International Journal of Applied Power Engineering (IJAPE)
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An Application of Ulam-Hyers Stability in DC Motors
Get PDFIn this paper, a generalization to nonlinear systems is proposed and applied to the motor dynamic, rotor model and stator model in DC motor equation. We argue that Ulam-Hyers stability concept is quite significant in design problems and in design analysis for the class of DC motor’s parameters. We prove the stability of nonlinear partial differential equation by using Banach’s contraction principle. As an application, the Ulam-Hyers stability of DC motor dynamics equations is investigated. To the best of our knowledge this is the first time Ulam-Hyers stability is considered from the applications point of view
Modeling Simulation and Design of Photovoltaic Array with MPPT Control Techniques
Get PDFThe Renewable energy is important part of power generation system due to diminution of fossils fuel. Energy production from photovoltaic (PV) is widely accepted as it is clean, available in abundance, & free of cost. This paper deals with modeling of PV array including the effects of temperature and irradiation. The DC-DC converter is used for boosting low voltage of the PV array to high DC voltage. Since the efficiency of a PV array is around 13% which is low, it is desirable to operate the module at the peak power point to improve the utilization of the PV array. A maximum power point tracker (MPPT) is used for extracting the maximum power from the solar PV array and transferring that power to the load. To track maximum power point (MPP) Perturb & Observe (P & O) algorithm is used which periodically perturbs the array voltage or current and compare PV output power with that of previous perturbation cycle which controls duty cycle of DC-DC converter. The entire system is simulated in MATLAB /SIMULINK and simulation results are presented
Towards An Accurate Modeling of Frequency-dependent Wind Farm Components Under Transient Conditions
Get PDFFrequency dependence complete model is set up for describing the lightning transient behavior of the wind turbines (WTs).To get an appropriate wind turbine model, a high frequency models of surge arrester protecting the boost transformer, transformer and ground electrode soil ionization are implemented. The transient responses and Ground Potential Rise (GPR) can be obtained at different locations in the WTs and connected grid in the time domain as well as in the frequency domain using Fast Fourier Transform (FFT). To check the validity of the model, Surge arresters protection level at different locations, at i.e. LV, MV and HV, is compared with ABB manufacture data sheet, Also a comparison has been made between simple and frequency dependence model of overall wind farm components using ATP/EMTP. This paper provides an accurate simulation of wind farm components under transient condition
Ash Cooler Heat Recovery Under Energy Conservation Scheme
Get PDFA healthy fluidization state in circulating fluidized-bed combustion (CFBC) combustor is attributed to proper quantity of hot bed material (ash), which acts as a thermal fly-wheel. It receives & stores thermal energy from the burning of fuel (lignite) & distributes uniformly throughout the combustor & helps in maintaining a sustained combustion. The quantity of bed ash inside the combustor or size of the bed, depends upon boiler load & subsequently upon combustor temperature, lignite feed rate and ash % in lignite. As these parameters varies during process continuously, sometimes it becomes necessary to drain out the ash from the combustor. As & when differential pressure across the bed is increased from a justified level, draining of hot bed ash starts into Ash Coolers. Bed ash is drained at very high temperature of 850 oC & it also contains burning particles of lignite. This paper describes the heat recovery from bed ash, unloaded from the combustor into ash cooler, by pre-heating the condensate water of turbine cycle in a 125 MW CFB boiler of Surat Lignite Power Plant in India. The thermal performance of ash cooler was derived by doing a heat balance calculation based on the measured temperature of ash and cooling water with different load. From the heat balance calculation influence of ash temperature and ash amount on heat transfer coefficient is determined. Simulation is carried out around main turbine cycle indicates improved thermal economy of the unit, higher plant thermal efficiency, lower plant heat rate and reduce fuel consumption rate. Also simulation result shows that the heat transfer coefficient increase with ash amount and decreases with increase in ash temperature
Influence of Static VAR Compensator for Undervoltage Load Shedding to Avoid Voltage Instability
Get PDFIn the recent years, operation of power systems at lower stability margins has increased the importance of system protection methods that protect the system stability against various disturbances. Among these methods, the load shedding serves as an effective and last-resort tool to prevent system frequency/voltage instability. The analysis of recent blackouts suggests that voltage collapse and voltage-related problems are also important concerns in maintaining system stability. For this reason, voltage also needs to be taken into account in load shedding schemes. This paper considers both parameters in designing a load shedding scheme to determine the amount of load to be shed and its appropriate location .The amount of load to be shed from each bus is decided using the fixed step size method and it’s location has been identified by using voltage collapse proximity index method. SVC is shunt connected FACTS device used to improve the voltage profile of the system. In this paper impact of SVC on load shedding for IEEE 14 bus system has been presented and analyzed
