC-DC converters connected in parallel to a dc link or dc bus. This work considers a stack of two similar high power DC-DC boost converters connected to a dc bus voltage of 400V working as controlled current sources instead of traditional voltage sources as in droop control schemes. The modelling and control of the high voltage (HV) DC-DC boost converter for DC microgrid have been done on LTSpice platform. The modelled converters work for a wide range of input voltage (200V-400V) catering to the wide range of output voltages of different sources connected to a microgrid. The major focus of this paper is to study and analyze the power-sharing between the current controlled HV DC-DC converters depending on the variable load demand. LTSpice being used for real-time circuit analysis, the proposed simulated model for high voltage application can be implemented in hardware in the future.
International Journal of Renewable Energy Research, 2018
This paper presents the design and development of a novel highly efficient synchronous buck conve... more This paper presents the design and development of a novel highly efficient synchronous buck converter operating both as a battery charge controller with five stage charging method and also as improved Maximum Power Point Tracker (MPPT) for operation in Solar Photovoltaic (PV) Systems. The algorithm regulates the duty cycle of the switching devices of the converter following a variable step size perturb and observe (P&O) MPPT technique. At the same time it provides precise control on the battery charging voltage and current according to five charging stages which is desirable for protection of battery health and maximizing charging rate. Thus the algorithm developed provides a combined solution for maximizing the transfer of solar electricity generated by the PV module(s) and also ensuring a long battery lifetime. Both these aspects, which are generally investigated separately earlier, are treated in an integrated fashion in this work. The work analyses in detail about the converte...
This paper demonstrates a smart energy management scheme for solar photovoltaic-biomass integrate... more This paper demonstrates a smart energy management scheme for solar photovoltaic-biomass integrated grid-interactive microgrid cluster system. Three interconnected microgrids were chosen as a cluster of microgrids for validation of the proposed community energy management scheme. In this work, a Global System for Mobile (GSM)-based bidirectional communication technique was adopted for real-time coordination among the renewable energy sources and loads. To realize the common phenomenon of local grid outage in rural distribution networks, a practical case study is designed in this work. The optimized scheduling of the energy sources and loadsof different microgrids and the distribution grid were implemented to ensure zero loss of power supply probability (LPSP) for dynamic load profiles. The laboratory-scale prototype of the proposed microgrid clustering was first developed in this work by establishing real-time communication among multiple energy sources and loads through different en...
International Journal on Smart Sensing and Intelligent Systems, 2014
A digital moisture measuring instrument based on phase angle measuring technique with porous sili... more A digital moisture measuring instrument based on phase angle measuring technique with porous silicon (PSi) or porous alumina (PA) as capacitive moisture sensor is proposed. The proposed technique can measure digitally the phase angle change of capacitive impedance of porous silicon or porous alumina sensor due to change in moisture concentration in terms of clock pulses. Analysis shows that the proposed circuit leads to higher precision by minimizing the errors caused by parasitic earth capacitance as well as offset voltage in the circuit. Simulation and experimental results are reported to confirm the effectiveness of the technique.
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