Optimal Scheduling and Loadsharing of a Hybrid Power Plant with Gensets and Battery Banks

Abstract

The increased power demand of shipboard electrical power system has produced considerable environmental pollution such as heavy fuel consumption and the emission of CO2 and NOx. In response to the degradation in the global environment, the maritime industry is experiencing a technical renovation at an ever-changing pace. The hybrid power system (HPS) which is a promising alternative to reduce fuel consumption, has aroused tremendous research interests. It takes the advantages of both a traditional electric-driven system and the energy storage devices (ESD), making it has not only higher energy efficiency but also lower noise and vibration level.

For a HPS, the demand for higher reliability and availability is higher than before. Therefore, a robust and smart power and energy management system (PMS/EMS) is required to control the power generation and distribution. PMS protects equipment from failure and reduces power loss, more importantly, maximises the performance through interaction with other control systems.

This thesis looks into the hybrid marine power system and uses the PMS to address the scheduling of gensets and Energy Storage System (ESS). Firstly, the configuration and mechanisms of the hybrid marine power system are described. The HPS model is developed in Simulink, including the genset, bus, ESS, and so forth. Secondly, the peak shaving strategy and optimal load sharing algorithms are proposed. The peak shaving strategy adopts the concept of energy band limited by ESS energy. The load sharing algorithm is based on the four working modes among the gensets and ESS. Lastly, two case studies of HPS subjecting to different level time-varying load are presented. The results show that good performances are achieved regarding load sharing with the mission of fuel consumption minimisation.