V. EXPERMENTATION RESULTS
The proposed control schemes were implemented on
a nonexpensive fixed point DSP (TMS320F240) based
PWM inverter system. The voltage-controlled PWM is
implemented by an IPM switching component that was
manufactured by Fuji Co. with a switching kequency
20kHz. The control intervals of the adaptive observation
system are set at 100 ps: and the control intervals of
the speed control loop are set at 3 ms. Because the
voltage model involves pure' integrator, which will
cause initial value and drift problems, Some researches
use low-pass filter to avoid these problems. Fig.7 shows
the modified model diagram. In this paper' the
integration is transferred to a ,low-pass filter with the
initial value setting to zero.