Abstract: In systems comprising at least two compressors, the present invention provides an adequately sized vessel or tank in either or both the suction line or the discharge line of multiple compressors, in such a fashion that if the conditions of the first compressor change, it does not have an immediate effect on the other compressors, the vessel acting as a means of dampening the change.

Abstract: A compact and efficient compressor is provided, based on using magnetic bearing technology, which can operate at high speed and comprises a reliable control system. The compressor of the present invention makes use of two separate compressors mounted on a single common motor, thus sharing a single drive. The balancing of the thrust at high RPM is improved by using a pair of electromagnetic bearings.

Abstract: The present invention provides a device and a method to enhance thrust load capacity in a rotor bearing system. The load-enhancing device comprises a stator and a rotor arranged in such as way as to achieve a magnetic thrust load capacity enhancement by employing a number of permanent magnets, which produce an attracting force of an expulsing force between the rotor and the stator.

Abstract: A system and method are provided for controlling a three-phased permanent magnet electric motor terminal voltages in relation to both changes in speed and torque of the permanent magnet electric motor, whereby phase currents are first rotated from a stationary frame to two decoupled current components in a rotor synchronous frame, which enable to derive a voltage along a quadrature axis and a voltage along a direct axis thereof, before rotating back the quadrature and direct axis voltages from the rotor synchronous frame to the stationary frame to yield the permanent magnet electric motor terminal voltages.

Abstract: A power control system (12) for an electric motor having at least one magnetic bearing includes a DC/DC converter (18) supplied from a DC link bus (179) connected to a main power supply (14), the bus (17) supplying power for the electric motor and for a bearing actuator the converter (18) provides low voltage DC power supplies for a motor controller (23), a bearing controller (24) and a supervisory controller (26), the later monitoring the main power supply and communicating with the motor controller (23) and bearing controller (24) so as to cause the motor to operate as a generator in the event of a failure of the main power supply (14) to thereby supply power to the DC link bus (17) to maintain operation of the magnetic bearing. Circuit switching components are connected to the motor winding and selectively switched in a manner causing current generated in the motor winding to flow in one direction into the DC link bus (17) only while the winding voltage is greater than that of the DC link bus (17).

Abstract: A power control system (12) for an electric motor having at least one magnetic bearing includes a DC/DC converter (18) supplied from a DC link bus (179) connected to a main power supply (14), the bus (17) supplying power for the electric motor and for a bearing actuator the converter (18) provides low voltage DC power supplies for a motor controller (23), a bearing controller (24) and a supervisory controller (26), the later monitoring the main power supply and communicating with the motor controller (23) and bearing controller (24) so as to cause the motor to operate as a generator in the event of a failure of the main power supply (14) to thereby supply power to the DC link bus (17) to maintain operation of the magnetic bearing. Circuit switching components are connected to the motor winding and selectively switched in a manner causing current generated in the motor winding to flow in one direction into the DC link bus (17) only while the winding voltage is greater than that of the DC link bus (17).

Abstract: A compact and efficient compressor is provided, based on using magnetic bearing technology, which can operate at high speed and comprises a reliable control system. The compressor of the present invention makes use of two separate compressors mounted on a single common motor, thus sharing a single drive. The balancing of the thrust at high RPM is improved by using a pair of electromagnetic bearings.