A temperature estimation device estimates a drive duty ratio by taking account of the influence of ambient temperature on the energization to a coil part, on the basis of a drive duty ratio and the ambient temperature, and estimates the power consumption of a motor when the coil part is energized with the estimated drive duty ratio, the power consumption of the motor, this power consumption being accompanied by the heat dissipation of the coil part, the power difference between both the power consumption values, the temperature time constant of the coil part, and a temperature variation during a period of the temperature time constant of the coil part, and estimates the temperature variation of the coil part from the ambient temperature on the basis of these estimated values and a last temperature variation of the coil part.

In a rotating electrical machine, in particular a generator, different components, such as, for example, rotor, stator rod and end zone, are cooled as required by associated external fans, whereby the cooling power requirement is reduced. The method for cooling includes a plurality of cooling fans arranged for cooling different components of the machine, wherein a cooling fan is individually controlled in its cooling performance in accordance with the temperature of the associated component.

In a rotating electrical machine, in particular a generator, different components, such as, for example, rotor, stator rod and end zone, are cooled as required by associated external fans, whereby the cooling power requirement is reduced. The method for cooling includes a plurality of cooling fans arranged for cooling different components of the machine, wherein a cooling fan is individually controlled in its cooling performance in accordance with the temperature of the associated component.

A motor system can include a motor configured to be operated according to at least a portion of an operation cycle specifying at least one target speed for the motor and a controller configured to obtain an estimated winding resistance of the motor, wherein the estimated winding resistance is determined based at least in part on an estimator gain factor, and wherein the estimator gain factor is inversely dependent on a speed of the motor; wherein the at least one target speed comprises at least one low speed such that at least a portion of the operation cycle is a low speed portion of the operation cycle, the at least one low speed having a speed of less than about 10 percent of a maximum speed of the operation cycle.

A gripper includes at least one movable finger. Each movable finger includes a first motor, a second motor, a first motor link having a first end coupled to a rotor of the first motor, a second motor link having a first end coupled to a rotor of the second motor, a finger link having a first end in pivotal connection with a second end of the second motor link and a gripper pad, and a connecting link having a first end in pivotal connection with a second end of the first motor link and a second end in pivotal connection with the finger link. The gripper further includes at least one controller programmed or configured to actuate the first motor and the second motor of each of the at least one movable finger.

A gripper includes at least one movable finger. Each movable finger includes a first motor, a second motor, a first motor link having a first end coupled to a rotor of the first motor, a second motor link having a first end coupled to a rotor of the second motor, a finger link having a first end in pivotal connection with a second end of the second motor link and a gripper pad, and a connecting link having a first end in pivotal connection with a second end of the first motor link and a second end in pivotal connection with the finger link. The gripper further includes at least one controller programmed or configured to actuate the first motor and the second motor of each of the at least one movable finger.

A motor protector and a method for operating the same. The motor protector includes: a power supply unit adapted to receive electric power from power supply lines of a motor to power the motor protector; a measuring unit adapted to measure electric parameters of the motor; and a controller configured to at least perform steps of: receiving from the measuring unit the electric parameters; determining, based on the electric parameters, whether the motor experiences a first failure related to overheating of the motor; enabling, in accordance with determination of the first failure of the motor, the power supply unit to power a closing mechanism of the motor protector after a predetermined time, thereby closing the closing mechanism to power the motor by the power supply lines; determining, based on the electric parameters, whether the motor experiences a second failure different from the first failure; and enabling, in accordance with determination of the second failure of the motor, the power supply unit to stop powering the closing mechanism. Hence, the motor protector can discriminate types of the motor failures and adopt corresponding measures for different failures.

A motor protector and a method for operating the same. The motor protector includes: a power supply unit adapted to receive electric power from power supply lines of a motor to power the motor protector; a measuring unit adapted to measure electric parameters of the motor; and a controller configured to at least perform steps of: receiving from the measuring unit the electric parameters; determining, based on the electric parameters, whether the motor experiences a first failure related to overheating of the motor; enabling, in accordance with determination of the first failure of the motor, the power supply unit to power a closing mechanism of the motor protector after a predetermined time, thereby closing the closing mechanism to power the motor by the power supply lines; determining, based on the electric parameters, whether the motor experiences a second failure different from the first failure; and enabling, in accordance with determination of the second failure of the motor, the power supply unit to stop powering the closing mechanism. Hence, the motor protector can discriminate types of the motor failures and adopt corresponding measures for different failures.

Residual voltage measurements taken after removal of electric power to an electric motor are used to improve the functioning of an electric motor monitoring system. For example, an intelligent electronic device (IED) may acquire residual voltage measurements of a motor after disconnected electric power to the motor. The IED may determine a thermal condition of the motor based at least in part on the residual voltage measurement. The IED may prevent starting of the motor based at least in part on the thermal condition.

Residual voltage measurements taken after removal of electric power to an electric motor are used to improve the functioning of an electric motor monitoring system. For example, an intelligent electronic device (IED) may acquire residual voltage measurements of a motor after disconnected electric power to the motor. The IED may determine a thermal condition of the motor based at least in part on the residual voltage measurement. The IED may prevent starting of the motor based at least in part on the thermal condition.