FIGS. 11A to 11J show a current signal isig(Te*, {tilde over (θ)}r, θr, ?i) according to the first angular error ({tilde over (θ)}r) and the injection angle (?i) when the torque command has a predetermined value (1 pu) according to an embodiment of the present disclosure. In FIGS. 11A to 11J, a bold line 11-1 represents a point where the current signal (isig) makes zero up-crossing, and the angle estimator 180 determines this point as a convergence point.
The embodiment FIGS. 11A to 11J represents a case where the compensation signal is not applied.
In an embodiment, the compensator 170 may apply the second compensation signal (icomp′) to the current signal (isig) as in Equation 11 below such that the angle estimator 180 is converged to a point where the angular error ({tilde over (θ)}r) is 0 for each injection angle.
