Negative impedance instability compensation in more electric aircraft DC power systems using state space pole placement control

In aerospace power systems, multiple power converters and multiple voltage power systems interact with each other and can result in unstable operation. When a dc-dc converter is loaded with a constant power load, it shows instability. This is because of the negative impedance characteristic of constant power load. Some poles of the converter with a constant power load are in the right half plane of the s-plane. This paper presents a compensation technique for buck converter using state space pole placement control. With a state space pole placement control, the unstable poles are relocated to the stable region, i.e. left half plane. Furthermore smaller output filter capacitor can be used.