GA of Celebrity Solstice.
particular regular cruiser, who had time and again preferred an aſt berth, on this ship near the pods, had commented that she had never experienced such a quiet cruise. Te supply voltage to the Azopid propulsion
motors is also higher than has previously been the case. According to ABB, a change in the overall drive type supplied (of which more later) has yielded a change in the pod’s voltage range, to 3000V. Mr Saliaris said that the new power capability
had brought discernable performance gains. “Tere has been a development of the electrical system to drive the motor on the frequency converter. What we have is a smaller motor but larger power. Te pod does not look bigger but, because of the developments on the electrical technology, more power is achieved. Te completely new control system is also an advance, and it has made us feel both comfortable and confident.”
Deeper thinking But ABB’s contribution stretches far beyond its latest podded propulsors and, indeed, it is the wider electrical systems provided by the company that lie at the heart of the ship’s global efficiency gains. ABB systems cover power production, propulsion and bow thruster, electrical motors and distribution, transformers and switchboards. The scope of supply includes four ABB
AMG 19312kVA main generators, with the same units producing power for both hotel and propulsion consumption, which allows minimal usage in each operational situation. Heikki Bergman, ABB lead engineer, project
design cruiseships, traced the advances being made in drive control to the wider application of integrated gate-commutated thyristors. In short, developments in semi-contactors has made it possible to increase the current through the drive in a more efficient manner. Because generators can now be designed with a high power factor, Mr Bergman said that they could be made more efficient, thus reducing fuel consumption of main engines. “Te operator may design the ship’s speed profile to match optimal engine loadings in each engine configuration.” In detail, the drive technology has been
developed such that pulse width modulation is now available for higher power ranges.
The Naval Architect February 2009
From the technical point of view, the resulting lower total harmonic distortion means less additional dimensioning for heat losses. Lower THD values contribute to the lifespan of the equipment, due to lower electric stresses. Te advance also means that smaller, lighter
and less costly generators achieve a higher power factor than was previously possible, and that these generators perform with less power loss. From an operational point of view,
according to Mr Saliaris, “Te result is that we do not waste power at sea. We have greater control over propeller speeds. Because the new approach does not use capacitors, with voltage
controlled directly, we achieve greater speed of control over the motors.” Mr Saliaris concluded that the performance
of the diesel electric propulsion used onboard Celebrity Solstice was a “big item” in its improved efficiency over other ships. “We can calculate a trip with a required speed and cut the power consumption in pieces. We can run three, two, or even one engine so that each runs at its maximum efficiency, with loads of between 83% and 85%, and because the propeller is not directly connected to the engine, we can run one engine for propulsion and another for the hotel side at maximum efficiency.”NA
39
Feature 1
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68 |
Page 69 |
Page 70 |
Page 71 |
Page 72 |
Page 73 |
Page 74 |
Page 75 |
Page 76 |
Page 77 |
Page 78 |
Page 79 |
Page 80 |
Page 81 |
Page 82 |
Page 83 |
Page 84 |
Page 85 |
Page 86 |
Page 87 |
Page 88 |
Page 89 |
Page 90 |
Page 91 |
Page 92