Three-phase Squirrel-cage Induction Generator Research Articles

Analysis of magnetic saturation effects in the squirrel cage induction generators

This work concerns an investigation on the analysis of the magnetic saturation effects in the three-phase squirrel cage induction generator which is considered as a main device in wind energy conversion systems. The magnetic saturation is considered as an important factor causing destructive effects on power qualities such as harmonics and distortion. Several approaches have been presented in the literature for the modeling of the electric machines considering magnetic saturation. The widely used and precise approach is the finite elements method which is particularly characterized by its high computational time. The novelty in this paper is that a state model has been developed for the healthy conditions of the three-phase squirrel cage induction generators considering the experimental variation of the magnetizing inductance in terms of the magnetizing current. Simulation and experimental tests are provided to extract some important signatures on stator voltages and currents. It will be deduced that the spectrum analysis of stator currents contains useful information on magnetic saturation. Experimental and theoretical results illustrate the consistency of this approach for the modeling and analysis of the squirrel cage induction generators considering the magnetic saturation.

Load Voltage Control of a Wind Turbine-driven Three-phase Squirrel-Cage Induction Generator in an Islanded Microgrid

The intermittent nature of the wind resources and reactive power consumptions are major issues associated with squirrel cage induction generator wind power system when operated in an island microgrid mode. The resultant effect of these two issues are continuous fluctuations of load voltage which has adverse effects on electrical devices. This paper proposes a voltage regulation technique based on proportional controller and phase deposition sine pulse width modulation (PDSPWM) for the control of 5-level neutral point clamped multilevel inverter. The instantaneous voltage tracking strategy based on root mean square value of microgrid voltage was adopted to regulate and maintain the output load voltage at 400 𝑉𝑟𝑚𝑠 despite rotor fluctuations with wind speeds. The simulation was carried out in a MATLAB/SIMULINK environment and the performance of the control scheme was found to be excellent.

Artificial Neural Network and Kalman Filter for Estimation and Control in Standalone Induction Generator Wind Energy DC Microgrid

This paper presents an improved estimation strategy for the rotor flux, the rotor speed and the frequency required in the control scheme of a standalone wind energy conversion system based on self-excited three-phase squirrel-cage induction generator with battery storage. At the generator side control, the rotor flux is estimated using an adaptive Kalman filter, and the rotor speed is estimated based on an artificial neural network. This estimation technique enhances the robustness against parametric variations and uncertainties due to the adaptation mechanisms. A vector control scheme is used at the load side converter for controlling the load voltage with respect to amplitude and frequency. The frequency is estimated by a Kalman filter method. The estimation schemes require only voltage and current measurements. A power management system is developed to operate the battery storage in the DC-microgrid based on the wind generation. The control strategy operates under variable wind speed and variable load. The control, estimation and power management schemes are built in the MATLAB/Simulink and RT-LAB platforms and experimentally validated using the OPAL-RT real-time digital controller and a DC-microgrid experimental setup.

Fault Ride-Through Study and Control of a Wind Turbine Driving Squirrel Cage or Doubly-Fed Induction Generator: A Comparative Study

The renewable energy systems are going to take over most of the non-renewable energy systems, so many scientific efforts are being made to ensure the stability and reliability of the renewable energy systems. This paper is concerned about the wind energy systems and ensuring their behavior and performance during and after the abnormalities like fault ride-through. Two complete models of a grid connected wind systems are going to be simulated in the MATLAB software program, the first one will be a grid connected wind turbine driving a three-phase squirrel-cage induction generator (SCIG) and the other model will be a grid connected wind turbine driving a three-phase doubly-fed induction generator (DFIG). The frequency of each system will be displayed and compared to the frequency of the other system upon fault ride-through (three-phase short-circuit fault) and under the effect of the PID controller which is tuned by genetic algorithm technique. The different responses of both generators are going to be analyzed graphically and compared to each other upon the ride-through fault and under the effect of the designed controller (genetic algorithm PID controller).Â

Active and Reactive Power Control of a Variable Speed Wind Energy Conversion System based on Cage Generator

This manuscript presents the modeling and control design for a variable speed wind energy conversion system (VS-WECS). This control scheme is based on three-phase squirrel cage induction generator driven by a horizontal-axis wind turbine through the overhead transmission network. In this manuscript, a static VAR compensator is proposed and connected with the squirrel cage induction generator terminals in order to regulate the system parameters, such as voltage, power. Through the pitch angle, the mechanical power was controlled through Simulink (Matlab) software. From the simulation results, the response of the proposed system offers good robustness and fast recovery under various dynamic system disturbances.

