VFD Challenges for Shipboard Electrical Power System Design

2Propulsion System Adjustable Speed Drive

Traditionally, the ship propulsion system propeller directly driven by the prime mover or through gear box has many mechanical challenges such as a long drive shaft and shaft alignment, and complex gear box.

The VFD for propulsion systems has gained popularity due to drive technology maturity for the following:

1. The propulsion shaft need not be in line with the engine.
2. The propulsion motor can be very close to the propeller, with total elimination of propulsion shaft and shaft alignments.
3. Electrical speed and torque control of the propulsion.
4. Electrical system smooth ramp‐up and down of the ship speed.
5. Propulsion diesel engines running at a synchronous speed for generator.
6. Eliminating propulsion engine noise due to varying engine speed.
7. The diesel engine location is variable as DG can be in any convenient location.
8. Ease of using solid state technology.

The shipboard power system design process has become very complex due to high power generation and variable drive. Traditional design experience is not sufficient to support the new challenges of high power generation, high power consumables, such as electrical propulsion, and other adjustable drive ship service applications. Traditional protection systems such as over load and short circuit protection is not sufficient. This book addresses both design and development issues namely:

1. System design process with VFD.
2. System developmental process with VFD.
3. Verification of the Design & ...