Abstract: A dynamic limitation device of a dynamic output parameter of an electric motor capable of receiving a working setpoint comprises: a generator of a dynamic maximum current proportional to a first working setpoint of the motor to supply the motor to generate a rotating torque of a shaft of the electric motor as a function of the first setpoint, a first estimator of a first dynamic output parameter of the electric motor, and a first dynamic limiter of the first output parameter of the motor, which comprises: a first comparator of the value of the first estimated parameter with a predefined maximum value of the first parameter, a first corrector to generate a first correction current, the value of which depends on the result of the comparison to be added to the dynamic maximum current to supply the motor. A dynamic limitation method implementing this device is provided.

Abstract: A voltage regulator includes circuitry for regulating a voltage output of the voltage regulator and a snubber circuit. The snubber circuit includes a switching device which is controlled to electronically connect or disconnect the snubber circuit with the circuitry of the voltage regulator device. The switching device may be controlled by a controller based on one or more parameters indicating a load of the voltage regulator device.

Abstract: Provided is a method of controlling a three phase equivalent voltage in a multilevel inverter including sensing a state of each of power cells of the multilevel inverter to determine whether or not failure occurs at each of the power cells, bypassing power cells which are determined as being failed to connect power cells operating normally to each other in series per each phase, calculating an offset voltage value using a phase voltage reference per each phase and a sum of each of direct current (DC) link voltages of the power cells which operate normally and configure each of the phases, and calculating a pole voltage reference per each phase for maintaining an equivalence of a three phase line-to-line output voltage using the phase voltage reference per each phase and the calculated offset voltage.

Abstract: A real current meter reads current from a current probe coupled around power lines of a transformer-based UPS system coupled to a transformer having a high resistance ground with a HRG resistance and determines a real current component of the current read from the current probe.

Abstract: A method for operating an electrical circuit, in particular of a converter is described. The circuit, in at least one embodiment, includes a line-side converter that is coupled to a capacitor. The line-side converter includes at least two series connections, each including at least two power semiconductor elements, and each of the at least two series connections being connected parallel to the capacitor. The line-side converter is coupled to an energy supply system. The DC voltage that is present at the capacitor is determined. A maximum voltage is predetermined. If the DC voltage present at the capacitor is determined to be greater than the maximum voltage, then at least two of the power semiconductor elements are switched into their conductive state in such a manner that the capacitor is discharged in the direction of the energy supply system.

Abstract: A converter including a converter control for a wind turbine and a chopper, wherein the converter control includes a dynamic limit value which is allowable for a first tolerance time and a static limit value of the converter. Furthermore, an overcurrent module is provided which includes a limit value expander which is designed to increase the static limit value by a portion of the difference from the dynamic limit value as additional current, and a dynamic module which interacts with the limit value expander in such a way that overcurrents between the static limit value which is increased by the additional current and the dynamic limit value are routed in a first stage to the converter and in a second stage at least partially to the chopper, wherein a switch is made to the second stage after a second tolerance time.

Abstract: A control device and a control method can improve a voltage utilization ratio of an inverter for a green car, in which an input DC voltage of the inverter is modulated by a maximum amount into an output AC voltage of the inverter by changing the output AC voltage incapable of being linearly output into a voltage capable of being linearly output. The control method includes steps of: generating a two-phase current command having two phases of a first current command and a second current command; generating a two-phase voltage command having two phases of a first voltage command and a second voltage command; generating a three-phase pole voltage command; modulating the three-phase pole voltage command into a linear output voltage capable of being linearly output; and calculating a voltage gain value, using the two-phase voltage command and an input DC voltage of the inverter.

Abstract: Electromagnetic state variables of an electromagnetic machine are represented by space vectors. A setpoint value for the vector of a manipulated voltage at the stator is preset and an actual value of the vector of the current at the stator is measured. A vector of an induced voltage is determined from the setpoint value and the actual value of the vector of the current. A value of a vector of the magnetic flux is estimated from a preset correction voltage and the induced voltage. A phase angle and a rotating field frequency are estimated from the vector of the magnetic flux. A factor is multiplied into the vector of the correction voltage when a torque-forming component of a current at the stator has an opposite mathematical sign to the estimated value of the rotating field frequency.

