Design of Cost-Effective Compensators to Enhance Voltage Stability and Harmonics Contamination of High-Power More Electric Marine Vessels

In recent years, due to the large spread of power electronics converters onboard shipboard power systems (SPSs), harmonic contamination became an inherent problem. Moreover, as the SPSs are mostly operating in an islanded mode with a limited rating of the generators that feed heavy variable loads, voltage stability issues became a challenge as well. To address these issues, implementing PWM-based FACTS devices using IGBTs such as the active power filters may not be very practical for high-power SPSs due to their limited rated powers, high implementation cost, and high losses. The passive power filters (PPFs) and fixed capacitor-thyristor controlled reactors (FC-TCR) can be effective alternatives due to their capability to operate in high-power applications, smaller losses and, lower cost. The aim of this article is to provide more in-depth analytical investigations to evaluate and compare the behavior of the PPFs and the FC-TCR compensator in reducing the harmonics and enhancing the voltage stability concurrently of high-power SPSs. In addition, details of the voltage stability concept are addressed to visualize the potential risk of the voltage collapse. Besides, the modeling of the FC-TCR and design of the closed-loop control algorithm to ensure voltage stability is conducted. Via intensive simulation studies of a practical ship, which are carried out in MATLAB/Simulink environment, it has been demonstrated that the FC-TCR based on the proposed design can enhance the power quality and voltage stability of SPSs better than traditional PPFs filters.