Introduction, Safety Briefing and Objectives of the Course
In marine field, voltage above 1kv is called as high voltage and voltage below 1 kv (1000v ac) is called as low voltage. 3.3 kv, 6.6kv and 11kv are the typical HV systems in marine. The usage of high voltage electrical systems in ships has been in an increasing state in the recent years. Though the applications of high voltage systems in ships are inevitable, the risks and consequences of electrical accidents involving high voltage are higher than low voltage installations. The main hazard for persons working in HV systems is electric shock. It is very important to follow safe working practices as per the guidelines. The design of electrical distribution system involving high voltage must be certified with the authorised sources. The HV electrical personnel should be trained on safety related work practices. It is also very important to secure the HV work place and danger notices have to be posted.
The HV electrical distribution systems in the ships includes switchboards, power panels, generators, essential loads, motor controllers, fuses, cables and protective devices and switch gears.
The various HV equipment which require HV installation are HV motors, HV generators, HV transformers, HV switchboard with HV protection devices, HV switch gear and HV cables. When working in these HV equipment, it is necessary to have a separate permit-to-work system. These equipment must be made dead or isolated or earthed before starting the work.
Electric propulsion with gas turbine or diesel engine driven power generation is used in hundreds of ships of various types. These electric propulsion systems require high current supply. The marine propulsion systems contain the integrated electric propulsion or full electric propulsion. For energizing the motors, three phase electricity generated either by the gas turbines or diesel generators or both is used. The main advantage of using electric propulsion system is less fuel consumption and maintenance.
At the end of this course, you will be able to