Electrical instability in a voltage source inverter-fed induction motor drive at constant speed

An electrical stability analysis of a voltage source inverter-fed induction motor drive system is presented assuming an infinite inertia load. With a quasisquare-wave scheme this system is characterised as a linear time varying system and its stability is investigated using Liapunov´s first method for stability, and also by a Routh-Hurwitz technique. The stability of each of the six individual modes is also investigated by evaluating the eigenvalues of the corresponding A matrices. The stability boundaries for the complete drive system are presented for various input filter parameter values.