Circuits and methods for preheating a rotor of a motor-generator device

摘要

The motor-generator circuitry of a flywheel energy conversion device can be utilized to preheat the rotor of the flywheel device. It may be desirable to preheat the rotor prior to normal operation because a rotor operating in cold temperature may be more susceptible to brittle fracture or other damage than a rotor operating at a specified operating temperature. The present invention may utilize the principle of induction heating to preheat the rotor. In preferred embodiments, high frequency current may be passed through armature windings of the motor-generating circuitry to induce surface currents into the periphery of the rotor. Heat may then be generated in portions of the rotor receiving the induced currents and then radiate from those portions to raise the rotor temperature to a desired level.