Dynamo hub dont work
 

Alfine Dynamo Hub DH-S50 when it rotate very slowly produce power but in hight speed it stop working does you guys knows why this happens

That, of course, is the opposite behavior from what you should be seeing. When you say, "high(t) speed", what do you mean? A bicycle wheel doesn't really rotate all that quickly. Says 100-400 RPM or so.

It sure sounds like there is some defect or fault in the hub.

When you say it stops working at higher speeds, how do you know that? I recall reading a review a few years ago of a dyno powered USB charger that when the dynohub put out too much power (from going down a hill or something) the USB charger shut down to avoid overloading the circuits. Could the device you have hooked up to the hub be the problem and not the hub itself?

On my hub with nothing attached to it other than a volt meter (one that measured AC), I measured over 30 volts going down a hill at 25 mph. That was why that USB charger was designed to cut out at higher speeds.