An autosynchronizer for use with a system having generator and bus voltages and having a breaker circuit for connecting the generator and bus voltages to each other. The autosynchronizer synchronizes the frequency and phase of the generator and bus AC voltages by controlling the generator voltage. A microprocessor compares the frequencies of generator and bus voltage signals, the microprocessor generating a proportional difference signal having a parameter representative of a proportional difference in frequency between the generator and bus voltage signals. The proportional correction range extends within the synchronization range. The microprocessor permits a sync signal when the frequency difference of the frequencies of the generator and bus voltage signals is within the synchronization frequency range. A first output circuit responsive to the proportional difference signal provides a correction signal to the generator for varying the frequency of the generator. A second output circuit responsive to the sync signal provides a breaker close signal to the breaker circuit for closing the breaker thereby enabling connection of the generator and bus voltages. A frequency correction dead band within the frequency range and a target slip band within the dead band define a zone of limited proportional correction to nudge the generator into synchronization and prevent a hung scope.
A power use circuit breaker includes an arc generating switching unit which adds an electrical resistance in a circuit during current interruption to attenuate a current to be interrupted, a vacuum bulb which is electrically connected in series with the arc generating switching unit and interrupts the attenuated current and a current conducting switching unit connected in parallel with the series circuit of the vacuum bulb and the arc generating switching unit. For current conduction the current conducting switching unit is closed after the vacuum bulb and the arc generating switching unit are closed, and for current interruption after opening the current conducting switching unit, the vacuum bulb and the arc generating switching unit are opened.
An automatic transfer switch (ATS) system and method of operating an ATS system to switch between first and second powers received from respective first and second power supplies, are disclosed. In one embodiment, the method includes sensing a first phase associated with the first power and a second phase associated with the second power, and determining whether the first and second phases have failed to become synchronized within a first time period. The method further includes providing a control signal at a second output port when it is determined that the first and second phases have failed to become synchronized within the time period, determining that the first and second phases have become synchronized in response to the control signal, and switching between the first and second powers once it is determined that the first and second phases have become synchronized.
A system and method for sensing alternator current levels are disclosed. The system includes the combination including an operational amplifier having an input and an output, an input resistor connecting the input to a signal indicative of an alternator current level, and a feedback resistor connected between the input and the output. The system further includes an adjustment resistor and a switching element coupled in series between the input and the output, in parallel with the feedback resistor, and a processor coupled to the output. The processor is operable, based upon a current indication related to a level of alternator current indicated at the output, to control the operation of the switching element such that the switching element is closed when the current indication increases to exceed a first threshold, and such that the switching element is opened when the current indication decreases to fall below a second threshold.
A genset controller that is configurable for controlling a variety of types of gensets, as well as a method of configuring a genset controller for controlling a genset, are disclosed. The genset controller includes a memory for storing a plurality of software routines, a personality profile data set, and a user-settable data set, and further includes a processor coupled to the memory for executing the software routines and reading data from the personality profile data set and the user settable data set to control the genset. The genset controller additionally includes an input port coupled to the memory for enabling changes to the personality profile data set and the user-settable data set to be downloaded into the memory. The personality profile data set and the user-settable data set include data that configures the genset controller for operation with a particular genset.
A method and apparatus are disclosed for controlling a genset having an engine and an alternator in order to prevent an excessive change in a speed of the engine because of a sudden change in a load on the alternator. The method includes obtaining a first measured value of an actual AC output power of the alternator at a genset controller during a first time period, and obtaining a second measured value of the actual AC output power of the alternator at the genset controller during a second time period. The method further includes determining at the genset controller a first output power based upon at least the first measured value, and a second output power based upon at least the second measured value. The method additionally includes determining at the genset controller, based upon the first output power and the second output power, whether the actual AC output power has changed in an amount greater than a first threshold, and providing a first control signal from the genset controller to the genset causing a position of a throttle to be modified when it is determined that the actual AC output power has changed in an amount greater than the first threshold.
