Due to its flexibility, energy efficiency and superior performance, electric propulsion is widely used in today's marine technology.
Functionally the propulsion drive can be divided into following parts : supply transformer, propulsion motor and frequency converter. In an AC drive, a frequency converter is used to control the speed and torque of electric motor. The speed of the AC electric motor can be controlled by varying the voltage and frequency of its supply. A frequency converter works by changing the constant frequency main electrical supply into a variable frequency output.
The benefits of this kind of controlling system are obvious. Precise and smooth speed control means less equipment stress resulting in lower maintenance costs. An electric motor itself is virtually maintenance-free.
The frequency converter drive provides stepless control of three-phase AC currents from zero to maximum output frequency, corresponding to a desired shaft speed both ahead and astern. High torque is available at all speeds.
Controller hardware and software are designed for safe operation in all conditions, as well as for high dynamic performance. Optional control parameters are flexibly prgrammable according to special requirements.