Dual Stator-winding Induction Generator Research Articles

Parameter Design and Static Performance of Dual Stator-Winding Induction Generator Variable Frequency AC Generating System With Inductive and Capacitive Loads

In this paper, the design methods of the auxiliary excitation capacitors and the filter inductances are investigated for the dual stator-winding induction generator (DWIG) variable frequency ac (VFAC) generating system with inductive and capacitive loads, and the system static performance is presented as well. For this generating system, the proper selection of the auxiliary excitation capacitors and the filter inductances can minimize the reactive power capacity of the control winding, reduce the capacity of the static excitation converter (SEC) and improve the system static performance of the output voltage. The corresponding design principles and methods are proposed based on the change law of the control-winding reactive power and the requirements of the control-winding current. The experimental results show that the proposed design methods are correct and valid, and the DWIG VFAC generating system has a good static performance with the minimum-capacity control-winding reactive power and a compact-size SEC.

Optimal Analysis on Reactive Capacity of Control Winding for Dual Stator-Winding Induction Generator

The minimizing to reactive power of control winding of the dual stator-winding induction generator is key to optimization of the novel generator system. It is determined by parameters of machine, load, rotating speed and speed range and exciting capacitors paralleled with the output terminal of power winding. In this paper, Based on analysis on working principle of conventional three-phase induction generator excited by capacitors with variable load and variable speed, the determination of excited capacitors to minimize the reactive power of control winding under variable load and speed is proposed, the control law of optimal excited current is presented. DOI : http://dx.doi.org/10.11591/telkomnika.v12i4.4757

Control Strategy and Dynamic Performance of Dual Stator-Winding Induction Generator Variable Frequency AC Generating System With Inductive and Capacitive Loads

This paper presents the control strategy and dynamic performance of the dual stator-winding induction generator variable frequency ac (VFAC) generating system with inductive and capacitive loads. In this generating system, the power winding produces the VFAC electricity to feed loads, and the control winding is connected to a static excitation converter to keep the output voltage stable. Based on the change law of the reactive power provided by the control winding, an improved instantaneous slip frequency control (IISFC) strategy both with the load active and reactive power feedforward is proposed to improve the system dynamic performance. The information of the load active and reactive power is employed through two feedforward loops to rapidly change the reactive power provided by the control winding, so as to quicken the regulation of the slip frequency and excitation reactive power. The simulations and experimental results show that the system using the IISFC strategy has a good dynamic performance with inductive and capacitive loads, and demonstrate the correctness and validity of the proposed control strategy.

Implementation, modelling and performance analysis of a dual stator‐winding induction generator

Purpose – The purpose of this paper is to develop and test a prototype of the dual stator‐winding induction generator (DWIG) and its dynamic model to verify the validity of this machine design as variable speed generator for renewable energy systems.Design/methodology/approach – Implementation and laboratory test of a DWIG prototype. Analysis and simulation of the developed DWIG model.Findings – The proposed DWIG makes a better use of energy than a squirrel cage induction generator (SCIG) in variable speed applications. The performance of DWIG with a bidirectional converter is very similar to those described in other studies with brushless doubly‐fed induction generators.Research limitations/implications – The results can be used to test different control techniques and to analyse the dynamic performance of DWIG‐converter system in variable load and speed conditions.Originality/value – The stator winding design does not involve a significant increase in the complexity of the machine assembly and cost of t...

A Research on the DC-Link Current and Capacitance of the Static Excitation Regulator on a 12/3-Phase Dual Stator-Winding Induction Generator

By proper simplifications, the static excitation regulator on the 12/3 phase dual stator winding induction generator is described by the switch-function model. On this basis, the switch-function expression of the DC-link capacitor current is obtained and the physical meanings are discussed, and the detailed exchange procedures between the generator and capacitor are analyzed. Considering the voltage endurance capability of the capacitor and IGBT, and the current endurance capability of the capacitor, the limitation capacitance equation of the DC-link capacitor is proposed.

Influence on the Excited Converter Capacity of Variable Speed Dual Stator-Winding Induction Generator System by Excited Capacitor

Excited capacitor of power winding has much influence on the capacity of excited converter of dual-winding induction generator. The capacity of excited converter can be optimized by changing the excited capacitor. The influence law of the capacity of excited converter by variable excited capacitor are compared under variable speed and variable load recured to simulation methods.

A Stand-Alone Dual Stator-Winding Induction Generator Variable Frequency AC Power System

This letter proposes a variable frequency ac (VFAC) stand-alone power system based on the dual stator-winding induction generator (DWIG) with the static excitation controller (SEC). A slip frequency control strategy using the information of the output voltage and the output power is employed to guarantee that the system has a desirable static and dynamic performance in a wide speed range. The experimental results on a prototype verify the principle and performance of the proposed control method.

Analysis of Dual Stator-Winding Induction Generator Based on Ansoft

Wind generating stand-alone supply systems has presented new demands for induction generator. The dual stator-winding induction generator is presented for these demands. In this paper, the electromagmeshic field analysis for an optimal sample of dual stator-winding induction generator is proposed via maxwell2D ANSOFT. The physical model and mesh cutting model of FEA are setup. The field analysis of no-load and rated-load are presented respectively. Post disposing results are analyzed.

Electromagnetic Design of Dual Stator-Winding Induction Generator System with Boost Converter

In this paper, the electromagnetic design of dual stator-winding induction generator with boost converter to raise output voltage under the minimum speed is presented. When the output voltage of power winding is very low and the output current very high, the large winding turns ratio between the control winding and power winding is proposed to reduce the current of control winding. The excited capacitor of power winding and filter inductor of control winding can be canceled. With the boost converter adjusting the out put voltage under the minimum speed, the demand of output voltage of the generator can be achieved. Design results show it is much benefit for reducing the dimension ,cost and weight of the system.

