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Module 6 — System studies ​

Module status: outline

This is the detailed outline for Module 6. The fully written core of the course is Module 1; chapter prose here is in development.

The final module assembles the pieces into realistic studies: balanced and unbalanced three-phase networks, faults, starting a simulation from a load-flow operating point, and running parts of a system at different time steps. It closes by pointing toward protection — the subject of a future course.

What you will learn ​

  • How three-phase networks are represented and how a per-phase view relates to the full three-wire model.
  • How to apply and clear faults (single-phase and three-phase) and read the resulting transients.
  • How to initialize a transient run from a steady-state load-flow so it begins in equilibrium rather than with a startup surge.
  • How multi-rate simulation lets a fast subsystem run at a finer step than the rest of the network.
  • How EMT results feed protection studies (the bridge to the planned protection course).

Planned chapters ​

  • 17. Three-phase networks. Balanced operation, sequence components, and where unbalance and mutual coupling matter; building a small three-phase model.
  • 18. Faults and disturbances. Fault types, application/clearing, and the transient signatures (DC offset, asymmetry) an EMT run reveals.
  • 19. Initialization and mixed time-frame ideas. Seeding a run from a power-flow solution; the idea of coupling a detailed EMT region to a simpler external system.
  • 20. Multi-rate and from transients to protection. Running a fast inner loop in a subsystem at a finer step (see multi-rate monitoring); what protection engineers extract from EMT waveforms, leading into the protection course.

Hands-on circuits ​

  • AC fault — a three-phase network with a fault, showing the fault transient. (Uses developer-tier three-phase / fault components.)

The palette includes three-phase sources, RLC, transformers, machines, breakers, and single- and three-phase fault elements, plus the power-flow solver for initialization. Worked course samples will add a line-energization overvoltage study and a fault-application/clearing sequence.

Practice themes ​

Expect problems on: relating a three-phase fault's symmetrical components to the phase waveforms; explaining the DC offset in fault current and its decay; and justifying when a load-flow initialization is necessary for a meaningful transient.

References ​

  • H. W. Dommel, Electromagnetic Transients Program (EMTP) Theory Book, Bonneville Power Administration.
  • J. Arrillaga and N. R. Watson, Power Systems Electromagnetic Transients Simulation, IET Power and Energy Series 39 — steady-state initialization, mixed time-frame simulation, and applications.
  • P. Kundur, Power System Stability and Control, McGraw-Hill — faults and system behavior.

Previous: Module 5 — Controls and machine controllers · Next: Appendices.