Abstract: A medium voltage variable frequency drive having a 2-high controller configuration with a dual bus system is described. The drive control system includes at least one motor control cabinet housing a fused medium voltage bypass controller, a non-fused transfer controller positioned above the fused medium voltage bypass controller, an extendable output bus coupled to the non-fused medium voltage transfer controller, and an extendable supply bus coupled to the fused medium voltage bypass controller. The drive control system further includes a variable frequency drive cabinet housing a variable frequency drive. The variable frequency drive is coupled to the extendable output bus and a power supply line. The power supply line may be further coupled to the extendable supply bus. The drive control system includes at least one cabling transition cabinet housing cabling between the at least one motor control cabinet, the power supply line, and the variable frequency drive.

Abstract: The invention provides a method and a device for controlling an electric motor using pulse-width modulated control signals. Control pulses having a setpoint duty factor and temporally varying pulse widths and pulse spacing are generated in the process, the temporally varying pulse widths and pulse spacing being selected as a function of a load and/or thermal loading of the electric motor and/or its control device.

Abstract: A braking system for an aircraft provided with undercarriage, wherein an axial-flux reversible electric machine is set between the wheel and the frame of the undercarriage; current-dissipating resistors are provided, which can be connected to the windings of the axial-flux reversible electric machine during rotation of said wheel for dissipating by the Joule effect the induced currents generated by the axial-flux electric machine, which behaves as current generator, and producing a braking effect that slows down the movement of the wheel, thus exerting a braking action.

Abstract: An integrated fan drive system for a cooling tower comprising a high-torque, low speed permanent magnet motor having a rotatable shaft, a fan comprising a hub that is directly connected to the rotatable shaft and a plurality of fan blades that are attached to the hub, and a variable frequency drive device in electrical signal communication with the permanent magnet motor to control the rotational speed of the permanent magnet motor. The high-torque, permanent magnet motor comprises no more than two bearings in operative association with the shaft. The variable frequency drive device has a variable frequency controller that has an input for receiving AC power and an output for providing electrical signals that control the operational speed of high-torque, permanent magnet motor. The variable frequency drive device also includes a user interface in electronic data signal communication with the variable frequency controller to allow a user to input motor speed control data.

Abstract: A method of controlling a power converter in an electric drive machine is disclosed. The method may include determining a first switching frequency and determining a second switching frequency. The method may also include comparing the first switching frequency and the second switching frequency. The method may further include selecting a power converter switching frequency from the lesser of the first switching frequency and the second switching frequency to control a power converter.

Abstract: The invention concerns a method and an apparatus for controlling a three-or-more-phase motor driven by a frequency converter. In the method, a change-over switch of the frequency converter is controlled to a continuously conducting state and at the same time the phase voltages or phase currents of the other phases are controlled by switching the change-over switches in those motor phases at a switching frequency substantially higher than the frequency of the fundamental wave of the phase voltage or phase current. The apparatus comprises in conjunction with the frequency converter a number of change-over switches, at least one change-over switch for each motor phase. The change-over switches comprise controllable change-over contacts. The apparatus further comprises in conjunction with the frequency converter means for determining the motor phase currents and means for controlling the change-over contacts.

Abstract: An integrated electric-drive compressor system utilizes a high frequency drive for powering the multi-pole pair motor. The electric motor and compressor are housed in a common pressure casing. The electric motor has added permanent magnets for achieving higher ratings and higher speeds.

Abstract: A motor bypass is controlled by a digital signal processor (DSP) with embedded control software that allows fault detection and annunciation, serial communications between both a variable frequency drive (VFD) and a bypass controller and the bypass controller and a host computer. The use of the DSP and embedded control software further allows for contactor coil control to provide fault tolerant operation as well as fault condition detection and annunciation to the user.

Abstract: A motor controller that outputs a drive signal to a direct-current motor to drive the motor is provided. The motor controller includes a drive circuit that generates the drive signal. The drive circuit superimposes on a direct-current voltage an alternating-current component having a frequency in the audible frequency range of the human ear, thereby generating the drive signal.

