Synchronous Motor
vs. Synchronous Generator

Two sides of the same machine — one consumes power, one creates it

Synchronous Motor

Electrical energy → Mechanical energy
Runs loads at fixed synchronous speed

Mechanical energy → Electrical energy
Produces AC power at synchronous speed

pf=1 Motor unity
power factor

0% Generator peak
efficiency

Ns Motor runs at
synchronous speed

Ns Generator outputs
at synchronous speed

Performance Comparison

Motor Generator

Motor Generator

Motor (const. speed) Generator (const. speed)

Motor Generator

Operating Sequence

Full Comparison Table

Aspect	Synchronous Motor	Synchronous Generator
Function	Converts electrical energy into mechanical energy. ⚡→🔧	Converts mechanical energy into electrical energy. 🔧→⚡
Operation	Requires external mechanical force to start rotating.	Requires an initial source of mechanical energy to induce rotation.
Speed	Operates at synchronous speed. Ns fixed	Generates electrical power at synchronous speed. Ns fixed
Construction	Often has additional mechanisms (e.g., squirrel cage rotor for starting).	Typically has a rotor with field windings excited by DC.
Torque	Produces torque to overcome mechanical resistance.	Requires mechanical input torque for electricity generation.
Load Handling	Can handle variable mechanical loads. Mech. load	Can handle variable electrical loads. Elec. load
Excitation	Does not require external excitation for operation.	Requires external DC excitation to produce the magnetic field. DC needed
Power Flow	Electrical power flows into the system. Consumer	Electrical power flows out of the system. Producer
Control	Controlled by adjusting the electrical input.	Controlled by adjusting mechanical input or excitation current.
Applications	Industrial machinery, fans, pumps, compressors, power factor correction.	Power plants, wind turbines, hydro plants, diesel generators.