Frequency Variation; Voltage Variation; Instantaneous Frequency Fluctuation & Instantaneous Voltage Drop - Yamaha EF3000iSE New Model Manual

Frequency variation

In case of conventional synchronous generators, the
engine speed with no load is set at approximately 6 %
higher than rated engine speed (3600rpm for 60 Hz) to
maintain rated frequency when full rated load is
applied. This is the reason why no-load frequency is
slightly higher than rated frequency.
However, adapting an inverter system, which generates
genuine sine wave electricity, the frequency variation of
inverter generator is not influenced by the engine speed.
Therefore, an inverter generator provides constant AC
output frequency even if the load changes which is
equivalent quality to the commercial power supplies.
The frequency variation of EF3000iSE is less than 0.1 %.

Voltage variation

The output voltage with no load is approximately 10 %
higher than rated voltage in the case of conventional
synchronous type generators to achieve the rated volt-
age when full rated load is connected. Thus the voltage
variation occurs due to the change in engine speed and
the influence of the internal resistance.
However, adapting an inverter system, the voltage vari-
ation can be maintained minimum level, because the
output voltage cannot be influenced directly from
engine speed.
The voltage variation of EF3000iSE is smaller than 3%.
The waveform distortion rate of EF3000iSE is smaller than 2.5%.
Instantaneous frequency fluctuation & instantaneous voltage drop
I Momentary frequency fluctuation:
The frequency and voltage fluctuates momentary when
the load is altered if the engine cannot follow up the
load changes in the case of conventional synchronous
generators.
In contrast, the momentary frequency fluctuation of
EF3000iSE is as stable as the commercial power source
with this new inverter system.
The frequency fluctuation rate of EF3000iSE is less
than 0.1 %.
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