Abstract: A step motor control circuit that does not fix a reference voltage of a step motor control signal. The step motor control circuit may include a digital-to-analog (DAC) signal generator configured to generate first and second DAC signals in response to a step motor error signal, a gain adjust block configured to control gains of the first and second DAC signals in response to a control signal and output first and second step motor control signals, and a gain controller configured to output the control signal in response to a mode signal and a gain control signal, in which the first and second step motor control signals are pulse trains including a reference voltage, and the reference voltage may be a fixed voltage when the mode signal indicates a normal mode and the reference voltage may be a variable voltage when the mode signal indicates a power consumption reduction mode.

Abstract: A driver (1) supplies an output voltage (VL) to an inductive load (30). The driver comprises an input to receive a pulse width modulated control signal (CS) having a controllable duty cycle within a predetermined range. A first switch circuit (10) receives a first switch signal (CS; ICS) to supply a first voltage (V1), a second switch circuit (13) receives a second switch signal (DCS; CSD) to supply a second voltage (V2), and the output voltage (VL) is the difference between the first voltage (V1) and the second voltage (V2). An inverter (11; 15) and delay circuit (12; 16) receives the control signal (CS) to supply the first switch signal (CS; ICS) and the second switch signal (DCS; CSD) being inverted and delayed with respect to each other. The delay (dT) of the delay circuit (12; 16) is selected to obtain an output voltage having a single polarity for each one of said controllable duty cycles within the predetermined range.

Abstract: A method for reducing audible motor noise in a motor drive, wherein the motor drive includes a motor controller driving a PWM space vector modulator providing gating pulses to an inverter providing phase currents to the phase windings of the motor, and wherein phase currents of the motor are determined by taking samples of the DC link current in a DC link powering the inverter. The method comprises determining the speed of the motor and comparing the speed to a preset threshold, the preset threshold defining a speed at which audible noise is generated by the motor due to a minimum pulse constraint being imposed on the motor phase currents in order to reliably sample the DC link current to measure the phase current. If the speed is below the threshold, the DC link current in the DC link is sampled using a reduced number of current samples for a PWM cycle of the PWM space vector modulator to reduce audible motor noise.

Abstract: The invention relates to a method for measuring a current that flows through a motor, in which a power switch that supplies the motor with electric energy is controlled by a control unit via a pulse width-modulation signal. The pulse width-modulation signal comprises a cycle of operation and the motor current is determined in a feeder to the power switch or a feeder to the motor. Since exactly one measured value representing the motor current is sampled in each cycle of operation, this permits the provision of a method for measuring the motor current, which determines the motor current in a more rapid, more cost-effective manner than in prior art. The method is used for the motor control of direct current motors.

Abstract: A transmission device includes a power output unit and a non-contact type sensing unit. The power output unit includes a power output member that is rotatable about an axis, and has at least one sensed portion that is co-rotatable with the power output member about the axis. The non-contact type sensing unit detects the sensed portion and generates a sensor output from which angular displacement and position of the power output member can be calculated.

Abstract: It is possible to reduce the size of a parallel multiplex matrix converter as a whole. The parallel multiplex matrix converter couples in parallel at least two matrix converters, each of which PWM-controls bidirectional switches coupling input phases from an AC power supply to each output phases so as to output an arbitrary AC voltage or DC voltage. The output sides of the matrix converters are directly coupled in parallel to each other without any reactor. The input sides of the matrix converters use reactors inserted between the input phases from the AC power supply and the AC power supply at each of the respective matrix converters coupled in parallel.

Abstract: As applications of variable frequency drives (VFD) (50) continue to grow so do challenges to provide VFD (50) systems meeting application specific requirements. For multiple reasons to include safety standards and electromagnetic interference, reduced ground leakage current is desirable. Building high output voltage VFDs (50) using transistors rated at voltages lower than the VFD output voltage is desirable for economic reasons. The apparatus and method described herein meet these challenges and others, in part by placing an electrically insulating plate (cp176) having high thermal conductivity, a low dielectric constant, and high dielectric strength between the heat sink plate of a VFD power semiconductor module and a grounded cooling plate (80 TE).

