Abstract: A power tool includes a power a motor, a driver circuit, a capacitor, a capacitor switch, a temperature detection unit, and a controller. The capacitor is configured to filter out current spikes in a power supply. The capacitor switch is configured to control a working state of the capacitor. The temperature detection unit is configured to detect a temperature of a related object. The controller is configured to: acquire the temperature of the related object; control the capacitor switch to be in a first on or off state such that the capacitor works in a first working state when the temperature is lower than a temperature threshold; and control the capacitor switch to be in a second on or off state such that the capacitor works in a second working state when the temperature is higher than the temperature threshold.

Abstract: A system includes one or more electric motors, this system comprising a set of at least one load and an inverter comprising transistors, the inverter being intended to convert a DC voltage into an AC voltage that is intended to electrically power the set of at least one load, the inverter being able to be in a set of states comprising a nominal regime and a transitory regime wherein the set of at least one load draws, from the inverter, a power higher than a maximum power drawn from the inverter when the inverter is in nominal regime, the electrical-energy-converting system comprising means for cooling the transistors comprising a holder that is joined to at least one of the transistors of the inverter, the holder comprising a phase-change material that is able to melt, the system comprising one or more electric motors being configured so that, at a preset ambient temperature, the phase-change material melts when the inverter is in the transitory regime and so that, at this ambient temperature, the phase-chan

Abstract: Control of temperature of water delivered by a dual-stage water heater having an external boiler with a first heater as first stage and an internal duct (water booster) with a second heater as second stage. A control loop based on a measured water temperature in the boiler and controls the first heater. A second loop calculate a reference booster water temperature based on the temperature error at the outlet (difference between a measured outlet water temperature and a reference outlet water temperature) and controls second heater based on error between reference booster water temperature and measured booster water temperature. The reference outlet water temperature depends on type of beverage (e.g. espresso, cappuccino) and includes a temperature profile with different temperature for different sub-beverages (e.g. coffee, milk). Takes into account physical response times, inertia of heater and anticipate sudden changes of reference water temperature at hot water outlet.

Abstract: A method for setting a gear in a transmission of a power tool, the power tool including an electric motor as well as a controller for setting the rotational speed of the electric motor. A transmission includes an operating device for selecting a gear in the transmission, a shift fork as well as an actuator, the operating device including a signal transmitter as well as a sensor for receiving a signal of the signal transmitter.

Abstract: Control apparatus and corresponding method for controlling a high power electric motor, preferably of the order of megawatts, preferably of or associated with a shredding plant which is preferably usable for shredding very bulky and heavy objects and is provided with a rotating shredding member connected to the rotor of the electric motor, where a control circuit is configured to control the electric motor so that it can operate selectively in different operating modes.

Abstract: An interactive toy includes a housing, a control module, a motor, a rotating shaft, and an external member. The rotating shaft is exposed outside the housing, and is connected to the external member. The control module is configured to control the motor to drive the rotating shaft to rotate. The toy further includes a measurement module and an analysis module. The measurement module is configured to measure an angle by which the rotating shaft rotates from an initial stationary state to the state in which its rotating speed reaches the maximum. The analysis module is configured to compare a preset reference angle with the angle by which the rotating shaft from the initial stationary state to the state in which the rotating speed of the rotating shaft reaches the maximum to determine whether the external member encounters an obstacle.

Abstract: A method determines a characteristic temperature of an electric or electronic system. The method includes: during operation of the system, measuring one or more characteristic parameters of the system; estimating the characteristic temperature based on a thermal model of the system and a first subset of the measured characteristic parameters; predicting a first value for a temperature-sensitive electrical parameter (TSEP) based on a TSEP model and the estimated characteristic temperature; determining a second value for the TSEP based on a second subset of the measured characteristic parameters; comparing the first value and the second value for the TSEP; and adapting the thermal model or the TSEP model based on a result of the comparison.

Abstract: A system attachable to a refrigeration circuit includes a recovery pump attachable to the refrigeration circuit to remove refrigerant. The recovery pump includes a pump, an electric motor, a battery pack, and a recovery pump controller for controlling the operation of the electric motor. The recovery pump controller has a first communication interface. The system further includes an accessory attachable to the refrigeration circuit concurrently with the recovery pump. The accessory includes a sensor for detecting a characteristic value of the refrigeration circuit, and an accessory controller electrically connected with the sensor to receive a signal corresponding with the characteristic value of the refrigeration circuit. The accessory controller has a second communication interface to communicate the signal to the recovery pump controller via the first and second wireless interfaces. The recovery pump controller controls the operation of the electric motor based upon the signal received from the accessory.