Performance Analysis of Voltage Stability Against Sudden Load Changes in Voltage Controlled Inverters for Distributed Generation
Get PDFDistributed Generation (DG) is playing an important role in the field of electricity generation by being a viable alternative to the Centralized Power Generation (CPG). Although, distributed generation has many advantages, it has some issues in the fields of protection, power control, stability, islanding detection etc. Amongst all the issues, this paper attempts to highlight the issue of voltage stability under sudden changes in loading conditions in a distributed generation systems operating in stand-alone mode. Proper design and tuning of compensators for closed loop operation in DG systems can ensure voltage stability. As the load demand increases, the output voltage of DG usually dips for a short time owing to the weak (smaller capacity) nature of renewable sources, after which it returns to steady state. This fall in the voltage profile could prove to be harmful if the settling time is more. The simulation and hardware results illustrate that, accurate compensator design, is one of the key factor in maintaining the voltage stability in DG system. This paper explores the effect of proper compensator design in maintaining voltage stability of DG
Implementation of Hybrid Generation Power System in Pakistan
Get PDFA solar-wind hybrid power generation system has been presented here. The application based system illustrated in this paper is designed on the basis of the solar and wind data for Pakistan. The power generated by the system is intended for domestic use. The most common source of unconventional power in homes is battery based UPS (Uninterrupted power supply) inverter. The UPS inverter charges the battery with conventional grid power. This system will charge the battery of UPS inverter by using only wind and solar power, which will make the system cost effective and more reliable. The reason for using both solar and wind is that recent studies have proven that combined system can be more productive and consistent and other thing is that neither of them can be used for continuous power generation. In the system illustrated in this paper the solar-wind system provides power periodically which is controlled by electronic methods and a microcontroller is used to monitor the power from both the inputs. The switching action is provided from the microcontroller to the battery charging based on the power received from solar photovoltaic panel and wind generators. In this paper, an efficient system has been presented comprising of solar panel, wind generator, charge controller and charge storage unit (battery). Solar panel is selected as the main input and the wind resource will be used only in the absence of the solar photovoltaic (PV) output
Remediation of Old Substations for Arc Flash hazard
Get PDFArc Flash is much different from the conventional shock hazard in the sense that it doesn’t involve direct contact of human beings with the live or energized part. The arcing energy involves high temperature of up to or beyond 20000K. This paper presents a case study of arc flash hazard analysis carried out in older industrial plant and the technological and work procedure changes that can be incorporated to reduce the incident energy level and thus provide a safer environment for the working personnels in plant
Smart Power Transmission System Using FACTS Device
Get PDFMaking of smart grids puts mounting pressure on the nation’s aging electric power transmission system. Just planting additional towers and stringing more line won’t practice the nation’s electric power transmission infrastructure to meet up the energy challenges ahead. Smart grids stand geared up to play a much larger role in the energy equation for reduction of transmission line losses. The FACTS controllers come out with the capability of enhancing transmission system control, reliability, and operation. This paper will discuss and express how Static Synchronous Compensator (STATCOM) has effectively been applied to power system for efficiently regulating system voltage and thus increase system load ability. This paper investigates the effects of (STATCOM) on voltage stability of a power system at different positions.The simulation analysis of this paper can be used as guideline for power industry. The study is thereby simulated using the MATLAB/SIMULINK software and simulation results show that STATCOM is effective in midpoint voltage regulation on transmission line. In this paper comparison is also performed between STATCOM and SVC under fault condition and it is proved that STATCOM have the capacity to provide more capacitive power for the period of a fault than SVC
Pilot Solar Thermal Power Plant Station in Southwest Louisiana
Get PDFSolar thermal plants are basically power plants that generate electricity from high-temperature heat. The difference between them and conventional power plants is that instead of deriving energy from gas, coal or oil, the sun provides the energy that drives the turbines. In this paper we will give a brief demonstration of solar thermal power and different system designs of solar thermal power plants. Then we will see the feasibility of implementing solar power plants in Louisiana which currently depends mostly on its conventional power plants which use traditional fuels such as gas, oil, and coal. This study was a part of a proposal that was funded by the US the Department of Energy to construct solar thermal plant near Lafayette, Louisiana. The power plant is currently under the construction and it will be completed by Summer of 2013