Preventing Generator Pole Slip

March 11th, 2013

Pole slip, also known as ‘out of step’ is a phenomenon caused either by low excitation, a faulty regulator or abrupt changes of load within the mains. It can cause severe mechanical stresses within the generator, putting winding at risk, causing shaft damage or adversely affecting the control operating system. Very high currents can cause thermal instability and ultimately lead to complete destruction of the generator and massive instability on the grid.

pole-slip-2Conventional protection, such as overcurrent, vector shift and ROCOF is not sufficient as it doesn’t respond quickly enough and is unreliable where large load jumps develop and cause oscillations.

ComAp InteliProThe new, patent-pending solution from ComAp strengthens the overall protection of synchronous generators by preventing unnecessary damage to embedded power systems. The new technology predicts imminent pole slip in time to minimise the destructive effects of lost synchronism without the need for complicated settings. It’s the perfect solution where pole slip protection is required on projects such as STOR (Short Term Operating Reserve). ComAp pole slip protection is now available in IntelPro, InteliGen and InteliSys controllers.

Contact the ComAp Controls team on for more information on pole slip protection.