Abstract: A condition of an engine is diagnosed based on information provided by signals from speed sensors associated with the engine or other signals associated with a generator operationally connected to the engine. Different types of degradation are distinguished based on discerning characteristics within the information. Thus, a degraded engine component can be identified in a manner that reduces service induced delay.

Abstract: An assembly for controlling an electric vacuum pump for a vehicle, which is connectable by at least one switch, which can be controlled by an electronic control unit, to a supply voltage, wherein the electronic control unit in a start-up phase connects the vacuum pump to an additional electrical resistor between the supply voltage and the vacuum pump.

Abstract: A variable-speed hoisting machine uses an electric motor having a pull-rotor brake as a hoisting motor and capable of supplying the electric motor with an electric current that can reliably release the pull-rotor brake at the time of starting an operation even in the case of a variable-speed hoisting machine such as an electric chain block in a variable-speed hoisting machine having an electric motor with a pull-rotor brake and an inverter controlling the speed of the electric motor in a soft-start manner, the inverter is set to operate according to a predetermined voltage-frequency (V-F) pattern.

Abstract: On condition that output of a torque of not lower than a preset reference torque from a motor continues for at least a predetermined time period in a vehicle stop state with output of a corresponding torque from the a second motor based on a detected accelerator opening, a torque command of the second motor is set to decrease the output torque of said motor by a torque decrease rate, which is set according to the corresponding torque and the accelerator opening in the vehicle stop state (initial accelerator opening). After a changeover of a current crowding phase in the second motor, the torque command of said motor is set to increase the output torque of said motor by a torque increase rate, which is set according to the accelerator opening in the vehicle stop state.

Abstract: A forced induction system for an engine comprising a compressor for increasing the pressure of gas into the engine and a turbine arranged to be driven by engine exhaust gas. The system further comprises a generator and an electric motor. The generator is arranged to be driven by the turbine and the motor is arranged to drive the compressor, wherein the generator and motor are electrically connected. The system comprises electrical control means arranged to receive the electrical signal output by said generator during operation and to apply an AC control signal to said electric motor whereby the compressor is driven at least in part by an output torque of the turbine via the electrical connection therebetween.

Abstract: A system and method for optimizing current filtering in a motor soft starter is disclosed. A motor soft starter includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, with the circuit being operable in a ramping mode and a bypass mode so as to control current flow and terminal voltages in the AC motor. The soft starter includes a controller connected to the circuit to control operation thereof, with the controller including a configurable current filter. The controller determines a current of an AC power provided to the input terminal of the AC motor from the soft starter, identifies a present operational mode of the soft starter as being one of the ramping mode and the bypass mode, and performs filtering on the determined current based on the present operational mode of the soft starter.

Abstract: The present invention relates to a system for controlling rotational speed on a rotating process machine, which for example is a turbine or a propeller, where the rotating process machine is connected to at least one motor and arranged to rotate with a given rotational speed given by the motor, the motor is connected to a control system and the rotational speed of the motor is arranged to be controlled by a control system. The rotating process machine comprises a load control arranged to be adaptable, the control system is connected to the rotating process machine. With the invention, one achieves soft transitions between several selectable rotational speeds and lower energy consumption by step by step adjusting the size and the rotational speed of the motor to varying energy requirement.

Abstract: Systems and methods for estimating an inertia and a friction coefficient for a controlled mechanical system are provided. In one or more embodiments, an inertia estimator can generate a torque command signal that varies continuously over time during a testing sequence. The velocity of a motion system in response to the time-varying torque command signal is measured and recorded during the testing sequence. The inertia estimator then estimates the inertia and/or the friction coefficient of the motion system based on the torque command data sent to the motion system and the measured velocity data. In some embodiments, the inertia estimator estimates the inertia and the friction coefficient based on integrals of the torque command data and the velocity data.

