Systems and methods for valve actuation use series-connected coils of
upper and lower electromagnets acting as electromagnetic generators that
attempt to maintain a constant magnetic flux, while their forces are
essentially independent. A valve controller initiates valve actuation by
reducing holding force of the holding electromagnet. As spring force
begins to move an armature away from the holding electromagnet, the
associated coil generates a voltage that attempts to maintain constant
flux. This generated voltage causes a large increase in current that
essentially transfers the flux to the other on-coming coil, which
attracts and holds the armature against its associated spring force to
open or close the valve. The internal voltage generated inside the two
coils operates even if the coils are supplied with zero external voltage
(shorted) to transfer stored energy directly between the coils. Energy
may be transferred indirectly using an energy storage device.