Principle of operation

The synchronizing and paralleling process can be divided

into the following blocks

Measuring

Voltage difference ΔU (amplitude), slip s (frequency diffe

rence), and phase-angle α, are all required for paralleling.

These values are formed from the two measurement signals

U1 and U2 (see illustration, left).

Matching

Voltage and frequency matching functions reduce the voltage

difference ΔU, and slip s by sending adjusting pulses to the

voltage or turbine regulators.

Monitoring of paralleling conditions

This function compares the actual values with their set

maximum values and releases paralleling (CHK RELEASE) if

all conditions are fulfilled simultaneously.