Research On Power System Of Exploration Sampling ROV

The ocean contains abundant resources and marine strategy is playing an increasingly important role in international competition.The development of underwater robot technology makes it possible for the human beings to explore the deep sea.The exploration sampling ROV(Remotely Operated Vehicle)plays an important role in ocean research as an underwater robot capable of collecting deep-sea images and acquiring seabed samples.The reliability of the ROV power system is the key to the ROV in the underwater operation.The rated voltage of the underwater motor is 3000 V.Considering the requirements of motor starting and speed regulation,this paper presents two kinds of ROV power system schemes by using constant voltage frequency ratio control strategy.One is the use of low voltage two-level inverter,supplying power to underwater motor through cables after filtering and boosting output voltage of inverter.The other is the use of multilevel inverter outputs 3000V-level voltage directly to the underwater motor through cables.Based on the mathematical model and control strategy of two power system schemes,simulation model is established on the Simulink platform respectively.In this paper,the starting and speed regulation performance,voltage drop and the characteristics of the two schemes are studied and compared in depth.Simulation and analysis results show that both schemes have their own advantages and disadvantages.The motor can achieve good start-up and speed regulation,verifying the feasibility and reliability of two schemes.Finally,a 3000V/127.5kW underwater asynchronous motor is designed.The magnetic field distribution and back EMF are analyzed by finite element method,and the performance indexes of the motor are calculated.The analysis results show that the magnetic field density of the motor is reasonable,the back EMF is sine wave,all the indexes meet the requirements and the rationality of the design scheme is verified.