Abstract: To provide a controller apparatus of a type, in which the controller is given the redundancy so that the control of the drive motor can be properly performed at all times when an abnormality such as the failure of the controller occurs, with the reliability consequently increased, a plurality of controllers are provided, each including a power circuit for outputting a drive current for the drive motor and a control circuit, which is a light electric circuit, for controlling the power circuit in response to a motor drive command fed from a higher control. An abnormality determiner is provided for determining an abnormality occurring in the controller then in use according to a prescribed rule and then generating a switching signal. A switch is provided, which is operable in response to the switching signal to change the controller then in a state of functioning relative to the drive motor.

Abstract: Sensorless driving of a brushless DC (BLDC) motor includes detecting a zero crossing time from back electromotive force (BEMF) voltage of the BLDC motor. An instantaneous BEMF voltage and an average BEMF voltage are compared to detect the crossover time, which can be used to change the commutation switching sequence. Since the average BEMF voltage differs for odd and even steps of the commutation switching sequence, average BEMF voltages are calculated separately for odd and even sequences and compared to instantaneous BEMF voltages to detect crossover points for the odd and even sequences. The times to commutations for the odd and even sequences are averaged to provide an average time to the next commutation cycle. The average time can be scaled by a reduction factor to reduce the effects of measurement noise.

Abstract: A fan rotary speed controlling device includes a first signal generating circuit, a second signal generating circuit, a pulse width modulation (PWM) circuit and a switching circuit. The first signal generating circuit receives a real frequency signal and a target frequency signal, and generates a first signal according to the real frequency signal and the target frequency signal. The second signal generating circuit generates a second signal according to the first signal. The PWM circuit generates a PWM signal according to the second signal. The switching circuit is electrically connected with the PWM circuit and outputs a control signal to control the rotary speed of the motor. Hence, the fan rotary speed controlling device boosts the accuracy and the stability of the fan rotary speed.

Abstract: A motor driving device comprises: an AC/DC converter that converts alternating current power into direct current power; a motor driving unit that operates based on the direct current power supplied from the AC/DC converter and outputs a driving signal to a motor; and a start-up auxiliary circuit that is arranged on a path connecting the AC/DC converter and the motor driving unit, wherein the start-up auxiliary circuit: delays an output of the driving signal for a first predetermined time period after the supply of the alternating current power from the alternating current power supply to the AC/DC converter starts; and gradually increases a driving voltage so that current flowing in a driving coil of the motor is limited to a predetermined value or smaller for a second predetermined time period after the output of the driving signal from the motor driving unit starts.

Abstract: A method and device for determining the motor moment constant kM of an electric motor by measuring motor parameters on the running motor. For reduction of the previously considerable measuring effort it is proposed that firstly the generator voltage UEMK produced by the motor is measured, and in that the motor moment constant kM is calculated by division of the generator voltage UEMK and the speed of rotation fMot of the motor, taking into consideration at least one further constant. The method and the device are suitable for DC motors and for 3-phase synchronous motors.

Abstract: Starter apparatuses are provided for multiple-winding motors. Such starters can function with a single/combined overload device/circuit, rather than requiring multiple overloads relays and separate overload trip circuits for each motor winding. A microcontroller can keep track of the applicable overload trip points and can control multiple discrete contactors appropriately, via a single/combined overload relay. For a specific implementation, additional and/or alternative desirable functionality can also be afforded, including universal voltage input, true power characteristic sensing for status output/annunciation, integrated damper control, and substantially automated trip point selection and/or implementation.

Abstract: A rotating electromechanical machine has a rotor having at least one current-carrying winding and at least one rotor-mounted sensor configured to sense a machine property or parameter during machine operation. Rotor-mounted circuitry dynamically modifies at least one property of the current-carrying winding during machine operation in response to the sensed machine property or parameter.

