Analysis Of Self-excited Induction Generator Research Articles

Performance Analysis of Three-Phase Self-Excited Induction Generator Using Genetic Algorithm

This paper presents a new technique for the analysis of a three-phase self-excited induction generator feeding a three-phase balanced unity power factor load. A genetic algorithm has been proposed to find the generated frequency and magnetizing reactance simultaneously. This leads to a complete analysis of the self-excited induction generator. Computed results have been compared with experimental results. The comparison confirms the validity and accuracy of the proposed method.

Genetic Algorithm-Based Performance Analysis of Self-Excited Induction Generator

This paper presents the implementation of a genetic algorithm to evaluate the performance of a self-excited induction generator under different operating conditions. Unlike with conventional methods of analysis, with the proposed method detailed mathematical derivations for each set of unknown parameters are not required; instead the same equation is optimized irrespective of the unknown parameters. Moreover, accurate selection of initial estimates is not needed. The other important feature of the proposed approach is the possibility of determining more than two unknowns in one solution. The present approach is validated by experimental test results.

Transient Analysis of Self-Excited Induction Generator With Electronic Load Controller (ELC) Supplying Static and Dynamic Loads

This paper presents a transient analysis of a self-excited induction generator (SEIG) with electronic load controller (ELC) used in stand-alone micro-hydro power generation employing uncontrolled turbines. In view of the need to feed both dynamic [three-phase induction motor (IM)] and static loads from such systems, the transient behavior due to switching in of such loads is of interest and is carried out here. A composite mathematical model of the total system has been developed by combining the modeling of prime mover, SEIG, ELC, and load. Simulated results are compared with the experimental ones, obtained on a developed prototype of an SEIG-ELC system for the starting of an IM and switching in a resistive load. For the starting of an IM, a star/delta starter is used to avoid inrush current. Harmonic analysis is carried out to find total harmonic distortion of the terminal voltage and current to assess its power quality.

Iterative Model for the Analysis of Self-Excited Induction Generators

This paper presents a new iterative method to analyze the operation of a self-excited induction generator operating under steady-state operating conditions. The iterative method proposed makes it very simple to compute the generated frequency. The iterative process takes four to five iterations to reach the final value with a difference of zero between the successive values of the generated frequency. The model is sufficient to predict the behavior of a self-excited induction generator for a given set of operating constraints. The theoretical results obtained have been verified experimentally for different machines operating under different operating conditions.

Load Rejection Analysis of Self-Excited Induction Generators for Autonomous Power Generation

The paper deals with a new analytical technique in the transient performance prediction of 3-phase self-excited induction generators for autonomous power generation based on load rejection tests. A new concept of generalized electromechanical current-controlled state space induction machine model is derived for this purpose. The previous electromechanical model presents a beneficial particularity to be linear for parameter identification needs. Numerical examples are given and discussed in detail in order to demonstrate the effectiveness of the proposed model, when the machine control variables are armature currents and mechanical torque. In the absence of speed regulator, simulation reveals that overvoltage generally follows load rejection tests of self-excited induction generator, with great change in the rotor speed variation.

Transient Analysis of Self-Excited Induction Generator Supplying Dynamic Load

This paper deals with the transient analysis of the Self-Excited Induction Generator (SEIG) feeding an induction motor (IM) load. Here, transient performance of the SEIG-IM system has been investigated to assess suitability of the SEIG to sudden switchings, such as starting of the IM. To predict the response of the system, quasi-stationary d-q axes model of the polyphase induction machine has been used. Transient response of the system has been presented for different operating conditions, and sample experimental results are given to validate the predicted ones. Useful guidelines for the design and operation of an SEIG-IM system for an isolated application, such as an IM-driven irrigation pump, have been suggested.

A Novel Approach for the Analysis of Self-Excited Induction Generators

This paper presents a simple, closed-form, analytical method for the analysis of self-excited induction generators (SEIG). In this method no numerical solution methods are required to obtain the frequency of operation of the SEIG, and an explicit analytical expression for the operating frequency corresponding to any speed, load impedance, and excitation capacitance is derived. The validity of the proposed method was checked by comparing its results with the results obtained by the use of the conventional methods in which numerical solution methods must be used. The results obtained from the proposed analytical method are identical at no-load condition and almost identical for other loading conditions, with the results obtained from previously used numerical methods.

Steady-state analysis of a self-excited induction generator including transformer saturation

Due to speed fluctuations of unregulated wind-turbines, the terminal voltage may increase to dangerously high levels which have been reported to cause capacitor failure at windfarms. This paper examines the steady-state analysis and performance characteristics of a stand-alone self-excited induction generator (SEIG) when a transformer is connected to its terminals to supply the load at a different voltage level or to step-up the terminal voltage for transmission. The transformer tends to saturate at higher speeds, and thus absorbs the excess reactive power and limits the increase in terminal voltage and improves voltage regulation. Transformer saturation introduces an additional nonlinearity which complicates the analysis considerably. A technique for formulating and solving the system's equations including transformer saturation is presented. The same technique is also applicable when the load itself is nonlinear. Experimental investigation has confirmed the accuracy of the proposed technique.

