Abstract: In accordance with various embodiments, there is a method for determining the capacity of a battery. Various embodiments include applying a predetermined current ramp to a fully charged lead-acid battery while measuring a battery terminal voltage. An Iup can be determined, where the Iup is a transition from charging to overcharging. A specific gravity of the lead-acid battery can also be determined. The capacity of the lead-acid battery can then be determined from the Iup using a correlation function that describes the relationship of the Iup to the capacity, where the correlation function depends on the specific gravity of the lead-acid battery.

Abstract: A composite tie rod comprises a plurality of coated fiber bundles stretched between two nut assemblies. Fiber holders, in combination with the nut assemblies, hold the fiber bundles in tension to provide a compressive force for maintaining component placements along the entire axial length of a turbomachinery rotor.

Abstract: An electrical power system includes an electric power source providing AC power to a load. A wideband voltage controller provides a wideband control signal vector to the electric power source. A fundamental component removal module interfaces to the AC power, receiving a fundamental component Park vector of the AC voltage, and providing a resonant frequency content in Park vector format of the AC current. A narrow band voltage regulator uses a resonant component Park vector of the AC current and the resonant frequency content in Park vector format to provide a narrow band output vector signal. A dead band compensating circuit rotates narrow band output vector signal by a transport lag compensation angle to provide a compensated control signal vector to the electric power source. The wideband control signal vector and compensated control signal vector are used to regulate the AC power so that the resonant frequency content is attenuated.