Abstract: A current sensing system comprises a current transformer; a burden resistor connected across a secondary of the current transformer; a piezo-optic sensor coupled to the burden resistor, comprising a piezoelectric transducer, an optical fiber and a first optical filter with a first bandwidth; and an optical interrogator, configured for sending an originating signal to the first bandwidth optical filter and receiving a resulting data signal and a second optical filter with a second bandwidth for filtering the resulting data signal.

Abstract: A system for transferring mechanical torque variably between a plurality of rotating machines in a turbofan engine. Two devices are used, where the first device relies upon magnetic properties of a planetary magnetic gearbox to couple the magnetic machines. The second device is used to variably control the torque transfer between the magnetic machines. The system couples rotating shafts rotating at differing speeds within a turbofan engine for controllably transferring power. To transfer power in the system, a fixed gear ratio is obtained by coupling the relatively high- and low-speed engine shafts to an epicyclic magnetic gearbox.

Abstract: An apparatus for detecting currents in a three-phase power transmission system includes a first detection circuit electrically coupled to a first phase of the three-phase transmission system, a second detection circuit electrically coupled to a second phase of the three-phase transmission system different than the first phase, and an event output switch electrically coupled to the first detection circuit and the second detection circuit and configured to actuate when a subsynchronous current at least one of the first phase and the second phase exceeds a pre-selected subsynchronous current setpoint.

Abstract: An apparatus for detecting currents in a three-phase power transmission system includes a first detection circuit electrically coupled to a first the three-phase transmission system, a second detection circuit electrically coupled to a second phase of the three-phase transmission system different than the first phase, and an event output switch electrically coupled to the first detection circuit and the second detection circuit and configured to actuate when a subsynchronous current at least one of the first phase and the second phase exceeds a pre-selected subsynchronous current setpoint.

Abstract: A distribution series capacitor control system is provided with a sub-harmonic detection module connected to an input signal and operable to detect the presence of at least two distinct types of sub-harmonic content in the input signal. A logical signal processor is electrically connected to the sub-harmonic detection module, and operates to independently determine the existence of self-excitation during induction motor starting and ferroresonant phenomena based upon the at least two distinct types of sub-harmonic content, respectively. A system controller is electrically connected to the logical signal processor and operates to eliminate effects of self-excitation during induction motor starting and ferroresonant phenomena on the system.