ComAp’s Protection Relays Compliant with EREC G59 Amendments

ComAp ensures that our products are kept up to date with the most recent regulation changes as well as providing our customers conformity compliance according to the latest G59 Engineering Recommendation (EREC G59) amendment. Therefore, ComAp’s protection relays, MainsPro and InteliPro, are compliant with the latest EREC G59 updates. The amendments, G59/3-4 and G59/3-5, are in effect as of July 2018.

The modification, G59/3-4, disallows future use of Vector Shift protection and provides new ROCOF (rate of change of frequency) requirements for the type-tested generation. The G59/3-5 modification requires that all generations <50MW must apply a ROCOF setting of 1Hz/s.

There are two main passive methods to detect loss of mains (LOM), ROCOF and Vector Shift. The ROCOF method detects the rate of frequency change which occurs due to a difference between the prime mover power and the electrical output of the embedded generator. The Vector Shift method is based on detecting the shift in the voltage curve as a result of a sudden change in the output of the embedded generator.

While there are advantages and disadvantages associated with both methods, EREC G59 outlines that: “Investigations in early 2017 have shown that Vector Shift protection is susceptible to spurious operation during voltage disturbances caused by faults on the transmission system and is less effective at detecting islands in the distribution system.”
 
For more information, please feel free to read the conformity declaration for InteliPro and MainsPro.