2.2 Calculation of Walsh harmonic component
The inductance-matrix [ L ] has the rotor direction
information as shown in (2). If the armature voltages and
the armature currents are measured, [L] can be
theoretically calculated by (1). However, the armature
current is composed of low frequency component for
drive and high frequency component for estimation. It is
necessary to extract high frequency component from the
armature current. The proposed method uses orthogonal
function to extract the high frequency component.