Comprehensive Dynamic Current Control of Electrically Excited Synchronous Machines With Magnetic Mutual Couplings

Electrically excited synchronous machines have become an attractive solution to electric vehicles. The excitation of the machine is controllable by adjusting the field current. However, due to the magnetic mutual couplings between stator and rotor windings, a voltage will be induced in the stator winding in case of a current rise in the field winding and vice-versa. In this article, a dynamic current control algorithm is proposed in which magnetic mutual couplings are comprehensively taken into consideration. To achieve this, first, the expected current derivatives are determined according to the error. Then, the voltages across all self- and mutual inductances are calculated correspondingly. In the end, the resistive voltages, inductive voltages, and the cross-coupling terms are summed up to construct the total controller output. To make sure that the control still works when the voltage output limit is reached, an antiwindup algorithm with adaptive bandwidth is proposed to cooperate with the dynamic current control algorithm. The results from simulations and experiments show that smoother responses can be achieved with the proposed control method.