Abstract: A method for operating an electrical machine is used to calculate a value of a first torque which can be provided at a maximum by the electrical machine in a future interval, wherein, by limiting the torque which is provided in the interval to the value, overheating of at least one semiconductor, which is required for transmitting the electrical power, due to a power loss is prevented and/or the threat of overheating and the onset of derating is diagnosed and therefore prevented.

Abstract: A system (10, 14) includes one or more sensors configured for acquiring data related to operational conditions of a motor actuator (12), a processor (62) configured for analyzing the data to determine a status of the motor actuator (12), and memory (64) for storing data representative of the operational conditions. A status indicator is generated based on the analysis of the operational conditions, for example to represent system capabilities, normal operating modes, and failure modes of the motor actuator (12). The system (10, 14) can be configured to communicate the status indicator to a user interface (21, 66) or higher-level controller (20, 22).

Abstract: The present disclosure provides a system and method for retrieving temperature information of GPUs of a server system via PCIe topology, and using a baseboard management controller (BMC) to control fan speed(s) of cooling fans based at least upon the temperatures of the GPUs. In some implementations, the management controller can determine a PCIe topology of the server system via an operating system (OS), and get the BusID of each GPU or GPU card of the server system. Based upon the BusID, the management controller can retrieve temperature information of a corresponding GPU from a GPU library (e.g., NVIDIA Management Library [NVML]), and further control fan speed of cooling fan(s) based at least upon the temperature information.

Abstract: A system for controlling an electric motor which includes three coils and a rotor, comprising a motion-profile-generator for generating a rotor-motion-profile and for producing a position-command, a position-controller for determining a velocity-command and a position-feedforward, for determining a forward-velocity according to the prediction of the velocity required to reach said position-command. The system further includes a first summer for producing a modified velocity, a velocity controller, for determining a current-command, a velocity feedforward, for determining a forward-current and a second summer for producing a modified-current. The system also includes a commutator, for determining respective modified-coil-currents for each of at least three current-control-loops and for dividing said modified-coil-currents between the said current-control-loops according to the position of said rotor.

Abstract: A power supply device includes: a power supply mounted in an apparatus; a conversion module including a plurality of conversion units configured to perform voltage conversion of power supplied by the power supply, the plurality of conversion units being electrically connected in parallel to each other; a selection unit that selects one of a plurality of patterns indicating a combination of the conversion units performing the voltage conversion for each operation number, which is the number of the conversion units performing the voltage conversion; and a control unit that controls the conversion module such that the conversion unit indicated by the pattern selected by the selection unit performs the voltage conversion. The selection unit changes the selected pattern with an operation on the switch. In the plurality of patterns, the combination of the conversion units performing the voltage conversion in at least one of the operation numbers is different.

Abstract: A method of monitoring a server rack system includes: initializing each of a rack management controller (RMC), a rack back plate (RBP) and a baseboard management controller (BMC); transmitting by the RMC an initiation message to RBP; transmitting by the RBP initiation messages to the BMC and the RMC, respectively; transmitting by the BMC an initiation message to RBP transmitting by the BMC a real-time monitoring output associated with a condition of a server to the RBP after receiving the initiation message transmitted by the RBP; and transmitting by the RBP at least a portion of the real-time monitoring output received from the BMC to the RMC after receiving the initiation message transmitted by the RMC.

Abstract: A machine tool controller according to an embodiment of the present invention, for controlling a spindle and a feed axis, includes a motor temperature obtaining unit for obtaining and outputting the winding temperature of a spindle motor as a motor temperature; an inverter temperature obtaining unit for obtaining and outputting the temperature of an inverter that drives the spindle motor as an inverter temperature; a motor temperature comparator for comparing the outputted motor temperature with an overheat temperature for the motor; an inverter temperature comparator for comparing the outputted inverter temperature with an overheat temperature for the inverter; and an overheating assessment unit for imposing a restriction on the output of the spindle motor according to the smaller one of the differences between the motor temperature and the overheat temperature for the motor and between the inverter temperature and the overheat temperature for the inverter.

