Dual Stator Induction Generator Research Articles

Performance of New Control Strategy of Dual Stator Induction Generator System Applied in Wind Power Generation

In order to improve the quality of energy and reduce the harmonics produced by the power electronics converters, it is proposed and developed in this article the direct torque control, in which the flux and torque are estimated from the only measurable electrical quantities. The direct torque control DTC method, to enhance the dynamic and static performances as well as the robustness of the control of the Wind Energy Conversion System (DSIG). DTC is a control technique that exploits the possibility of imposing torque and flux on alternating current machines in a decoupled manner, once powered by a voltage inverter without current regulation made by a feedback loop, ensuring a decoupling, similar to that obtained from a vector control. The technique involved rapid torque response, insensitivity to parametric variation, in particular the machine's rotor time constant and systematic suitability for control without speed sensor. The main function of the generator side controller is to track the maximum power through controlling the rotational speed of the wind turbine using PI controller. The performance and the effectiveness of the proposed control system are tested via simulation results in terms of reference tracking, and robustness against parameters variations of the DSIG. Simulation results for 1.5 MW DSIG control show robust with respect to the parametric variation 2 Rs, 1,5 Rs et 0.5 Rs, and fast dynamic behavior of system, with the temps of response is 0.02 s, active power extracted 0.15 MW with lambda 9 and Cp 0,5 that the wind turbine can operate at its optimum power point for a wide range of wind speed and power quality can be greatly improved.

Air‐gap flux‐oriented vector control of dual stator induction generator used in wind energy conversion system with novel 13‐zone time optimized space vector‐based hybrid bus clamping PWM

This work presents a novel speed sensor less air-gap flux-oriented vector control of dual stator induction generator (DSIG) used for grid connected, variable speed wind energy generation system. The DSIG consists of two stator windings electrically separated by an angle of 30° with dissimilar pole numbers, which are in the ratio of 1:3. This arrangement offers reduced magnetic core saturation and less harmonics in stator currents, which results into reduced stator winding losses. Moreover, presence of two stator windings makes DSIG suitable to be used in high power application. In conventional rotor-flux-oriented control, the rotor flux is oriented along the d-axis of the rotor winding. But the rotor flux is not easily accessible. Air-gap flux-oriented vector control (AGFOVC) is advantageous as compared to conventional vector control because the air-gap flux is easily accessible and does not require any special arrangement for the measurement of variables. Moreover incorporation of this novel speed sensor less air-gap flux-oriented vector control also eliminates the use of speed encoder as the rotor speed is estimated from the machine terminal variables. Elimination of speed encoder not only reduces the cost of the overall system but also nullifies the error due to mismeasurement of speed and enhances control flexibility and robustness. As a result of which robustness of the system increases. Here, two separate converters are used for the two stator windings of the machine. And the converter switching's are being performed by space vector-based novel dwell time optimized 13-zone hybrid PWM. This special PWM results in better harmonic performance, reduced torque pulsation, and minimal switching loss. The simulation of the overall system is performed in MATLAB environment and the simulated results are validated experimentally using dSPACE controller board DS1104. Close proximity in simulated and experimental waveforms justifies the effectiveness of the proposed work.

A New Control Strategy of Dual Stator Induction Generator with Power Regulation

In this paper modelling and analysis of stand-alone dual stator induction generator (DSIG) with non-identical parameters under a new method has been done. The induction machine has two sets of stator three-phase windings spatially shifted by 30 electrical degrees. One supplied power to the DC load via a rectifier bridge and AC capacitors, and the other was connected to the battery banks by an inverter to store energy and restore it to regulate the power of the first stator in weak wind. We develop the steady state model and show the performances of different configurations by the simulation results.

