Dynamic performance enhancement of a grid-connected wind farm using doubly fed induction machine-based flywheel energy storage system

This paper presents the dynamic performance enhancement of a wind farm connected to an IEEE-39 bus New England test system using doubly-fed induction machine (DFIM)-based flywheel energy storage system (FESS). The variable wind speed causes fluctuations in the output power of the wind farms. The use of FESS smoothes the power of the wind farm and improves the dynamic response of the system during fluctuating wind speeds. A DFIM-based FESS is proposed in this study which works on an effective control technique. The cascaded black-box optimization technique based proportional-integral (PI) control strategy is implemented on the FESS. The PI controllers are used to control the insulated gate bipolar transistor (IGBT) based rotor side converter (RSC) and the grid side converter (GSC) of the DFIM. The PI controller In-depth modeling and control strategy of the system under study is presented. The effectiveness of the proposed system is tested under real-time wind speed data. The validity of the system is verified by the simulation results which are carried out using PSCAD/EMTDC

Steady-state analysis of three-phase self-excited reluctance generators

A three-phase reluctance machine can be made to operate as a self-excited generator when its rotor is driven at suitable speed by an external prime mover and its excitation is provided by a capacitor bank connected to the stator terminals. The reluctance generator has almost all the advantages of its counterpart induction generator and has in addition the advantages of constant frequency operation and low core and copper losses. This paper introduces an analysis of the three-phase self-excited reluctance generator. The developed analysis avoids the limitations of the previous works whereby the effect of the core loss is soundly taken into consideration. The analysis is suitable for variable speed, load and excitation capacitance operations. The validity of the proposed analysis is confirmed experimentally. The effect of neglecting the core loss is also studied

Transient stability improvement of a grid-connected wind farm using doubly fed induction machine based flywheel energy storage system

This paper presents the transient stability improvement of a grid connected wind farm using doubly-fed induction machine (DFIM) based flywheel energy storage system (FESS). The control strategy of the FESS relies on a frequency converter with insulated gate bipolar transistors (IGBTs) using cascaded proportional-integral (PI) controllers. These PI controllers are used to control the rotor side converter (RSC) and the grid side converter (GSC) of the DFEVI. The detailed modelling and the control strategy of the system under study are investigated. The effectiveness of the proposed control strategy is tested under a severe symmetrical fault condition. The validity of the system is verified by the simulation results which are carried out using PSCAD/EMTDC environment

Control of grid connected induction generator using naturally commutated ac voltage controller

The paper presents complete analysis of induction generator linked to the network through ac voltage controller utilizing anti-parallel thyristors. The performance characteristics regarding the harmonic contents, active power, reactive power, power factor and efficiency have been computed. These characteristics have been determined with the help of a novel abc-dq circuit model. The model posses the advantages of both the dq and direct phase models.GENNUM Corp., Bell Simpatico Canada, IEEE Canada, General Electric Canad

Magnetization-Dependent Core-Loss Model in a Three-Phase Self-Excited Induction Generator

Steady-state, transient, as well as dynamic analyses of self-excited induction generators (SEIGs) are generally well-documented. However, in most of the documented studies, core losses have been neglected or inaccurately modeled. This paper is concerned with the accurate modeling of core losses in SEIG analysis. The core loss is presented as a function related to the level of saturation. This relation is determined experimentally and integrated into a nonlinear model of the SEIG. The nonlinear model is solved using a mathematical optimization scheme to obtain the performance parameters of the SEIG. A new set of curves describing accurate behavior of the SEIG parameters is produced and presented in this paper. The computed parameters of the model are validated experimentally, and the agreement attained demonstrates the functionality and accuracy of the proposed core-loss model