摘要 |
<p>A reconfigurable electric motor includes a rotor containing rotatable permanent magnets or non-magnetically conducting shunting pieces. The magnets and/or shunting pieces have a first position producing a weak magnetic field for asynchronous induction motor operation at startup and a second position producing a strong magnetic field for efficient synchronous operation. The motor includes a squirrel cage for induction motor operation at startup with the permanent magnets and/or shunting pieces positioned to product the weak magnetic field to not interfere with the startup. When the motor approaches or reaches synchronous RPM, the permanent magnets and/or shunting pieces rotate to produce a strong magnetic field for high efficiency synchronous operation. The position of the magnets and/or shunting pieces may be controlled by a centrifugal mechanism, or viscous damping may delay rotation of the magnets and/or shunting pieces, or electrically controlled apparatus may control positions of the magnets and/or shunting piece.</p> |