| 摘要 |
<p>1487976 Bringing A.C. systems into parallel SUNDSTRAND CORP 1 April 1975 [29 March 1974] 13278/75 Heading H2H A paralleling control apparatus for an electrical power generating and distributing systern having a first electrical power source which includes an A.C. generator driven by a variable speed engine by way of a controllable, constant speed driving device, and a second A.C. electrical power source, the paralleling control apparatus comprising means for providing an A.C. phase reference signal the phase of which corresponds to that of the second power source, a comparator for comparing the phase of the A.C. generator output with the phase reference signal, means responsive to the output of the phase comparator for developing a cumulative phase difference signal which phase difference signal is applied to the constant speed driving device so as to synchronize the phase of the A.C. generator with that of the reference signal, switch means to connect the electrical sources in parallel and means responsive to the phase comparator for actuating the switch means to connect the electrical power sources in parallel when the phase difference between the A.C. generator and the reference signal is within selected limits. The second power source may be formed by a further A.C. generator driven by a variable speed engine by way of a controllable, constant speed driving device or, in applications where the A.C. generators are installed in aircraft, it may be an A.C. source external to the aircraft. The A.C. phase reference signal may be derived from any one of the power sources selectable according to which source is to be synchronized. The switch means for paralleling the power sources may be made responsive either to the cumulative phase difference signal or to an instantaneous phase difference signal. A tachogenerator may be associated with each A.C. generator whereby the output frequency of the generated can be controlled.</p> |
