Synthesis and CAD of permanent magnet DC brushless motors The paper presents an algorithm and software for the optimal design of permanent magnet brushless DC motors. Such motors are powered by DC voltage sources via semiconductor switches connected to the motor phase belts. The software is adjusted to the design of motors with NdFeB high energy density magnets. An attention has been given to issues important in the design of the motors, i.e., permanent magnet selection, structure of magnetic circuit, and armature windings. Particularly, precision of calculation of the permanent magnet operating point, visualization of selection process of the winding belts, and magnetic circuit dimensioning have been investigated. The authors have been trying to make the equations more specific and accurate than those presented in the literature. The user software interface allows changes in the magnetic circuit dimensions, and in the winding parameters. It is possible to examine simultaneously the influence of these changes on the calculation results. The software operates both with standard and inverted (outer rotor) motor structure. To perform optimization, a non-deterministic method based on the evolution strategy (μ + λ) - ES has been used.
Poland’s National Vaccination Program is an essential element in the strategy of prevention of infectious diseases and their complications, here considered with a particular focus on combination vaccines and the need for the Program’s further expansion.
“The influenza virus behaves just as it seems to have done for five hundred or a thousand years, and we are no more capable of stopping epidemics or pandemics than our ancestors were,” wrote Charles Cockburn from the World Health Organization back in 1973. Is his remark still just as apt today?