Abstract: A Variable Frequency Drive (VFD) supplies power to rotate a motor, controlling both the speed and direction. The method normally used for this power conversion by the VFD results in energy losses and line harmonics. When the motor is driven by the VFD to be rotating at the same speed and direction as if the motor was straight across the incoming AC power, a transfer in power supply to the motor can be made using contactors to bypass the VFD. When in this bypass mode, the energy losses of the VFD are greatly reduced, and the line harmonics due to the VFD are greatly reduced. When it is subsequently recognized that the speed reference has deviated from being the same speed and direction as if the motor was straight across the incoming AC power, a transfer in power supply can be made from using contactors to once again drive the motor from the VFD.

Abstract: To provide a motor control circuit that variably controls the speed of a motor, in which an appropriate advance angle value corresponding to the speed of the motor that is set can be automatically set. The motor control circuit according to the present invention includes an advance angle setting means that adds a reference advance angle value to an advance angle correction value obtained by multiplying a proportional coefficient by a correction amount and outputs an advance angle setting signal, and an advance angle setting correction means that uses a ratio of a correction reference period relative to a period of a reference signal input from the outside as a correction amount and corrects the reference advance angle value by an advance angle correction value obtained by multiplying the correction amount by a predetermined proportional coefficient of the advance angle setting means.

Abstract: A current source inverter device according to an embodiment includes an inverter that supplies AC power to a number n (integer of 1 or greater) of AC motors each having a number m (integer of 2 or greater) of windings per phase; and a controller that controls the inverter and AC motor. The inverter includes a switching unit, in which a number n×m+1 of switching elements per phase are connected in series, and a number n×m of nodes among the switching elements are respectively connected with a number n×m of different windings with the same phase among the windings of the number n of the AC motors. The controller includes a mode selector that selects at least one winding as a supply target of the AC power from the number n×m of the windings based on a rotation speed of the AC motor.

Abstract: In a system that receives power from an electric power grid, a variable frequency AC drive has an output connected to an AC electric motor, and an input connected to the power grid. The motor is in 1 connection with a load, and the AC drive includes an active converter having a predetermined maximum apparent power capacity. The converter is coupled to a controller programmed to regulate reactive power generation and consumption of the variable frequency AC drive so that the drive produces reactive power when the converter is utilizing less than its maximum apparent power capacity. This reactive power is fed to the power grid. A device monitors current and voltage in the power grid and calculates power factor, which is then used as a feedback to an external controller that generates a reactive power reference signal intended to control the system's power factor.

Abstract: Apparatuses and methods are described for implementing adjustable speed drives. For instance, an apparatus may comprise an inverter circuit configured to drive a multi-phase electrical load, the inverter configured to be powered by first and second direct-current (DC) bus lines, a fan drive circuit configured to be powered by the first and second DC bus lines, a fan configured to be controlled by the fan drive circuit and having a plurality of windings coupled together at an electrical node, a first capacitor having a first terminal coupled to the first DC bus line and a second terminal coupled to the electrical node, and a second capacitor having a first terminal coupled to the second DC bus lines and a second terminal coupled to the electrical node.

Abstract: A method and arrangement for operating a pump system are disclosed, the pump system including a pump arranged to be rotated with an AC motor, an inverter, the output of which is electrically connected to the AC motor, and a photovoltaic panel system electrically connected to feed DC power to the inverter. The method can include setting a voltage limit, and determining continuously voltage obtained from the photovoltaic panel system. When the determined voltage of the photovoltaic panel system is below the set voltage limit, frequency of the inverter can be controlled such that the ratio between output voltage of the inverter and the output frequency is substantially constant. When the determined voltage of the photovoltaic panel system exceeds the voltage limit, the inverter frequency can be controlled for keeping voltage of the photovoltaic panel system substantially at the voltage limit.