Abstract: To reduce noise by limiting a current peak value to a predetermined value or less and by smoothing the waveforms of drive currents during the current limitation, switching control means (30) according to the present invention turns ON all of one-side drive transistors selected from the high-side drive transistors (21, 22 and 23) and the low-side drive transistors (25, 26 and 27) of power supply means (20) for a predetermined period, and turns OFF all of the other-side drive transistors for a predetermined period in response to a current control signal for the current peak value to a predetermined value or less.

Abstract: Systems and methods for synchronous operation of variable speed drives having active converters include extending the synchronous operation of an active converter to the AC mains voltage during complete line dropout. A phase angle control circuit includes a squaring amplifier, a first phase-lock loop circuit associated and a second phase-lock loop circuit. The squaring amplifier receives the AC power source and outputs a rectangular output signal to a pair of phase lock loop (PLL) circuits. The first PLL circuit with a first lag-lead filter is configured with a high cutoff frequency to provide the converter stage with a phase angle parameter; and the second phase-lock loop circuit including a second lag-lead filter configured to have a low cutoff frequency to provide the lag-lead filter the capability of storing the phase angle of the mains voltage during mains interruption.

Abstract: A cooling fan, system and method for controlling cooling fans in a personal computer. A unique series of sensing points is placed on a rotating hub of a cooling fan in order to uniquely identify the particular type of cooling fan. A tachometer sensor mounted in the cooling fan detects the unique series of sensing points as the cooling fan rotates and generates a sequence of pulses corresponding to the detected sending points. This generated pulse signal may be transmitted by the sensor to the fan control code. The fan control code may determine a particular type of cooling fan that the cooling fan is based on the generated pulse signal. Once the fan control code determines the particular type of cooling fan that the cooling fan is, the fan control code uses particular control parameters set for that particular type of cooling fan to control the cooling fan so that it operates optimally.

Abstract: The invention relates to an electric motor drive for operating an alternating-current motor. The electric motor drive comprises a frequency converter for controlling the motor, which frequency converter comprises a rectifier and an inverter implemented using semiconductor switches arranged in a bridge, and an intermediate circuit placed between the rectifier and the inverter and comprising a capacitor.

Abstract: A controller includes a power source unit, a drive circuit, and a state control circuit. The drive circuit is coupled to the power source unit, and includes a drive coil and a switching transistor unit. The switching transistor unit is operable in one of a circuit-making state for making an electrical circuit between the drive coil and the power source unit so as to enable the drive coil to drive rotation of a rotor of a brushless direct current motor, and a circuit-breaking state for breaking the electrical circuit between the drive coil and the power source unit. The state control circuit is coupled to the power source unit, and includes a pulse width modulator, a sensing coil, and a control transistor coupled electrically in series. The state control circuit controls operation of the switching transistor unit according to magnetic position of the rotor relative to the sensing coil.

Abstract: A controlling method of a motor state described herein detects the motor operation in a regeneration state or a motor state. The output frequency value of an AC motor drive is calculated and adjusted to stabilize the voltage of a DC bus such that over-voltage protection is avoided. Therefore, a stable load current is obtained and the time for slowing down the motor is shortened.

Abstract: A motor control device having memory for storing data indicative of a control mode and a pulse width modulation (PWM) value and logic that applies the pulse width modulation value to a voltage provided to a motor if the data indicative of the control mode indicates voltage mode. The logic further controls the voltage applied to the motor based upon a motor set point value representative of the data indicative of the pulse width modulation value when the data indicative of the control mode indicates current mode.

Abstract: A method and apparatus for use with a controller that supplies voltages to an induction machine via supply lines, the voltages including a fundamental voltage component and an injected voltage component, the line voltages also including harmonic voltage components where the harmonic voltage components include at least a high frequency first harmonic component having a frequency substantially equal to the sum of the fundamental component frequency and the injected component frequencies, the method for identifying the high frequency first harmonic component and comprising the steps of sensing the line voltages, identifying a zero sequence voltage component of the line voltages, rectifying the zero sequence voltage component to generate a rectified signal and using the rectified signal to identify the high frequency first harmonic component.

