3000W Chinese Gensets Info.

eljefino wrote:


So here's a question that I didn't see answered in the first 170 pages I read, what is the purported advantage of AVR? If my load suddenly lessens, the engine speeds up... if it cuts alternator load to keep from over-volting what's left, that only causes the engine to speed up even faster. Is that the point? To get the governor to correct the engine speed faster? A more precise feedback loop?

Capacitors are frequently used in short shunt self exciting Chinese synchronous generators for one major reason - they are cheap!

Unfortunately, the capacitor used as a regulator can allow for wide swings in voltage for different loads. They also depend upon a diode across the capacitor going into avalanche about half way through a rising or falling AC cycle to "clip" the field current. This dip is often interpreted by the load device as a change in voltage polarity (zero crossing detectors) that can make performance erratic. For example, clocks may run at 2x speed in microwave ovens and some older ferro-resonate converter/chargers will not function. We will also find a significantly higher level of harmonic distortion of the AC sine wave in capacitor regulated synchronous gnerators.

That said, most every appliance in an RV - with the exception of some microwave ovens and really old converter/chargers, operate safely and functionally from a capacitor regulated generator.

The AVR, or Automatic Voltage Regulator, provides a more precise voltage regulation by quickly varying the voltage to the exciter winding as load changes. It is somewhat independent of engine speed. AVR controlled generators also show less THD and appear to operate microwave ovens in RVs with fewer problems.

None of this applies to "inverter" generators which create their own waveform and regulation from 3 phase alternators with totally electronic control modules.