Abstract: A filter for reducing radiated emissions in switching power converters such as a motor drive is disclosed. The switching power converter modulates a DC voltage input to generate a desired AC voltage output. Capacitors are connected in parallel between each output phase and a common connection, which may be a ground connection. The magnitude and layout of the capacitors are selected to minimize current conducted by the capacitors. The capacitors may be surface mount technology located proximate to the switching devices or the capacitors may be incorporated in the circuit board on which the switching devices are mounted. The filter may be applied to any of the switching elements in a motor drive, such as the inverter section, an active rectifier section, or a switched mode power supply.

Abstract: A resonance suppression control block includes a high-pass filter for extracting an AC component of DC link voltage, and a gain section for outputting a correction signal obtained by multiplying the AC component by a gain. A control unit controls an inverter based on a signal obtained by adding the correction signal to the voltage instruction. Thus, a power conversion apparatus with a simple configuration can be obtained that can suppress resonance of a DC link section and omit extra work for performing adjustment again in accordance with a power supply frequency.

Abstract: A motor control system is disclosed. The motor control system includes a level-shifting unit, a motor unit and a control unit. The level-shifting unit receives an original pulse width modulation (PWM) signal to generate an output PWM signal. When a first high level of the original PWM signal is larger than a first reference value, the level-shifting unit shifts a second high level of the output PWM signal to a set high level. When a first low level of the original PWM signal is lower than a second reference value, the level-shifting unit shifts a second low level of the output PWM signal to a set low level. The control unit controls the speed of the motor according to the output PWM signal.

Abstract: The invention relates to a method of control implemented in a variable speed drive, said method comprising the following steps of: for a switching of a transistor (100) of the rectifier stage (1), determination of a first control signal (Ce) corresponding to a first gate current (Ige) to be applied to the gate of the transistor to be switched so as to act on the rate of the variation of a first voltage (Vrec) generated by the switching, for a switching of a transistor (200) of the inverter stage (2), determination of a second control signal (Cs) corresponding to a second gate current to be applied to the gate of the transistor to be switched so as to act on the rate of the variation of a second voltage (Vine) generated by the switching, determination of a first instant of switching (te) of the transistor of the rectifier stage and of a second instant of switching (ts) of the transistor of the inverter stage (2), the first control signal (Ce), the second control signal (Cs), the first instant of switching a

Abstract: The invention comprises a high frequency inductor filter apparatus coupled with an inverter yielding high frequency harmonics and/or non-sixty Hertz output. For example, an inductor/converter apparatus is provided that uses a silicon carbide transistor to output power having a carrier frequency, modulated by a fundamental frequency, and a set of harmonic frequencies. A filter, comprising an inductor having a distributed gap core material and optional magnet wires, receives power output from the inverter/converter and processes the power by passing the fundamental frequency while reducing amplitude of the harmonic frequencies.

Abstract: An apparatus for modifying voltage command for detecting output current in inverter is disclosed to modify a PWM voltage command by determining a sector in a voltage hexagon, the sector having a PWM voltage command therein, by comparing the PWM voltage command, determining an area, the area having the PWM voltage command, within a current detection disabled area by converting a minimum sampling time to a minimum sampling PWM and using the converted minimum sampling PWM, and determining an adjusting voltage and a restoring voltage using a minimum injection voltage based on the determined area.

Abstract: There are provided a signal duty detecting apparatus detecting a duty of a pulse width modulation (PWM) signal by counting a signal, among signals present in a preset period of the PWM signal, having a predetermined level or higher and a motor driving apparatus having the same. The signal duty detecting apparatus includes: a level detector detecting levels of an input signal; a counter counting the levels detected by the level detector; and a duty calculator calculating a duty of the input signal based on the levels counted by the counter.

Abstract: Systems for controlled resonance in electrical power devices are described. A programmed signal processor generates output control signals from input electrical signals based on resonant control parameters for a target power device. Analog electrical control systems for controlled resonance, power devices incorporating controlled resonance, and opto-programmed controllers for use in controlled resonance applications are described, with example embodiments for electro-mechanical systems with resonant constructive power drive action for electric motors.

