Generator Rotor Protection Relay: MRR1

FEATURES
  • Detection of high impedance earth faults with a low frequency test voltage.
  • Short circuit and overvoltage-proof measuring input for the earth fault protection
  • Exciter current measurement galvanically isolated, measuring range 0-20A
  • Display of insulation resistance and of the excitation current
  • Excitation current over & undercurrent protection with independent settings for current and delay time
  • Detection of diode failures by supervision of the ripple component of the excitation current
  • Two-stage supervision of the rotor insulation resistance with independent settings for resistance and time delay
  • Digital inputs for blocking and for remote reset
  • Programmable function of the blocking input
  • Programmable assignment of protective functions to output relays
  • Remote interfacing via RS-485 (optional)

The generator rotor protection relay MRR1 combines rotor earth fault protection, excitation over- and under-current protection. Thus providing a powerful protection regarding the rotor of synchronous generators.

  • DC undercurrent relay
  • Field relay
  • Rectification failure relay
  • Ground detector relay
  • DC overcurrent relay

The rotor earth fault element detects high- and low-resistance earth faults of the rotor winding. It is equipped with two stages, one for alarm, one for trip. The protective functions are: Undercurrent, overcurrent and ripple detection for diode failure protection. Because of the combination of three protective functions in one device, the MRN2 is a very compact mains de-coupling device.

Multifunction Generator Rotor Protection Relay MRR1 provides comprehensive protection by integrating multiple functions into one device, which enhances system reliability, reduces downtime, and simplifies maintenance.

  • Combination of several crucial protections in a single compact unit (MRR1 combines rotor earth fault, excitation over/undercurrent, and rotating diode failure protection).
  • The relay prevents severe damage to the generator by detecting and isolating faults and abnormal conditions quickly (such as voltage fluctuations, overloads, and earth faults), thereby extending its operational life.
  • The relay’s fast and selective tripping action ensures only the faulty section is isolated, minimising disruption to the rest of the system and enabling quick fault isolation.
  • The device stores detailed information about fault events with date and time stamps, and may include disturbance recording.
  • Integrating multiple functions into one device reduces the need for separate relays, saving panel space and potentially lowering installation and inventory costs.
  • Modern C&S relays often include communication ports and other monitoring systems, allowing for remote operation and control.