This unique solution (DGM) ensures total protection of industrial power plants and vessels from faults that are not easily detected by normal protection functions. Specifically, these faults are over/under fueling of diesel engines and over/under excitation of generators.
DGM solution protects the generators in isochronous load sharing, droop load sharing and base load modes. It performs topology determination to identify the diesel generators connected in its own electrical network and exchanges relevant data with all other Relion REX640 protection relays having DGM function and present in the same IEC61850 network.
The DGM identifies a fault in the generator by comparing its behavior to its current governor mode or with reference to other generators in the network. When a fault is detected, the function will signal the fault to the Power Management System (PMS). If the fault condition deteriorates, the function issues commands to stop the engine or to de-excite the generator. It then issues a trip command to the Generator Circuit Breaker (GCB). Additional actions like closing fuel value can be implemented as additional logic.
The solution comprises of single or multiple Relion REX640 protection relays utilizing the full potential of the IEC 61850 standard for substation communications.
Scope
- Correlation algorithm to monitors each generator individually, detects over/under fueling and over/under excitation faults
- Voting algorithm are used to compare generators running in parallel. If one generator loading deviates excessively from the others, it is identified as faulty. Voting algorithms are provided for both active (fueling) power and reactive (excitation) power.
- Monitoring of fuel rack position and excitation current of generator; alarm raised if they deviate from set operation mode.
- Sends an indication to PMS to start back-up generators or to alter power sharing amongst healthy generators.
- Activates stop engine, de-excites generator, opens generator circuit breaker as a local action, if fault deteriorates.
- In case of unsuccessful generator circuit breaker tripping, section circuit breaker(s) can be opened.
- Maximum network configuration: 8 generators, 8 Generator Circuit breakers and 3 subnetworks.
Product benefits
- Ensures complete safety of generator and switchgear equipment
- Distributed solution, fully based on IEC 61850 and offers interoperability with REX640
- Safeguards customer investment