A method of performing monitoring of parameters of a DC bus capacitor bank, composed of at least one capacitor, in a power converter with a front-end, an output stage and PWM control of gates of switches of the output stage, said power converter having current sensing means (5, 6) on output phases of the output stage and a voltage sensing means (8, 81) on the DC-bus, said voltage sensing means comprising a conditioning circuit to extract and scale HF ripple of the DC-bus voltage, said method comprising the steps of calculating a HF part of the output stage input current (linv) through current measurements sensed by said current sensing means at selected time locations between switching states of the output stage and calculating a HF part of the DC-bus voltage (Vdc) through voltage measurements sensed by said voltage sensing means within selected switching states, wherein the front end is a DC front end providing a DC bus voltage, characterized in that said method comprises: - determining for a switching cycle, sampling locations (11, 12) of phase currents and voltage ripple within different switching states (100, 101, 102, 103) of said cycle where said switching states correspond to particular combinations of gates activation for a switching duration ΔT, and where said sampling locations are located at a first position (21, 24) and a second position (20, 23) within said switching state duration; - measuring phase currents of the output stage with said current sensing means (5, 6), sampling the phase currents at said sampling locations for providing phase current values at said locations and calculating the input current linv of the output stage based on said phase currents and switching state at said locations; - calculating the HF capacitor current at the said sampling locations by using the input current linv of the output stage at said locations; - reconstructing the HF capacitor current Icap_HF at the beginning of a switching state by linear extrapolation of the HF part of the capacitor current at said locations over said switching state; - calculating ΔIcap_HF as the difference of capacitor HF current at the beginning of a new switching state and the value at the end of a previous switching state; - measuring the DC bus voltage with the voltage sensing means and conditioning such voltage to extract and scale the HF ripple of the DC bus voltage ripple and sampling said voltage ripple at said sampling locations for providing voltage ripple values in said switching state; - reconstructing the HF capacitor voltage through calculating a value of capacitor voltage ripple at the beginning of a switching state by linear extrapolation of the DC bus voltage ripple at said locations over said switching state; - calculating ΔVcap_HF as the difference of HF capacitor voltage ripple at the beginning of a new switching state and the value at the end of a previous switching state; and wherein said current ripple and voltage ripple are ripples generated by the standard operation of the power converter without injection of disturbances in the converter. - determining for a switching cycle, sampling locations (11, 12) of phase currents and voltage ripple within different switching states (100, 101, 102, 103) of said cycle where said switching states correspond to particular combinations of gates activation for a switching duration ΔT, and where said sampling locations are located at a first position (21, 24) and a second position (20, 23) within said switching state duration; - measuring phase currents of the output stage with said current sensing means (5, 6), sampling the phase currents at said sampling locations for providing phase current values at said locations and calculating the input current linv of the output stage based on said phase currents and switching state at said locations; - calculating the HF capacitor current at the said sampling locations by using the input current linv of the output stage at said locations; - reconstructing the HF capacitor current Icap_HF at the beginning of a switching state by linear extrapolation of the HF part of the capacitor current at said locations over said switching state; - calculating ΔIcap_HF as the difference of capacitor HF current at the beginning of a new switching state and the value at the end of a previous switching state; - measuring the DC bus voltage with the voltage sensing means and conditioning such voltage to extract and scale the HF ripple of the DC bus voltage ripple and sampling said voltage ripple at said sampling locations for providing voltage ripple values in said switching state; - reconstructing the HF capacitor voltage through calculating a value of capacitor voltage ripple at the beginning of a switching state by linear extrapolation of the DC bus voltage ripple at said locations over said switching state; - calculating ΔVcap_HF as the difference of HF capacitor voltage ripple at the beginning of a new switching state and the value at the end of a previous switching state;