Abstract: A method for operating a controller includes receiving a first accumulated thermal value of an electrical machine and an associated first time stamp from a memory, initializing a processor of the controller with the first accumulated thermal value and the associated first time stamp, determining whether a second time stamp has been received, calculating a difference between the second time stamp and the first time stamp responsive to determining that the second time stamp has been received, calculating a second accumulated thermal value as a function of the first accumulated thermal value, the first time stamp, and the second time stamp, and updating the first accumulated thermal value with the second accumulated thermal value.

Abstract: An exemplary embodiment of the present disclosure includes a medium voltage inverter control apparatus and a medium voltage inverter system using the same. The medium voltage inverter control apparatus determines input voltage information by receiving an input voltage of a medium voltage inverter, compares an output command of the medium voltage inverter with an output of a first PLL unit to output a difference therebetween, and synchronizes the output command of the medium voltage inverter using the difference.

Abstract: A motor drive system comprising: an inverter that supplies power to a three-phase motor; and a control unit that, when first stopping and then commencing supply of alternating current to three phases of the three-phase motor, switches from first control to third control and then to second control, the first control putting switching elements in the inverter in a non-conduction state, the second control being PWM control of the switching elements, and the third control putting and keeping a switching element of each of an upper arm and a lower arm in the conduction state until commencement of the supply of current, the upper arm corresponding to a phase through which current flows in a direction entering the motor upon commencement of the supply, the lower arm corresponding to a phase through which current flows in a direction exiting the motor upon commencement of the supply.

Abstract: The invention relates to a method of controlling the run-up of an electronically commutated electric motor (1) to drive a tool. A rotor (7) rotates in the rotating field (21) of the stator (2). The field windings (3, 4, 5) alternately have a supply voltage applied thereto via an actuation unit (10) in order to obtain an advancing motor rotating field. For advancing the rotating field in the rotational direction (29) of the rotor (7), the inductance of the arrangement of the field coils (3, 4, 5), which is ascertained via a changing measuring current (IM), is evaluated and the advancement is carried out upon reaching a maximum.

Abstract: An apparatus includes an inverter including a high-side switch coupled to a low-side switch, the inverter generating a time-varying drive current from a plurality of drive control signals, a positive rail voltage, and a negative rail voltage wherein controlling the switches to generate the time-varying drive current produces a potential transitory overshoot condition for one of the switches of the inverter; a drive control, coupled to the inverter, to generate the drive control signals and to set a level of each of the rail voltages responsive to a plurality of controller signals; and a controller monitoring one or more parameters indicative of the potential transitory voltage overshoot condition, the controller dynamically adjusting, responsive to the monitored parameters, the controller signals to reduce a risk of occurrence of the potential transitory voltage overshoot condition.

Abstract: A protection relay for an electrical switching apparatus for a load includes a number of voltage sensors structured to sense voltage applied to the load, a number of current sensors structured to sense current flowing to the load, and a processor cooperating with the number of voltage sensors and the number of current sensors. The processor determines a fault current available at the load. An output cooperates with the processor. The output is structured to output the determined fault current and a number of: incident energy at the electrical switching apparatus, and a personal protective equipment level operatively associated with the electrical switching apparatus. The processor determines from the determined fault current the number of: the incident energy at the electrical switching apparatus, and the personal protective equipment level operatively associated with the electrical switching apparatus.

Abstract: A self-adapting soft-starter device includes an electric current limiter limiting electric current supplied to the motor to a preset maximum current limit, a ramp-up time determiner determining the actual ramp-up time of the electric motor, a storing device storing a preset minimum ramp-up time, a comparator comparing the determined actual ramp-up time with the preset reference ramp-up time, a replacing device replacing the preset maximum current limit with an auto-adapted current limit based upon the outcome of the comparison between the determined actual ramp-up time and the preset reference ramp-up time. The soft-starter automatically optimizes the maximum current limit driven by the motor to match its load requirements which is useful to cater for load variations with time during the lifetime of the product in the application by avoiding the need for human intervention to change the soft-starter settings. Wear and tear is also reduced, extending motor lifetime.