Improved differential evolution‐based Elman neural network controller for squirrel‐cage induction generator system

An improved differential evolution (IDE) algorithm-based Elman neural network (ENN) controller is proposed to control a squirrel-cage induction generator (SCIG) system for grid-connected wind power applications. First, the control characteristics of a wind turbine emulator are introduced. Then, an AC/DC converter and a DC/AC inverter are developed to convert the electric power generated by a three-phase SCIG to the grid. Moreover, the dynamic model of the SCIG system is derived for the control of the square of DC-link voltage according to the principle of power balance. Furthermore, in order to improve the transient and steady-state responses of the square of DC-link voltage of the SCIG system, an IDE-based ENN controller is proposed for the control of the SCIG system. In addition, the network structure and the online learning algorithm of the ENN are described in detail. Additionally, according to the different wind speed variations, a lookup table built offline by the dynamic model of the SCIG system using the IDE is provided for the optimisation of the learning rates of ENN. Finally, to verify the control performance, some experimental results are provided to verify the feasibility and the effectiveness of the proposed SCIG system for grid-connected wind power applications.

Squirrel Cage Induction Generator System Using Wavelet Petri Fuzzy Neural Network Control for Wind Power Applications

A wavelet Petri fuzzy neural network (WPFNN) controller is proposed to control squirrel-cage induction generator (SCIG) system with an ac/dc power converter and a dc/ac power inverter for grid-connected wind power applications. First, the ac/dc power converter and the dc/ac power inverter are developed to deliver the electric power generated by a three-phase SCIG to power grid. Moreover, the ac/dc power converter and the dc/ac power inverter are mainly designed to control the mechanical rotor speed, dc-link voltage, and reactive power output of the SCIG system, respectively. Furthermore, since the varying active power outputs of the dc/ac power inverter seriously affect the tracking control of the dc-link voltage, a novel intelligent WPFNN controller is proposed to replace the traditional proportional-integral controller for the tracking control of the dc-link voltage in this study. In addition, the network structure and the online learning algorithm of the proposed WPFNN are described in detail. Finally, some experimental results are provided to show the effectiveness of the intelligent controlled-SCIG system using the proposed WPFNN controller for grid-connected wind power applications.

Squirrel-cage induction generator system using hybrid wavelet fuzzy neural network control for wind power applications

An intelligent controlled three-phase squirrel-cage induction generator (SCIG) system for grid-connected wind power applications using hybrid wavelet fuzzy neural network (WFNN) is proposed in this study. First, the indirect field-oriented mechanism is implemented for the control of the SCIG system. Then, an AC/DC power converter and a DC/AC power inverter are developed to convert the electric power generated by a three-phase SCIG to power grid. Moreover, the dynamic model of the SCIG system and an ideal computed torque controller are developed for the control of the square of DC-link voltage. Furthermore, an intelligent hybrid WFNN controller and two WFNN controllers, which are computation intensive approaches, are proposed for the AC/DC power converter and the DC/AC power inverter, respectively, to improve the transient and steady-state responses of the SCIG system at different operating conditions. In the intelligent hybrid WFNN controller, to relax the requirement of the lumped uncertainty in the design of the ideal computed torque controller, a WFNN is designed as an uncertainty observer to adapt the lumped uncertainty online. Finally, the feasibility and effectiveness of the SCIG system for grid-connected wind power applications are verified with experimental results.

Intelligent controlled three‐phase squirrel‐cage induction generator system using wavelet fuzzy neural network for wind power

An intelligent controlled three-phase squirrel-cage induction generator (SCIG) system for grid-connected wind power application using wavelet fuzzy neural network (WFNN) is proposed in this study. First, the indirect field-oriented mechanism is implemented for the control of the SCIG system. Then, an AC/DC power converter and a DC/AC power inverter are developed to convert the electric power generated by a three-phase SCIG from variable-voltage and variable-frequency to constant-voltage and constant-frequency. Moreover, the intelligent WFNN controller is proposed for both the AC/DC power converter and DC/AC power inverter to improve the transient and steady-state responses of the SCIG system at different operating conditions. Three online trained WFNNs using backpropagation learning algorithm are implemented as the tracking controllers for the DC-link voltage of the AC/DC power converter and the active power and reactive power outputs of the DC/AC power inverter. Furthermore, the network structure and the online learning algorithm of the WFNN are introduced in detail. Finally, some experimental results are provided to demonstrate the effectiveness of the proposed SCIG system for wind power.

