A fan motor stopping apparatus includes a conversion circuit that converts alternating-current voltage supplied from an alternating-current power supply into direct-current voltage, a smoothing capacitor that is connected to a fan motor included in an air conditioner and smooths the direct-current voltage from the conversion circuit, a voltage detection circuit that detects a voltage across the smoothing capacitor, and a fan motor shutdown circuit that suspends the fan motor in operation when the voltage detection circuit detects a voltage less than or equal to a threshold that is preset for suspending the operation of the fan motor.

A motor drive apparatus includes: a rectifier; an inverter; a DC link voltage detection unit; an input current detection unit configured to detect input current inputted to the rectifier; a DC link voltage comparison unit configured to compare a DC link voltage with a first voltage threshold value and with a second voltage threshold value; a current comparison unit configured to compare the input current with a current threshold value; and an abnormality detection unit configured, in a case that the DC link voltage is smaller than the first voltage threshold value or that the DC link voltage is greater than the second voltage threshold value, to determine that a first abnormality has occurred when the input current is smaller than the current threshold value and to determine that a second abnormality has occurred when the input current is equal to or greater than the current threshold value.

The present disclosure provides a motor driving device capable of inhibiting unstable driving of a motor even in the occurrence of a sudden fluctuation of a power supply voltage. The motor driving device includes a power supply voltage sudden fluctuation detector, a power supply voltage fluctuation width generator and a current limit value setting unit. The power supply voltage sudden fluctuation detector detects a sudden fluctuation in a direction in which the power supply voltage rises. The power supply voltage fluctuation width generator detects a fluctuation width of the power supply voltage. When the sudden fluctuation is detected by the power supply voltage sudden fluctuation detection unit, a current limit value of the current limit value setting unit is reduced from a normal value and corrected by the correction width corresponding to the fluctuation width of the detected power supply voltage.

A motorized hand tool, such as a cordless ratchet wrench, that has a motor, one or more electronic components and/or integrated circuits, and a step-up converter that are housed or disposed in a housing of the tool. The step-up converter is adapted to prevent a voltage of a battery of the tool from dropping below a threshold voltage of a component or integrated circuit when current draw from the battery increases, thus preventing a “brownout” condition.

A capacitor capacitance estimation device including processing circuitry to segment a section signal into a plurality of signals and to generate a plurality of pieces of frequency domain data by converting each of the plurality of signals obtained by the segmentation into a plurality of component values in a frequency domain. Each of the plurality of signals having a predetermined duration. The processing circuitry further configured to extract a component value of a frequency corresponding to a carrier frequency from the plurality of component values in each of the plurality of pieces of frequency domain data, to use the extracted component value as a value at time corresponding to the corresponding one of the extracted signals, and to generate time-series data representing a plurality of the extracted component values in a time series, to estimate a capacitance of a capacitor from processed and filtered time-series data.

The present disclosure discloses an IGBT driving circuit for an electric-motor controller and an electric-motor controller. The IGBT driving circuit includes: a function safety circuit provided on a driver board of the electric-motor controller, and a detection feedback circuit and a pulse-width-modulation (PWM) buffer circuit that are connected to the function safety circuit. The detection feedback circuit is configured to detect an IGBT module of the electric-motor controller, and when a specified malfunction of the IGBT module is detected, send a specified-malfunction signal to the function safety circuit. The function safety circuit is configured to judge according to a preset malfunction treating rule and the received specified-malfunction signal, and then output a corresponding controlling signal to the PWM buffer circuit. The PWM buffer circuit is configured to generate according to the corresponding controlling signal a PWM signal that drives the IGBT module, to control ON/OFF of the IGBT module to protect the IGBT module. The technical solutions of the present application have multiple functions of protection, which improves the stability and the safety of the IGBT, and has quick action and timely protection.

A system, apparatus and method for managing an electromechanical system is provided. In an embodiment, the method includes receiving, by a processing unit, operational data associated with the electromechanical system from one or more sensing units in real-time. Furthermore, the method includes detecting an event associated with a power supplied to the electromechanical system based on the operational data. Also, the method includes configuring a virtual replica of the electromechanical system using the operational data, based on the event detected. Additionally, the method further includes generating one or more simulation results by simulating the configured virtual replica in a simulation environment. Moreover, the method includes predicting an effect on the electromechanical system due to the event based on the simulation results.

A control device configured to control operation of an electric motor of which a rotational shaft is rotatable by an external force which servo-controls the electric motor by an inverter circuit when a voltage value between power-supply input terminals of the inverter circuit is detected to be at or above a given voltage value required for the servo-control of the electric motor, and applies dynamic braking to the electric motor by forming a short circuit in the inverter circuit when the voltage value between the power-supply input terminals of the inverter circuit is detected to be below the given voltage value.

A method for detecting a stall condition of an electric motor. The method can include initiating an open-loop phase. During the open-loop phase, the method can include increasing a rotational speed of an electric motor and obtaining data indicative of a voltage associated with the electric motor while increasing the rotational speed of the electric motor. During the open-loop phase, the method can also include determining a difference between the voltage and a time varying target voltage and detecting a stall condition based at least in part on the difference between the voltage and the time varying target voltage. When a closed-loop condition is satisfied, the method can include initiating a closed-loop phase.

Provided are a motor device, a gear motor, a detection method, and a computer readable medium capable of detecting a load fluctuation and performing highly accurate preventive maintenance. The motor device comprises: a motor; a power detection circuit that detects power supplied to the motor; a temperature sensor that measures a temperature of the motor; a storage unit that stores a regression equation expressing a relationship between power detected by the power detection circuit and a temperature measured by the temperature sensor, and a physical quantity used to derive an output shaft torque of the motor; and a processing unit that derives the output shaft torque of the motor from the power detected by the power detection circuit and the temperature measured by the temperature sensor by using the physical quantity obtained by the regression equation.