Vector Control Of Wind Driven Self Excited Induction Generator Connected To Grid Using Twenty Four Pulse AC-DC Converter Employing Pulse Doubling Technique

This paper deals with multipulse AC-DC converters for improving the power quality in vector-controlled wind driven self excited induction generator at the point of common coupling. These multipulse AC-DC converters are realized using a reduced rating autotransformer. Moreover, DC ripple reinjection is used to double the rectification pulses resulting in an effective harmonic mitigation. The proposed AC-DC converter is able to eliminate up to 21st harmonics in the supply current. The effect of load variation on Vector Controlled Self Excited Induction Generator(VCSEIG) is also studied to demonstrate the effectiveness of the proposed AC-DC converter. A set of power quality indices on input AC mains and on the DC bus for a VCSEIG fed from different AC-DC converters .The complete electromechanical system is modeled and simulated in MATLAB using Simulink and simpower system block set. The simulated results are presented and compared for regulating voltage and frequency of SEIG driven by wind turbine. Keywords: Autotransformer, Multipulse AC DC converter, DC ripple reinjection, Pulse doubling, VCSEIG

Stator Flux Oriented Vector Control of Wind Driven Self Excited Induction Generator Connected to Grid through Cycloconverter

This paper deals with the stator flux oriented vector control of wind driven self excited induction generator through the cycloconverter at the point of common coupling. The control strategy of supplying the firing pulses is based on the stator flux oriented vector control of Self excited induction generator. The proposed cycloconverter is able to eliminate up to 21st harmonics in the supply current. The effect of load variation on Vector Controlled Self Excited Induction Generator (VCSEIG) through the cycloconverter is also studied to demonstrate the effectiveness of the proposed method. The complete electromechanical system is modeled and simulated in MATLAB using Simulink and simpower system block set. The simulated results are presented for regulating voltage and frequency of SEIG driven by wind turbine. The present study includes circulating current and semi-circulating current modes of operation with study of measuring and correction of output power factor of the cycloconverter and output voltage waveform harmonics. Keywords: Cycloconverter,VCSEIG,step up transforme

Modeling and Analysis of Wind turbine Driven Self-Excited Induction Generator Connected to Grid Interface with Multilevel H-Bridge Inverter

This paper deals with the stator flux oriented vector control of wind driven self excited induction generator This paper presents an investigation of Hybrid nine level inverter (HNLI) used along with the voltage source rectifier unit as interface between Self excited induction generator and grid. Making use of HNLI benefits of low harmonics distortion, reduced number of switches to achieve the nine level output over the conventional cascaded nine level inverter and reduced switching losses results in improvement of the p.f at grid, to compensate the reactive power and to suppress the total harmonic reduction. The generated voltage of the wind driven self excited induction generator mainly depends on the wind velocity, appropriate excitation capacitance and grid conditions. The main objective of this paper is to track the maximum power of the grid connected SEIG driven by wind turbine. In previous literature there no discussion about the grid connected SEIG interface with the AC/DC link. The variable magnitude, variable frequency, voltage of the generator can be controlled by the proper modulation index.  The modulation index of the proposed HNLI is adjusted to obtain the maximum output power. The results are valid through MATLAB/SIMULINK software. Keywords: Self excited induction generator (SEIG), Wind turbine, Hybrid nine level inverter, voltage source rectifier, grid

Selection of Capacitors for the Self Excited Slip ring Induction Generator with External Rotor Capacitance

The self regulating feature of a Self Excited Induction Generator (SEIG) by connecting additional capacitors is examined with the slip ring induction generator. The system consisting of external rotor capacitors at rotor has been analyzed. A methodology has been explained to choose appropriate set of values of these rotor capacitors for desired voltage regulation. Based on the steady-state equivalent circuit model, consideration of the circuit conductances yields a 7th-degree polynomial in the frequency. The polynomial can be solved for real roots, which enables the value of C, to be calculated. Critical values of load impedance and speed, below which the machine fails to self-excite irrespective of the capacitance used, are found to exist. Closed form solutions for C are derived for different loads. Using the Same numerical approach, an iterative procedure is also developed for predicting the capacitance required for maintaining the terminal voltage at a preset value when the generator is supplying load. Results of a detailed investigation on a conventional 3.5 kW induction motor operated as a SEIG are presented to illustrate the effectiveness of the proposed method. Close agreement between predicted and test results has been observed thereby establishing the validity of the analysis carried Keywords: capacitance requirements, self-excitation, slip ring induction generator, external rotor capacitanc