Abstract: Motor drives and control methods are presented for sensorless motor speed control in which inverter output currents are sampled from the inverter output and a frequency modulation value is determined based on the current feedback. A speed or frequency setpoint is adjusted at least partially according to the frequency modulation value to provide an adjusted frequency or speed setpoint value that is then used in controlling the inverter to provide stability control to mitigate hunting or motor stoppage.

Abstract: A device for generating electric power of a traction system of a motor vehicle powered by a battery, including a first rectifier stage configured to be connected to a power supply network or to a load to be powered, a second inverter stage configured to be connected to the battery, a mechanism regulating average current flowing between the first stage and the second stage, and a controller controlling a transfer of electric power between the power supply network and the battery or the powering of a load.

Abstract: The present disclosure discloses a converter system, which at least includes the first and second back-to-back converters. The first back-to-back converter includes a first rectifier module and a first inverter module. The first rectifier module is used to convert a first AC voltage to a first DC voltage. The first inverter module is used to convert the first DC voltage to a second AC voltage. The second back-to-back converter includes a second rectifier module and a second inverter module. The second rectifier module is used to convert the first AC voltage to a second DC voltage. The second inverter module is used to convert the second DC voltage to the second AC voltage. The converter system can suppress the circular current through the synchronous operation of the first and second rectifiers or the synchronous operation of the first and second inverters.

Abstract: A motor control device and a motor control method are disclosed herein, where the motor control device includes a signal conversion unit, a frequency multiplication unit, a profile generation circuit and a frequency converter unit. The signal conversion unit receives a rotation speed signal from a motor and converts the rotation speed signal into a digital signal. The frequency multiplication unit generates a frequency multiplication signal based on the digital signal. The profile generation circuit performs frequency division on the frequency multiplication signal to get a profile signal. The frequency converter unit generates a reference signal and compares the reference signal with the profile signal to output a motor control signal.

Abstract: A PWM output apparatus includes a calculating circuit configured to calculate an output width of a PWM output signal of a first signal and a second signal, which have phases different from each other, based on a command value of a PWM output. A comparing circuit compares the output width and a reference period which is set longer than a predetermined dead time period. A PWM output signal generating circuit outputs the PWM output signal to a dead time inserting block as a corrected PWM output signal, when a set/clear signal generating circuit outputs the set signal, and carries out a correction of setting the first signal of the PWM output signal to be inactive to output to the dead time inserting block as the corrected PWM output signal, when the set/clear circuit outputs the clear signal. The dead time inserting block corrects the corrected PWM output signal.

Abstract: An apparatus with reduced torque ripple is disclosed. The apparatus includes a back electromotive force (BEMF) detector, a harmonic identifier, and a compensator circuit. The BEMF detector is configured to detect a BEMF voltage waveform. The harmonic identifier is configured to receive the BEMF voltage waveform and is further configured to identify at least one harmonic contributing to a torque ripple. The compensator circuit is configured to compensate for the at least one harmonic to reduce the torque ripple.

Abstract: An electrical gear configured to supply electrical drive power to a machinery to be rotated at high speed, such as a subsea motor/pump or a subsea motor/compressor assembly, the electrical gear including a high input voltage AC-motor having a low pole number, the AC-motor drivingly connected to a medium output voltage AC-generator having inverted design, wherein in the AC-generator the field windings are supported on a rotor which is journalled for rotation inside an outer stator carrying a high number of magnet poles, the AC-motor is configured to run on high voltage alternating current at a first frequency, and the AC-generator is configured to deliver medium voltage alternating current at a second frequency, higher than said first frequency, to an AC-motor to be energized having a low pole number.

