Introduction to Onshore Power

Shore power or shore supply is the delivery of shore side electrical power to a ship at berth while its main and auxiliary engines are turned off. Object of the system is to provide a system including a power converter for converting shore power to shipboard use which is easy to use and cost effective.

Most modern military and commercial ships have a variety of electrical equipment requiring alternating current (AC) power for operation. While AC power is supplied at sea by the ship's Auxiliary engines and service generators, in port it is desirable to connect to a dockside source of AC shore power to permit electrically disconnecting the auxiliary generators and then deactivating the ships auxiliary engines. In this way, fuel is conserved and also maintenance on the ships generator system can be performed, without interrupting power to various shipboard electrical components.

Before connecting the ship's main distribution to AC shore power, the ship's main distribution must be disconnected from the ship's generator AC output which can cause a power interruption to the shipboard electrical components. Furthermore, it happens that the electrical characteristics of shore power sources can vary widely from port to port and for this reason, it is sometimes necessary to convert power having first characteristics of voltage, frequency and phase, to ship service power having second characteristics of voltage, frequency and phase, to permit energizing shipboard electrical components with the shore power. For example, the ship's electrical components frequently requires a 60 Hz frequency and yet the shore power may be a 50 Hz power supply in some ports.

As a result of the above, it is advantageous to provide a power converter which can convert shore power to shipboard use and also transfer the ship's main power distribution to the AC shore power without interrupting power to various shipboard electrical components. It is, therefore, an object of the shore power system to provide a power converter for converting shore power to shipboard use and to transfer the ship's load from one power path to another without interrupting power to various shipboard electrical components and which can be used in ports around the world.

ship-with-power-plug

EU Recommendation 2006/339/EC: "Member States should consider the installation of shore-side electricity for the use by ships at berth in ports, particularly where air quality limit values are exceeded or where public concern is expressed about high levels of noise nuisance, and more especially in berths situated near residential areas."