Active and reactive power control of a dual stator induction generator for wind energy conversion

This paper deals with the active and reactive power control of a dual stator induction generator (DSIG) based wind energy conversion system (WECS).The DSIG is used instead of a doubly fed induction generator (DFIG) to avoid the main drawback of the slip-ring system. The DSIG has two three-phase windings in the stator; one is used as a power winding (PW) and the other as a control winding (CW). The aim of this paper is to establish the relationships between the powers delivered from the power winding and the voltages applied at the control winding terminals, to build a simplified diagram of the DSIG which permits to synthesise easily PI regulators. The DSIG based WECS is modelled and implemented under Matlab-Simulink environment and a set of simulation tests for both hypo-synchronous and hyper-synchronous operating modes are performed to prove the feasibility and the validity of the developed control laws.

Active and reactive power control of a dual stator induction generator for wind energy conversion

This paper deals with the active and reactive power control of a dual stator induction generator (DSIG) based wind energy conversion system (WECS).The DSIG is used instead of a doubly fed induction generator (DFIG) to avoid the main drawback of the slip-ring system. The DSIG has two three-phase windings in the stator; one is used as a power winding (PW) and the other as a control winding (CW). The aim of this paper is to establish the relationships between the powers delivered from the power winding and the voltages applied at the control winding terminals, to build a simplified diagram of the DSIG which permits to synthesise easily PI regulators. The DSIG based WECS is modelled and implemented under Matlab-Simulink environment and a set of simulation tests for both hypo-synchronous and hyper-synchronous operating modes are performed to prove the feasibility and the validity of the developed control laws.

Active and Reactive Power Control of a Dual Stator Induction Machine (DSIM) using PI Controllers

In this paper, we present the active and reactive power control of a Dual Stator Induction Generator (DSIG). Contrary to the Doubly Fed Induction Generator (DFIG), which is controlled by its rotor and which delivers power from its stator, in the DSIG, one of the two stator windings plays the role of control winding and the other plays that of the power winding. The aim of this article is to establish, using some simplifying assumptions, the relationships between the active and the reactive powers delivered from the power winding and the voltages applied at its control winding terminals. Based on these relationships, a functional diagram is built and the active and reactive power regulators are synthesized. A model of the controlled DSIG is implemented under MATLAB-Simulink environment and the simulation results showed the feasibility and the performances of the developed control laws.

Active and Reactive Power Control of a Dual Stator Induction Machine (DSIM) using PI Controllers

In this paper, we present the active and reactive power control of a Dual Stator Induction Generator (DSIG). Contrary to the Doubly Fed Induction Generator (DFIG), which is controlled by its rotor and which delivers power from its stator, in the DSIG, one of the two stator windings plays the role of control winding and the other plays that of the power winding. The aim of this article is to establish, using some simplifying assumptions, the relationships between the active and the reactive powers delivered from the power winding and the voltages applied at its control winding terminals. Based on these relationships, a functional diagram is built and the active and reactive power regulators are synthesized. A model of the controlled DSIG is implemented under MATLAB-Simulink environment and the simulation results showed the feasibility and the performances of the developed control laws.

Performance of Boost Converter with Fuzzy Logic Controller to Increase the DWIG Speed Range in Wind Power System

In this paper the wind energy conversion with a variable speed of wind turbine connected to the grid which is based on dual stator induction generator (DWIG) which is excited by Static Excitation Controller (SEC) on the Control winding side which utilized by Control –Winding Voltage Oriented Control (CWVOC), and followed by Step up converter at the power winding side which utilized Fuzzy Logic Controller in its control strategy to increase the speed range of DWIG. The performance of boost converter with FLC in increasing the wide range of speeds can be executed by using mat lab/Simulink.