Abstract: A method and apparatus are provided for off-line testing of a multi-phase alternating current machine. A method includes determining, at a first rotor position, a physical stator quantity of each stator winding by applying a test signal to each stator winding, and determining a first joint physical stator quantity by summing the determined physical stator quantities of the stator windings. A method includes determining, at a second rotor position, a physical stator quantity of each stator winding by applying a test signal to each stator winding, determining a second joint physical stator quantity by summing the determined physical stator quantities of the stator windings, comparing the second joint physical stator quantity with a previously determined first joint physical stator quantity, and determining a fault condition of said multi-phase alternating current machine if the first joint physical stator quantity differs from the second joint physical stator quantity.

Abstract: A power conversion apparatus includes a plurality of power supply circuits each including a primary side circuit, and a secondary side circuit that is magnetically coupled to the primary side circuit via a transformer. Electrical power that changes according to a phase difference between switching of the primary side circuit and switching of the secondary side circuit is input and output to and from the power supply circuit. The power conversion apparatus includes a first power supply circuit, a second power supply circuit that uses, as an input side thereof, an output side of the first power supply circuit, and a control unit that adjusts residual power obtained by subtracting input power of the second power supply circuit from output power of the first power supply circuit, by controlling a phase difference of the first power supply circuit and a phase difference of the second power supply circuit.

Abstract: A method includes controlling multiple networked input-parallel/output-parallel inverters of a fuel cell system as a single inverter assembly by a master controller. A fuel cell system includes a plurality of fuel cell segments, a plurality of DC/DC converters and at least one DC/AC inverter, where an output of each of the plurality of the fuel cell segments is connected to a pair of DC/DC converters, and each of the pair DC/DC converters is connected to an opposite polarity bus being provided to the inverter.

Abstract: A method and apparatus for controlling an electric motor. A switching frequency meeting a desired operating condition is identified from information relating to operation of the electric motor. A switching of a current supplied to the electric motor with the switching frequency identified is controlled.

Abstract: A brushless electrical machine has at least one phase winding which produces torque to drive a load. The control system for the machine is able to vary the flux and current supplied to a phase so as to vary the torque output as a function of the rotor position. The energization is reduced at particular angles to produce a dip in the torque profile, thus ensuring that, if the drive stalls, it does so at a predetermined position, for example where the losses in the drive are minimized.

Abstract: Power converters and methods are presented for driving an AC load connected through an intervening filter circuit, in which at least one filter current or voltage signal or value is determined according to feedback signals or values representing an output parameter at an AC output of the power converter, and AC electrical output power is generated at the AC output based at least partially on the at least one filter current or voltage signal or value.

Abstract: At least one example embodiment discloses a control device for controlling an alternating current (ac) machine. The control device includes a processor configured to select a modulation mode from a plurality of modulation modes, determine a plurality of present phase voltages corresponding to phases of an inverter based on the selected modulation mode, the determination compensating for deadtimes associated with the selected modulation mode and phases of the inverter, the inverter configured to drive the ac machine and determine an estimated terminal voltage based on the plurality of present phase voltages.

Abstract: A motor control device includes an energization pattern output portion and an inverter circuit. The energization pattern output portion cyclically outputs a plurality of energization patterns. The inverter circuit selectively connects respective coils provided in a motor to a rectifier circuit according to the output energization pattern. The energization pattern output portion delays the output timing of the energization pattern according to a rotation speed of the motor.

Abstract: A motor control device includes an energization pattern output portion and an inverter circuit. The energization pattern output portion cyclically outputs a plurality of energization patterns. The inverter circuit selectively connects respective coils provided in a motor to a rectifier circuit according to the output energization pattern. The energization pattern output portion delays the output timing of the energization pattern according to a rotation speed of the motor.

Abstract: A conveying system includes: a linear induction motor including a stator provided with a plurality of primary coils arranged along a conveying path and a mover provided movably along the conveying path; one or more first inverters that are provided corresponding to at least one of the primary coils in one or more areas requiring positioning on the conveying path to perform vector control with a sensor; one or more second inverters that are provided corresponding to at least of the primary coils in one or more areas requiring no positioning on the conveying path to perform V/F control; and a controller that is configured to output a speed reference to the first second inverters to control electric supply to the primary coils and to output the speed reference based on a feedback position received from a detector to the first inverter, to perform position control.