Influence on the Excited Converter Capacity of Variable Speed Dual Stator-Winding Induction Generator System by Excited Capacitor

Excited capacitor of power winding has much influence on the capacity of excited converter of dual-winding induction generator. The capacity of excited converter can be optimized by changing the excited capacitor. The influence law of the capacity of excited converter by variable excited capacitor are compared under variable speed and variable load recured to simulation methods.

An Excitation-Capacitor-Optimized Dual Stator-Winding Induction Generator With the Static Excitation Controller for Wind Power Application

This paper presents an optimal scheme of excitation capacitor to decrease the capacity of static excitation controller (SEC) for dual stator-winding induction generator (DWIG) system applied in wind power generation. The investigations into reactive excitation power released by the excitation capacitor and SEC illustrate that the optimal excitation capacitor is not only related to generator parameters, speed range, and load, but also affected by wind turbine power curve. Based on the objective of minimizing the capacity of SEC, several methods are employed here to select an appropriate excitation capacitor. Through the analysis of DWIG control mechanism and model of SEC in the stator-voltage-orientation synchronous d-q frame, a decoupling control strategy using the space vector modulation is obtained. On the basis of this, the simulation and experimental works from the prototype of 18-kW six/three-phase DWIG wind power system are carried out to verify the optimal scheme. The results demonstrate the correctness and effectiveness of this optimization scheme.

A novel dual stator-winding induction generator system applied in wind power generation

This paper presents a novel usage of 6/3-phase dual stator-winding induction generator (DWIG) with a static excitation power controller (SEC) as a wind power generator. This generator is composed of a standard squirrel-cage rotor and two sets of winding housed in the stator slots. One is referred to as the 6-phase power winding, and the other is defined as the 3-phase control winding. On the basis of the instantaneous power theory, the control mechanism of DWIG wind power system is analysed, and the control winding flux orientation control strategy is obtained consequently. The simulation and experimental results from a prototype of 18 kW 6/3-phase DWIG wind power system are presented to verify the correctness and feasibility of control strategy, and a desirable performance is implemented.

The Capacity Optimization for the Static Excitation Controller of the Dual-Stator-Winding Induction Generator Operating in a Wide Speed Range

The dual-stator-winding induction generator (DWIG) designed to achieve wide-speed-range operation with reduced capacity of the static power controller is presented. The DWIG consists of a standard squirrel-cage rotor and a stator with two separate windings wound for the same number of poles. This generator has a diode bridge rectifier load connected across to the power winding and a static excitation controller (SEC) to the control winding. Investigations into the reactive power released by the fixed excitation capacitor bank versus rotor speed under various loads represent that the minimal capacity of SEC can be achieved by an appropriate selection of excitation capacitor bank. With the help of instantaneous power theory, the control mechanism for the DWIG system working with a variable rotor speed is analyzed. Moreover, the system control strategy which is fit for the wide-speed-range operation using the stator flux orientation is consequently proposed. An 18-kW DWIG system with a 270-V high voltage DC output is developed. The simulation and experimental results illustrate a desirable performance, and the compact implementation of SEC is obtained.

Optimal design of a self-excited capacitor in a dual-stator winding induction generator

The design requirement of the self-excited capacitor in a dual-stator winding induction generator (DSWIG) is different from that of the conventional induction generator, because there are numerous combinations between the reactive capacitance of two windings. The efficiency optimisation is taken as the design aim for a self-excited capacitor in this paper. Based on the equivalent circuit model of the induction generator-rectifier system, the characteristic analysis of a three-phase bridge rectifier with an AC capacitor is presented, especially the comprehensive analysis on the condition with neglecting commutation angle. Moreover, the relation between self-excited capacitor and corresponding stator loss is derived, and the value of self-excited capacitor at maximum efficiency is obtained. The coincidence between the experimental results and analytical results verifies the validity of the analytical method. The results obtained herein are of importance to the optimal design of the self-excited capacitor in DSWIG.

A Novel Stand-Alone Dual Stator-Winding Induction Generator With Static Excitation Regulation

On the basis of the new idea of electric power integration, a novel stand-alone dual stator-winding induction generator (DWIG) system is built. In this generator, there are two sets of windings to be embedded in the stator slots. One, referred to as the 12-phase power winding, supplies power to the dc load via a 12-phase bridge rectifier, and the other, called the 3-phase excitation winding, is connected to a pulsewidth modulation (PWM) voltage source static excitation regulator (SER). A solid iron squirrel cage rotor is suitable for high speed generation. Experiments and simulations show the ac capacitors can reduce the inductance of rectifier loads and help to reduce the capacitance of the SER. A simple control methodology based on stator voltage orientation (SVO) is presented to regulate the output voltage of the 12-phase bridge rectifier in this paper. Moreover, the electric energy quality and the relative influence factors are studied by detailed experiments and analyses. The proposed system is especially suitable for self contained electrical systems, such as those found on electric vehicles, ships, and aircraft, where high performance and compact size are essential.

PWM-VSI inverter-assisted stand-alone dual stator winding induction generator

This paper presents a novel usage of a dual stator winding three-phase induction machine as a stand-alone generator with both controlled output load voltage magnitude and frequency. This generator, with both three-phase power and control windings housed in the stator structure, has the load connected to the power winding and a three-phase pulsewidth modulation (PWM) voltage-source inverter sourcing the control winding. The input to the PWM inverter is either a battery source or a charged DC capacitor. The operational characteristics of these generator schemes with either of the two inverter sources are investigated and shown to have desirable performance. How the load voltage magnitude depends on the various control and design parameters such as rotor speed, compensating capacitance, and load impedance is determined using a detailed mathematical model of the system.