ADSIG as Gen-Former providing three port network for soft coupling of distribution feeders in addition to wind energy harvesting

With increase in the Electric Vehicle (EV) load the coupling of feeder in the distribution has become essential. The paper prescribes the use of multiple Asymmetrical Dual Stator Induction Generator (ADSIG) acting as ‘Gen-Former’ to draw out coupling of feeders for bidirectional power transfer in addition to energy harvesting from the feed on its rotor from wind energy source. The paper presents an analysis of soft coupling for two feeders by providing route for power to flow from one power feeder to other power feeder region in addition to harvesting power from wind energy turbine. Asymmetrical Dual Stator Induction Generator (ADSIG) is modeled and analyzed for enacting as soft coupler for power transaction between two feeders together with wind energy harnessing. An experimental study is also done on a scaled down 3.75 kW developed prototype in the laboratory. The performance of the proposed system is analyzed and results show effective coupling between the feeders with power injection and effective power distribution by ADSIG under perturbing load conditions on either of the connected feeders.

Stator flux‐oriented vector control of dual stator induction generator with time optimised 11‐zone hybrid PWM for grid connected wind energy generation system

This work presents a novel stator flux-oriented vector control (SFOVC) of a dual stator induction generator (DSIG) used for a grid connected, variable speed wind energy generation system. The DSIG consists of two stator windings electrically separated by an angle of 30° with dissimilar pole numbers, which are in the ratio of 1:3. In conventional vector control, the rotor flux is oriented along the d-axis of the rotor winding. However, the rotor variables are not easily accessible. So, in the SFOVC, the total flux is made to be oriented along the d-axis of the stator winding. SFOVC is advantageous as compared to conventional vector control because the stator variables are easily accessible and do not require any special arrangement for the measurement of variables which increases the robustness of the system. Here, two separate converters are used for the two stator windings of the machine and the converter switching is being controlled by a novel space vector based 11-zone hybrid pulse-width modulation (PWM). This special PWM results in better harmonic performance, reduced torque pulsation and minimal switching loss. The overall simulation is being performed in MATLAB Simulink environment and the simulated results are also being validated experimentally.

Wind energy conversion system based on dual stator induction generator controlled by nonlinear backstepping and pi controllers

To capture wind energy and to produce electrical power, many conversion systems have been proposed. This work treats also the modeling and the control of dual stator induction generator DSIG integrated in wind energy conversion system. In order to increase the flow of the power to the grid and to ensure an optimum operating point, it is very important to act on the generator side controllers and the conversion system output variables. The Proportional integral PI controllers have been widely used to control alternative machines. In this case, the inverters, which fed the DSIG, are controlled simultaneously with a displaced angle of 30°. So, the synthesis PI gains still difficult. To solve this problem, a nonlinear backstepping control is proposed. For that, the suggested study presents the comparison of the performances of the two strategies. Different simulation tests are conducted to evaluate the efficiency and the validity of the proposed control strategies. We notice that in the steady state, the two controls allow the same performance (tracking). In transient mode, the backstepping command is better in terms of response time and overshoot.

A New Configuration of Dual Stator Induction Generator Employing Series and Shunt Capacitors

Doubly fed induction generators are suitable for systems having limited speed range as the overall control can be carried out by fractionally rated converters. However, brushes and slip-rings used in these generators reduce system reliability and demand greater maintenance. Dual stator winding induction generator (DSWIG), being brushless, removes this limitation. Two distributed windings are embedded in the stator and the rotor is squirrel-cage. One of the windings is interfaced to an uncontrolled rectifier and the other to a fractionally rated PWM converter. Uncontrolled rectifier degrades the power quality within the generation system. At the same time, reactive power demand in induction generators increases with loading. This paper deals with design and control of a standalone dc system based on DSWIG, where a combination of passive tuned filter and series capacitor is utilized to address the voltage regulation and power quality issue. Simulation results using MATLAB/Simulink and experimental results (obtained from a laboratory prototype) have been presented, compared, and discussed to demonstrate the effectiveness of the proposed alternative.

