A semiconductor device according to an embodiment includes: a silicon carbide layer; a silicon oxide layer; and a region disposed between the silicon carbide layer and the silicon oxide layer and having a nitrogen concentration equal to or more than 1×10.sup.21 cm.sup.−3. A nitrogen concentration distribution in the silicon carbide layer, the silicon oxide layer, and the region have a peak in the region, a nitrogen concentration at a first position 1 nm away from the peak to the side of the silicon oxide layer is equal to or less than 1×10.sup.18 cm.sup.−3 and a carbon concentration at the first position is equal to or less than 1×10.sup.18 cm.sup.3, and a nitrogen concentration at a second position 1 nm away from the peak to the side of the silicon carbide layer is equal to or less than 1×10.sup.18 cm.sup.−3.

An elevator automatic rescue and energy-saving control method, the method comprising: when the power grid supplies power normally, selecting a single current in a three-phase power grid (9) as an AC power supply for an elevator control system (10); controlling a DC-DC converter (2) to charge the super capacitor module (1) connected to the DC-DC converter to a specified standby electric energy level; and when the power grid is suddenly interrupted, selecting to use the electric energy stored in the super capacitor module (1) as a rescue electric energy for a traction motor (7) and the elevator control system (10). The described method uses a super capacitor module, so that a stable and reliable elevator rescue power supply is provided when the power grid is suddenly interrupted, and the regenerative electric energy dissipated during elevator braking operation is stored and utilized during elevator operation, thereby conserving energy.

A semiconductor device of an embodiment includes a silicon carbide layer having a first plane and a second plane and includes a trench located on a first plane side and has a first region and a second region, a first silicon carbide region of an n-type, a second silicon carbide region of a p-type between the first silicon carbide region and the first plane, a third silicon carbide region of the n-type between the second silicon carbide region and the first plane, and a fourth silicon carbide region of the p-type between the second region and the first silicon carbide region; a gate electrode in the first region; a first electrode on the first plane side of the silicon carbide layer, a part of the first electrode is located in the second region and is in contact with the third and the fourth silicon carbide region; and a second electrode.

A permanent magnet (PM) synchronous electric motor (34) includes a plurality of phases, and a plurality of motor drives (55,58) electrically connected to the PM synchronous electric motor. Each of the motor drives is operatively connected to a corresponding one of the plurality of phases. The plurality of motor drives is configured and disposed to deliver a torque current divided equally between each of the plurality of phases and independently deliver flux current to the corresponding one of the plurality of phases. A controller (44) is operatively connected to each of the plurality of motor drives to selectively control the PM synchronous electric motor, and a rescue module (120) operatively connected to the controller, the rescue module being configured and disposed to determine a failure of one of the plurality of motor drives and control the PM synchronous electric motor in a reduced operation profile employing remaining ones of the plurality of motor drives.

An electric linear motor, an elevator and a method for controlling rotation of a mover with respect to a stator beam are presented. The electric linear motor includes a number of stator beams, wherein at least one of the stator beams includes a plurality of stators extending in a longitudinal direction of the stator beam, a number of movers, wherein at least one of the movers includes a plurality of armatures, wherein each one of the armatures is adapted for establishing an electromagnetic coupling with a corresponding one of the stators for moving the mover along said stator, and wherein at least one of the armatures is arranged to be offset from the aligned position with respect to the corresponding one of the stators in a perpendicular direction relative to the longitudinal direction.

In a method for performing a manual drive in an elevator after mains power-off, the frequency converter of the motor is separated from mains, any safety blocking of the brake drive and/or motor drive is disabled, current is supplied from the battery to the brake drive to open the elevator brake and current is supplied from the battery to the drive control to allow regulation of the motor speed via the inverter bridge, the manual drive control observes the motor speed via the speed sensor and starts a speed feedback loop to regulate the motor speed to a manual drive reference value by feeding a three phase-AC current to the motor windings via the semiconductors of the inverter bridge, which manual drive speed reference is lower than the speed reference for normal elevator operation, when the car reaches a floor level the floor level indicator is activated, and the actuator is released whereafter the current supply from the battery to the elevator brake is interrupted and the previous disabled safety blocking of the brake drive and/or motor drive is enabled again.

An electric linear motor, an elevator and a method for controlling rotation of a mover with respect to a stator beam are presented. The electric linear motor includes a number of stator beams, wherein at least one of them includes stators extending in a longitudinal direction of the beam. The motor also includes a number of movers, wherein at least one them includes armatures, wherein each armature is adapted for establishing an electromagnetic coupling with a corresponding stator for moving the mover. The motor also includes an air gap regulator for regulating movement of the mover with respect to the stator beam, wherein the air gap regulator includes guide element(s) arranged for limiting the rotation of the mover with respect to the stator beam.

A semiconductor device of an embodiment includes a silicon carbide layer having first and second plane, the silicon carbide layer including trench having a first portion and a second portion, the second portion having a width smaller than the first portion, an n-type first silicon carbide region, a p-type second silicon carbide region between the first silicon carbide region and the first plane, a p-type third silicon carbide region between the second silicon carbide region and the first plane and having a p-type impurity concentration lower than the second silicon carbide region, an n-type fourth silicon carbide region between the third silicon carbide region and the first plane, and an n-type fifth silicon carbide region between the second portion and the second silicon carbide region and having an n-type impurity concentration higher than the first silicon carbide region; and a gate electrode in the trench.

A semiconductor device of an embodiment includes a silicon carbide layer having a first plane and a second plane and includes a trench located on a first plane side and has a first region and a second region, a first silicon carbide region of an n-type, a second silicon carbide region of a p-type between the first silicon carbide region and the first plane, a third silicon carbide region of the n-type between the second silicon carbide region and the first plane, and a fourth silicon carbide region of the p-type between the second region and the first silicon carbide region; a gate electrode in the first region; a first electrode on the first plane side of the silicon carbide layer, a part of the first electrode is located in the second region and is in contact with the third and the fourth silicon carbide region; and a second electrode.

The present invention relates to a conveyor system comprising: a drive machine, a conveyor control unit configured to control operation of a conveyor device, a sensor array comprising at least one sensor mounted to the drive machine and adapted to measure one or more properties of the drive machine, a processing unit associated with the drive machine, wherein the processing unit is connected to the sensor array and configured to obtain and process measurement data from the sensor array to generate in-formation about an operation of the drive machine, and a communication channel between the conveyor control unit and the processing unit. The conveyor system may be an elevator system, an escalator system or a moving walk system.