MRP2

Productomschrijving

The power relay MRP2 is used in 3-phase systems for active power measurement. In the single-phase relay type MRP2-1, the load of the three phases is assumed to be symmetrical so that a single phase power measurement can be realized.

For application fields (i.e. turbine movers) where two reverse power switching points with higher precision are required, the relay type MRP2-R is avail-able.
Among others, the MRP2-relays serve:

• for supervision of load flow between two systems. (MRP2)

If the generated power of one system fails, unimportant consumers have to be disconnected by the power relay. Thereby the mains is stabilized and the supply of important consumers maintained. If gen.-sets are operating in parallel, these consumers can be disconnected if the load remains below the set minimal value or – in peak load operating mode – they can be connected if a limit value for the mains power is exceeded.

• as reverse power relay to protect turbines and diesel gen.-sets from reverse power if this prime mover fails. (MRP2 and MRP2-R)

For generators operating in parallel with a mains or another generator, it is imperative to supervise the power direction. If for example the prime mover fails the alternator operates as a motor and drives the prime mover (diesel or turbine). The MRP2 “recognizes” the reverse of the power direction and – in case of this error – switches off the alternator. This way, power losses and damages of the prime mover are avoided.

• as voltage dependent reverse power relay for mains decoupling

The criterium for tripping the voltage-dependent reverse power element is the reverse power with simultaneous voltage decrease as a result of an external mains fault. Decoupling prevents external mains faults from affecting the own mains section. Internal faults are selectively detected by other protection devices.

Unit MRP2 still has another feature besides those described in the general MR-namely:
• Measuring of the actual power by means of multiplication and integration of the instantaneous values of current and voltage.
• Correct measuring even at unequally loaded phases (MRP2-3).
• Switchable measuring for delta or star connection of v.t.’s.
• Indication of current, voltage and power
• Serial interface
• Three adjustable power switching-points.
• voltage dependent reverse power element
• Plug-in type design with automatic short-circuiters for current transformer circuits.
• Circuit Breaker failure protection
• Storing of trip values and breaking times (tCBFP) of eight fault events
• Ability of serial data transmission via RS485 interface optional with SEG Electronics RS485 Pro Open Data Protocol or Modbus Protocol