Study Of Dynamic Simulation Experimentation On Flexible Power Conditioner Based On Flywheel Energy Storage

In this thesis, dynamic behavior of the doubly fed induction machine during three-phase voltage dips and dynamic simulative experiment based on Flexible Power Conditioner are studied. Between two issues, the former is studied more carefully. The main objective of the work is to design an algorithm that would enable the system to control the initial over currents that appear in the generator during voltage sags, which can damage the RSC (rotor side converter), without tripping it. Using the algorithm, the RSC will not disconnect the doubly fed induction machine during the voltage dips. Therefore, it become possible to inject the reactive power during grid voltage dips that guarantee the stability of the grid voltage.In order to gain a control strategy under the voltage dips, the whole components of the system are studied carefully during the voltage dips, including GSC (grid side converter), RSC, and DFIM (doubly fed induction machine). As the basement of the study, dynamic modeling of DFIM, GSC and RSC and its vector control in the dq reference frame are presented in chapter 2. In chapter 3, a control strategy during grid voltage dips for GSC during the voltage dips is presented and the simulations are carried out in the MATLAB/SIMULINK software to validate the control strategy. In chapter 4, the most important chapter, the dynamic characteristics of the doubly fed induction machine and the machine side converter are studied. The proposed analysis contributes to understanding the cause of the problem and represents a very useful tool to improve the existing solutions and propose new alternatives. Simulation results are collected using PSCAD/EMTDC software, which are in good agreement with those obtained theoretically. Finally, in chapter 5, the experimental results of several statuses, for example, energy storage, active and reactive power generation status, operation as a condenser status, small disturbance status, are compared and analyzed. The results prove that it is effective to control small disturbance in the grid.