Abstract: A method of synchronizing a cross-compound generator system on one or more turning gears during startup includes determining, via a notch monitor controller, first and second angular velocities, respectively, of a first and a second rotor. The method also includes simultaneously exciting, via the notch monitor controller, the first and second rotors to attain electromechanical coupling therebetween. The method further includes determining, via the notch monitor controller, a value of a time at which a calibration value of an offset is a constant value, where the offset is representative of a phase alignment of the first rotor relative to the second rotor, and where the offset is indicative of a successful electromechanical coupling therebetween. The method also includes disengaging the one or more turning gears from the cross-compound generator system.

Abstract: In accordance with an embodiment, an apparatus for analyzing signals comprises a spectrum analyzer and a frequency extension module. The spectrum analyzer includes an IF switch which switches between an internal IF signal and an external IF signal, and a LO coupler which is configured to output a portion of one or more LO signals. The frequency extension module is configured to receive the one or more LO signals from the spectrum analyzer and send an IF signal to the spectrum analyzer. A diplexer band switch is used to direct the low band signals to the spectrum analyzer and to direct the high band signals to the frequency extension module where they are downconverted to the external IF which is output to the IF switch.

Abstract: Systems provide for a test system for capacitors in a digitally controllable oscillator (DCO). The system includes: capacitor toggling logic configured to switch on and off a selected one of the capacitors at a modulation frequency; a tone generator configured to generate a tone; a mixer configured to receive the tone and an output carrier signal from the DCO while the capacitor toggling logic is switching the selected one of the capacitors on and off and to output an intermediate frequency signal having FM sidebands based on the modulation frequency and relative capacitor size; and an evaluation circuit configured to evaluate a frequency deviation associated with the selected one of the capacitors based on at least one of the FM sidebands.

Abstract: A method for determining an offset of a periodic signal is provided, wherein an offset value caused by a level change of the periodic signal is suppressed. The periodic signal is fed to first and second integrators and to a periodicity recognition unit, wherein the first integrator is integrated over a full period. The second integrator is integrated over a full period offset by a half period. Starting times of integrations are controlled by the periodicity recognition unit. Output signals of the integrators are stored in two memories, wherein the output signals are summed and a sum signal represents the offset of the periodic signal. The output signals are fed to a comparator circuit. The sum signal is stored in a further memory as an output signal, wherein the comparator circuit triggers the further memory to continue outputting a value of the output signal stored in the further memory.

Abstract: The invention relates to protective apparatus used on AC power lines. An embodiment of an apparatus for putting the invention into practice comprises impedance sensing means having an impedance characteristic defining at least three distinguishable zones in its RX diagram, and being arranged to produce respective different signals, one for each zone, indicating the zone in which the sensed impedance lies. The movement of the point representative of the apparent impedance of the line across these zones is different according to whether the movement is due to loss of synchronism between the generators supplying the line or due to power oscillations. A logic circuit is provided to detect this difference in movement.

Abstract: This invention relates to a system for simulating a power plant synchroscope in which a digital computer supplies the information which indicates when two alternators are, or are not, in synchronism. Digital words are supplied by the computer to two separate registers whose parallel outputs are applied to the inputs of two separate frequency multipliers, one for each register. A single oscillator supplies its output to the second inputs of both of the multiplier, and the frequency of the oscillator is therein multiplied by the value of the words from the computer. The outputs from the two multipliers are supplied to two separate channels, one representing each of the two alternators. The square waves in each channel are converted into sine waves which are then applied to the incoming and running windings of a standard synchroscope. In addition, the information in the two channels is applied to the inputs of a phase difference detector which produces a digital phase difference.