lized PWM inverter is the motor terminal
voltage. The voltage-decoupled transvector
control method described in [4] eliminates
any current feedback and/or sensing. since
motor leakage inductances are usually of
small value. The resulting circuit construction,
therefore, becomes simplified.
This elimination of a current control loop
is based on the fact that both actual torque
and flux current components follow the corresponding
current commands in the order
of the motor time constant. In an actual situation,
however, the flux current component
may be varied to realize field control. In such
a case, the discrepancy between the command
and actual currents suggests the necessity
of some additional strategy to assure
stable operation of the inverter.
This paper proposes the utilization of an
optimal-speed regulator [7] designed by
model reference adaptive control (MRAC)
theory [8]. The resulting system exhibits
good performance characteristics by adoption
of the exact model-matching method.
together with maintaining a simplified circuit
construction of voltage decoupling, which
uses only a speed loop.