Performance and robustness evaluation of dc-link stabilization

A new approach is presented to evaluate active stabilization of electric power systems containing constant power loads (CPLs). Through derived transfer functions, performance is assessed in terms of the CPL power modification generated by stabilization and the achieved dc-link voltage damping. Internal CPL control dynamics may be included or neglected and for the latter case, sensitivity functions are derived to evaluate robustness to un-modeled control dynamics. The method is demonstrated to e.g. show that the Non-linear System Stabilizing Controller (NSSC) obtains close to minimal integral square error (ISE) performance but shows poor robustness to non-ideal CPL dynamics at low powers. (C) 2015 Elsevier Ltd. All rights reserved.