Abstract: A control device controls an inverter controlling an output of a motor by PWM control. The control device calculates a reference frequency based on a torque and a rotation speed of the motor, calculates a random coefficient using two data tables, and calculates, as a random frequency, a value obtained by adding, to a reference frequency, a value obtained by multiplying a prescribed width by the random coefficient. The control device calculates control limit lines based on the rotation speed of the motor, and corrects the random frequency so as to fall within a range that is higher than the control limit line and lower than the control limit line. The control device generates a carrier signal having a random frequency as a carrier frequency.

Abstract: In an electric tool, in order to carry out a phase control or an antiphase control using a transistor, constant voltage generating means of the tool includes a series circuit including a resistor and a diode, and a parallel circuit including a capacitor and a Zener diode. One end of the resistor is connected between an AC power supply and an AC motor. A cathode of the diode is connected to one capacitor end and a cathode of the Zener diode. The other capacitor end and an anode of the Zener diode are connected to transistor sources. One ends of resistors are connected to gates of the transistors, and a voltage at the other ends of the resistors are switched between a voltage at a node between the series circuit and the parallel circuit and a voltage of the source of the transistors to turn the transistors ON or OFF.

Abstract: Methods and systems for programming an electric motor are provided. An electric motor controller configured to be coupled to an electric motor is configured to control the electric motor to produce torque when direct current (DC) link voltage has up to 100% voltage ripple. The controller includes a first power input, a second power input, and a third power input, an energized line detection device, and a microprocessor. Each power input is configured to receive power from an alternating current (AC) power source. The energized line detection device is configured to sense which power input has received power from the AC power source and output an isolated signal. The microprocessor is coupled downstream from the energized line detection device and is configured to determine an operating profile for the electric motor based on the isolated signal.

Abstract: To minimize switching losses in a rotating electrical machine, exemplary embodiments of the present disclosure proposes an iterative control method which calculates optimal switching states in advance. A rotating electrical machine can be controlled on the basis of this iterative control method.

Abstract: A drive signal generating unit generates a drive signal used to alternately deliver a positive current and a negative current to a coil with a nonconducting period inserted between conducting periods. A driver unit generates a drive current in response to the drive signal generated by the drive signal generating unit and supplies the drive current to a coil. An induced voltage detector detects an induced voltage occurring in the coil during the nonconducting period. A zero-cross detecting unit detects the zero cross of the induced voltage detected by the induced voltage detector. The drive signal generator estimates the eigen frequency of the linear vibration motor based on a detected position of the zero cross, and the frequency of the drive signal is brought close to the estimated eigen frequency.

Abstract: A control apparatus for a switching circuit includes a controller, a target-rotational-speed acquiring device, a target-torque acquiring device, and an ON-time varying device. The controller is configured to turn on a bidirectional conduction switching device provided parallel to a reverse conducting device through which a commutation current flows. The target-rotational-speed acquiring device is configured to acquire a target rotational speed of an alternating current motor. The target-torque acquiring device is configured to acquire a target torque of the alternating current motor. The ON-time varying device is configured to vary, on a basis of the target rotational speed and the target torque, an ON time period during which the bidirectional conduction switching device provided parallel to the reverse conducting device through which a commutation current flows is turned on.

Abstract: A power conversion apparatus includes a power conversion element; a capacitor; a control circuit that outputs a control signal to control operation of the power conversion element at the time of driving a load; a discharge control unit that outputs a discharge control signal to control operation of the power conversion element at the time of discharging the capacitor; a power supply circuit that generates a power supply voltage, on the basis of a voltage between both ends of the capacitor; and a driver unit that outputs a driving signal to operate the power conversion element, on the basis of the control signal or the discharge control signal. The power conversion element is operated according to the discharge control signal, a current is flown from the capacitor to the load through the power conversion element, and the capacitor is discharged.

Abstract: Power conversion systems with active front end converters for example motor drives and power generation systems for distributed energy sources are presented with adaptive harmonic minimization for grid-tie converters for minimized or reduced total harmonic distortion in the line current spectrum including the source harmonic current, the load harmonics and the PWM harmonics.