Abstract: A relay is provided in a power supply line from a battery to a motor of a starter in a vehicle. The relay is selectively switched between a contact side state where contacts short-circuit and a resistor side state where the contacts open and a resistor is inserted into the power supply line in series. When an engine is started, an ECU controlling the starter energizes the motor by driving the relay to the resistor side only for a first predetermined time in order to suppress inrush current and voltage fall due to the inrush current. The ECU detects a contact side state fixation abnormality of the relay based on a battery voltage at the time when the motor is energized by driving the relay to the resistor side.

Abstract: In a method and apparatus for controlling of a servo-drive, in particular of a solid state actuator in which the servo-drive is controlled during each control process by means of a two-point regulator (R2P), the two-point regulator (R2P) has a power signal (I) as control signal for actuation of the servo-drive. An upper switch point (PO) of the two-point controller (R2P) is allocated to one maximum power value (ÎOn) and a lower switch point (PU) of the two-point controller (R2P) is allocated to one minimum power value (ÎUm). The upper switch point (PO) and the lower switch point (PU) are established during the controlling process so that they are separated in pairs by at least a minimum default spacing (Dmin).

Abstract: A driving device of a brushless DC motor for a fan includes a protection circuit, a storage circuit, a control circuit and a bridge circuit. The protection circuit is electrically connected with an auxiliary power. The storage circuit electrically connected with the protection circuit receives the auxiliary power. The control circuit is electrically connected with the protection circuit and the storage circuit. The bridge circuit electrically connected with the control circuit has a first switching unit, a second switching unit, a third switching unit and a fourth switching unit. The first and second switching units are coupled with one end of a motor coil. The third switching unit and the fourth switching unit are coupled with the other end of the motor coil. The first switching unit is electrically connected with the third switching unit, and the second switching unit is electrically connected with the fourth switching unit.

Abstract: A rotary electric machine control device includes a positive/negative determination section that determines whether an output torque of the rotary electric machine is positive or negative; a correction parameter setting section that sets as a correction parameter a phase difference of a sinusoidal ripple correction wave for reducing torque ripple of the rotary electric machine with respect to a magnetic pole position of the rotary electric machine depending on whether the output torque is positive or negative; and a correction wave generation section that generates the ripple correction wave on the basis of the correction parameter.

Abstract: A method and a device for monitoring the startup of an electric drive, which has a polyphase machine, a pulse-controlled inverter and a control unit. The control unit is provided to compare rotational speed values that are successive in time to one another during the startup of the drive, and when recognizing a non-increase in the rotational speed of the rotor shaft, to detect a mixup of phase lines or pulse-controlled inverter lines.

Abstract: A fan motor control device for controlling the soft start of a fan motor is disclosed. The fan motor control device comprises a converter, a starting capacitor, and a controller. The converter sends out a control signal to the controller based on an input pulse-width modulation signal. The starting capacitor is coupled between a voltage source terminal and a controlled terminal of the controller. Thereby, based on an input voltage to the controlled terminal, the controller controls the soft start of the fan motor. For the soft start period, the magnitude of the input voltage is determined by the base working voltage outputted via the voltage source terminal. While for normal operation, based on the input voltage to the controlled terminal, the controller controls the speed of the fan motor, with the magnitude of the input voltage determined by the control voltage outputted by the converter.

Abstract: In a motor control device, a control calculation unit obtains a phase voltage instruction value. A current detecting unit detects an electric current which flows into the brushless motor. A rotational position detecting unit detects the rotational position of a rotor in the brushless motor. A correction unit corrects the phase voltage instruction value based on the detection results of the current detecting unit and the rotational position detecting unit so that a dependency of a ratio on an electric angle shown by a secondary harmonic component of the ratio concerning the electric angle of the brushless motor. The ratio is a ratio of a q-axis or d-axis component of the electric current, which flows into the brushless motor, to a q-axis or d-axis instruction value. A driving unit drives the brushless motor based on the phase voltage instruction value after the correction by the correction unit.