Performance analysis of a new configuration of three-phase self-excited induction generator feeding a single-phase load

This paper presents a steady-state performance analysis for a new configuration of self-regulated self-excited three-phase squirrel cage induction generator feeding single phase loads. The proposed scheme provides the required reactive power for excitation, small voltage regulation, acceptable phase balance and large output power. Using an equivalent circuit model incorporated with the method of symmetrical components, the total impedance equation of the generator’s model is derived. This non-linear equation is minimised to obtain the operating frequency and magnetising reactance. Based on the derived circuit model, the performance of the generator under different operating conditions is predicted. To confirm the validity of the proposed scheme, simulation results are compared with their corresponding test results.

Closed Loop Speed Control of Induction Generator with Scalar-control Inverters

A closed loop speed control for an induction generator is presented. The system was developed for a space vector modulation-voltage source inverter and the three-phase squirrel-cage induction generator to regulate speed and generator voltages with scalar control technique. The aim of this research was to a generated voltage with a constant speed at variable mechanical torque of prime mover. The simulation results show a good performance of the system can be achieved by the proposed speed controller.

Simulation of the Different Transmission Line Faults for a Grid Connected Wind Farm with Different Types of Generators

This paper aims to simulate a wind farm model that includes a wind turbine and three different types of generators , which are three-phase synchronous generator, three-phase squirrel-cage induction generator and three-phase doubly-fed induction generator ,these generators are the main machines that generally used in the field of wind energy generation. All generators are connected in parallel at the point of common coupling (pcc) and connected to the utility grid . This model is a simple representation of the actual model of zafarana, which is the biggest wind farm in Egypt and further to use it in different kinds of simulations, and display the difference in response among all generators with the same power rating (500 kw) and subjected to the same operating conditions and faults. This paper describes the simulation of the different faults that occur along the transmission line of the power system such as single-line fault, line to line fault, double lines to ground fault, and finally three line faults. The response of the wind turbine and the different generators will be analyzed and discussed to compare the transient response of all generators at the different types of faults, where the fault period is selected to be 300 ms. The model is created in MATLAB software that enables the dynamic and static simulations of electric, electromagnetic and electromechanical systems. The machines are standard blocks in the software library. DOI: http://dx.doi.org/10.11591/ijece.v2i1.113

Simulation of a Transient Fault Controller for a Grid Connected Wind Farm with Different Types of Generators

This paper aims to simulate a wind farm model that includes wind turbine and three different types of generators , which are three-phase synchronous generator, three-phase squirrel-cage induction generator and three-phase doubly-fed induction generator ,these generators are the main machines that generally used in the field of wind energy generation. All generators are connected in parallel at the point of common coupling (PCC) and connected to the utility grid. This model is a simple representation of the actual model of Zafarana, which is the biggest wind farm in Egypt and further to use it in different kinds of simulations, and display the difference in response among all generators with the same power rating (500 kW) and subjected to the same operating conditions and faults. This paper describes the simulation of the different faults that occur along the transmission line of the power system such as single-line fault, line to line fault, double lines to ground fault, and finally three line faults. The response of the wind turbine and the different generators will be analyzed and discussed to compare the transient response of all generators at the different types of faults, where the fault period is selected to be 300 ms. The model is created in MATLAB software that enables the dynamic and static simulations of electric, electromagnetic and electromechanical systems. The machines are standard blocks in the software library. Keywords : transient faults, wind farm, simulation model. DOI: http://dx.doi.org/10.11591/ijpeds.v1i2.104

Voltage regulator for an isolated self-excited cage induction generator

A voltage regulator for a three-phase self-excited cage induction generator (SEIG) is developed for maintaining its terminal voltage constant irrespective of the nature and amount of load. The proposed regulating scheme consists of a fixed-value capacitor bank and saturable core reactors with appropriate feedbacks. This simple static exciter at the induction machine terminals is capable of meeting its reactive power demand and regulating the terminal voltage. The developed regulator is used for a 5 hp, three-phase squirrel cage induction generator and provides inherent voltage regulation at resistive, inductive and motor loads. Extensive tests are carried out to study the steady-state and dynamic performance of the system. The relevant recorded voltage and current waveforms and other test results are given and discussed in detail. The proposed regulator is also compared with a thyristor controlled reactor type of regulator for an SEIG and is found to be superior to the latter in several aspects.