Abstract: An electrical system includes a direct current (DC) voltage bus, a power supply providing a supply voltage to the DC voltage bus, an electric machine connected to the power supply, a reverse current protection (RCP) circuit positioned between the power supply and the electric machine, the RCP circuit including an energy dissipating element, and a controller. As part of an associated method, the controller detects a reverse current condition in which a current flows from the electric machine toward the power supply when an induced voltage of the electric machine exceeds a voltage level of the voltage bus. The controller transmits a control signal to the RCP circuit to direct the electrical current through the energy dissipating element for a duration of the reverse current condition or for a predetermined duration equal to or greater than that of the reverse current condition.

Abstract: The invention relates to a device for controlling an alternator of the type that controls a DC voltage (B+A) generated by the alternator (11) according to a predetermined set voltage (U0) by monitoring the intensity of an energizing current (IEXC) flowing through an energizing circuit of the alternator. According to the invention, the device includes a voltage-control loop (7) and a temperature-control loop (17) which comprises a temperature sensor supplying a current temperature (T) of components of the alternator, a subtracter (19) supplying a temperature error (?t) between the current temperature (T) and a maximum acceptable temperature (Tmax) and a control module (20) supplying a maximum admissible energizing percentage (rmax) in accordance with the temperature error according to a predetermined control law.

Abstract: A method of operating an air conditioning system includes cooling a selected space with the air conditioning system. The air conditioning system includes two or more compressors and two or more crank case heaters. Each crank case heater of the two or more crank case heaters is operably connected to a compressor of the two or more compressors. Operation of the two or more compressors is stopped, thus initiating operation of the two or more crank case heaters. The air conditioning system is switched to a conservation mode, including de-powering at least one compressor of the two or more compressors and a connected at least one crank case heater or the two or more crank case heaters.

Abstract: A method and a device for operating an electrical machine having separate excitation, especially a synchronous machine. With the aid of a sensor system, a variable characterizing a rotor temperature and/or a stator temperature are/is determined, and an excitation current and stator currents for the electrical machine are specified by a control unit as a function of the variable characterizing the rotor temperature and/or the stator temperature, at least in specifiable operating ranges.

Abstract: A motor, and a starter for a vehicle including a motor are described. The motor includes an excitation coil and a thermal element. The excitation coil is electrically connected with the bus terminal through which current flows when the motor is in operation. The bus terminal has a thermal contact surface. The thermosensitive element is fixed onto the bus terminal and has a collection surface in thermal contact with the thermal contact surface. The motor is provided with a thermal protection function.

Abstract: A fan rotational speed adjusting system includes a power supply unit, a fan, a current detecting circuit and a temperature detecting circuit. The current detecting circuit detects a first DC voltage from the power supply unit, compares the first DC voltage with a first reference voltage, and outputs a first adjusting voltage. The temperature detecting circuit detects a temperature change of the power supply unit, and outputs a second adjusting voltage. The temperature detecting circuit receives the first adjusting voltage, compares the first adjusting voltage and the second adjusting voltage with a second reference voltage, and outputs a third DC voltage to the fan. The fan rotates in the corresponding rotational speed, and dissipates heat for the power supply unit.

Abstract: Control circuits and related methods are provided. One exemplary control circuit includes a solid state switching device for coupling to a first tap of a motor and a control device coupled to the solid state switching device. The control device is configured to switch the solid state switching device to apply a signal to the first tap in response to a demand for operation of the motor at a second parameter to operate the motor at the second parameter. The control device is also configured to switch the solid state switching device to apply a signal to the first tap in response to a demand for operation of the motor at a first parameter to operate the motor at the first parameter.

Abstract: A controlling circuit for outputting a square wave circuit to control a fan rotating speed is disclosed, where an output unit continuously outputs the square wave signal and the output unit is electrically connected to a time-delaying adjustment circuit, so that a duty-ratio formed not equal to 50% is outputted to control the fan rotating speed, whereby a particular duty-ratio is provided to control the fan rotating speed after a control chip for fan rotating speed is pulled out.

Abstract: An electric compressor capable of following temperature changes of a power element even if a temperature measurement unit is disposed separately from the power element. In the electric compressor, the temperature measurement unit (34) measures the temperature of a substrate (36) on which the power element (31) is disposed. A rotational speed detection unit (35) detects the rotational speed of a motor. A control unit (33) estimates the temperature of the power element (31) on the basis of the rotational speed of the motor detected by the rotational speed detection unit (35) and the temperature measured by the temperature measurement unit (34).

