Magnet-less and brush-less rotating transformer excited synchronous machine and method of its control

A synchronous machine (100) excited using a rotating transformer (108), the synchronous machine comprising:

• a housing (102) having a first opening (102A) and a second opening (102B);
• a shaft (106) having a first end (106A) and a second end (106B);
• a main motor (116) comprising:
• a main rotor (110) co-axially mounted and positioned between the first end (106A) and the second end (106B) of the shaft (106), and having Direct Current (DC) field windings;
• a main stator (112) co-axially assembled over the main rotor (110) and mechanically supported by the housing (102), said main stator (112) having electrically coupled Alternating Current (AC) poly-phase distributed windings and a first predefined number of poles;
• a rotating transformer (RT) (108) co-axially mounted and positioned between the first end (106A) and the second end (106B) of the shaft (106), said RT (108) having an RT rotor (120) configured to be rotatably coupled on the second end (106B) of the shaft (106),
• said RT rotor (120) including AC poly-phase distributed windings and having a second predefined number of poles;
• an RT stator (122) co-axially assembled over the RT rotor (120), wherein the RT stator (122) has AC poly-phase distributed windings and the second predefined number of poles;
• and
• a three-phase rectifier (124) assembled on the shaft (106), wherein the three-phase rectifier (124) converts an AC current from the RT rotor (120) to a DC current, and wherein the DC current from the three-phase rectifier (124) is transmitted to the DC field windings of the main rotor (120) in order to excite the synchronous machine;
• a first endcap (104A) configured to be attached to the first opening (102A) of the housing (102), wherein the first endcap (104A) is provided with an aperture (113) for the first end (106A) of the shaft to support an external radial load;
• and
• a second endcap (104B) configured to be attached to the second opening (102B) of the housing (102), wherein the second endcap (102B) is provided with a groove (105) configured to support the second end (106B) of the shaft (106) and enable rotational movement of the shaft (106).