Towards sensorless observers for sinusoidal electric machines with variable speed and no mechanical model: A promising approach for PMSMs

A new signal injection‐based method for estimation of position in interior permanent magnet synchronous motors

“…The parameter adjustment principle of ℓ i (i = 1, 2, 3) is to make the infimums and supremums of the signals ŷ v 1 p and ŷ v 2 p coincide with the ones calculated from (9). For more details, we first run the motor at a constant speed, with the obtained estimates y^v approximating some periodic signals, the means and amplitudes of which may differ from the calculations from (9).…”

“…For more details, we first run the motor at a constant speed, with the obtained estimates y^v approximating some periodic signals, the means and amplitudes of which may differ from the calculations from (9). We then tune ℓ i in order to let y^v have the same means and amplitudes with the ones in (9). It is clear that ℓ 1 and ℓ 3 are proportional to the amplitudes, and ℓ 2 affects the mean value.…”

“…without signal injection. From (9) it is clear that the angular position θ can be recovered from the virtual output y v , i.e. θ = 1 2 arctan…”

“…The first one is a model-based method, which is known in applications as the back-emf or fluxlinkage estimation. In this method, the fundamental components of the electrical signals are used to design a back-emf observer or a flux observer [1][2][3][4][5][6][7][8][9]. The second one is a saliency-tracking-based method, in which information is extracted from the high-frequency components of stator currents via high-frequency signal injections [10][11][12][13].…”

“…As a matter of fact, because of the inability to deal with this complex dynamics, the overwhelming majority of papers published by the control community in sensorless control operating in medium‐ or high‐speed regions are concerned with SPMSMs, see e.g. [2–5, 8, 9]—with [15, 16] a notable exception. In contrast, the saliency‐tracking methods at low speeds have received more attention from the applied journals in the context of IPMSMs.…”