Abstract: A device for processing graphics data may include a plurality of graphics processing units. The device may include a fan to dissipate thermal energy generated during the operation of the plurality of graphics processing units. Each of the plurality of graphics processing units may generate a pulse width modulated signal to control the speed of the fan. The device may include one or more monitoring units configured to monitor a signal controlling the speed of the fan. One or more of the plurality of pulse width modulated signals may be adjusted based on the monitored signal. One or more of the plurality of pulse width modulated signals may be adjusted such that a signal controlling the fan maintains a desired duty cycle.

Abstract: An electric power tool of the present invention includes: a lighting unit; a motor that drives a tool element; a setting switch that is turned ON/OFF to change an operation mode setting and a lighting mode setting; a setting switching unit that changes the operation mode setting and the lighting mode setting corresponding to a manner of operation provided to the setting switch; a motor control unit that controls the motor according to a control method for one of the operation modes currently set by the setting switching unit; and a lighting control unit that controls the lighting unit corresponding to one of the lighting modes currently set by the setting switching unit. When the setting switch is turned on, the setting switching unit changes one of the operation mode setting and the lighting mode setting corresponding to a duration time of an ON state of the setting switch.

Abstract: A motor driven power steering (MDPS) may include: a vehicle speed sensor configured to sense vehicle speed; a temperature sensor configured to sense a temperature of a power pack; a current sensor configured to sense an amount of current applied to the MDPS; a storage unit configured to store a thermal resistance value based on the vehicle speed with respect to the temperature of the power pack; and a control unit configured to calculate an estimated temperature by reflecting the thermal resistance value based on the vehicle speed with respect to the temperature of the power pack and the current amount applied to the MDPS into a temperature estimation function, and drive a motor according to the calculated estimated temperature.

Abstract: A method of derating a retarding grid assembly of a machine is provided. The method may determine the temperatures of resistive elements and insulators associated with the retarding grid assembly, generate a trigger if any one of the temperatures of the resistive elements and insulators exceeds a respective temperature threshold, and determine a magnitude of deration to be applied to a drivetrain associated with the machine in response to the trigger. The magnitude of deration may be based at least partially on feedback and feedforward analyzes of the temperatures of the resistive elements and insulators. The magnitude of deration may correspond to a reduction in retarding capacity of the drivetrain.

Abstract: Temperature rise in semiconductor switching element that is part of a power conversion device is estimated to assess the degradation and remaining lifetime of the switching element. This is accomplished with a heat generation amount calculation unit in a calculation processor, where current command values Id* and Iq* and voltage command values vu*, vv* and vw* are used to calculate a chip loss. Current values iu*, iv* and iw* of all output phases are estimated from the current command values. The ON/OFF loss of the chip is represented by a function of an estimated value for a current flowing in each output phase, and the loss can be derived by integration with a PWM carrier frequency f. With respect to a conduction loss, a conduction time is integrated with the estimated current value and a saturation voltage, which is a function of the estimated current value.

Abstract: A rotation speed control circuit is disclosed. The rotation speed control circuit includes a temperature-controlled voltage duty generator, a pulse-width signal duty generator, a multiplier and a rotation speed signal generator. The temperature-controlled voltage duty generator converts temperature-controlled voltage to digital temperature-controlled voltage and executes linear interpolation operation according to a first setting data so as to output temperature-controlled voltage duty signal. The pulse-width signal duty generator coverts pulse-width input signal to a digital pulse-width input signal and executes linear interpolation operation according to a second setting data so as to output a pulse-width duty signal. The temperature-controlled voltage duty signal and the pulse-width duty signal are executed for multiplication by the multiplier so as to output mixing-duty signal.

Abstract: An electric drive system may include a plurality of heat sensitive components, at least one temperature sensor positioned in or on each of the components and a system controller. The temperature sensors may be interconnected with the system controller to transmit temperature data from their respective heat sensitive components to the system controller. The system controller may be configured to transmit a reduced performance command in the event that a reached-temperature-threshold-limit signal is received from any one or more of the temperature sensors. System shutdown due to over temperature faults may be avoided.

Abstract: A synchronous machine control apparatus is characterized by including a magnet condition estimation unit (7, 7a) that estimates the temperature or the magnetic flux of a permanent magnet that forms the magnetic field of a synchronous machine (1), and is characterized in that the magnet condition estimation unit (7, 7a) coordinate-converts an armature current into currents on the ?-? axis consisting of the ? axis and the ? axis that is perpendicular to the ? axis, based on the rotor position and the estimated ? axis, and estimates the temperature or the magnetic flux of the permanent magnet, based on the control command for the synchronous machine (1) and the ?-? axis currents.

