said determined/estimated motor values correspond to an estimated torque (T) of said electric motor (2) and said motor reference values correspond to a torque reference (Tref), - said regulator system (114) being configured to receive said estimated torque (T) and said torque reference (Tref) and control the switching units of said electrolytic capacitor-less inverter (5) based on said estimated torque (T) and said torque reference (Tref), said method comprising the step of regulating said torque reference (Tref) of said regulator system (14) in order to cause said DC-link capacitor voltage (Vdc(t)) to be limited within said predetermined voltage range. 38. Method according to claim 37, comprising the step of regulating said torque reference (Tref) of said regulator system (114) in order to cause said DC-link capacitor voltage (Vdc(t)) to be limited within said predetermined voltage range, without using said lines currents and/or DC-link currents. 39. Method according to claim 38, comprising: receiving first voltage signals (Ua(t), ( ί )) indicative of the duty cycles of said switching signals; receiving first current signals ( ( ί ), ( ί )) indicative of said output currents (iu, iv, iw) provided to said electric motor (2) receiving said voltage (Vdc(t)) of the DC-link capacitor (11), determining a torque limit value (Tref_lim) based on said first voltage signals (Ua(t), ( ), said first current signals ( ( ί ), ( ί )), and said voltage (Vdc(t)) of the DC-link capacitor (11). 40. Method according to claim 39, comprising: determining an active current (ia(t)) based on said first voltage signals (Ua(t), ( ί )) and said first current signals ( ( ί ), ( ί )); determining an instantaneous maximum allowable regeneration current