Investigation of Power Quality Issues in Cold Ironed (Shore Connected) Grid Connected Electric Ships

Electrification of the transportation industry has become a fast reality in the past decade. This is promoted by increased investment in the development and commercialization of electric based vehicles. Like its air and land counterparts, electric vehicles for short distances are now completely electrified by battery storage systems. However, cargo ships and large cruisers are still running on hybrid engines. Recently it was proposed to electrify these large cargo/cruise ships, when they are on – shore and loading/unloading operations are going on. This process is termed as shore – to – ship power. However, the impact of onboard loads on the offboard utility grid must be analyzed. This helps in identifying any underlying problems that may deteriorate the grid performance and stability. In this paper, large cargo/cruise ships’ load (consisting of different low voltage and high voltage dc lines powered loads) are first studied and then its connection to onboard diesel generator/utility grid is emulated using Simulink/MATLAB®. The impact of different types of loads on the quality of electric power consumed by the electric ship is quantified and its impact on the point of common coupling (PCC) voltage is analyzed.