Research On Non-contact Charging System For Autonomous Underwater Vehicle

Automatic underwater vehicle(AUV)as the primary dynamic observation platform plays an important role in undersea exploration and maritime patrol.But AUV need to return to the ship for charging batteries,which limits its operation area and efficiency.In order to overcome this disadvantage,non-contact charging system for AUV is researched to charge AUV's batteries by docking system without direct electrical connection.Non-contact charging system for AUV includes two subsystems:underwater inductively coupled power transfer(ICPT)system and charge management system.In order to improve transmission capacity of ICPT system and reduce switching losses generated in inverter circuit,a new design method was proposed,that is using phase-shift technology to make the primary circuit achieve soft-switching when the secondary circuit achieve resonance compensation.What's more,charge management system based on limited space and high-capacity batteries was designed to monitor charging status and balance the status of batteries with microcontroller.Finally,in order to make the whole system work stably,voltage gain function and charging power curve can be derived by ICPT system's equivalent model and battery's model.Non-contact charging system for AUV includes three major contents.Firstly,air coil was designed by determining the number of turns of the coil and sealing method.Secondly,there was many design of hardware circuit,such as inverter circuit,rectifier circuit,buck circuit,charging circuit,charge management circuit,voltage sampling and equalization circuit,and the main control circuit.Thirdly,the software was designed to drive functional device and create an interface with python.A prototype of non-contact charging system was built and had some experimental results.First of all,soft-switching can be achieved in ICPT system when phase shift angle is in a reasonable range.In addition,charging power curve of AUV's batteries can be measured by charge management system.Last,the prototype can work stably and transfer power up to 524W with non-contact charging.