Rotor systems are provided comprising rotor, magnetic bearings and a magnetic bearing controller. The controller is one which varies in accordance with linear parameters and is preferably responsive to linear matrix inequalities. High speed, low loss flywheel systems, especially electromagnetic flywheel batteries are facilitated through such rotor systems.

A magnetic suspending device which can detect the temperature of a controlled object and assure a safe operation thereof without any need for any special construction or work to the device and any special maintenance is disclosed. In the magnetic suspending device comprising a pair of electromagnets (11, 13) disposed opposite to each other, a magnetizable controlled object (15) disposed between the pair of electromagnets (11, 13) and position displacement detection sensors (12, 14) disposed opposite to each other for detecting a position displacement of the controlled object (15), wherein detection signals from the position displacement detection sensors (12, 14) are inputted to a control circuit unit (20) for performing phase compensation and gain adjustment, wherein control outputs from the control circuit unit (20) control magnetic attractive or repulsive forces of the pair of electromagnets (11, 13), and wherein the controlled object is magnetically suspended by the pair of electromagnets without contact at an arbitrary position, a temperature operational circuit unit (30) is provided for detecting the size and temperature of the controlled object (15) using the detection signals from the position displacement detection sensors (12, 14).

A seal assembly includes a seal element having a plurality of movable seal segments and further includes a plurality of actuators, each associated with a respective one of the seal segments. Each of the seal segments has a coil that generates electrical energy in the presence of a varying magnetic field. Each of the actuators receives energy from the associated seal segments and in response thereto produces a force that causes the segment to move toward or away from a surface on an opposing seal member. A method for fabricating a seal element for a gas turbine engine includes providing a wafer, forming seal segments on the wafer, dividing the wafer into a plurality of seal segments, and arranging at least two of the plurality of seal segments into a seal element.

Control system for electromechanical arrangements having open-loop instability. The system includes a control unit that processes sensing signals and provides control signals to maintain a movable member, such as a rotor or shaft, in the desired position. The control unit according to the invention includes a unifying plant compensation filter, which isolates the open-loop instability characteristics so that the shaft is treated as a mass having substantially no open-loop structural properties. In magnetic bearings, the open-loop instability is manifested as negative stiffness. The invention isolates the negative stiffness thus providing for better positive stiffness and improved bandwidth. Various filters, summers, and other operators required to carry out the invention are preferably implemented on a programmed processing platform such as a digital signal processor (DSP) or an arrangement of multiple digital signal processors.

A compact bearingless machine drive system includes: a first rotor segment; a first stator segment with the first stator segment including a drive winding and a first control winding; a second rotor segment; a second stator segment with the second stator segment including the drive winding and a second control winding; and a rotor shaft. The first and second rotor segments are attached to the rotor shaft. A common end ring is coupled between the first and second rotor segments. A drive inverter controls the drive winding to generate torque, and first and second control inverters control the first and second control windings to generate radial forces on the first and second rotor segments.