What are SB, PV and PQ Generators?

The choice of generator depends on how the generators on the network react to changes in load. One needs to consider both static load-flows and TMS studies.

At least one swing bus generator (or utility) is needed on a network to act as either an infinite source of power, or as a load if there is excess generation.

A PV (regulated) generator produces a fixed amount of real power, and the required amount of reactive power (up to its limit) instantaneously (instantaneous excitation response, fixed governor). A PV generator will keep the voltage fixed at unity, as long as the amount of reactive power needed to do so isn't greater than its limits.

A PQ (non-regulated) generator produces a constant amount of real and reactive power (fixed governor and exciter, and no inertia).

Both the PQ option and the PV option could result in more power being produced than is needed on the network, so this excess power would be absorbed by the swing bus.

Both DAPPER and TMS assume a constant frequency, which is fine for networks with a strong grid infeed. However, this assumption isn't acceptable for studies looking at, for example, starting large motors with no grid infeed. For these types of studies, I*SIM should be used instead of TMS, in which case I*SIM's governor and exciter models are used.

Click here for more details about running a TMS study.