Yamaha EF4500iSE - Inverter Generator, Theory & Diagnostics Manual

Page: 9 / 218

1-5
Section
Yamaha Generator Inverter System
The control unit and multi-pole alternator cooperate to generate AC output. The inverter, controlled by a 16-bit
microcomputer, is a Pulse Width Modulation (PWM) sine wave inverter.
1. The generator’s output frequency remains unchanged even when the engine speed varies.
2. The output voltage is stable.
3. The output waveform is a sine wave with a distortion ratio of less than 2.5%, equivalent to household
electricity.
Control unit
*
EF3000iSE new model guide 3/14/03 4:20 PM Page 2
PRINCIPLES OF POWER GENERATION WITH AN INVERTER PORTABLE GENERATOR
*An alternator that uses highly efficient ferrite magnets generates three-phase AC.
• 120V Model: AC 135 to 225V, 300 to 550 Hz
• 230V Model: AC 260 to 488V, 300 to 550Hz
Synchronous Generator — Theory & Troubleshooting
4–11
THEORY FOR DAMPER WINDINGS
For generators with a condensor control
(non AVR), the electricity output is not
a very high quality sine-wave, but does
meet most requirements for "rough use"
power demand.
When the generator begins to get a load
applied, the sine wave is altered by the
load voltage running through the stator and
inducing its own magnetic field, which alters
the path of the rotor coil’s magnetic flux.
The altered flux line distorts the output sine.
This altered sine wave can cause some
problems for appliances with microcomputer
or are sensitive to waveform "ripples".
Sometimes, the ripples are seen as freque-
-ncy problems and disturb the appliance.
Condens
e
r Winding Sine Wave
Inverter Sine Wave
Damper Winding Sine Wave
Synchronous Generator — Theory & Troubleshooting
4–11
THEORY FOR DAMPER WINDINGS
For generators with a condensor control
(non AVR), the electricity output is not
a very high quality sine-wave, but does
meet most requirements for "rough use"
power demand.
When the generator begins to get a load
applied, the sine wave is altered by the
load voltage running through the stator and
inducing its own magnetic field, which alters
the path of the rotor coil’s magnetic flux.
The altered flux line distorts the output sine.
This altered sine wave can cause some
problems for appliances with microcomputer
or are sensitive to waveform "ripples".
Sometimes, the ripples are seen as freque-
-ncy problems and disturb the appliance.
Condens
e
r Winding Sine Wave
Inverter Sine Wave
Damper Winding Sine Wave
CONVENTIONAL SINE WAVE
INVERTER SINE WAVE