Stability investigation of inverter motor drive system with input filter — Optimisation of the DC-link capacitance value

The objective of this paper is to detail an analytical method allowing the stability study of an electric system constituted by an input filter connected to an actuator (inverter - Permanent Magnet Synchronous Motor or induction motor). The proposed approach supposes that a classical control structure of the actuator is used. This control structure is slightly modified to implement an oscillation compensating block which allows increasing the stability margin and thus permits a reduction of the DC-link capacitance value. An example with an input filter connected to an inverter-PMSM system designed for aircraft application is treated. The influence of the control and the input filter parameters on the stability of the DC power supply will be discussed.