Abstract: Embodiments of the present invention provide a device and method for generating initial operating points for controlling an interior permanent magnet (IPM) machine. The method includes loading an inductance lookup table, first calculating a maximum torque per Ampere (MTPA) trajectory for a first threshold speed based on machine parameters of the IPM machine, second calculating a truncated voltage limit ellipse with monotonically increasing torque for a first speed based on the machine parameters, if the first speed is higher than the first threshold speed, determining an operating trajectory at the first speed based on at least one of the calculated MTPA trajectory and the calculated truncated voltage limit ellipse, and generating an Id,Iq map that maps an Id value and an Iq value to each torque command of a plurality of torque commands for the first speed based on the determined operating trajectory.

Abstract: A method to permit a start time of a heat engine of a vehicle to be controlled. The heat engine is mechanically coupled to a polyphase rotary electrical machine connected to an on-board electrical network. The method is of the type consisting of carrying out pre-fluxing by establishing an excitation current in the inductor for a predetermined pre-fluxing time (Tpref) before the phase currents are established. In accordance with the method, the predetermined pre-fluxing time (Tpref) is a function of the voltage (Vbat+X) of the on-board electrical network. Typically, the predetermined pre-fluxing time (Tpref) is increased when the voltage (Vbat+X) of the on-board electrical network reduces within a nominal voltage range (V 1, V2).

Abstract: A motor driving circuit receives a control pulse signal pulse-width modulated according to a target rotational speed, and drives a fan motor. A start pulse signal generating unit generates a start pulse signal having a predetermined duty ratio. A driving unit drives the fan motor by pulse width modulation according to the driving pulse signal received from a control unit. When the duty ratio of the control pulse signal is switched from zero to a nonzero value when the fan motor is in the stopped state, the control unit commences the driving operation for the fan motor. The control unit outputs, as the driving pulse signal, the start pulse signal, in a predetermined start period Ts from the commencement of the driving operation. After the start period elapses, the control unit outputs the control pulse signal as the driving pulse signal.

Abstract: When it is determined that a rotor is initially in a stationary state, a current vector is applied to a coil by a vector control method so as to rotate the rotor in a forward direction from a present position of the rotor regardless of a predetermined start position of the rotor. Therefore, a motor can be stably started with less power consumption and noise/vibration.

Abstract: A motor control device has a drive circuit that drives an electric motor with a battery as a power supply, a switch element that is provided between the battery and the drive circuit, the switch element supplying a current from the battery to the drive circuit when being put into an on state, the switch element cutting off the current from the battery to the drive circuit when being put into an off state, a voltage detector that detects a voltage at the drive circuit, and a controller that operates the drive circuit to control the electric motor. The controller turns on the switch element when the voltage at the drive circuit, which is detected by the voltage detector, is greater than or equal to a first predetermined value during stopping of the control of the electric motor.

Abstract: An input circuit includes an interface structured to output a logic signal from an alternating current signal of a pair of elongated conductors. A load is switchable to the elongated conductors. A processor outputs a control signal to switch the load to the elongated conductors asynchronously with respect to the alternating current signal for a first predetermined time, inputs the logic signal, determines if the input logic signal is active a plurality of times during the first predetermined time and responsively sets a first state of the alternating current signal, and, otherwise, sets an opposite second state of the alternating current signal, and delays for a second predetermined time, which is longer than the first predetermined time, for the opposite second state before repeating the output, and, otherwise, delays for a third predetermined time, which is longer than the second predetermined time, for the first state before repeating the output.

Abstract: A system and method for optimizing current filtering in a motor soft starter is disclosed. A motor soft starter includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, with the circuit being operable in a ramping mode and a bypass mode so as to control current flow and terminal voltages in the AC motor. The soft starter includes a controller connected to the circuit to control operation thereof, with the controller including a configurable current filter. The controller determines a current of an AC power provided to the input terminal of the AC motor from the soft starter, identifies a present operational mode of the soft starter as being one of the ramping mode and the bypass mode, and performs filtering on the determined current based on the present operational mode of the soft starter.