Control of dual stator induction generator integrated in wind energy conversion system

This paper deals with the modeling and the control of a dual stator induction generator (DSIG) integrated into a wind energy conversion system with a variable speed wind turbine. DSIG is increasingly used because of its advantages in better reliability and supply division. It consists of two fixed three-phase stator windings displaced with an electrical angle 𝛼𝛼. To minimize the harmonic distortion (THD), the objective of this work is to study the influence of the angle between these two stator windings on the grid generated current quality. To improve the performance of the system, the proposed control is demonstrated through an illustrative simulation.

Dual Stator Induction Generator For Rural Electrification

Dual Stator Induction Generator For Rural Electrification

Performance evaluation of self-excited DSIG as a stand-alone distributed energy resources

Multi-phase induction generators which may be operated in grid or self-excited mode, are found to be successful machines for wind energy conversion. Out of these two, self-excited mode is gaining importance due to its ability to convert the wind energy into electrical energy for large variations in operating speed. For this purpose, in this paper modelling and analysis in an isolated self-excited mode of dual-stator induction generator (DSIG) with a new algorithm have been done. We develop the steady-state model of a DSIG, for stand-alone renewable generation dispenses with the segregating of real and imaginary components of the complex impedance of the induction generator. Steady-state performances and characteristics of different configurations are clearly examined and compared. Simulated results as found using proposed “FZERO” algorithm are verified using experimental results on a test machine. Results obtained show that the system has sufficient capability for practical use in stand-alone power generation.

Modeling of a Dual Stator Induction Generator with and Without Cross Magnetic Saturation

This paper discusses general methods of modelling magnetic saturation in steady-state, two-axis (d & q) frame models of dual stator induction generators (DSIG). In particular, the important role of the magnetic coupling between the d-q axes (cross-magnetizing phenomenon) is demonstrated, with and without cross-saturation. For that purpose, two distinct models of DSIGs, with and without cross-saturation, are specified. These two models are verified by an application that is sensitive to the presence of cross-saturation, to prove the validity of these final methods and the equivalence between all developed models. Advantages of some of the models over the existing ones and their applicability are discussed. In addition, an alternative is given to evaluate all saturation factors (static and dynamic) by just calculating the static magnetizing inductance which is simply the magnitude of the ratio of the magnetizing flux to the current. The comparison between the simulation results of the proposed model with experimental results gives a good correspondence, especially at startup.

Analysis of Saturated Self-Excited Dual Stator Induction Generator for Wind Energy Generation

This paper presents the modeling of saturated dual stator induction generator (DSIG) for analysis of its transient and dynamic behavior for stand-alone operation. In the analytical model, the effect of common mutual leakage reactance between the two three-phase winding sets and the cross saturation have been considered. For this purpose, a detailed description of a procedure to introduce magnetic saturation in found models is presented. Paper also discusses the possibility of DSIG for supplying two individual loads by presenting the results of analytical and experimental study of transient behavior under various operating conditions. Use of such models leads to more accurate predictions in industrial drives, especially wind driven power generation systems. This is verified by experimental lab tests.

Fuzzy logic control strategy of wind generator based on the dual-stator induction generator

The work presented in this paper is the evaluation of the variable speed wind turbine based on dual star induction generator (DSIG) connected for power optimization in the conversion chain connected to the electrical grid. This optimization is concretized by two methods, namely, the Maximum Power Point Tracking ‘MPPT’ algorithm in the case where the characteristic of the turbine is known and the nonlinear method based on the theory of fuzzy logic controlled torque which is most appropriate when there is a lack of information on the characteristic (Cp(λ)) of the turbine. However, the limitation of power is performed by action on the generator control only. Simulation results are presented and discussed.

Effect of the Stator Mutual Leakage Reactance of Dual Stator Induction Generator

Effect of the Stator Mutual Leakage Reactance of Dual Stator Induction Generator

Optimized PI and Fuzzy Speed Vector Control of Dual Stator Induction Generator Used in a Variable Speed Wind

Optimized PI and Fuzzy Speed Vector Control of Dual Stator Induction Generator Used in a Variable Speed Wind