Abstract: A temperature calculation unit calculates a temperature T1 of one power semiconductor chip as a temperature estimating target, from a reference temperature, a temperature difference ?T1, and a temperature difference ?T2. The temperature difference ?T1 is calculated based on an electric power loss Q1 generated in all power semiconductor chips of a power semiconductor module containing one power semiconductor chip as the temperature estimating target. The temperature difference ?T2 is calculated based on the electric power loss Q1 and an electric power loss Q2 generated in all power semiconductor chips of a power semiconductor module other than the power semiconductor module containing one power semiconductor chip as the temperature estimating target.

Abstract: An apparatus for temperature-dependent control of an electric motor, includes a control device for adjusting the power output of the electric motor, and means for detecting the temperature of a component of the electric motor, wherein the control device reduces the power of the electric motor in the case of a component temperature above a temperature threshold, and wherein the temperature detection means distinguish between self-heating and external heating, wherein the control device counteracts only the self-heating by reducing the power.

Abstract: A control circuit for a fan includes a fan controller, a switch controller, and a frequency detector. When a pulse-width modulation (PWM) signal output pin of the fan controller outputs PWM signals, the frequency detector outputs a high level signal, connecting an input pin of the switch controller to an output pin of the switch controller. The fan receives the PWM signal. When the PWM signal output pin of the fan controller does not output PWM signals, the frequency detector outputs a low level signal, such that the output pin of the switch controller does not output any signal. In this state, the fan receives a high level signal through a resistor and a power supply, enabling the fan to continue operating.

Abstract: A condition monitoring method for an electrical machine is provided. The method includes providing at least one first sensor element embedded in or disposed on at least one substrate element located in a stator core for obtaining a first set of data. The method also includes providing at least one second sensor element for obtaining a second set of data from the electrical machine. Further, the method includes generating signals indicative of changes in characteristics of the first sensor element based on the second set of data. Finally, the method includes refining the first set of data by combining the first set of data with the generated signals.

Abstract: A system to monitor the temperature of power electronic devices in a motor drive includes a base plate defining a planar surface on which the electronic devices and/or circuit boards within the motor drive may be mounted. The power electronic devices are mounted to the base plate through the direct bond copper (DBC). A circuit board is mounted to the base plate which includes a temperature sensor mounted on the circuit board proximate to the power electronic devices. The temperature sensor generates a digital signal corresponding to the temperature measured by the sensor. A copper pad is included between each layer of the circuit board and between the first layer of the circuit board and the sensor. The circuit board also includes vias extending through each layer of the board. The copper pads and vias establish a thermally conductive path between the temperature sensor and the base plate.

Abstract: A method for starting an electric motor, the motor having a main machine, exciter, and permanent magnet generator (PMG), each having a stator and a rotor, with each rotor mounted to a common shaft, the method comprising starting the main machine in an asynchronous mode by applying a starting current to the stator of the main machine to induce a damper current in a damper winding of the main rotor to generate a starting torque that initiates the rotation of the common shaft, and then running the main machine in synchronous mode by supplying running current from the exciter rotor to the main machine rotor.

Abstract: A method for testing rotation speed of a fan receives a duty cycle ratio related to the fan sent from a dial switch on a test board connected to the fan. The method transmits a pulse width modulation (PWM) signal based on the duty cycle to the fan to power rotation of the fan, then detects the PWM signal transmitted to the fan and a tachometer (TACH) signal transmitted from the fan. The method gathers the duty cycle ratio related to the fan from the PWM signal and an actual rotation speed of the fan from the TACH signal, and displays the duty cycle ratio and the actual rotation speed together on the test board.

Abstract: An HVAC system includes a blower motor and a variable speed motor drive. The variable speed motor drive is configured to receive line power and provide modulated power to the motor. The blower motor is configured to produce airflow in response to the modulated power. A unit controller is configured to bypass the variable speed motor drive to provide the line power directly to the blower motor in the event that a measured airflow is less than a predetermined value.

Abstract: Improved protection for a rechargeable battery from damage by being discharged below a cut-off voltage is provided. The measured voltage of a battery under load is lower than the measured voltage of the battery under no load. As the cut-off voltage for the battery is specified as a no load voltage, comparing the measured voltage of the battery under load to the cut-off voltage would result in stopping use of the battery with useable charge remaining. Through testing, a set of relationships for estimating the no load voltage of a battery under load has been determined. Using this set of relationships with battery measurements, an estimated no load voltage for the battery is determined. This estimated no load voltage is compared to the cut-off voltage. This allows for full use of the battery while stopping use of the battery when its voltage reaches the cut-off, thereby preventing damage.

