发表于:2003-02-07 18:47:00
2楼
0。86和100%对我已足够,谢谢,下面是该书的一点资料。
VLT series 3000 and 3500 HVAC
VLT3000 series requency converters use an inverter control systerm known as the Voltage Vector Control(VVC)
developed by Danfoss,
this VVC principle is supperior to the traditional PWM(pulse width modulation) principle used in most mordern frequency converters in the following ways:
full-rated motor voltage at rated motor frequency.
near perfect resemblance to the sinusoidal mains supply.
extremely low switching losses. resulting in high converter efficiency.
if you want more,please email me.(wsmcjm@sohu.com)