International Journal of Applied Power Engineering (IJAPE)
Not a member yet
508 research outputs found
Sort by
An Enhanced Control Strategy for the Stable Operation of Distributed Generation during Grid-Connected and Islanded Mode
Get PDFThe incident of islanding occurs while the distributed generator fed constant power into the grid after power flow on the source of essential utility has been intermittent. If islanding is not rapidly detected, it can reason serious security and harmful condition. This paper presents coordinated manage of solar photovoltaic unit through maximum power point tracking technique to make available voltage and frequency support for an islanding condition. In normal condition, structure works as constant current control mode subsequent to islanding the structure switched to voltage control mode. The projected technique is capable to discriminate involving an islanding and a non-islanding occurrence. In this paper phase locked loop detection technique designed for detecting islanding situation is conceded out. The authentication of proposed system is established efficiently using MATLAB/ Simulink environment. The simulated results exhibit that the islanding detection technique has zero nondetection zone property and be able to detect islanding within few second
A Novel on Stability and Fault Ride through Analysis of Type-4 Wind Generation System Integrated to VSC-HVDC Link
Get PDFNow-a-days pollution is increasing due to “Non Renewable Energy Sources”. In order to enhance the efficiency of conventional grid and to generate the electrical power in eco-friendly way, the renewable energy sources are employed. In this paper a type 4 wind generation system is implemented to analyse the system under fault conditions and to analyse the grid stability. In the proposed system type-4 wind generation system integrated to grid through VSC-HVDC link analysis is done by considering a fault on the grid side by the system gets isolated and wind generation system transfers voltage to local load and remote load. When a DC fault is occurred on the VSC-HVDC link then the grid side breaker and wind side breaker gets open, then system gets isolated. This is implemented by considering “Low Voltage Ride Through” (LVRT) conditions, According to the Indian grid code of contact wind generation maintain constant even the voltage collapse is occurred on the grid side. The proposed VSC-HVDC based Type-4 Wind Generation System give more reliable to operate in LVRT condition and can meet the Load demand when the system is under fault condition to some extent; The proposed method is Type –4 Wind generator is of 4.4MW/2.2kV each with a total plant capacity of 110MW operated with VSC based HVDC transmission system with 110kV DC bus voltage connected to 220kV grid. The results obtained shows the Grid is operates under fault ride through conditions stability
Implementation of Ultra-Modified Symmetric Sequence Algorithm for Space Vector Modulation of Matrix Converter
Get PDFThis paper proposes an ultra- modified symmetric sequence algoritm of space vector modulation of matrix converter. The ultra-modified technique improves the drawbacks of the modified one where it provides a reduction of the total harmonic distortion for both output voltage and output current. Some of the advantages of matrix converter are introduced in this paper. These advantages represented in the output frequency of matrix converter which may be greater than input frequency, controlling rms value of the output voltage and the ability to control the input displacement factor.At the end of this paper simulation and experimental results are introduced which give a presice proof to the proposed algorithms
Sensorless Control of Brushless Doubly-Fed Generator Using Luenberger Observer Based Wind Energy Conversion Systems
Get PDFThis paper investigates the use of Luenberger observer for sensorless power control of brushless double fed induction machine (BDFM) in wind energy conversion systems, the control strategy for flexible power flow control is developed by applying flux oriented vector control (technique), In order to estimate the rotor speed, an adaptive algorithm based on Lyapunov stability theory will be design. Finally the analyzed and simulation results in MATLAB/ Simulink platform confirmed the good dynamic performance of this new sensorless control for BDFG based variable speed wind turbines
Solar Energy System Based Impedance-Source Inverter for Grid Connected System
Get PDFIn this work, the fickleness of solar energy can be overcome by using Maximum Power Point Tracking algorithm (MPPT). Perturb and Observation (P&O) MPPT algorithm accomplish fast the maximum power point for rapid change of environmental conditions such as irradiance intensity and temperature. The MPPT algorithm applied to solar system keep the boost converter output constant. Output from boost converter is taken to three phase impedance-source inverter with RL load and grid system. Impedance-source inverter performs the transformation of variable DC output of the solar system in to near sinusoidal AC output. This near sinusoidal AC output consecutively is served to the RL load first and then to grid system. The simulation is carried out in matlab/simulink platform both for RL load and grid system and the simulation results are experimentally validated for RL load arrangement only
Islanding Detection in a Distribution System with Modified DG Interface Controller
Get PDFIslanding detection of Distributed Generation (DG) is considered as one of the most important aspects when interconnecting DGs to the distribution system. It was the crucial problem in distributed generation. This detection phenomenon having a great importance. These detection methods are divided into active and passive islanding detection. These two methods are based on changing in parameters such as frequency, voltage and current harmonics. But these methods have some challenges such as reduction in power quality and large Non Detection Zone (NDZ). In this paper, the proposed method is change of Total Harmonic Distortion (THD) will be studied for islanding detection diagnosis. The studied system was considered by following the standard IEEE-1547 and UL-1741. The system was simulated using MATLAB/ SIMULINK
