3000W Chinese Gensets Info.
professor95 wrote: EDIT ADDED 45/5/2013- When this thread started in March of 2005, I never expected to see it survive this long or amass the quantity of information that has been shared here. In...
Forum Discussion
Here is a new type of generator head for china gens.
http://www.made-in-china.com/china-products/productviewyGYnxkmvOJsN/Permanent-Magnet-Generator-Sets.html
Yes you heard that right. Permanent magnet setup. Of course it can’t have an AVR. But it doesn’t have any field coils or anything. So there is nothing to break in that department. Being PM, it should be able to stand capacitive reactance with no problem, unlike electrically powered excitation systems. Pure sine wave without brushes.
There is one type of excitation system I haven’t seen on any china generators. Brush type, non AVR. The type with rotating field, and a LV DC winding on the stator that feeds a rectifier and capacitor to feed DC to the field. It puts out a high enough voltage for the head to reach magnetic saturation, which is It’s normal operating point. It is a relatively common system with colemans and the like. I have seen capacitor excited brushless, and AVR brush type, but never any non AVR brush type generator heads on china genneys. It’s exactly like an AVR head but with just a simple diode and capacitor to feed DC to the field, and the proper number of turns to achieve the right voltage output.
The design has the benefit of pure sine wave output like the AVR gensets. No suppressed voltage peaks resulting from capacitive pumping causing stator saturation, at 90 and 270 degrees on brushless gensets. And with no problems from AVRs.
It is a design that was common on American gensets but I haven’t seen a single Chinese unit with that setup.
The voltage regulation is similar to the brushles units. It operates at saturation so voltage is determined by number of turns in the output windings. Voltage will go up or down proportionally with speed. So an engine with tighter govern control will produce a more stable output voltage.
And now comes a some modification ideas.
You could turn an AVR head into a non AVR saturation limited head by taking the AVR out and putting in a simple bridge diode/capacitor setup to feed the field coil. You would have to play with the number of stator turns on the winding that supplies it to get the field to the saturation level, but not push the voltage high enough that it melts the field windings. Then you would have to pull a specific number of turns off the 120V output windings to get the proper 120V.
You will have basically turned an AVR head, into a brush type, non AVR head.
Another interesting idea that has accrued to me. Wind the stator with a heavy gauge three phase winding, with enough turns to get 15 VDC out of a proper 3 phase rectifier. Have a low current single phase winding to power the field coil at 40 to 60VDC and use the 15VDC high current output to charge batteries. If you modified the generator properly, you could get around 200A of battery charging ability out of a 3KW generator. If you was real fancy, you could rewind the field (armature) with heaver wire so it would be able to obtain full output voltage with a field drive a little under 12V. That would allow you to use a normal automotive regulator to regulate the voltage output of the generator.
The only type of gen head I am sure I won’t see on a cheap china genny is like the ones on the winco and old homelite that I have worked with. The type with the output windings on the armature. With the solid cast stator with big pole pieces. They are built like a tank.
http://www.made-in-china.com/china-products/productviewyGYnxkmvOJsN/Permanent-Magnet-Generator-Sets.html
Rare Earth Permanent Magnet Generator:
1, Compact Structure, Small Bulk, The weight is 30% lighter than the regular.
2, Without Field Winding, Exciter, AVR, brush. etc. High reliability. Maintenance-free, without Electromagnetism disturn. simply to operate. it's the main advantage than the regular generator.
3, With the same power, double efficiency than the regulars.
4, power factor. can reach 0.98.
5, Can save gasoline more than 20% than the regular. which has more important meaning in nowaday's world.
6, Almost perfect Waveform.
7, Life time can reach ten years.
HS Code: 85013200
Trademark: Rano
Origin: China
Packing: CTN
Min. Order: NEG
Transportation: FOB/CFR/CIF
Company: Shanghai Roco Magnetics Co., Ltd.
Yes you heard that right. Permanent magnet setup. Of course it can’t have an AVR. But it doesn’t have any field coils or anything. So there is nothing to break in that department. Being PM, it should be able to stand capacitive reactance with no problem, unlike electrically powered excitation systems. Pure sine wave without brushes.
There is one type of excitation system I haven’t seen on any china generators. Brush type, non AVR. The type with rotating field, and a LV DC winding on the stator that feeds a rectifier and capacitor to feed DC to the field. It puts out a high enough voltage for the head to reach magnetic saturation, which is It’s normal operating point. It is a relatively common system with colemans and the like. I have seen capacitor excited brushless, and AVR brush type, but never any non AVR brush type generator heads on china genneys. It’s exactly like an AVR head but with just a simple diode and capacitor to feed DC to the field, and the proper number of turns to achieve the right voltage output.
The design has the benefit of pure sine wave output like the AVR gensets. No suppressed voltage peaks resulting from capacitive pumping causing stator saturation, at 90 and 270 degrees on brushless gensets. And with no problems from AVRs.
It is a design that was common on American gensets but I haven’t seen a single Chinese unit with that setup.
The voltage regulation is similar to the brushles units. It operates at saturation so voltage is determined by number of turns in the output windings. Voltage will go up or down proportionally with speed. So an engine with tighter govern control will produce a more stable output voltage.
And now comes a some modification ideas.
You could turn an AVR head into a non AVR saturation limited head by taking the AVR out and putting in a simple bridge diode/capacitor setup to feed the field coil. You would have to play with the number of stator turns on the winding that supplies it to get the field to the saturation level, but not push the voltage high enough that it melts the field windings. Then you would have to pull a specific number of turns off the 120V output windings to get the proper 120V.
You will have basically turned an AVR head, into a brush type, non AVR head.
Another interesting idea that has accrued to me. Wind the stator with a heavy gauge three phase winding, with enough turns to get 15 VDC out of a proper 3 phase rectifier. Have a low current single phase winding to power the field coil at 40 to 60VDC and use the 15VDC high current output to charge batteries. If you modified the generator properly, you could get around 200A of battery charging ability out of a 3KW generator. If you was real fancy, you could rewind the field (armature) with heaver wire so it would be able to obtain full output voltage with a field drive a little under 12V. That would allow you to use a normal automotive regulator to regulate the voltage output of the generator.
The only type of gen head I am sure I won’t see on a cheap china genny is like the ones on the winco and old homelite that I have worked with. The type with the output windings on the armature. With the solid cast stator with big pole pieces. They are built like a tank.