Abstract: The present invention provides a power converter which, while ensuring safety, implements control for the flow of a constant current in a specified switching element, more accurately determines the lifetime of a switching element, and reduces the number of temperature detectors. The power converter is provided with a mechanism which causes a brake device to operate or which confirms that a brake mechanism is operating. The power converter supplies current to the d-axis and the q-axis of a rotational coordinate system, within the range of the braking torque of the brake mechanism, and passes the desired current to the desired element. Furthermore, temperature detectors are attached only in chips in sections where a crack readily develops in the upper solder layer or peeling is readily generated in the wire bonding, and in chips where a crack readily develops in the lower solder layer.

Abstract: A pump system. The pump system includes a pump, a motor coupled to the pump, a sensor coupled to a power source, and a controller. The motor operates the pump. The sensor detects an electrical characteristic of the power source. The controller executes a fault check, controls the motor, detects a change in the electrical characteristic, and suspends the execution of the fault check for a predetermined period of time when the detected change in the electrical characteristic is outside of a valid characteristic range.

Abstract: A fan motor control device for controlling the soft start of a fan motor is disclosed. The fan motor control device comprises a converter, a starting capacitor, and a controller. The converter sends out a control signal to the controller based on an input pulse-width modulation signal. The starting capacitor is coupled between a voltage source terminal and a controlled terminal of the controller. Thereby, based on an input voltage to the controlled terminal, the controller controls the soft start of the fan motor. For the soft start period, the magnitude of the input voltage is determined by the base working voltage outputted via the voltage source terminal. While for normal operation, based on the input voltage to the controlled terminal, the controller controls the speed of the fan motor, with the magnitude of the input voltage determined by the control voltage outputted by the converter.

Abstract: A motor control apparatus includes a target acceleration setting unit, a control unit, an acceleration upper limit estimation unit, a mode switching unit, a detection unit and a trajectory setting unit, wherein the mode switching unit controls the target acceleration setting unit to execute a first setting processing, in which the target acceleration at each time point is set corresponding to a first target acceleration trajectory in which the target acceleration at each time point is set corresponding to a first target acceleration trajectory, a second setting processing in which a target acceleration is set corresponding to the acceleration upper limit, or a third setting processing in which the target acceleration is set corresponding to the second target acceleration trajectory, based on the acceleration upper limit, the target acceleration, the speed of the motor.

Abstract: Motor control systems comprise a motor control circuit, a processing circuit operably coupled to the motor control circuit, and a current sensor operably coupled to the processing circuit. The current sensor may be configured to sense a current and to convey a signal to the processing circuitry proportional to an amount of current sensed. The processing circuitry may be configured to sample the signal to obtain a plurality of current values, to store the plurality of current values and to generate an operation profile from the plurality of current values. Folding partitions comprising motor control systems are also disclosed, as well as methods of monitoring an operation of an electric motor and of monitoring for an obstruction of a folding partition.

Abstract: A cooling system is provided with a motor drive device, a fan motor, and a Hall element. The motor drive device includes a lock protection circuit and a lock controller. When a control signal instructing rotation of the fan motor that is to be driven instructs stoppage of the motor for a predetermined time-period or longer, the lock controller has the lock protection circuit inactive. At an occasion when the control signal has continued to instruct stoppage of the fan motor for a first time-period or longer, a standby controller starts time measurement, and after a further predetermined second time-period has elapsed, makes at least a part of the motor drive device transition to a standby mode.