Abstract: An electric drive system may include a plurality of heat sensitive components, at least one temperature sensor positioned in or on each of the components and a system controller. The temperature sensors may be interconnected with the system controller to transmit temperature data from their respective heat sensitive components to the system controller. The system controller may be configured to transmit a reduced performance command in the event that a reached-temperature-threshold-limit signal is received from any one or more of the temperature sensors. System shutdown due to over temperature faults may be avoided.

Abstract: A rotation speed control circuit is disclosed. The rotation speed control circuit includes a temperature-controlled voltage duty generator, a pulse-width signal duty generator, a multiplier and a rotation speed signal generator. The temperature-controlled voltage duty generator converts temperature-controlled voltage to digital temperature-controlled voltage and executes linear interpolation operation according to a first setting data so as to output temperature-controlled voltage duty signal. The pulse-width signal duty generator coverts pulse-width input signal to a digital pulse-width input signal and executes linear interpolation operation according to a second setting data so as to output a pulse-width duty signal. The temperature-controlled voltage duty signal and the pulse-width duty signal are executed for multiplication by the multiplier so as to output mixing-duty signal.

Abstract: A first calculation unit subtracts third digital data which indicates the minimum value of the duty ratio from first digital data which indicates the duty ratio of the PWM driving operation. A slope calculation unit generates slope data which is dependent on the temperature based upon second digital data which indicates the temperature. A second calculation unit multiplies the slope data by the output data of the first calculation unit. A third calculation unit sums the output data of the second calculation unit and the third digital data. A selector receives the output data of the third calculation unit and the third digital data, selects one data that corresponds to the sign of the output data of the first calculation unit, and outputs the data thus selected as a duty ratio control signal.

Abstract: The present invention relates to a system and method controlling motor rotation speed and provides a cooling system and method configured to control a temperature associated with an integrated circuit. The cooling system includes a brushless motor, a temperature monitoring input, a clock input, and a motor controller.

Abstract: A motor driving device includes a motor driving circuit, an element temperature sensor, a control circuit, an ambient-temperature estimator, and an overheat protection processor. The motor driving circuit has a plurality of switching elements. The element temperature sensor is configured to detect a temperature of each of the switching elements. The ambient-temperature estimator is configured to estimate an ambient temperature around the control circuit based on a temperature of at least one of the switching elements detected by the element temperature sensor if the at least one of the switching elements is not performing the switching operation. The overheat protection processor is configured to execute a first overheat protection process to protect the control circuit from overheating if the ambient temperature around the control circuit estimated by the ambient-temperature estimator exceeds a first overheat criterion temperature.

Abstract: A method for operating an electric motor is provided. The method includes receiving a torque request; determining long term torque capabilities and short term torque capabilities of the electric motor; generating a torque command based on the torque request and at least one of the long term torque capabilities or the short term torque capabilities; and controlling the electric motor in accordance with the torque command.

Abstract: An inverter includes a warm-up control section and a switching control section. In a state in which an electric motor is not operating, the warm-up control section controls switching elements of an inverter circuit to perform warm-up control, in which direct currents are supplied to the coils of the respective phases of the electric motor, when the temperature of the capacitor is lower than a prescribed temperature. When a warm-up control is switched to a normal operation control, the switching control section sets initial phases of alternating currents such that the relationship between the values of the alternating currents supplied to the coils of the electric motor in the normal operation control matches with the relationship between the values of the direct currents that have been supplied to the corresponding coils of the electric motor in the warm-up control.

Abstract: A motor driving apparatus is provided that performs AC/DC conversion by suppressing harmonics of the input at the time of normal operation, while on the other hand, allowing system operation to continue in the event of an overload by avoiding system stoppage.

Abstract: A microcomputer calculates an internal resistance value of a motor, and subsequently calculates an internal resistance value of a switching element of a motor drive circuit. When the internal resistance value of the motor is a semi-abnormal value, the microcomputer sets an upper limit current. When the internal resistance value of the motor drive circuit is a semi-abnormal value, the microcomputer sets an upper limit current. The microcomputer sets a smaller one of the upper limit current and the upper limit current as an upper limit current of the motor. In this manner, the progress of degradation of the motor and the motor drive circuit can be suppressed.