Abstract: A method of PWM regulating a motor through a half-bridge drive stage includes sampling the motor current to obtain sampled values during driving intervals or during current decay intervals, and comparing a last sampled value with a current threshold. The motor is coupled in a slow decay electrical path for the duration of a current decay interval if the last sampled value does not exceed the current threshold. Otherwise the motor is coupled in a fast decay electrical path for a portion of the duration of the current decay interval, and is coupled in the slow decay electrical path for a remaining part of the duration of the same current decay interval.

Abstract: Short circuit safe rectifier stage for a subsea power grid It is described a rectifier stage (251) for converting an input AC voltage to an output voltage, the rectifier stage comprising: a first AC input terminal (255); a second AC input terminal (257), wherein the input AC voltage is applicable between the first input terminal and the second input terminal; a first DC output terminal (267); a second DC output terminal (268); a first thyristor (261) connected between the first DC output terminal (267) and the first AC input terminal (255); a second thyristor (263) connected between the first DC output terminal (267) and the second AC input terminal (257); a gate control circuit (272) adapted and connected to control a first conductance state of the first thyristor (261) and to control a second conductance state of the second thyristor (263) such that the first thyristor and the second thyristor provide a rectified AC voltage between the first DC output terminal (267) and the second DC output terminal (268) a

Abstract: There are provided a constant voltage circuit that outputs a stable constant voltage for an analog electronic clock, and an analog electronic clock featuring low current consumption and prolonged battery life. The constant voltage circuit has a first voltage holding circuit connected between the gate of an output transistor and an output terminal and a second voltage holding circuit connected between the gate of the output transistor and a ground terminal, and carries out control such that the second voltage holding circuit is enabled when the motor is operated.

Abstract: A method for controlling a multiphase machine which is connected to a direct current voltage source. The machine has a DC link which is provided with a DC link capacitor, phase windings, and a high side switch and a low side switch for each phase. The switches associated with the individual phases are acted on by control signals from a control unit. For reducing the DC link current, the control unit provides block-shaped control signals for the switches associated with the individual phases in such a way that trapezoidal or pulsed phase currents are predefined, at least one phase current is connected at any point in time in each control cycle, and the value of the amplitude ratio of the predefined phase currents is selected in such a way that the connected phase currents correspond to the instantaneous current of the direct current voltage source.

Abstract: A motor drive PWM rectifier includes a control section which generates the PWM signal in accordance with either a three-phase modulation scheme or a two-phase modulation scheme in which a PWM voltage command for one phase selected from among three phases each constituting the PWM voltage command in the three-phase modulation scheme is set and held at a level equivalent to a maximum value or minimum value of the PWM carrier and in which a PWM voltage command for the other two phases created by also applying an offset, required to achieve the setting, to the other two phases, a detecting section which detects three-phase AC current and outputs a detected current value, and a selecting section which selects the two-phase modulation scheme when the detected current value is larger than a first threshold value but smaller than a second threshold value, and otherwise selects the three-phase modulation scheme.

Abstract: A motor control device includes an inverter, a power device temperature obtaining unit, a motor temperature obtaining unit, a power device temperature determination level storage unit, a motor temperature determination level storage unit, a PWM frequency storage unit that stores at least two PWM frequencies including a high PWM frequency a low PWM frequency, a power device temperature determining unit that determines whether or not a temperature of a power device is equal to or higher than a power device temperature determination level, a motor temperature determining unit that determines whether or not a temperature of a motor is equal to or higher than the motor temperature determination level, and a PWM frequency selecting unit that selects a PWM frequency to be given as a command to the inverter.

Abstract: Proposed is a parallel inverter drive system including includes a plurality of inverter drives connected in parallel with each other, in which each inverter drive includes a switch; a PWM controller connected to the switch for controlling switching operations of the switch device according to a duty cycle signal; and a circulating current suppressor for collecting current information associated with the current of each inverter drive and a summation current, and generating an index according to the collected current information and the desired circulating current quantity. A zero-sequence voltage is generated for each phase of a three-phase voltage command according to the index and the voltage command and the operating mode of the inverter drive, thereby injecting the zero-sequence voltage into the voltage command with a feed-forward configuration so as to fix the voltage command. The PWM controller can generate the duty cycle signal according to the fixed voltage command.

