clarity of the description. The flux weakening stage 22 is configured to: operate in the two-phase d-q coordinate system and generate a reference current idref being indicative of the reference rotor current in the d-axis of the d-q coordinate system. With regard to the active voltage limiter unit 15, it is configured to regulate the current references supplied to the current regulator system 23 in order to limit the DC- link capacitor voltage Vdc(t) within a predetermined voltage range. Preferably, the active voltage limiter unit 15 is configured to regulate the current references for the Id-Iq current regulators based on the DC-link capacitor voltage Vdc(t) and the measured current values id(t) and iq(t). Conveniently, the active voltage limiter unit 15 is configured to regulate the current references for the Id-Iq current regulators without using any current measurement in the DC-link. In other words, the inverter-based apparatus 1 does not comprise any current sensor on the DC-link 10. Preferably, the active voltage limiter unit 15 is configured to receive in inputs: the current reference iqref, the current reference idref, the voltage Vdc(t) of the DC- link capacitor 11, two signals Uq(t) and Ud(t) indicative to the duty cycles in a d-q coordinate system (hereinafter disclosed in detail) and the measured current values id(t) and iq(t) in a d-q coordinate system. The active voltage limiter unit 15 is further configured to determine two constrained axis-wise current corrections iqcorr(t) and idcorr(t) by implementing the control method hereinafter disclosed in detail. With reference to Figure 3, the current regulator system 14 further comprises an adder unit 30, an adder unit 31, a subtracting unit 32 and a subtracting unit 33. The adder unit 30 is configured to: receive the current reference iqref and the q-axis-wise current correction iqcorr(t) and provide in output a modified current reference iqrefmod(t) based on the addition of the current reference iqref and the current correction iqcorr(t). The adder unit 31 is configured to: receive the current reference idref and the d-axis-wise current correction idcorr(t) and provide in output a modified current reference idrefmod(t) based on the addition of the current reference idref and the