An Enhanced Control Strategy for Standalone Brushless Doubly Fed Induction Generator Under Unbalanced Load Using Reactive Power Loop

Without brushes and slip rings, the brushless double-fed induction generator (BDFIG) can operate more stably and reliably, so it is prospective to be one of important machines for standalone systems in the next few years. The stability of amplitude of voltage and frequency of power winding (PW) is major aim of control in off-grid system. Also, the standalone system is oversensitive to abnormal running situations, especially with unbalanced conditions. The unbalanced loads would lead to harmful phenomena, such as the unbalanced impact of current and voltage of PW. To handle this issue, the reactive power loop is presented to minimize voltage unbalance of PW through creating control winding (CW) compensation voltage via converter of machine side (MSC). The simulation is executed to test the performance of presented method.