Abstract: In a DC feed system configured by a plurality of DC electrical circuits being combined, when an arc fault occurs, it is difficult to identify a DC electrical circuit in which an arc has occurred. For this reason, a DC electrical circuit protection apparatus includes: a plurality of DC electrical circuits, each of which has a current sensor provided in at least one of a positive or a negative electrical path and has arc noise absorbing mechanism on the upstream side of the current sensor; and an arc detection device which compares respective arc noise signal strengths of the DC electrical circuits from current signals detected by the current sensors of the DC electrical circuits, and based on the signal strengths, identifies a circuit in which an arc has occurred, wherein a DC electrical circuit in which an arc has occurred is identified.

Abstract: The power transmission mechanism abnormality diagnostic device includes a monitoring diagnosis unit for performing determination as to abnormality of a power transmission mechanism, and a current detector connected to a power supply of an electric motor, wherein the monitoring diagnosis unit includes an analysis unit for analyzing current transmitted from the current detector and an abnormality determination unit for performing determination as to abnormality of the power transmission mechanism on the basis of a result of analysis by the analysis unit.

Abstract: The power transmission mechanism abnormality diagnostic device includes a monitoring diagnosis unit for performing determination as to abnormality of a power transmission mechanism, and a current detector connected to a power supply of an electric motor, wherein the monitoring diagnosis unit includes an analysis unit for analyzing current transmitted from the current detector and an abnormality determination unit for performing determination as to abnormality of the power transmission mechanism on the basis of a result of analysis by the analysis unit.

Abstract: In an electromagnetically moving device 100, a magnetic-flux variation measuring unit 3 is placed at a position which is outside a closed magnetic path established when a movable core 6 and a stationary core 5 are being attached to each other due to permanent magnets 7, and at which a leakage magnetic-flux variation due to movement of the movable core 6 can be measured, so that a behavior of a movable part in a switch, etc. is estimated such that an inflection point time is calculated from the measurement of time-series data of the magnetic-flux variation.

Abstract: In a DC feed system configured by a plurality of DC electrical circuits being combined, when an arc fault occurs, it is difficult to identify a DC electrical circuit in which an arc has occurred. For this reason, a DC electrical circuit protection apparatus includes: a plurality of DC electrical circuits, each of which has a current sensor provided in at least one of a positive or a negative electrical path and has arc noise absorbing mechanism on the upstream side of the current sensor; and an arc detection device which compares respective arc noise signal strengths of the DC electrical circuits from current signals detected by the current sensors of the DC electrical circuits, and based on the signal strengths, identifies a circuit in which an arc has occurred, wherein a DC electrical circuit in which an arc has occurred is identified.

Abstract: In an electromagnetically moving device 100, a magnetic-flux variation measuring unit 3 is placed at a position which is outside a closed magnetic path established when a movable core 6 and a stationary core 5 are being attached to each other due to permanent magnets 7, and at which a leakage magnetic-flux variation due to movement of the movable core 6 can be measured, so that a behavior of a movable part in a switch, etc. is estimated such that an inflection point time is calculated from the measurement of time-series data of the magnetic-flux variation.

Abstract: An electromagnetically operated device includes: a moving member of the electromagnetically operated device; a drive coil that is energized to generate magnetic flux for driving the moving member; a permanent magnet provided between a stationary member and the moving member for holding the moving member; and a holding force adjusting member for adjusting the holding force applied to the moving member by the permanent magnet, wherein the holding force adjusting member is placed at a position that will not be included in the main magnetic path of the magnetic flux caused by the drive coil so as to be removable.

Abstract: An AC motor drive control device including: an inverter, having a plurality of switching elements subjected to on-off control, for converting a DC voltage to an AC voltage with a desired frequency to drive an AC motor; a motor opening contactor connected between the inverter and the AC motor; a switching operation beforehand detection unit for detecting a switching operation of the motor opening contactor prior to the contact or detach of main contacts and outputting a switching operation beforehand detection signal; and a control unit having an inverter control unit for performing the on-off control for the plurality of switching elements and switching control for the motor opening contactor, and controlling the inverter based on the switching operation beforehand detection signal.

Abstract: An electromagnetically operated device includes: a moving member of the electromagnetically operated device; a drive coil that is energized to generate magnetic flux for driving the moving member; a permanent magnet provided between a stationary member and the moving member for holding the moving member; and a holding force adjusting member for adjusting the holding force applied to the moving member by the permanent magnet, wherein the holding force adjusting member is placed at a position that will not be included in the main magnetic path of the magnetic flux caused by the drive coil so as to be removable.

Abstract: An object is to provide a driving controller for an AC motor that can prevent generation of an excessive voltage between lines of a motor and between contacts of a motor cut-off contactor and a continuous arc between contacts of the motor cut-off contactor, regardless of the type of a fault occurred, even when a phase in which a current zero point is not generated and a phase in which a current zero point is generated coexist in a fault current that flows between an inverter and the motor. A control unit is configured to open a motor cut-off contactor not at a time when a state of a detected current is determined to be abnormal but at a time when the state of the current is determined to be normal, even when a basic contactor-close command MKC0 becomes off (L level).

Abstract: An object is to provide gas insulated switchgear that is able to inhibit heat generation of a pressure container. Electrically-conductive members that are non-magnetic and have higher electric conductivity than that of the material of which the pressure container is made, are provided on the inside and on the outside of the pressure container, while being positioned along a main bus and being attached via a flange of the pressure container. Thus, eddy current that occurs when an electric current flows through the main bus are caused to flow through the electrically-conductive members having higher electric conductivity than that of the pressure container. Also, a current return path for the eddy current is formed by a flow path including the electrically-conductive members. Consequently, it is possible to reduce the eddy current flowing on the pressure container and to inhibit an increase in the temperature of the pressure container.

