The actuator drivers are rarely transplanted among different contactors because the self-tuning of excitation control parameters either takes a long time or is relevant to many contactor structural parameters. An adaptive actuator driver for ac contactors is proposed based on the coil impedance estimation and mathematical equations between the coil impedance and excitation control parameters. The coil impedance estimation and its error correction are established through the voltage balance equation when the contactor is in the open position. The coil inductance estimation is established through the zero-state response equation when the contactor is in the closed position. The mathematical equations are established based on the equivalence of the electromagnetic force under different excitation methods, the power consumption model, and the control system's transfer function. A geometric feature of the flux linkage waveform is established to identify whether a contactor is in the closed position and realize the self-transition of the driver's working state. Then, self-tuning regulators for the excitation control parameters are realized. This driver has a plug-and-play function for ac contactors and can reduce the contactor's power consumption. This driver may be prospectively reduced to a chip.

In order to break from the status que that the mainstream design method of intelligent controllers for contactors is one for one, a digital controller is proposed, which can be applied to series of AC contactors without adjustment through estimating the control parameters based on the online measurement results of coil impedance. During the closure, the duty is constant and the pull-in consumption is reduced by the electro-magnetic interference filter with a capacitor-free coil drive circuit. When contactors are in closed position, the closed-loop control parameters are designed according to the online measurement results. During the opening, the voltage of coil became negative so that the coil current decrease rapidly. Series of double-E type AC contactors from 18A to 170A are used as prototypes to experiment. The results show that the digital controller for series of AC contactors performs well.

For the frequent occurrence of pulse power load operation and load switching disturbances in AC/DC shipboard microgrids, a large-signal stability analysis method based on hybrid potential theory is proposed. The proposed method utilizes a mixed potential function to analyze the impact of interconnected converters on system stability. First, the entire system is equivalently modeled as a DC system in a d-q rotating reference frame. Then, a mixed potential function model of the AC/DC system is established for stability analysis, leading to the development of a large-signal stability criterion for the system. Using this criterion, the boundary values of bidirectional power transfer for the interconnected converters are derived. Finally, a simulation model of the AC/DC hybrid microgrid system was built in Simulink for verification, and further validation was carried out on the RT-lab hardware-in-the-loop (HIL) simulation platform. Simulation and experimental results show that the proposed criterion can effectively ensure the stability of the AC/DC hybrid microgrid system under large disturbances.