Abstract: It is possible to suppress vibration of a rotary machine in a rotary machine control apparatus. A drive control system of a fuel cell vehicle having a rotary machine includes a control unit having: a drive permission power calculation module which calculates the rotary machine drive permission power according to the states of a fuel cell and an accumulator as power sources of the rotary machine: a limit torque calculation module which calculates a limit torque of the rotary machine according to the drive permission power; and a filter processing module which performs a low-pass process on the limit torque calculation. A storage device of the control unit stores a filter processing region map indicating the region where the filter process is executed by correlating the region with the drive permission power and the rpm.

Abstract: In a vehicle control system that includes an engine, a first rotary electric machine, a second rotary electric machine and a transmission, a control unit includes a shift state acquisition module that acquires a shift state of a vehicle; a stepped-up voltage reduction permission module that determines whether reduction of a system voltage is permitted on the basis of the acquired shift state; a stepped-up voltage reduction execution module that reduces the system voltage to a predetermined upper limit voltage when reduction of the system voltage is permitted; and a drive control module that controls operations of a converter and inverter to thereby control the first rotary electric machine and the second rotary electric machine.

Abstract: An electrical switching apparatus is for another apparatus including a number of insulators, a number of temperature sensors operatively associated with the number of insulators, and a number of conductors operatively associated with the number of insulators. The electrical switching apparatus includes a number of separable contacts, an operating mechanism structured to open and close the separable contacts, a number of sensors structured to sense a number of currents flowing through the separable contacts and through the conductors, a processor structured to input the sensed currents from the sensors, and an output. The processor calculates at least one of: (a) a thermal age of the other apparatus from a number of sensed temperatures from the temperature sensors, and (b) the thermal age of the other apparatus from the sensed currents. The output includes the thermal age of the other apparatus.

Abstract: An energy converter includes magnetic coils of N phases (N is an integer of 3 or more), and a PWM drive circuit for driving the magnetic coils of N phases, wherein the magnetic coil of each phase can be independently controlled by the PWM drive circuit.

Abstract: Method and arrangement for connecting an AC electric motor (M1, M2, . . . MN) to an AC electricity network (L) in a system which comprises a frequency converter (FC), with which the motor is started, and contactors (S11, S12, S21, S22, SN1, SN2), in which method the supply source is changed by means of the contactors from the frequency converter to a direct network supply, in which method the frequency converter is stopped before changing the supply source, and in which method in connection with changing the supply source the control of the contactors is started before stopping the frequency converter.

Abstract: A fan duty cycle controlling system and method are implemented by a computing device. The fan duty cycle controlling system obtains an optimum duty cycle range of a fan around a central processing unit (CPU), and controls the fan to operate at the optimum duty cycle range. By implementing the system and method, the computing device can obtain an optimum cooling efficiency of the computer system, and reduce system noise generated by the fan when the fan operates at the optimum duty cycle range.

Abstract: An object of the present invention is to provide a motor control apparatus that can perform an abnormality diagnosis of current sensors and achieve cost reduction. When the outputs from three current sensors, which detect individual phase currents of a 3-phase AC current supplied from an inverter to a 3-phase AC motor, indicate that the sum of the individual phase currents of the 3-phase AC current is greater than a predetermined value, a sensor abnormality judgment unit of a motor control unit judges that one of the three current sensors is abnormal. The sensor abnormality judgment unit identifies an abnormal current sensor, which is one of the three current sensors, and performs calculations in accordance with the remaining two normal current sensors to output the current in the phase detected by the abnormal current sensor.

Abstract: A control system for a motor, including a first detector providing signals indicative of the sign and zero-crossings of a supply voltage, and a second detector providing signals indicative of the sign and the zero-crossings of BEMF developed in the stator winding. A switch is driven to cause a first current pulse through the winding at a first delay relative to the zero-crossing of the supply voltage. The system checks if the BEMF has a first zero-crossing within a predetermined period of time preceding a third zero-crossing of the voltage, and if so, causes an opposite second current pulse through the winding with a second delay relative to the third zero-crossing of the supply. If not, the first current pulse is repeated, reducing or increasing the duration of the first delay if the first zero-crossing of the BEMF took place after or before the predetermined period of time.