Abstract: A submodule of a high-voltage inverter has a first sub-unit with a first energy storage device, a first series circuit of two power semiconductor switching units connected in parallel with the first energy storage device, each including a switchable power semiconductor, having the same pass-through direction, and each being conductive opposite the nominal pass-through direction. A first connection terminal is connected to the potential point between the power semiconductor switching units of the first series circuit. A second sub-unit has a second energy storage device, a second series circuit of two power semiconductor switching units connected in parallel with the second energy storage device, each including a switchable power semiconductor, having the same pass-through direction, and each being conductive opposite the nominal pass-through direction.

Abstract: Embodiments according to the present invention provide methods and a system for a control approach that effectively maintains the DC link voltage at a constant set value under variable system conditions and keeps the converter operating with an optimal power factor range while limiting power quality effects and phase balance.

Abstract: A control unit controls driving of a motor by controlling a first inverter unit and a second inverter unit, specifically by controlling on/off operations of FETs. The control unit functions as an abnormality detection device. The control unit detects a short-circuit abnormality between a first winding set and a second winding set or between the first inverter unit and the second inverter unit, before starting to control driving of the motor, based on phase current values detected by current detectors when a high-side FET of the first inverter unit and a low-side FET of the second inverter unit are turned on.

Abstract: A method for operating an electrical circuit, in particular of a converter is described. The circuit, in at least one embodiment, includes a line-side converter that is coupled to a capacitor. The line-side converter includes at least two series connections, each including at least two power semiconductor elements, and each of the at least two series connections being connected parallel to the capacitor. The line-side converter is coupled to an energy supply system. The DC voltage that is present at the capacitor is determined. A maximum voltage is predetermined. If the DC voltage present at the capacitor is determined to be greater than the maximum voltage, then at least two of the power semiconductor elements are switched into their conductive state in such a manner that the capacitor is discharged in the direction of the energy supply system.

Abstract: A voltage source inverter comprises a rectifier having an input for receiving single-phase AC power from an AC source and converting the AC power to DC power on a DC bus. The DC bus has first and second rails to provide a relatively fixed DC voltage. A DC bus capacitor is across the first and second rails to smooth voltage ripple. An inverter receives DC power from the DC bus and converts the DC power to AC power. An active front end circuit comprises a pair of filter capacitors in series across the first and second rails to create a midpoint. A bidirectional switch is connected between the rectifier input and the midpoint. The bidirectional switch is controlled to inject current into the midpoint of the DC bus.

Abstract: A method for the phase diagnosis of a multiphase converter for detecting potential errors in individual converter phases is provided, wherein a symmetrical load distribution for the individual converter phases is regulated. During the operation of the converter, the distribution of the load prescribed for each individual phase of the converter is detected at least two different times, at different temperatures, and in any order.

Abstract: In one embodiment, there is provided a controller that performs control to supply driving electricity to a secondary winding of a variable-speed generator-motor from a secondary exciter and thereby start the variable-speed generator-motor from a standstill state in a variable-speed pumped storage system. The controller performs control to complete a start-up by the driving electricity from the secondary exciter and connect the variable-speed generator-motor in parallel with an electric power system, in a state where a rotating speed of the variable-speed generator-motor is lower than a lower limit speed of a variable-speed operation range.

Abstract: A pitch drive circuit that operates in an emergency mode, for a wind or water power plant. The circuit has at least one rectifier unit, at least one DC intermediate circuit, two inverter units and a pitch rotary current motor with motor trains that can be contacted on both sides. A first contact side of the motor trains is connected to a first inverter unit and a second contact side of the motor trains is connected to a second inverter unit. At least one switching element is connected to at least one contact side of the motor trains. In a normal operating mode of a first switching state of the switching element the motor trains can be energized via both inverter units, and in an emergency operating mode of a second switching state of the switching element, the motor trains can be energized via a single inverter unit.

Abstract: A three-phase AC motor (4) has a configuration in which a q-axis inductance is larger than a d-axis inductance by a predetermined amount or more to allow smoothing of power fluctuations due to the power supply voltage of the AC power source (3).