Analysis of self-excited induction generators using an iterative method

This paper describes the steady-state analysis of self-excited induction generators (SEIG) using an iterative method. By considering the conductances connected across the air gap nodes, an iteration procedure is developed for the determination of the self-excited per-unit frequency, which enables the equivalent circuit to be completely solved. The proposed method involves only simple algebraic calculations, but the accuracy is good and convergence is rapid. The method is subsequently extended to include core loss effects and the analysis of SEIG with series capacitance compensation. Very good agreement between experimental and computed results has been obtained on a 2 kW laboratory machine.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Steady-state analysis of self-excited induction generators

Two solution techniques for the steady-state analysis of a self-excited induction generator (SEIG) are presented in this paper. The first technique employs a novel parameter elimination procedure to yield a 7th-degree polynomial in the per-unit frequency, numerical solution of which enables the performance of the SEIG to be determined. The second technique employs symbolic programming for the derivation and solution of the the high-order polynomial. The symbolic programming technique is further extended to the analysis of a voltage compensated SEIG using long-shunt connection. Very good agreement between experimental and computed results have been obtained on a 2 kW laboratory machine. >

Steady-state analysis of self-excited induction generators

Steady-state analysis of self-excited induction generators

Analysis of Self-Excited Induction Generators Using Symbolic Programming

Analysis of self-excited induction generators using symbolic programming Using the symbolic programming language MACSYMA, the self-excited induction generator may be analysed in a straightforward manner with a high degree of accuracy. Very little manual effort need be spent on algebraic manipulation, numerical analysis and computer programming. Typical program sessions are cited to illustrate the elegance of this approach.

Steady-state analysis of a self-excited induction generator with an AC-DC conversion scheme for small-scale generation

In the present paper, the steady-state analysis of a three-phase self-excited induction generator (SEIG) having discrete switching capacitors and an AC-DC link is investigated. A model of the whole system is developed to accommodate the various combinations of converters in the AC-DC link. A computer algorithm for predicting the system performance is developed. The number of switching capacitors required for loading the machine from no load to full load is computed. A discrete capacitor switching scheme for the generator to feed the isolated load directly while maintaining its terminal voltage within certain limits from no load to full load is investigated. The effect of speed on the excitation requirement of the machine is also studied.

Steady-state and transient analysis of self-excited induction generators

This paper describes a method for accurately predicting the minimum value of capacitance necessary to initiate self-excitation with a stand-alone induction generator. Final steady-state self-excitation voltages and frequencies are also calculated for loaded and unloaded operations, taking into account the rotor parameter variations with the frequency. It is shown that the calculated and measured results are in strong agreement, and for the loaded generator they agree considerably more so than when constant rotor parameters are used. The theory is also extended to include the transient build up of voltage during the initiation stage of self-excitation, and the perturbations of the terminal voltage and the stator current which result from load changes.

Design-based computational procedure for performance prediction and analysis of self-excited induction generators using motor design packages

A computer algorithm is explained in order to determine the performance of capacitor self-excited induction generators (SEIG) taking the machine design details as the input data. The magnetisation characteristic which forms the basis of analysis is obtained using the B/H curve of the core material and by employing a curve-fitting technique. The predicted parameter and performance characteristics of a normal induction motor operating as SEIG are compared with corresponding experimental results. Effects of variation of realistic design parameters are studied to obtain guidelines on optimum design. Typical results on a range of normal induction machines are presented to assess their suitability as SEIG.

Wind-driven self-excited pole-changing induction generators

Pole-changing single-winding schemes are applied to self-excited induction generators for the first time and shown to be suitable for wind-driven applications with wide variations in the driving speed. An attempt has also been made to present an analysis of self-excited induction generators by a new approach which is shown to be simple and elegant compared to the earlier methods. Results on a test machine wound with a 4/6-pole combination amply demonstrate the usefulness of pole-changing windings for induction generators. Experimental and predicted performances agree closely, validating the analysis proposed.

Steady State Analysis of Capacitor Self-Excited Induction Generators

The paper presents a method for the steady state analysis of self-excited induction generators using balanced terminal capacitors. Operational and steady state equivalent circuits of the induction machine are employed to predict the steady state performance under different load conditions. The analytical procedure and the related computer program is described in the paper. Simulated results are presented and compared with corresponding results obtained experimentally.

Analysis of self-excited induction generators

An analytical technique using the ‘Newton-Raphson’ method is presented to identify the saturated magnetising reactance and the generated frequency of a self-excited induction generator for a given capacitance, speed and load. The technique is shown to be very efficient in analysing such systems under steady state. Computed results are compared with the experimentally obtained values on a laboratory machine, and a reasonable correlation has been observed. Effects of various system parameters on the steady-state performance have been studied, and the results presented provide guidelines for optimum design of such systems.