Woodward MSLC Master Synchronizer and Load Control Synchronizer

Synchronizer

The MSLC uses digital signal processing techniques to derive both true RMS

voltages and relative phase angles of the fundamental frequencies of the utility

and the local bus voltage wave forms. Digital signal processing techniques offer

significantly improved measurement accuracy in the presence of wave form

distortions, particularly since the phase measurement does not depend on zero

crossings of the voltage wave forms.

Either phase matching or slip frequency synchronizing may be selected. Phase

matching provides rapid synchronizing for critical standby power applications.

Slip frequency synchronizing ensures that the initial flow of power will be either

out of the local system (export) or into the local system (import), depending on

whether a positive or negative slip is chosen. For both synchronizing methods,

the MSLC uses actual slip frequency and breaker delay values to anticipate an

adjustable minimum phase difference between the utility and the local bus.

Additional synchronizer functions include voltage matching, time delayed

automatic multi-shot reclosing, auto-resynchronizing, and a synchronizer timeout

alarm. Each of these features may be enabled or disabled during setup.