Design of Brushless DC Motor and Drive For Radiographic Mobile Surgery System

Radiography techniques are widely used in the medical industry domain due to their capability of analyzing internal parts of the human body. Setting up a complete surgical room for radiography can be complex and time-consuming. In some cases, it is not feasible for patients to transfer to the surgical room. Hence mobile surgical solutions (movable surgical systems) are developed for a patient-friendly experience. Mobile systems are helpful for radiographic imaging of patients who are admitted to emergency operating rooms or to intensive critical care units and cannot be shifted to the radiology section. These systems are designed to move horizontally and vertically. To achieve smooth horizontal and vertical movements electric motors are used in the mobile surgery systems. At present conventional three phase induction motors are used in this system. In this paper, the conventional three phase induction motor is replaced by BLDC (Brushless DC motor) to achieve higher efficiency, compact motor size and to get ease over sophisticated control. Later, the design of the BLDC motor to function for horizontal movement of the system is carried out using the Ansys maxwell tool. Efficiency and smooth torque are two important performance characteristics from the perspective of mobile surgery systems. The motor design is improved for maximum efficiency and minimum cogging torque by varying stator steel grade and rotor pole embrace. The required parameters are extracted from the Ansys simulation and used in MATLAB Simulink for the implementation of closed loop speed control drive of the proposed motor.