Use of Sensorless BLDC Motors for the Hydraulic Power Unit of an Oil Pipeline Inspection Robot

The challenges encountered in the oil and gas industry require complex solutions and development effort. Related to oil lifting and gathering, it concerns severe conditions as space restraints. Given the confined space inside oil pipelines, robots for inspection requires technologies compatible with it, increasing its complexity, where the minimum required and maximum effective components of the robot is crucial for its construction. In this scenario, the use of sensorless BLDC motors becomes a key point, increasing robustness and reducing harness, being important factors in terms of feasibility, due to connector limitations. Thus, the more motors used — which contributes to the robot's movement — the more advantageous this approach becomes, considering that there is no need for sensing signals for controlling. This work presents an extended version of a paper published on COBEP/SPEC 2023, with new achievements: development of a baseboard motor controller, using TMS320F28027F MCU and DRV8353RSRGZR driver; practical results for sensorless controlling motor; hardware thermal analysis. As results, considering the set point of 5000 rpm rotation speed and a load pressure of 300 bar, the control system obtained a maximum error of 2%.