Reduced Rating 30-pulse AC-DC Converter for Power Quality Improvement
Get PDFThis paper presents the design and analysis of a novel polygon connected autotransformer based 30-phase ac-dc converter which supplies Direct Torque Controlled Induction Motor Drives (DTCIMD’s) in order to have better power quality conditions at the point of common coupling. The proposed converter output voltage is accomplished via three paralleled 10- pulse ac-dc converters each of them consisting of 5-phase diode bridge rectifier. An autotransformer is designed to supply the rectifiers. The proposed converter requires only three inter-phase transformers in the dc link that leads to the reduced kilovolt ampere rating, size, weight, and cost of the proposed rectifier. The design procedure of magnetics is in a way such that makes it suitable for retrofit applications where a six-pulse diode bridge rectifier is being utilized. The aforementioned structure improves power quality criteria at ac mains and makes them consistent with the IEEE-519 standard requirements for varying loads. Furthermore, near unity power factor is obtained for a wide range of DTCIMD operation. A comparison is made between 6-pulse and proposed converters from view point of power quality indices. Results show that input current Total Harmonic Distortion (THD) is less than 3% for the proposed topology at variable loads
Small Scale Wind Generation System: Part I – Experimental Verification Of Flux Reversal Generator Block
Get PDFThis research work, titled Small Scale Wind Generation System, reported in part I and part II, proposes modeling, analysis and control of a small scale wind energy conversion system employing a direct driven Flux Reversal Generator (FRG) connected to the micro grid through a Quasi-Z-Source Inverter (QZSI). The application of QZSI using FRG to feed micro grid is proposed for the first time in this research work. The QZSI can realize buck/boost, inversion and power conditioning in a single stage with improved reliability. Also it features a wide range of voltage gain which is suitable for applications in wind systems, due to the fact that the wind generator output varies widely with wind velocity. In addition, the modified Space Vector PWM (SVPWM) technique is proposed in this paper to satisfy the shoot-through characteristic of QZSI. This also adds to the contribution of this research work. In this part I of this full research, modelling of the small scale FRG for wind system using Finite Element Analysis (FEA) is presented. The major parameter of FRG viz, voltage, current, torque and power are analyzed, validated and then represented in d-q model. The simulation results are validated with the analytical results. An experimental set-up to run the full procedure reported in this paper. These results form the basis for part II of this research work
On Load Characteristic of the New Design Permanent Magnets Reluctance Generator
Get PDFThese The new design of a permanent magnet reluctance generator claimed to be able to convert the energy of the permanent magnet is the source of the main field into electrical energy, so that the generator output power can reach 167% compared with the input power axis. In this paper will discuss the characteristics of the generator voltage when under load, pure resistance, inductive load and caThese The new design of a permanent magnet reluctance generator claimed to be able to convert the energy of the permanent magnet is the source of the main field into electrical energy, so that the generator output power can reach 167% compared with the input power axis. In this paper will discuss the characteristics of the generator voltage when under load, pure resistance, inductive load and capacitive load. The results showed that when given a purely resistive load, the terminal voltage tends to be constant, but if given the inductive load, the voltage drop occurs significantly approaching zero voltage at full load current. It is very different when loaded capacitive load. When the generator under load is capacitive, the generator voltage at full load increased by 224.7% from no-load voltage.pacitive load. The results showed that when given a purely resistive load, the terminal voltage tends to be constant, but if given the inductive load, the voltage drop occurs significantly approaching zero voltage at full load current. It is very different when loaded capacitive load. When the generator under load is capacitive, the generator voltage at full load increased by 224.7% from no-load voltag
Small Scale Wind Generation System: Part II – A Novel Quasi-Z-Source Inverter and FRG-QZSI-Micro Grid Interface
Get PDFThis paper proposes modelling, analysis and control of a small scale wind energy conversion system employing a direct driven Flux Reversal Generator (FRG) connected to the micro grid through a quasi-Z-source inverter (QZSI). This entire research is made up of two major parts viz., FRG and QZSI. In the part I report of this research work, the role of FRG has been thoroughly modelled and verified. In this part II, the modelling and analysis of QZSI for this purpose is presented. In addition, the modified space vector PWM (SVPWM) technique is proposed in this paper to satisfy the shoot-through characteristic of QZSI, which is a novel. The interface of FRG and QZSI to inject power in to micro grid has been finally presented. The simulation results are validated with the analytical results. Section I discusses the open loop control of QZSI. The mathematical modelling of QZSI for this purpose is given and analytically validated. This flowed by section II in which the proposed SVPWM is presented. The procedure to obtain triggering pulses using this proposed modulation technique is discussed. Section III presents closed loop control strategies for QZSI. Section IV presents the micro gridinte face and power injection