船舶相关资料培训(23页).pdfVIP

POWER ELECTRONIC CONVERTERS FOR SHIP PROPULSION ELECTRIC MOTORS Damir Radan Marine Cybernetics-Energy Management Systems Part of the NTNU project All Electric Ship Department of Marine Technology, NTNU 1. Introduction The predominant type of prime movers for DP propulsion plants is the electric drive. Practically every DP propulsion device installed in newly constructed vessels as well as in most of the conversions is driven by an electric motor. In the beginning of DP technology (which coincided with the advent of the DC/SCR technology), either AC motors were utilized driving CP propellers at constant RPM or SCR controlled DC motors were utilized driving fixed-pitch propellers at variable RPM. In recent years, variable speed AC drives have become available and have been used in some applications for DP propulsion. The most commonly used motor drives are: • DC converters, or SCR (Silicon Controlled Rectifier) for DC motors • Cycloconverters (Cyclo) for AC motors, normally for synchronous motors • Current source inverter type (CSI) converters for AC motors (synchronous motors) • Voltage source inverter (VSI) type converters for AC motors, i.e. asynchronous, synchronous and permanent magnet synchronous motors. Fig. 1. Variable speed drive, showing a frequency converter with DC Link, typically for VSI and CSI type converters (Cyclos do not have DC link) [1] 1 2. AC Systems with Controllable Pitch Propeller • Several generators which feed AC of constant frequency and voltage (4160 - 6000 VAC) into a common bus. • Constant-speed motor drive motors drive the propeller • Usually cage-type inductio