Voltage control solutions to face the CPL instability in MVDC shipboard power systems

Abstract

Voltage control represents one of the main challenges in the development of Medium Voltage DC power systems on ships. The presence of non-linear loads (high-bandwidth controlled converters, CPLs) may cause dangerous voltage oscillations or even instability in presence of small or large disturbances (e.g. connection/disconnection of loads). To face this important issue, the voltage actuator approach appears as an effective solution by using DC/DC converters as sources of stabilizing power. Such controlling action is obtained by imposing control signals determined by different techniques. In this regard, the main goal of this paper is to analyze the action of three control techniques (State Feedback, Active Damping and Linearization via State Feedback) in order to suggest the implementation considering the system criticality (e.g. the CPL power or the filter damping factor). Numerical simulations are useful to compare the proposed methods by observing the control action in presence of growing disturbances.