Copper Loss Optimization Strategy of Fault-Tolerant Operation for Doubly Salient Electromagnetic Generator Under Excitation Loss

The excitation loss of doubly salient electromagnetic generator (DSEG) can be caused by the fault in the excitation winding due to aging, overheating, and external force impacts, as well as the fault in the excitation power converter due to reasons such as overcurrent and reverse voltage shocks, which makes the system exhibit abnormal operation. Consequently, a fault-tolerant power generation (FTPG) strategy is proposed for the DSEG system under excitation loss, which can enhance the DSEG’s fault-tolerant capability and mitigate the copper loss. First, this article analyzes the fundamental principles of normal power generation in DSEG, establishes its mathematical model under excitation loss, and investigates the fault-tolerant control strategy. Subsequently, this article analyzes the mechanism behind the high copper loss issue in implementing the positive and negative excitation angle control (PNEAC) strategy during the fault-tolerant operation of the DSEG under excitation loss. Furthermore, a positive and negative current given control (PNCGC) strategy with an advanced angle is proposed for FTPG, to optimize the copper loss of DSEG under excitation loss. According to the mentioned hypothesis, some experiments are performed on an 18-/12-pole DSEG system to demonstrate the feasibility and effectiveness of the proposed strategy.