Abstract: A speed-control drive circuit for a D.C. brushless fan motor includes a pulse width modulation input end for receiving an external pulse width modulation signal for controlling (and changing) the motor speed, and a motor winding drive circuit. The motor winding drive circuit and the pulse width modulation input end are connected to a set of motor windings. The pulse width modulation signal controls the motor winding drive circuit to cause excitation/unexcitation of the set of motor windings and to alternately changes a direction of current such that the set of motor windings adjusts a speed of the fan motor in response to excitation of the set of motor windings responsive to the pulse width modulation signal. The speed of the fan motor increases when an operational period of the pulse width modulation signal increases, and the speed of the fan motor decreases when the operational period of the pulse width modulation signal decreases.

Abstract: A driving device for an oscillatory actuator in which a FLL (Frequency Locked Loop) is employed for detecting an electromotive force generated in a driving coil resulting from mechanical oscillation during a period in which no driving current is supplied to the oscillatory actuator, and for controlling an oscillation frequency on the basis of a relative time ratio between positive and negative polarities of the electromotive force to thereby pull a driving frequency into a neighborhood of a self-resonance frequency of the oscillatory actuator.

Abstract: A control system for an electric motor including an inverter for providing power to the electric motor, a controller for controlling the inverter, a first motor speed control block in the controller injecting a high frequency signal into the electric motor to determine the speed and position of the electric motor, where the first motor speed control block includes a tuned moving average filter to determine the magnitude of high frequency current in the electric motor.

Abstract: A rotation detection circuit of a dc brushless motor using a fixed bias voltage includes a transistor, and a signal adjuster. The signal adjuster is connected in series between the transistor and driver circuit of the dc brushless motor, for adjusting a signal output by the driver circuit to the according to a fixed bias voltage. The signal adjuster can be selectively supplied with a fixed bias voltage or connected in series with a zener diode. The signal adjuster can be adjusted according to the characteristics of the motor driver circuit, thereby enhancing the design of the rotation detection circuit.

Abstract: The present invention relates to a flexible and compact motor control module based on the Controller Area Network (CAN) communication network. More specifically, the present invention relates to a motor control module which is based on the ISO11898 standard Controller Area Network (CAN), recognized for its suitability in the communication of intelligent sensors and actuators, and also capable of obtaining the location, speed and torque control commands of a motor and executing digital control functions irrespective of motor's type and power consumption, transmitting feedback data.

Abstract: A dual stator winding induction machine has two windings with input terminals which are supplied separately with drive power. The two stator windings have a different number of poles to essentially eliminate the magnetic coupling between the two windings and to decouple the torques produced by each set of windings. Power is supplied to the two windings by two separate variable frequency inverter drives to provide two independently controllably torque components. At low speed, the power supplied to one of the windings can produce torque which opposes the torque from the power applied to the other winding, so that very low speed and standstill operation can be achieved while the frequency of the power supplied by the inverters is always greater than the minimum frequency. At higher operating speeds, power is supplied to the two windings so that the torque from the windings adds. The dual stator machine can be built with minimal modifications to standard winding configurations.

Abstract: An electric power steering control system reducing steering torque without making a driver feel uncomfortable torque oscillation, including a rotation speed observer for estimating the rotation speed of a motor based on the output of a torque sensor high pass filter (HPF) and the output of a drive current HPF obtained by removing a steering frequency component from a drive current detection value.