Abstract: A control system for an electric motor (10) comprises a current sensing means (14) arranged to produce a current sensing output indicative of electric current in the motor, current control means (20) arranged to receive a current demand and to control voltages applied to the motor, and correction means (26) arranged to receive the current sensing output and the current demand, and use them to generate a correction signal. The current control means (20) is arranged to receive the correction signal and to use the correction signal to correct the voltages applied to the motor.

Abstract: A portable fuel cell system includes a fuel cell having a fluid path, a pump having a pumping chamber disposed in the fluid path and a mechanical input, an electric motor having a power signal input and having an oscillatory mechanical output coupled to the mechanical input, the mechanical output having unwanted vibration primarily at a first drive frequency of a power signal, a spring and mass assembly coupled to the mechanical output so as to vibrate out of phase with, and to reduce the unwanted vibration of, the mechanical output at the drive frequency, a vibration transducer physically coupled to the mechanical output and having a vibration transducer signal output, and an electrical control system having an input coupled to receive the vibration transducer signal output and having a control output coupled to the power signal input.

Abstract: A method is described for activating a multiphase machine that has a link circuit equipped with a link circuit capacitor, phase windings, and one high-side switch and one low-side switch per phase. The switches associated with the individual phases have control signals applied to them by a control unit. The control unit provides, in successive activation cycles, pulse-shaped control signals for the switches, the pulse widths and pulse onsets of which are respectively varied within an activation cycle in such a way that the link circuit current is reduced.

Abstract: A fan control circuit includes a hardware controller, a rectifier circuit, first to third electronic switches, and a fan. When the hardware controller outputs a pulse width modulation (PWM) signal to the rectifier circuit and the fan, the rectifier circuit transforms the PWM signal into a direct current (DC) voltage and outputs the DC voltage to the first electronic switch. The first electronic switch is turned on, and the second and third electronic switches are turned off. A rotation speed of the fan is controlled by the PWM signal received from the hardware controller. When the hardware controller does not output the PWM signal, the first electronic switch is turned off, the second and third electronic switches are turned on, a DC power supply supplies power to the fan through the third electronic switch, and the fan rotates at full speed.

Abstract: There are provided a motor driving control apparatus, a motor driving control method, and a motor using the same. The motor driving control apparatus includes a controller, a duty ratio calculation unit, and a driving signal generation unit. The controller generates a speed control signal by using at least one of a speed signal of a motor device and a speed command signal input from the outside. The duty ratio calculation unit calculates a duty ratio of the speed control signal. The driving signal generation unit generates a driving control signal for controlling driving of the motor device by using the duty ratio.

Abstract: A propulsion system is presented, the system comprising primary and secondary electromagnetic field generators being attached to a frame at a predetermined distance between them, and a control unit connected thereto and configured to create pulsating electromagnetic fields generated by at least one of the electromagnetic field generators. The pulsating electromagnetic field is configured to pulsate at time intervals determined in accordance with retardation time caused by said predetermined distance between the primary and secondary electromagnetic field generators. Interaction between the electromagnetic field generators and electromagnetic fields generated thereby provides a total net force acting on the system.

Abstract: An electric machine may include: an alternating current electric motor comprising a first semi-winding and a second semi-winding; an inverter comprising a first inverter branch electrically connected to the first semi-winding and a second inverter branch electrically connected to the second semi-winding; and a control unit configured to provide a first control signal to the first inverter branch, so as to induce a first alternating current in the first semi-winding, and a second control signal to the second inverter branch, so as to induce a second alternating current in the second semi-winding. The first and second alternating currents may have a first frequency. The first and second control signals may have a second frequency that is less than the first frequency. The first and second control signals may be reciprocally out of phase by substantially 180° relative to the second frequency.

