Abstract: A commutation circuit includes a coil connected to an H bridge, the H bridge including four main switches for reversing polarity and a resulting coil current in the coil. The commutation circuit further includes a voltage source configured to generate a bypass current, and at least one auxiliary switch for controlling the bypass current to thereby decrease a switch current through at least one of the main switches. By generating an appropriate bypass current with help of a voltage source, a switch current through a desired main switch in a leading state can be decreased and eventually brought to zero. Zero current in its turn enables the use of thyristors as main switches as it results in the thyristors to be turned off automatically. Furthermore, decreased switch current at the switching moment reduces switching losses even in different types of switches such as GTOs and IGBTs.

Abstract: For identifying the machine type of an alternating current machine, a direct current is first applied to the stator for aligning the d-axis of the rotor and the magnetic field direction of the stator. Secondly, a direct current is applied to the stator at a current angle which causes the rotors of a permanent magnet machine and a synchronous reluctance machine to exert torque in different directions. The torque direction of the rotor is detected and the machine type is identified based on the torque direction information. The machine type is recognized as a permanent magnet machine or a synchronous reluctance machine depending on the torque direction. If no torque is detected, then the machine type is recognized as an induction machine.

Abstract: A commutation circuit includes a coil connected to an H bridge, the H bridge including four main switches for reversing polarity and a resulting coil current in the coil. The commutation circuit further includes a voltage source configured to generate a bypass current, and at least one auxiliary switch for controlling the bypass current to thereby decrease a switch current through at least one of the main switches. By generating an appropriate bypass current with help of a voltage source, a switch current through a desired main switch in a leading state can be decreased and eventually brought to zero. Zero current in its turn enables the use of thyristors as main switches as it results in the thyristors to be turned off automatically. Furthermore, decreased switch current at the switching moment reduces switching losses even in different types of switches such as GTOs and IGBTs.

Abstract: A production system has at least one mechanical press driven at least in part by a flywheel powered by a first motor. The system further includes a second motor which is a servo motor. The power of the first motor powering the flywheel is arranged controlled by a control unit dependent on a function of the power of at least one second motor, the servo motor. In this way, the peak power of at least the first and the second motor may be limited. A method for operating the system and a computer program are also contemplated.

Abstract: A method for synchronizing a first machine of a manufacturing process section arranged to carry out a production cycle including a working part and a non-working part. The first machine is operated in conjunction with at least one second machine. The first machine carries out a process during the working part of the cycle on a workpiece that is loaded into and/or unloaded out of the first machine by the at least one second machine during the non-working part of each process cycle. Also, a system for carrying out the method and a computer program.

Abstract: For identifying the machine type of an alternating current machine, a direct current is first applied to the stator for aligning the d-axis of the rotor and the magnetic field direction of the stator. Secondly, a direct current is applied to the stator at a current angle which causes the rotors of a permanent magnet machine and a synchronous reluctance machine to exert torque in different directions. The torque direction of the rotor is detected and the machine type is identified based on the torque direction information. The machine type is recognized as a permanent magnet machine or a synchronous reluctance machine depending on the torque direction. If no torque is detected, then the machine type is recognized as an induction machine.

Abstract: A press drive motor upgrade kit for adapting a mechanical press of the flywheel-driven type to a servo press including a drive motor and a drive train, and a mechanical press so modified. The kit includes at least one servo motor adapted for driving the mechanical press and a drive transmission apparatus or gear transmission or the like, connected to the servo motor and adapted for engagement with at least one gear or shaft of the drive train of said mechanical press. The kit may also include a baseplate or mounting structure on which the servo motor and transmission are arranged.

Abstract: A production system has at least one mechanical press driven at least in part by a flywheel powered by a first motor. The system further includes a second motor which is a servo motor. The power of the first motor powering the flywheel is arranged controlled by a control unit dependent on a function of the power of at least one second motor, the servo motor. In this way, the peak power of at least the first and the second motor may be limited. A method for operating the system and a computer program are also contemplated.

Abstract: A method for operating a mechanical press including an electric drive motor, a drive control for controlling the motor, a ram, a flywheel, a clutch and a member for translating rotational motion of the flywheel in a first rotation direction into a linear motion of the ram arranged to be lowered and raised along a linear path for operating the press to carry out a press production cycle. The press cycle includes a pressing part and one or more non-pressing parts. The press includes a second drive motor or actuator arranged connected to the ram and by providing a control output to the drive control, the speed of the second drive motor is made variable during at least one part of the press production cycle. The press may be reversed between production cycles. A press and system including such a press.

Abstract: A method for synchronizing a first machine of a manufacturing process section arranged to carry out a production cycle including a working part and a non-working part. The first machine is operated in conjunction with at least one second machine. The first machine carries out a process during the working part of the cycle on a workpiece that is loaded into and/or unloaded out of the first machine by the at least one second machine during the non-working part of each process cycle. Also, a system for carrying out the method and a computer program.

Abstract: A press drive motor upgrade kit for adapting a mechanical press of the flywheel-driven type to a servo press including a drive motor and a drive train, and a mechanical press so modified. The kit includes at least one servo motor adapted for driving said mechanical press and a drive transmission apparatus or gear transmission or the like, connected to the servo motor and adapted for engagement with at least one gear or shaft of said drive train of said mechanical press. The kit may also include a baseplate or mounting structure on which the servo motor and transmission are arranged.

Abstract: An press line including at least one mechanical press with at least one electric drive motor, a ram, a mechanical unit for operating the press, and one other device or auxiliary production device. The press is arranged so that the speed of the at least one said drive motor may be varied during at least one pressing or non-pressing part of a press cycle. Improved operating characteristics and optimised energy use and cycle times are obtained by controlling the speed of the motor and synchronizing a movement of the press to a movement or position of at least other device, loader or other press. A system includes the press. A computer program controlls the press line.

Abstract: A method for operating a mechanical press including at least one electric drive motor, a drive control for controlling the at least one motor, a ram, a mechanical element for translating rotational motion of the at least one motor to linear motion of the ram in a first rotation direction, into a linear motion of the ram arranged to be lowered and raised along a linear path for operating the press to carry out a press cycle including a pressing part and one or more non-pressing parts of the press cycle, and by providing a control output to the drive control such that the speed of the at least one drive motor is varied during at least one pressing or non-pressing part of the press cycle. The press may be reversed between production cycles. Also press and system including a such press.