Magnetically geared generator

An energy conversion apparatus adapted for converting rotational energy having a varying rotational frequency into electrical energy having a fixed frequency, the energy conversion apparatus comprising:

• a drive shaft for inputting the rotational energy;
• a rotation sensor for detecting the rotational frequency;
• a magnetically geared generator, comprising
• a inner winding unit having a first number of pole pairs;
• an outer winding unit arranged coaxially around the inner winding unit and having a second number of pole pairs;
• and
• a rotatable magnetic flux modulator arranged coaxially between the inner winding unit and the outer winding unit, wherein
• rotational input energy provided at the rotatable magnetic flux modulator is converted into electrical output energy provided as an alternating output current at one of the inner winding unit and the outer winding unit, wherein
• an output frequency of the alternating output current is controlled by communicating output energy as an alternating feedback current to the other one of the inner winding unit and the outer winding unit and by adjusting a feedback frequency of the alternating feedback current;
• and
• an electrical output unit for outputting the electrical energy.

A wind turbine comprising a rotor adapted for converting wind energy into mechanical energy, the rotor having a main shaft and a plurality of rotor blades, and a hub, said wind turbine further comprising a magnetically geared generator adapted for converting the mechanical energy into electrical energy, comprising:

• an inner winding unit having a first number of pole pairs;
• an outer winding unit arranged coaxially around the inner winding unit and having a second number of pole pairs;
• and
• a rotatable magnetic flux modulator arranged coaxially between the inner winding unit and the outer winding unit, wherein
• rotational input energy provided at the rotatable magnetic flux modulator is converted into electrical output energy provided as an alternating output current at one of the inner winding unit and the outer winding unit, wherein
• an output frequency of the alternating output current is controlled by communicating output energy as an alternating feedback current to the other one of the inner winding unit and the outer winding unit and by adjusting a feedback frequency of the alternating feedback current.

A method for converting mechanical energy into electrical energy, the method comprising

• providing an inner winding unit having a first number of pole pairs;
• providing an outer winding unit arranged coaxially around the inner winding unit and having a second number of pole pairs;
• and
• rotating a rotatable magnetic flux modulator arranged coaxially between the inner winding unit and the outer winding unit, wherein
• rotational input energy provided at the rotatable magnetic flux modulator is converted into electrical output energy provided as an alternating output current at one of the inner winding unit and the outer winding unit, wherein
• an output frequency of the alternating output current is controlled by communicating output energy as an alternating feedback current to the other one of the inner winding unit and the outer winding unit and by adjusting a feedback frequency of the alternating feedback current.