Nonlinear Stabilization of a DC-Bus Supplying a Constant Power Load

Abstract

The presence of an LC input filter in an electrical system often leads to degradation of dynamic performance and instability of the system. This paper addresses the global stability study of an electrical system containing a DC power supply, an LC Filter and a constant power load. This latter is realized by a voltage source inverter–Permanent Magnet Synchronous Motor or Induction Motor. To stabilize the system, the control structure is slightly modified to implement a nonlinear stabilization block. This allows reducing the dc-link capacitance value and size which is important in aerospace applications. A drive consisted of an LC input filter connected to an inverter-PMSM designed for aircraft application is treated as an illustrative example. Simulations and experimentations confirm the validity of the proposed approach. Keywords-Nonlinear systems, ac drives, dc-link capacitance, stabilization, robustness.