The quantitative and qualitative analysis was performed to find how much cross current (called “load unbalance cross current”) was running in accordance with the unbalance rate of load share when two synchronous generators were in parallel running, how much bus voltage fluctuation and increasing rate of cross current (as troubled cross current) were caused if one generator offered defects in any modes to make external voltage abnormal.
As an example to apply the trouble characteristics in parallel running, the automatic parallelreleasing device for troubled generator is referred to protect the blackout of power source by finding out the troubled generator to be released out of the parallel. The device is recognized to operate satisfactorily when mounted on actual ship.