The article is concerned with the problem of planning of the amount of sample tests of heat power equipment components using time-series techniques. In the operation process of thermoelectric power stations (TPS) their expensive components (turbines, bearings, oil systems, generators, transformers, pipelines etc.) require securing of preset level of reliability and safety. For achievement of this aim it is necessary to develop corresponding plan of sample tests. Peculiarity of heat power equipment components is that they are devices consisting of elements’ totality of mechanical, hydraulic, pneumatic, electronic and other types. The basis of the proposed sample tests amount planning technique is the condition of test sample restorability after failure through improvements. In this case, the risk of developer (supplier) is assumed to be close to zero (α = 0). Improvement will be considered effective if carried out tests are successful in the same amount after improvement. Novelty of the proposed test amount planning technique for one preset level of reliability allows getting required output characteristics of heat power equipment in shorter period.
In India, around 70% of the population is living in remote areas and is not able to get proper electricity from utility grid. Around 20% of the total population has no access of electricity at all, which is not commendable for any developing country like India. Most of the electricity requirement is fulfilled by diesel generator only which is not a feasible solution because of fuel cost, greenhouse gas emission etc. Therefore, there is a need of an alternative solution for power generation in such remote areas. In view of the above, the feasibility analysis of renewable energy based hybrid system has been carried out for a remote area of district Sonipat, Haryana, India. In this study, major renewable energy sources including solar, wind, biomass and small hydro are considered to perform the feasibility analysis. A standalone hybrid model based on solar-biomass is found the feasible and viable option. The cost of power generated from proposed hybrid model is $ 0.086 per unit and is almost free from greenhouse gas emission which is at par in cost with the conventional supply and better in terms of clean production. Such hybrid systems can be very useful for electrification of other similar remote areas.
Renewable energy technologies offer clean abundant energy gathered from self-renewing resources such as the sun, micro hydro, etc. Nowadays, due to the ever increasing demand of electricity, renewable energies are becoming the best option for electrification especially for remote area and to meet relatively small load. The standard empirical formula, the collected sunshine hour data have been changed to solar radiation. The results obtained in the proposed work based on empirical formulas were compared with expand these words NASA and SWERA data. The selected area has 5.13kWh/m2/d amount of annual average solar radiation, which shows the area is rich of solar energy. Primary river flow data had been taken for modeling the existing micro-hydro power at MenkoToli River in Ethiopia. The river has an annual average flow rate of 1.131m2/s. HOMER software had been used for modeling optimized result of the hybrid power generation system. 500 households are considered under studied with a total annual consumption of 31,911 kWh per year. The study included the electrical load of primary school and clinic. From the HOMER software optimization result, 10KW PV, 14KW hydro, 14KW converter and 32 battery string had been selected as an optimized option for electrifying MenkoToli in Ethiopia., with an initial capital cost $55,200, total net present cost of $76,128 and unit cost of $0.045. In the study all combinations of hybrid sources for the HOMER software have been observed for cost effective design.
This paper proposes a novel low-cost switched power filter compensator (SFC). This proposed SFC is considered as a new topology of distribution FACTS. The proposed SFC scheme is based on a switching on/off process for connecting /disconnecting double tuned arm filters intermittently with two parallel capacitor-banks. The parallel capacitor-banks are connected at the two sides of series capacitor bank. When the switch is on, the SFC works as a double tuned filter while when the switch is off, the SFC works as series/shunt compensator. The switching process is controlled by a pulsing signal generated from PWM circuit. The modulation control signal of PWM is generated from a multi-loop traditional control. The Matlab Simulink environment is used to validate the ability of SFC to mitigate power quality problems, stabilize the system voltage and enhance the system power factor. The results show that the effectiveness of SFC to solve the system quality problems. This novel topology might be extended to be used with renewable energy resources interconnection and microgrids performance applications.
Considering the uncertainty of load and the random variation of wind farm output power in power system, a probabilistic voltage stability analysis method is proposed based on unscented transformation technique. According to the statistical characteristics of random variables in power system, the statistical characteristics of voltage stability margins, such as mean, standard deviation and moments, can be calculated by using a small number of samples and the conventional method. The maximum entropy method is applied to determine the probability distribution of voltage stability margin. In compared with Monte Carlo method, the effectiveness of the proposed method is verified on 39-bus and IEEE 57-bus system. The results show that the proposed method can accurately compute the statistical characteristics and the probability distribution of the voltage stability margin, and the computational efficiency is improved.
