DG Synchronizing

It is essential to synchronise genset breakers prior to connecting to a busbar already supplied by another power source. Microprocessor controlled, easy-to-install packages with no moving parts, PMAS’s synchronisers are market-leading choices for checks of frequency, voltage, phase angle and more.

PMAS’s synchronising units always calculate when to close the breaker to get the most accurate synchronisation. The close signal will be issued when phase L1 of the synchronising genset is close to the 12 o’clock position compared to the busbar which is also in 12 o’clock position.

In dynamic synchronisation, the synchronising genset runs at a different speed from the generator on the busbar. Typically, the synchronizing genset runs with this difference, called a positive slip frequency, meaning that it runs with a higher speed than the generator on the busbar. The objective is to avoid a reverse power trip following the synchronisation.

In these cases, it is possible to synchronise relatively fast because of the adjusted minimum and maximum slip frequencies: even while the unit is aiming to control the frequency towards its setpoint, synchronising can still occur as long as the frequency is within the limits of the slip frequency adjustments.

In static synchronisation, the synchronising genset runs at a speed close to the generator speed on the busbar. The aim is to let them run at exactly the same speed, and with the phase angles between the generator and busbar’s 3-phase systems matching exactly.