Novel Fault Ride-Through Configuration Scheme for Doubly-fed and Self-excited Induction Generators

  • Suud Ademnur Hasen

Student thesis: Master's Thesis

Abstract

This thesis proposed new grid interface topologies for enhancing the fault ride through (FRT) competency of Doubly Fed Induction Generator (DFIG) and Self-Exited Induction Generator (SEIG) based wind turbines. These compromise shunt and series compensation grid interfaces and consider dynamic series braking resistor, HTS-cable and HTS-transformer. Thus, a novel modulated series dynamic braking resistor (MSDBR) FRT configuration scheme is developed to enhance the FRT of DFIG and SEIG, along with static synchronous compensator (STATCOM). The new configuration introduces modulated compensation for voltage dips acting as voltage booster and provides a mean of power discharge to mitigate the power imbalance during grid faults. To accomplish a flexible control solution for symmetric and asymmetric voltage dips, the MSDBR topology engages a modulated pulse signal generating controller for each phase individually. For DFIGs, in order to analyze the system dynamics of the proposed scheme a small-signal linear model is designed and inspected. Hence, the controller is adjusted to stabilize both voltage regulation capability and system stability with respect to various operating conditions based on the mathematically derived model. For SEIGs, collaboration of both MSDBR and STATCOM, operating as a series and shunt compensation respectively, configuration is developed to mitigate system oscillation and improve system performance in slight grid disturbances. The developed topologies demonstrate a simple protection assembly, low component usage and enhanced capability of FRT performance with effective compensation to the grid networks. An inclusive simulation results proved the FRT enhancement capability of the proposed topology.
Date of AwardMay 2014
Original languageAmerican English
SupervisorMohamed El Moursi (Supervisor)

Keywords

  • Induction Generators; Automatic Control; Doubly Fed Induction Generator (DFIG); Low Voltage Ride Through (LVRT); stator voltage.

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