Every transmission system has voltage stability limit which may lead to voltage collapse if an undetected bulk transmission network is operated close to its operating limit. This research work uses continuation power flow method to identify voltage collapse point for Bangladesh Power System Network (BPSN). For the identification of weak buses, an analytical based technique of tangent factor has been presented. The risk of voltage collapse has been mitigated by placing SVCs at the weak buses of the system using load flow analysis. Moreover, sensitivity based approach has been introduced to determine optimal location of Static VAR Compensator (SVC) for the voltage security enhancement. A comparative analysis has been documented considering the size of reactive power to improve the loading factor of the overall network at the end of this work.
Generalized Unified Power Flow Controller (GUPFC) is a voltage source converter (VSC) based Flexible AC Transmission System (FACTS) controller for shunt and series compensation among the multiline transmission systems of a substation. This research presents the result of the power flow analysis of Nigerian power system incorporating GUPFC modeled in rectangular form to control active and reactive power in transmission lines and reduce the system active power loss without violation of the bus voltage profile. The steady state modeling of GUPFC combined with power system network equations were solved using Newton-Raphson solution method. A MATLAB based program for steady state power flow analysis was developed to solve the resulting equation using Newton-Raphson method. The result of the power flow analysis of Nigerian transmission system indicates disproportionate power flow and high power losses. Application of GUPFC resulted in enhancing active power flow control, reduced system losses and improvement of the system voltage profile.
The present article reports an analysis and investigation of direct AC-AC quasi-resonant converter. A bidirectional power device, whose switching frequency is lower than the frequency of the current passing through the load, is used for its realisation. A mathematical analysis of the processes has been made and comparative results from computer simulation and experimental study have been brought. The converter can find application in wide areas of power electronics: induction heating, wireless power transfer, AC-DC converters.
The present article examines the design and implementation specifics of High Voltage Isolated Driver for control of serially connected SCR. The driver features the use of current transformers for the impulses applied to the control electrodes of simple-connected primary coils, as well as control pulses transmission through optical fibre. Results from the experimental study are provided.
This paper presents the results from the research of the indexes in regard to the power supply network, when a change is applied to the power supply tension of the Compact Fluorescent Lamps and LED Lamps with power up to 30W of different manufacturers. Comparision data is presented for the power factor, the displacement factor and the total harmonic distortion of the current, and the relevant conclusions have been made.
This paper presents a comparative analysis of two current control methods of single phase on-grid inverter- the hysteresis current control and the fuzzy logic hysteresis current control method. The aim of the paper is to compare the values of the main researched parameters of the on-grid inverter and to show which control method is more energy efficient. The research model is established by means of differential equations with the software MATLAB/SIMULINK. The comparison of the operation of the inverter with both control methods is analyzed in two different cases of the output power of the system - 800W and 1600W approximately.
This paper deals with a new autonomous wind-hydro hybrid generation system consists of one squirrel-cage induction generator (SCIG) driven by a variable-speed wind turbine and another SCIG driven by a constant-power hydro turbine feeding three-phase four-wire medium loads. The proposed system consists of two back-to-back-connected pulse width modulation controlled insulated-gate-bipolar-transistor based voltage source converters (VSCs) with a efficient battery energy storage system at their dc link. The main purpose of the control algorithm for the VSCs are to acquire maximum power tracking (MPT) by rotor speed control of a wind turbine driven SCIG under varying wind speeds and control of the frequency and magnitude the of the load voltage. This wind hydro hybrid system has the ability of bidirectional reactive and active power flow, by which it controls the magnitude and the frequency for voltage. The proposed system using cage generators, MPT controller, and a voltage and a frequency controller are studied and simulated in MATLAB using Simulink and SimPower System toolboxes, and the proposed system are studied for various types of linear and nonlinear, under balanced and unbalanced conditions. The performance of the proposed system is presented to demonstrate its voltage and frequency control (VFC), harmonic elimination, and load balancing.
Subsynchronous oscillations (SSO), especially, subsynchronous resonance are potential problems in series compensated power system. A fixed speed wind farm employing single cage induction generator (IG) and double cage IG connected to series compensated line are prone to SSR problem. This paper presents some investigations on SSO resulting from induction generator effect (IGE) with the wind turbine generator (WTG) modelled either as single cage IG or double cage IG. Eigenvalue analysis is carried out for various levels of series compensation for different sizes of wind farm with varying power outputs. Eigenvalue analysis is validated by the electromagnetic transient simulations using PSCAD/EMTDC software. The possibility of steady state SSR (IGE) and transient SSR is investigated in depth using PSCAD/EMTDC for the modified IEEE first bench mark (MFBM) model. SVC is employed for mitigating SSR. A new voltage regulator (VR) model of SVC is proposed and linear state space model of SVC is developed. Eigenvalue analysis conducted with the proposed voltage regulator reveals that the proposed VR model is more effective in mitigating SSR compared to VR models that are reported in the literature.
