Servo Drive for thruster control on underwater vehicles.

I127 is a brushless AC motor servo drive ready for operation at 1600 m deep, developed for control propulsion system on manned submersibles, AUVs, ROVs or any other underwater vehicle. It uses advanced sensorless flux-vector control algorithms that allow a safe and efficient motor control without any external feedback device.

This custom servo drive has been specially designed for AC brushless motor thrusters and can operate at high hydrostatic pressures without the need of expensive pressure relief vessels.

Maximum storage pressure is 250 bar while operation has been tested up to 160 bar, equivalent to 1600 meter deep immersion.  i127 uses cutting edge power MOSFET semiconductors to drive the 2.5 kW propellers from the 170 V battery bus with maximum efficiency.

Solutions that withstand pressure
Working with pressure tolerant electronics brings many advantages over installation inside low pressure vessels:

• Weight and volume of containers are reduced.
• Power and electronic systems are not placed in the submarine cabin.
• Reduced number of connections through pressure barriers.
• Less complex and reliable cooling systems.
• Reduced system cost and complexity.
• Increased reliability.

Reliability is key
The driver for the thrusters control is conceived as a critical system, and reliability is crucial. Some key points that ensure the best reliability from the design are:

• Full isolation between power and logic connections
• Dynamic braking through onboard high power shunt braking resistor
• Full disconnection for operation from batteries
• Self monitoring systems onboard for voltage, current and temperature supervision.
• Protection systems without non resettable devices (all protections are electronic)

 Advanced features
I127 servo drive includes advanced features to increase efficiency and performances:

• Advanced control schemes for velocity and current/torque loops.
• Field Oriented Control sensorless algorithm with back-emf estimator based on observer.
• CANopen network (DS-301, DS-402) for drive operation and monitoring.
• External analog operation for safety control.
• Motion controller capabilities for tasks monitoring / data logging.

The  i127 DC servo drive incorporates all the power electronics and control building blocks required to control  AC brushless motor thrusters. The servo drive has been carefully engineered for reliability, ruggedness, and performance in a wide range of operating conditions.

For more information

Ingenia Motion Control
www.ingeniamc.com