Abstract:
An arrangement for compressing a gas or fluid comprises at least one high power compressor (31, 32), an electric machine (33, 34) for each said compressor, in which the machine is arranged to drive the compressor, a device having at least one electric generator (23-25) and at least one gas turbine (20-22) adapted to drive the generator for generating electric power for operation of said electric machine (33, 34), and an apparatus (30) adapted to adjust the frequency of the electric power of said electric machine operation. The apparatus (30) comprises means adapted to control the frequency of the electric power by controlling the rotational speed of an output shaft of said gas turbine.
Abstract:
A gas compression system comprising a compressor (1) for compressing a gas fed to the compressor, an electric motor (4) driving the compressor, a compressor motor drive unit (5) producing current to said motor, a pipe (20) for feeding back gas from the outlet of the compressor to the inlet of the compressor, a recycle valve (22) controlling the gas flow in the pipe, an actuator (25) for actuating the recycle valve, and a control unit (24) generating a control signal to said actuator for controlling the opening and closing of the recycle valve. The actuator comprises an electric motor (26) controlling the opening and closing of the recycle valve. The gas compression system further comprises measuring equipment (32) for measuring the input voltage to the compressor motor drive unit, and the control unit is adapted to determine whether there is a risk of surge of the compressor based on the measured input voltage to the compressor motor drive unit, and to generate a control signal for opening the recycle valve if it is determined that there is a risk of surge of the compressor.
Abstract:
There is presented a transformer arrangement for mitigating transient voltage oscillations. The transformer arrangement comprises a transformer. The transformer comprises a transformer core comprising at least one core leg. A winding is wound around one of the at least one core leg. The winding extends from a first winding terminal to a second winding terminal and comprises a first winding section along a first conductor extending from the first winding terminal to a first intermediate end point, and a second winding section along a second conductor extending from a second intermediate end point to the second winding terminal. The transformer arrangement further comprises an external passive electric component connected between the first intermediate end point and either the second intermediate end point or the second winding terminal arranged to decrease an effective difference between capacitive and inductive voltage distributions between the intermediate end points such that transient voltage oscillations in the winding are mitigated.
Abstract:
There is presented a transformer arrangement for mitigating transient voltage oscillations. The transformer arrangement comprises a transformer. The transformer comprises a transformer core comprising at least one core leg. A winding is wound around one of the at least one core leg. The winding extends from a first winding terminal to a second winding terminal and comprises a first winding section along a first conductor extending from the first winding terminal to a first intermediate end point, and a second winding section along a second conductor extending from a second intermediate end point to the second winding terminal. The transformer arrangement further comprises an external passive electric component connected between the first intermediate end point and either the second intermediate end point or the second winding terminal arranged to decrease an effective difference between capacitive and inductive voltage distributions between the intermediate end points such that transient voltage oscillations in the winding are mitigated.