Abstract: A power converting apparatus for electric motor vehicle propulsion is provided that is suitable for a use in which power regeneration from an inverter unit to a power storing unit or power supply from the power storing unit to the inverter unit is frequently used. The apparatus includes a converter unit that receives input of a power supply voltage from the outside, converts the power supply voltage into a direct current of a predetermined value, and outputs the direct current, the inverter unit that is connected to an output side of the converter unit and drives an electric motor, and the power storing unit that is connected to the output side of the converter unit. A converter control unit included in the converter unit generates a current command for the converter unit and controls charging and discharge currents to and from the power storing unit based on this current command.

Abstract: Provided is a pump system. The pump system includes an AC (alternating current) electric motor, a converter, a smoothing unit, an inverter, a volt/hertz pulse width-modulation controller, and a main controller. The AC electric motor operates a pump which is a load. The converter receives AC power and converts the AC power into DC (direct current) power. The smoothing unit smoothes a DC voltage converted by the converter. The inverter converts the DC voltage output from the smoothing unit into an AC voltage. The volt/hertz pulse width-modulation controller applies switching voltage to a semiconductor switching device of the inverter. The main controller changes an operating frequency according to a load detected when the Ac electric motor is in operation and puts the AC electric motor to a sleep mode after determining a load operation status.

Abstract: Provided is a power converter that is capable of ensuring a conduction current without expanding the configuration of a DC voltage conversion circuit such as a DC chopper. Power can be supplied from both a DC chopper and a voltage source rectifier converting AC power into DC power, to a voltage source inverter. The voltage source rectifier has an upper arm part and a lower arm part having switching elements. The voltage source rectifier converts AC power obtained from an alternator into DC power, performs a DC chopper operation using the upper and lower arms thereof and a winding wire of the alternator, and supplies power of a DC power source to the voltage source inverter.

Abstract: An output control apparatus for an electric motor includes a phase-current instruction-value setting device, a draw-current allowable-value storage device, a phase-current allowable-value setting device, and a phase-current instruction-value limiting device. The draw-current allowable-value storage device is configured to store a draw current allowable value of an electric storage device corresponding to an allowable current value of a system disconnecting-connecting device provided in a power system from the electric storage device to the electric motor. The phase-current allowable-value setting device is configured to set a phase current allowable value based on the draw current allowable value and an ON time of a switching element in a power converter. The phase-current instruction-value limiting device is configured to compare the phase current instruction value with the phase current allowable value to limit the phase current instruction value so as not to exceed the phase current allowable value.

Abstract: An electric motor drive apparatus includes multiple inverter sections arranged corresponding to winding sets of a motor, multiple relays that controls power supplies to the inverter sections, and a control unit. Each inverter section and corresponding winding set are referred to as a system. The control unit includes an obtaining section that obtains a winding current, a determination section that determines a fault occurrence, a specifying section that specifies a faulty system in which the fault occurs, an interrupting section that controls the relay corresponding to the faulty system to interrupt the power supply to the faulty system, and a vibrating section that controls the inverter section of a properly-operating system to add a vibration to an output torque from the electric motor. The vibrating section gradually increases a vibration component of the vibration added to the output torque from the electric motor.

Abstract: Provided are a method for compensating instantaneous power failure in medium voltage inverter and a medium voltage inverter system by using the same, the method for compensating instantaneous power failure in medium voltage inverter including a plurality of power cells supplying a phase voltage to a motor by being connected to the motor in series, the method including decreasing an output frequency of the plurality of power cells by as much as a predetermined value at a relevant point where an input voltage of the plurality of power cells is less than a reference value, decreasing the output frequency at a predetermined deceleration gradient, and maintaining the output frequency during restoration of input voltage as long as a predetermined time, in a case the input voltage is restored.

Abstract: Protection of a motor controller from a transient voltage and/or an over-voltage condition is described. A drive circuit includes a rectifier portion and at least one inductive device coupled to the rectifier portion. The drive circuit further includes at least one voltage clamping device coupled in parallel with the at least one inductive device, and at least one switching device configured to open as a function of a direct current (DC) link voltage value.

Abstract: An SR motor control apparatus includes: a first half-bridge circuit connected to a neutral node of an SR motor; a second half-bridge circuit connected to a U-phase coil of the SR motor; a third half-bridge circuit connected to a V-phase coil of the SR motor; a fourth half-bridge circuit connected to a W-phase coil of the SR motor; and a switching unit including at least two power modules on which the first to fourth half-bridge circuits are mounted.

