A cart may include: a driving wheel; a motor configured to rotate the driving wheel; a motor drive circuit configured to drive the motor; a motor brake circuit configured to electrically brake the motor; a rotation speed sensor configured to detect a rotation speed of the motor; and a control device configured to control the motor via the motor drive circuit and the motor brake circuit based on a target rotation speed of the motor and the rotation speed detected by the rotation speed sensor. The motor brake circuit may include an electronically variable resistance element configured to operate in a linear mode and a switching mode in response to a control input signal. The motor brake circuit may be configured to operate. the electronically variable resistance element in the linear mode when braking the motor.

The determination of a slip constant is simplified upon driving a motor for which the slip constant is unknown, based on the acceleration time when accelerating an induction motor from start up to a predetermined rotation speed. A parameter determination support device for motor driving includes: an automatic measurement part which automatically measures characteristic information including the acceleration time upon driving an induction motor to accelerate from start up to a predetermined rotation speed set in advance, relative to each slip constant, based on a plurality of slip constants set in advance; and an estimation part which estimates, as the slip constant of the induction motor, a slip constant at which the acceleration time up to a predetermined rotation speed becomes the shortest, among a plurality of slip constants, based on the characteristic information.

The determination of a slip constant is simplified upon driving a motor for which the slip constant is unknown, based on the acceleration time when accelerating an induction motor from start up to a predetermined rotation speed. A parameter determination support device for motor driving includes: an automatic measurement part which automatically measures characteristic information including the acceleration time upon driving an induction motor to accelerate from start up to a predetermined rotation speed set in advance, relative to each slip constant, based on a plurality of slip constants set in advance; and an estimation part which estimates, as the slip constant of the induction motor, a slip constant at which the acceleration time up to a predetermined rotation speed becomes the shortest, among a plurality of slip constants, based on the characteristic information.

Systems and methods described herein provide for controlling a conduction angle applied to a motor, such as a power tool motor. Operations for controlling the conduction angle includes receiving by a motor controller, a desired speed signal, and monitoring a speed of the power tool motor. The operation further includes a motor controller determining an error value between the desired speed signal and the monitored speed and determining a conduction angle signal based on the error value. The operation also includes the motor controller determining whether the conduction angle signal is greater than the error value and increasing a conduction angle of the power tool motor in response to the conduction angle signal being determined to be greater than the error value.

A shift range control apparatus controls a shift range switching system that switches shift ranges by controlling driving of a motor. This control apparatus calculates a motor angle based on a motor rotation angle signal, acquires an output shaft signal based on a rotation position of an output shaft from an output shaft sensor, sets a target rotation angle based on a target shift range and the output shaft signal, and controls driving of the motor such that the motor angle becomes the target rotation angle. The control apparatus sets the target rotation angle to a target limit value, in response to the target rotation angle that is set based on the output shaft signal being a value at which rotation occurs that is further toward a back side in a rotation direction than the target limit value that is set based on shift ranges before and after switching.

A shift range control apparatus controls a shift range switching system that switches shift ranges by controlling driving of a motor. This control apparatus calculates a motor angle based on a motor rotation angle signal, acquires an output shaft signal based on a rotation position of an output shaft from an output shaft sensor, sets a target rotation angle based on a target shift range and the output shaft signal, and controls driving of the motor such that the motor angle becomes the target rotation angle. The control apparatus sets the target rotation angle to a target limit value, in response to the target rotation angle that is set based on the output shaft signal being a value at which rotation occurs that is further toward a back side in a rotation direction than the target limit value that is set based on shift ranges before and after switching.

A motor control device executes fluctuation suppression control when a power supply voltage for driving a motor supplied from a power supply temporarily decreases and then increases to a normal power supply voltage after recovery. The fluctuation suppression control suppresses fluctuation in a rotation speed of the motor which is caused by following fluctuation in the power supply voltage.

A blockage detector for detecting a blocked state of an electrical machine has: a first power determiner and a second power determiner for determining a first power consumption and a second power consumption of the electrical machine while a first phase voltage and a second phase voltage for operating at a first rotating field speed and a second rotating field speed are applied to the electrical machine, a quotient former for producing a power quotient between the first power consumption and the second power consumption; and a comparator for comparing the power quotient with a threshold value for the power quotient. The invention also relates to an inverter controller, an inverter, a drive, ventilation or air-conditioning system and a vehicle having a blockage detector according to the invention. In addition, the invention relates to a corresponding method for detecting a blocked state of an electrical machine.

A blockage detector for detecting a blocked state of an electrical machine has: a first power determiner and a second power determiner for determining a first power consumption and a second power consumption of the electrical machine while a first phase voltage and a second phase voltage for operating at a first rotating field speed and a second rotating field speed are applied to the electrical machine, a quotient former for producing a power quotient between the first power consumption and the second power consumption; and a comparator for comparing the power quotient with a threshold value for the power quotient. The invention also relates to an inverter controller, an inverter, a drive, ventilation or air-conditioning system and a vehicle having a blockage detector according to the invention. In addition, the invention relates to a corresponding method for detecting a blocked state of an electrical machine.

Disclosed is a disconnection detection apparatus of a sinusoidal wave signal. The disconnection detection apparatus of the present disclosure converts a first sinusoidal wave and a second sinusoidal wave into absolute values, respectively, and determines that disconnection occurs when a value of the first sinusoidal wave is less than a first comparison value that is greater than a minimum value and a value of the second sinusoidal wave is less than a second comparison value that is less than a maximum value.