Abstract: A system for controlling reactive currents in a generator is provided. A control system receives current and voltage feedback from the generator. The control system determines a phase angle based on the current and voltage feedback. The control system determines a compensation signal corresponding to the phase angle and current. The control system modifies a generator excitation signal based on the compensation signal and a bi-linear transformation technique.

Abstract: A cross current compensation system for controlling reactive currents in a generator is provided. A control system for receives voltage feedback from a first generator of a plurality of generators and cross current feedback from at least a second generator of the plurality of generators. The control system determines a phase angle based on the voltage feedback from the first generator and cross current feedback from the at least a second generator. The control system determines a compensation signal corresponding to the phase angle and cross current feedback. The control system modifying a generator excitation signal for the first generator based on the respective compensation signal and a bi-linear transformation technique.

Abstract: A hybrid active filter shunts three-phase power with passive elements tuned to have low impedance at a frequency of harmonic distortion. The passive elements are in series with controlled voltages sources providing cancelling currents to the harmonic currents. Rapid determination of the harmonic currents is provided in real-time through the use of a Park transformation reducing the variables which need to be manipulated. Measured currents as transformed are used to model undistorted current based on an average power consumed by the load. When the undistorted current is subtracted from the actual current, a harmonic current signal is produced that may be used to drive the voltage sources. The time domain method requires rapidly computed running averages and thus may be performed in-between the acquisition of the measured current samples.

Abstract: A harmonic analyzer using a short sampling window eliminates truncation artifacts in the sampling of an AC power waveform by equating the length of the sample period to a period of the sampled waveform. The period of the AC power waveform is estimated from the waveform and used to produce a set of "resampled" points evenly spaced within that period as estimated from the sampled. By performing a spectrum analysis on the resampled points, artifacts at the harmonic intervals are reduced to zero.

Abstract: Yarns of balanced low tensile characteristics, especially low tensile factor (TE.sup.1/2) are produced in high speed spinning (e.g. greater than 10000 fpm) operations including an annealing stage by process control, particularly inverse spinning temperatures for given yarn. Polyethylene terephthalate yarns of balanced tensile characteristics and tensile factor of as little as 15-17 are prepared directly from a spin draw line at maximum productivity.