This simulator models a wound-field synchronous generator — the machine behind most utility and standby power — from mechanical input through the exciter, breaker and out to either an infinite grid or an isolated island load. Run the prime mover, adjust governor and excitation modes, synchronize onto the bus, then study the resulting phasors, power-angle behavior and protection response.
• A real-time 3D cutaway of the rotor, field poles, stator windings, exciter and breaker, with camera views for the full machine and the end/slip-ring region, plus a cutaway toggle. • Prime mover, exciter and breaker controls: enable/disable the prime mover, close or open the breaker, and step or run simulation time (0.1 s, 1 s, 10 s steps). • Governor modes — isochronous speed control, droop governor, or manual mechanical input — and excitation control modes — automatic (voltage/grid vars) or manual field excitation. • Electrical destination toggle between an infinite grid (parallel generation) and an island with an isolated constant-impedance load. • A synchroscope and synch-check permissives (sequence, voltage, frequency, phase window) for practicing a live-bus breaker close, plus a separate dead-bus permissive for island energization. • Analysis views: the phasor equation E = V + (Ra + jXs)I, a grid power-angle curve, a P–Q operating point chart, three-phase terminal waveforms, and adjustable per-unit machine parameters on a 100 kVA / 400 V / 50 Hz / four-pole base. • Fault and protection tests — loss of field, loss of prime-mover power, grid voltage sag, island load step — with modeled inverse-time overcurrent, reverse-power, frequency and pole-slip trips. • An operating-history trend chart (power, reactive power, frequency, terminal voltage, EMF angle) and a 27-check model verification bench.
A prime mover turns the rotor's DC-fed field winding, and the exciter supplies that field current across slip rings. As the field spins, it induces a three-phase voltage in the stationary stator windings — the internal EMF, E. Once the machine is at speed and voltage, closing the breaker connects it either to an infinite grid, where terminal voltage and frequency are fixed by the bus, or to an island load that the generator alone must supply.
On the grid, governor droop sets how mechanical power input responds to frequency, while automatic excitation tracks reactive power because the bus already fixes voltage. On an island, the governor and excitation controls directly set the frequency and voltage the load sees. The relationship between internal EMF, terminal voltage and stator current is captured by E = V + (Ra + jXs)I, and real power transferred to the grid follows a power-angle curve driven by the angle between E and V.
Before paralleling with a live bus, the synch-check requires matching phase sequence, voltage within ±5%, frequency within ±0.1 Hz and phase within ±10° — demonstration thresholds, not commissioning values. The synchroscope pointer shows the open-breaker phase relationship; once closed, the rotor's EMF angle becomes the power angle rather than an open-breaker mismatch.
The analysis tab plots the power-angle curve (including armature resistance, so its peak is below the idealized EV/Xs sinδ), the P–Q operating point against a 1 pu apparent-power reference circle, and balanced three-phase terminal waveforms. This is a classical round-rotor model with constant parameters and a stiff infinite bus: it does not solve subtransient currents, saliency, saturation, harmonics, unbalanced faults or detailed turbine thermodynamics, so treat large speed departures as qualitative illustrations of the model's limits rather than a precise machine study.
A classical round-rotor, wound-field synchronous generator — a 100 kVA, 400 V, 50 Hz, four-pole representative machine — with prime mover, exciter, breaker, governor and excitation controls, connectable to either an infinite grid or an isolated island load. Balanced fundamental-frequency phasors are coupled to a swing equation with simplified governor and excitation dynamics.
The teaching synch-check requires matching phase sequence, voltage within about ±5%, frequency within about ±0.1 Hz, and phase angle within about ±10°. These are explicit demonstration settings, not site commissioning values. Energizing the isolated island load instead requires generator voltage of at least 0.8 pu and speed within about ±5%, since it is a dead bus rather than a live parallel source.
Isochronous control holds speed (and therefore grid frequency contribution) constant regardless of load. Droop governing lets frequency fall slightly as load increases, which is how multiple generators share load stably in parallel. Manual mode applies a fixed mechanical input directly, without automatic speed correction.
The test bench can inject loss of field command, loss of prime-mover power, a 30% grid voltage sag, or an 80% island load increase. With modeled protection enabled, the machine can trip on inverse-time overcurrent, sustained reverse power, sustained frequency excursion, or rotor-angle pole-slip detection — teaching thresholds rather than real relay coordination.