An Adaptive Actuator Driver for AC Contactors

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.