Abstract: A fractional-power electric motor is provided to generate varying amounts of output torque supplied to a driven member over a wide range of RPM speeds so as to reduce power consumption on a battery-powered source. The electric motor includes a rotor and a stator assembly. The stator assembly is disposed around the rotor and is inductively coupled to the rotor. The stator assembly further includes a plurality of poles, each having a main winding and at least one fractional-power winding. The main winding and associated at least one fractional-power winding on each of the stator poles are wound so that the magnetic fluxes generated therefrom are added. Power switching circuits are provided for independently energizing the main and fractional-power windings on each of the stator poles. A controller is used to control selectively the frequency and duty cycle energization of the power switching circuits to vary the rotational speed of the rotor and the amounts of torque supplied to the driven member.

Abstract: The invention provides an apparatus and a method for controlling the rotation frequency of an infinite variable-speed drive in which, when an error is caused in an output rotation frequency of the infinite variable-speed drive during a processing time period, a target rotation frequency is calculated in view of the error, so as to control the rotation frequency in the remaining processing time period in accordance with the calculated target rotation frequency. The target rotation frequency is calculated on the basis of the remaining processing time period and a pulse number to be counted in the remaining processing time period.

Abstract: A fractional-power electric motor is provided to generate varying amounts of output torque supplied to a driven member over a wide range of RPM speeds so as to reduce power consumption on a battery-powered source. The electric motor includes a rotor and a stator assembly. The stator assembly is disposed around the rotor and is inductively coupled to the rotor. The stator assembly further includes a plurality of poles, each having a main winding and at least one fractional-power winding. The main winding and associated at least one fractional-power winding on each of the stator poles are wound so that the magnetic fluxes generated therefrom are added. Power switching circuits are provided for independently energizing the main and fractional-power windings on each of the stator poles. A controller is used to control selectively the frequency and duty cycle energization of the power switching circuits to vary the rotational speed of the rotor and the amounts of torque supplied to the driven member.

Abstract: A method for sensing motor commutation pulses during motor braking without creating negative voltages, which some junction isolated technologies substantially cannot tolerate. For instance, a commutation pulse sensing circuit containing junction isolated technology may only be able to detect commutation pulses intermittently. An H-bridge motor drive configuration is used to drive and brake a motor. High side clamp diodes are coupled between the motor terminals and a high potential source for high side braking of the motor. As an alternative to high side clamp diodes, any other suitable device may be used, including operating the pair of transistors in the upper portion of the H-bridge in an inverse mode. A commutation pulse sensing circuit is coupled to a terminal of the motor. The use of the high side brake clamp diodes avoids generating negative voltages at the motor terminals.

Abstract: A device for the transmission of electrical power signals of variable frequencies and phases from a stationary assembly to a rotary assembly wherein the primary winding of a rotary transformer is supplied by an electrical power source of fixed frequency, and the power output from the secondary winding of the transformer is supplied to a chopping feed of a signal generating system including a digital memory storing a digital signal having the desired characteristics of the signal to be generated, a digital-to-analogue converter for receiving the digital signal from the memory under the control of a clock pulse generator, and an amplifier connected to the converter to give the desired power to the analogue signal received from the converter.

Abstract: A plurality of individual frames or stampings provided in a sheet strip material by a stamping device are passed in proximity to a sensing device. As each individual frame or stamping is passed in proximity to the sensing device, the sensing device provides a voltage signal to a controller. The voltage signal is proportional to the amount of, or mass of, metallic material in each frame or stamping and the distance between the frame or stamping and the sensing device. The controller generates an individual waveform from the voltage signal for each frame passed in proximity to the sensing device. Each individual waveform is a function of the position of the movable portion of the stamping device for one cycle. As the plurality of individual frames are passed in proximity to the sensing device, a plurality of individual waveforms are generated within the controller. The waveforms are compared within the controller to detect a deviation between waveforms.

Abstract: A control system for a magnetic tape apparatus having two spool carriers driven by D.C. drive motors to control the current in one of the motors in order to maintain a uniform tape transport speed comprises a pulse generator driven by the tape, a comparator which compares the timing of the pulses from the generator with a standard and generates a pulse-width modulated output, a transistor switch amplifier, a low-pass filter converting the amplified pulse-width modulated signal to a control voltage, and a direct voltage amplifier supplying a current to the drive motor controlled by the control voltage.