In NEPLAN there are two explicit modules to handle protection devices, these are
- Over current protection and
- Distance protection
All other protection devices could be defined in NEPLAN and the corresponding calculation or simulation module uses the particular device to perform its duties. Especially the module Dynamic Analysis is able to model any protection device and show its behaviour during an event in the network.
Frequency relays (used for dynamic analysis)
- Monitored variable is the frequency or its derivative
- Up to four tripping stages could be defined
- Event definition for each stage (e.g. disconnect of loads)
- Circuit breaker delay time
Maximum relay nodes (used for dynamic analysis)
- Monitored variable is voltage and voltage angle or their derivatives (voltage relay)
- Up to four tripping stages could be defined
- Event definition for each stage (e.g. disconnect of loads, generator)
- Circuit breaker delay time
Minimum relay nodes (used for dynamic analysis)
- Monitored variable is voltage and voltage angle or their derivatives (voltage relay)
- Up to four tripping stages could be defined
- Event definition for each stage (e.g. disconnect of loads, generator)
- Circuit breaker delay time
Maximum relay elements (used for dynamic analysis)
- Monitored variable is current and current angle, active and reactive power, impedance magnitude and angle, resistance and reactance or their derivatives (power relay)
- Up to four tripping stages could be defined
- Event definition for each stage (e.g. disconnect of loads, generator)
- Circuit breaker delay time
Minimum relay elements (used for dynamic analysis)
- Monitored variable is current and current angle, active and reactive power, impedance magnitude and angle, resistance and reactance or their derivatives (power relay)
- Up to four tripping stages could be defined
- Event definition for each stage (e.g. disconnect of loads, generator)
- Circuit breaker delay time
Pole slip relay (used for dynamic analysis)
- Out-of-step protection for generators
- Monitored value is the apparent impedance seen by the generator terminals
Differential protection (used for reliability analysis)
- Monitored value is the sum of incoming and outgoing currents (busbars, transformers, etc.)
Advanced modelling for dynamic analysis
- Exact relay behaviour could be modelled with function blocks
- Monitored values for phase voltages and currents after a disturbance are input values to the relay model
- More than 30 function block types are available, e.g. summation, if-then-else, pickup delay, reset delay, polygon, time dependent delay