Abstract: An inverter control device is equipped with an inverter and a command value calculation unit calculates command values for the alternating current voltage output from the inverter. A phase compensation unit compensates the phase of the command values or the phase of the detected values. An inverter control unit controls the inverter on the basis of the command values or detected values that have been compensated by the phase compensation unit. A motor rotational velocity detector detects the rotational velocity of a motor. The phase compensation unit calculates the phase lead amount on the basis of a phase compensation time that is set for the purpose of obtaining a prescribed phase margin and on the basis of the rotational velocity and, in accordance with the phase lead amount, compensates the phase that is based on the specific characteristics of the motor.

Abstract: A system for controlling an electric motor, based on an N-MOS switching device, allowing operation in reverse battery polarity condition and protecting the switching device against voltage peaks when in direct battery polarity condition. The system includes a power source, a switching device connected in series with the motor to switch the same between the “on” and “off” states, a control device to control the switching device, and a thyristor connected in parallel with the motor, whereby its gate terminal, and consequently its conducting or non-conducting state, are controlled by the control device. Also a method is provided for controlling an electric motor, such as in a system defined above, comprising the steps of switching a state of the thyristor in direct battery polarity conditions such that the thyristor conducts current and switching the state of the thyristor in reverse battery polarity conditions such that the thyristor does not conduct current.

Abstract: Apparatuses and methods are described for implementing adjustable speed drives. For instance, an apparatus may comprise an inverter circuit configured to drive a multi-phase electrical load, the inverter configured to be powered by first and second direct-current (DC) bus lines, a fan drive circuit configured to be powered by the first and second DC bus lines, a fan configured to be controlled by the fan drive circuit and having a plurality of windings coupled together at an electrical node, a first capacitor having a first terminal coupled to the first DC bus line and a second terminal coupled to the electrical node, and a second capacitor having a first terminal coupled to the second DC bus lines and a second terminal coupled to the electrical node.

Abstract: According to one embodiment, a low frequency drive control circuit for use with an inductive load comprises a comparator configured to receive a high frequency signal at a first input and a smoothly varying low frequency signal for modulating the high frequency signal at a second input. The comparator is further configured to produce a pulse width modulated output of the low frequency drive control circuit for use in generating a smoothly varying low frequency load current in the inductive load. In one embodiment, the inductive load can comprise a DC brushed motor. In one embodiment, the low frequency drive control circuit can be implemented as part of an integrated circuit further comprising a switching circuit configured to use the pulse width modulated output of the comparator to generate the smoothly varying low frequency load current, which may be a substantially sinusoidal load current, for example.

Abstract: An electric motor, having a stator (465), a rotor (470), and an apparatus for evaluating a signal provided for controlling said motor (110), comprises a receiving unit (430, 440) for receiving a control signal (PWM_mod), which is a pulse width modulated signal (PWM) onto which a data signal (DIR, DATA) is modulated. An evaluation unit (440) is provided for evaluating the modulated control signal (PWM_mod). The unit is configured to extract, from the modulated control signal (PWM_mod), data provided for operation of the motor (110). The control apparatus includes a signal generator (450) configured to generate, on the basis of the extracted or ascertained data provided for operation of the motor (110), at least one control signal for the motor (110), such as a commanded direction of rotation. Piggybacking other control data onto the PWM power level signal reduces hardware investment, by permitting omission of a signal lead which would otherwise be required in the motor structure.

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 rotating electrical-machine control system is provided with: a rotating electrical-machine comprising a rotor further comprising permanent magnets that are divided into a dividing-number of sections; an inverter circuit that drives the rotating electrical-machine by PWM control, using a carrier wave having a carrier frequency; a storage unit that has stored therein a relationship file that indicates the relationship between the dividing-number of the magnets, the magnet temperature, and the carrier frequency; and a control apparatus.