Protective Relay RS 2001 – Successful Implementation of the “Two Out of Three“ Principle
For future new high-voltage direct-current projects, the Chinese State Grid Corporation is requesting that all systems are equipped with controller protection devices with three contacts. In compliance with the requirements of energy supply customers and the State Grid Corporation, we have now developed, tested and manufactured an oil-flow controlled protective relay with three independent contacts.
The relay has been specially designed by MR to protect on-load tap-changers and has been aligned with the design of the MR on-load tap-changers so that the safety of the tap-changers is ensured to the fullest extent. The main function of the protection device is to increase the reliability of the system. The new requirement for three contacts is an effective measure for increasing the reliability of the relay signal processing. The quality of the relay itself is of crucial significance and it is also extremely important that the function of the protected on-load tap-changer is also taken into consideration in the design. Both of these factors were taken into account during our development.
Of course, this protective relay is an advanced development based on the current version of the RS 2001, which has a maximum of two contacts. We have retained all the design features affirmed in practice as well as the type designation, thus offering our customers a protective relay with maximum reliability. The product has of course also passed all IEC tests smoothly.