Dynamic Modeling and Control of BDFRG under Unbalanced Grid Conditions

Abstract

The Brushless Doubly-Fed Reluctance Generator (BDFRG) is a potential alternative to the Doubly Fed Induction Generator (DFIG) in wind power applications owing to its reasonable cost, competitive performance, and high reliability. In comparison with the Brushless Doubly-Fed Induction Generator (BDFIG), the BDFRG is more efficient and easier to control owing to the cage-less rotor. One of the most preferable advantages of BDFRG over DFIG is the inherently better performance under unbalanced grid conditions. The study conducted in this paper showed that conventional vector control of the BDFRG results in excessive oscillations of the primary active/reactive power, electromagnetic torque, and primary/secondary currents in this case. In order to address such limitations, this paper presented a new control strategy for the unbalanced operation of BDFRG-based wind generation systems. A modified vector control scheme was proposed with the capability to control the positive and the negative sequences of the secondary currents independently, thus greatly reducing the adverse implications of the unbalanced supply. The controller performance has been validated by simulations using a 1.5 MW BDFRG dynamical model built upon the positive and negative sequence equations. The main benefits of the new control strategy are quantified in comparison with conventional PI current control design.

Efficiency and Performance Optimization of State-of-the-Art “Multi-Phase, -Level, -Cell, -Port, -Motor” Electrical Drives and Renewable Energy Systems

“…In ref. [1] is proposed a system for the dynamic modeling and control of a brushless doubly fed reluctance generator (BDFRG), considering specific conditions of operation, such as unbalanced grid conditions. The BDFRG is presented as a prospective replacement to the doubly fed induction generator for wind power applications, where aspects related to the cost, performance, and reliability are highlighted.…”

A Proposed Controllable Crowbar for a Brushless Doubly-Fed Reluctance Generator, a Grid-Integrated Wind Turbine

“…Energies 2022, 15, 3894 2 of 29 Moreover, considering the lack of rotor copper losses, the BDFRM is expected to outperform the BDFIM in terms of efficiency [6][7][8]. As a result, the brushless doubly fed reluctance generator (BDFRG) is discovered to be the most appealing for WECS [9][10][11].…”

Research on Control Strategy of Grid-connected Brushless Doubly-fed Wind Power System Based on Virtual Synchronous Generator Control

“…In order to make the control mode more flexible, some scholars have studied the control strategy based on open winding [13], and further developed the fault-tolerant control strategy [14]. And the control strategy of BDFRG under unbalanced grid voltage is proposed in [15], [16]. The above strategies are conventional power control strategies, aiming at the rapid response of power, so that the system can transmit more active current to the power grid as much as possible.…”