Electricity generation is a key source to global emissions of greenhouse gases (GHG) and their related environmental impact. Sustainable development requires methods and tools to measure the environmental impacts of human activities for various products viz. goods, services, etc. Life-cycle analysis is an invaluable tool for evaluating the environmental profile of a product or technology from cradle to grave. Such life-cycle analysis of energy technologies are essential, especially as material and energy flows are often interwoven, and divergent emissions into the environment may occur at different life-cycle-stages. Photovoltaic system is a technology for the production of electricity from renewable sources that is rapidly growing thanks to its potential to reduce the energy consumption from traditional sources and to decrease the air pollution. During the operational phase, there are no emissions and the only input is solar power. However, it should be noted that, considering the entire life cycle of a plant, photovoltaic systems, like any other means of electricity production, give rise to emissions that focus especially in the manufacturing stage and installation of components. In this study, the environmental load of photovoltaic power generation system (PV) during its life cycle by energy payback time (EPT) and Greenhouse Gas emissions are reviewed through LCA study to the state of art of the photovoltaic technologies.
In this proposed study, Transformerless FPGA Controlled 2-Stage PV System is proposed for 3-phase electrical power generation. In this present scheme, to get AC power, power conditioning has been proposed in two stages; namely in first stage maximum power will be extracted and in second stage DC power will be converted into AC power. In this research paper conversion topology has been proposed for transformer less PV system and verified its results in MATLAB Simulink which is interfaced with Xilinx system generator. To extract optimum DC power from solar PV modules MPPT charge controller is designed. In this study, constant voltage MPPT charge controller is designed based on small signal analysis of converter with PM=57° and GM=14.7dB. After this charge controller output fed to Multi level inverter for the conversion of dc to ac. Proposed multilevel inverter is offering very low line voltage THDs compared with conventional inverter and observed that they are very low, hence required less size and cost of the filter.
The secondary battery (or rechargeable battery) is such battery where electrical energy can be stored as chemical energy and this chemical energy is then converted to electrical energy as when required. Batteries are used for this purpose from more than a century. Use of battery for off grid power supply can increase overall system efficiency, and provide economic savings across the system life cycle. Reliability of power supply from renewable and conventional sources can improve by using battery as energy storage medium. Battery can be charge by using solar energy for use of renewable energy or by power supply for use of conventional energy supply. Different battery shows different voltage and current characteristics when charged by using power supply. This paper outlines the charging and discharging characteristics of Lead acid and Li-ion batteries Experiment was conducted in Solar Lighting Lab at TERI, New Delhi. The main aim of this paper is to introduce the reader to the concept of end of charge and discharge of battery.
Adaptive voltage control method is proposed for DSTATCOM to regulate voltage. The proposed adaptive controller force compensation system to regulate local voltage dynamically near the end user load. Adaptive control method has advantage of flexibility and adaptability over conventional proportional integral control. Adaptive control automatically tunes proportional and integral gain to assure system stability with fast response. This paper will solve voltage regulation problem in distribution power system. The DSTATCOM is modeled under varying load and its performance is studied using MATLAB (using power system Simulink tool). Its performance found satisfactory under time varying load.
Electricity supply is rapidly becoming more complex and variable where energy efficiency rules are still evolving only to limited end. A near future with millions of electric vehicles and industrial loads will dramatically increase the necessity of a demand modulation system. The best way of practicing demand management is user responsive load management at the consumer ends. It will be difficult to alter consumer behavior in the direction of energy savings unless consumers are more exposed to market prices than at present. The proposed system introduces a distributed smart meter that intelligently notifies the power consumption rate at various time intervals based on demand factors and power loss factors. It also notifies the characteristic behavior of consumption to the consumer via GSM communication system, and isolates the supply for various faults and power theft. A new intelligent TLPF algorithm has been implemented that confronts all these features and executed using a SCADA controller.
The relatively static, slow-changing power transmission and distribution market is finding itself at the confluence of energy, telecommunications and information technology (IT) markets, driving necessary change and innovation in support of a 21st century intelligent utility network, a “Smart Grid.” This paper serves to provide clarification of what the Smart Grid is, from end-to-end, and where it's going as the infrastructure is built out and the applications are ultimately defined and delivered. It does so by explaining the market drivers, benefits and challenges; walking through the many market segments and technologies; laying out the current and future applications.
