The processes of the direct energy conversions of the ICF-microexplosion in magnetic fields are discussed and investigated by both the methods of their simulations in the experiments with usual Laser-Produced Plasma Clouds and via their numerical PIC-modelling in 3D-schemes. The problems of additional energy losses of exploding plasmas which could prevent to achieve more than 50% efficiency of such electrical conversion in uniform magnetic field are studied by comparison of experimental and numerical data. The opportunities of such common approach to simulation future NIF experiment with dipole field's thrust are shown.