ELECTRIC MACHINES WITH TWO ROTATING MAGNETIC FIELDS

Electrical machines with two rotational magnetic field (RMF) have three fundamental elements: stator (S), rotor 1 (R1) and rotor 2 (R2). RMF flow between S and R1 also R1 and R2. RMF is created by coils on S and R2 or a coil on R1. At first case R1 is following RMF synchronously or asynchronously and R2 can have double rotational speed of RMF or zero rotational speed, rest. At another case S and R2 in relation to R1 rotate in identical direction, synchronously or asynchronously, or one synchronously another asynchronously. By reason of increase of specific powder, double increase of rotational speed and zero rotational speed, these electrical machines can be used: for direct drive of machines with large rotational speed, as drive machines in small portable devices, as generators driven by high-speed rotating turbines, as asynchronous generators (direct) driven by low-speed rotating (wind) turbines.