Abstract: An AC motor drive control device including: an inverter, having a plurality of switching elements subjected to on-off control, for converting a DC voltage to an AC voltage with a desired frequency to drive an AC motor; a motor opening contactor connected between the inverter and the AC motor; a switching operation beforehand detection unit for detecting a switching operation of the motor opening contactor prior to the contact or detach of main contacts and outputting a switching operation beforehand detection signal; and a control unit having an inverter control unit for performing the on-off control for the plurality of switching elements and switching control for the motor opening contactor, and controlling the inverter based on the switching operation beforehand detection signal.

Abstract: In an electromagnetic switch for an auxiliary-rotation starter according to the present invention, the magnetic bypass core is disposed at a place that is an air gap portion, in a magnetic circuit, through which the plunger moves due to magnetic attractive force produced by energizing the attraction coil and the holding coil and that is between the outer circumference of the plunger and the inner circumference of the bobbin, in such a way that one end thereof makes contact with one end of the case and the other end thereof faces the end of the core by the intermediary of an air gap.

Abstract: A three-stable oscillating electromagnetic actuator includes a cylindrical stator from which a plurality of first magnetic poles project toward a center direction, a mover that extends in a circumferential direction inside the stator and is reciprocatingly and rotatably supported along the circumference, and a plurality of coils that are wound around the first magnetic poles and bias the mover to cause it to stop in three positions, which are a first stable position that is on one end side of a rotation range of the mover, a second stable position that is on the other end side, and a neutral position that is an intermediate position. The three-stable oscillating electromagnetic actuator further includes a second magnetic pole made of a magnetic material that abuts against a rotation-direction end of the mover to stop the mover in the first stable position and the second stable position.

Abstract: An object is to provide gas insulated switchgear that is able to inhibit heat generation of a pressure container. Electrically-conductive members that are non-magnetic and have higher electric conductivity than that of the material of which the pressure container is made, are provided on the inside and on the outside of the pressure container, while being positioned along a main bus and being attached via a flange of the pressure container. Thus, eddy current that occurs when an electric current flows through the main bus are caused to flow through the electrically-conductive members having higher electric conductivity than that of the pressure container. Also, a current return path for the eddy current is formed by a flow path including the electrically-conductive members. Consequently, it is possible to reduce the eddy current flowing on the pressure container and to inhibit an increase in the temperature of the pressure container.

Abstract: A state grasp device that needs no optical adjustment, and can be downsized. An exciting current waveform of an opening electromagnetic coil of an electromagnetic operating set functioning to drive a moving contact of a switching device includes an inflection point appearing subsequently to a maximum value, the inflection point taking place at the time of the contact being parted. Accordingly, a wear amount of contact from the change over time can be obtained. A position of the inflection point is obtained, for example, by focusing the rate of change in current; and a wear amount of a switching contact is obtained from the change over time of a time when the inflection point takes place. With the device, the use of a mechanical detection device, such as an optical detector, can be eliminated.

Abstract: A three-stable oscillating electromagnetic actuator includes a cylindrical stator from which a plurality of first magnetic poles project toward a center direction, a mover that extends in a circumferential direction inside the stator and is reciprocatingly and rotatably supported along the circumference, and a plurality of coils that are wound around the first magnetic poles and bias the mover to cause it to stop in three positions, which are a first stable position that is on one end side of a rotation range of the mover, a second stable position that is on the other end side, and a neutral position that is an intermediate position. The three-stable oscillating electromagnetic actuator further includes a second magnetic pole made of a magnetic material that abuts against a rotation-direction end of the mover to stop the mover in the first stable position and the second stable position.

Abstract: An object is to provide a driving controller for an AC motor that can prevent generation of an excessive voltage between lines of a motor and between contacts of a motor cut-off contactor and a continuous arc between contacts of the motor cut-off contactor, regardless of the type of a fault occurred, even when a phase in which a current zero point is not generated and a phase in which a current zero point is generated coexist in a fault current that flows between an inverter and the motor. A control unit is configured to open a motor cut-off contactor not at a time when a state of a detected current is determined to be abnormal but at a time when the state of the current is determined to be normal, even when a basic contactor-close command MKC0 becomes off (L level).

Abstract: In an electromagnetic switch for an auxiliary-rotation starter according to the present invention, the magnetic bypass core is disposed at a place that is an air gap portion, in a magnetic circuit, through which the plunger moves due to magnetic attractive force produced by energizing the attraction coil and the holding coil and that is between the outer circumference of the plunger and the inner circumference of the bobbin, in such a way that one end thereof makes contact with one end of the case and the other end thereof faces the end of the core by the intermediary of an air gap.

Abstract: A state grasp device that needs no optical adjustment, and can be downsized. An exciting current waveform of an opening electromagnetic coil of an electromagnetic operating set functioning to drive a moving contact of a switching device includes an inflection point appearing subsequently to a maximum value, the inflection point taking place at the time of the contact being parted. Accordingly, a wear amount of contact from the change over time can be obtained. A position of the inflection point is obtained, for example, by focusing the rate of change in current; and a wear amount of a switching contact is obtained from the change over time of a time when the inflection point takes place. With the device, the use of a mechanical detection device, such as an optical detector, can be eliminated.