Abstract: A power conversion method including: receiving an input voltage which is a single-phase AC voltage; designating a first target voltage and a second target voltage respectively representing consecutive target values of a first-phase output voltage and a second-phase output voltage which form a two-phase AC voltage; cyclically connecting and disconnecting a pair of input terminals and a pair of first output terminals at a duty cycle corresponding to a ratio |ref1/in| during a time period in which an instantaneous absolute value of the input voltage is greater than an instantaneous absolute value of the first target voltage; and cyclically connecting and disconnecting the pair of the input terminals and a pair of second output terminals at a duty cycle corresponding to a ratio |ref2/in| during time periods in which the instantaneous absolute value of the input voltage is greater than an instantaneous absolute value of the second target voltage.

Abstract: A motor driving system including command value output means configured to output an analog value according to a rotation speed command; a first power line having first switching means; a drive circuit, to which power is supplied via the first switching means and the first power line, driving a motor supplying rotation based on the analog value; and switching control means configured to make the first switching means nonconductive when the analog value is smaller than a first predetermined value, and independent of the command value output means.

Abstract: A control device for a railway vehicle controls an inverter device based on a direct-current link voltage Vfc between the opposite terminals of a filter capacitor. A direct-current voltage applied to the inverter device during regeneration is the sum of a voltage Vb of power storage equipment and an overhead wire voltage Vs, so that only detecting the direct-current link voltage Vfc is not enough to separate the voltage Vb of the power storage equipment and the overhead wire voltage Vs from each other. The power storage equipment can be connected in series with the inverter device, and a voltage sensor that detects the overhead wire voltage Vs is provided between a current collector device and a grounding point. The power storage equipment is controlled based on the detection result from the voltage sensor.

Abstract: A power inverter is provided that can apply to an AC rotary machine three-phase voltages of high amplitudes and low distortion while suppressing ohmic loss attributed to current detection resisters. The power inverter includes a superimposed voltage command computing device which is configured to compute and output a superimposed voltage command depending on the difference between a maximum value and a minimum value of three-phase voltage commands; a voltage command modification device which is configured to add the superimposed voltage command to each of the three-phase voltage commands and outputting modified three-phase voltage commands; and a power output device which is configure to output the three-phase voltages based on the modified three-phase voltage commands.

Abstract: A power supply unit for a press machine having a converter (converter circuit) connected to a commercial AC power supply, and an inverter (inverter circuit) connected to a press motor, includes an electrical energy bank, an inrush prevention circuit, an inrush prevention instruction signal generation section, and a contactor switch section, wherein contactors of the inrush prevention circuit are switched from on ON state to an OFF state and inrush prevention resistors of the inrush prevention circuit are connected to AC phase current paths on condition that the inrush prevention instruction signal generation section has generated and output an inrush prevention instruction signal (Sres) during press operation.

Abstract: Embodiments of the present disclosure relate to methods, systems and apparatus for generating voltage command signals for controlling operation of an electric machine. The disclosed embodiments can reduce current and torque oscillation, which can in turn improve machine efficiency and performance, as well as utilization of the DC voltage source.

Abstract: A frequency converter and a method for determining the position of the rotor of an electric machine are provided. The frequency converter includes a load bridge and a control of the load bridge, for supplying electricity between the load bridge and an electric machine connected to the load bridge. The frequency converter includes a determination for at least one electrical parameter of the electric machine, and includes a determination for the position of the rotor of the electric machine. The load bridge is fitted to supply a first alternating electricity excitation signal, which is formed in relation to the electrical angle of the electric machine, to the electric machine. The frequency converter is further fitted to determine the first alternating electricity response signal corresponding to the first alternating electricity excitation signal, and the position of the rotor is determined on the basis of the first alternating electricity response signal.

Abstract: The invention relates to power converter circuits which are suitable, in particular, for mobile drive systems with stringent requirements in terms of weight minimization and availability as well as direct attachment to rotating field machines. Inter alia, the strictly modular design of the electronics and the very low expenditure on passive filter elements by virtue of the principle involved are characteristic.

Abstract: A direct current bus management system can include a power management and distribution unit, having a source management section, a bus management section coupled to the source management section, a load management section coupled to the bus management section, a DC bus coupled to the power management and distribution unit, a plurality of DC sources coupled to the source management section and a plurality of loads coupled to the load management section, wherein the bus management section is configured to reconfigure excess DC power on the DC bus from the DC inputs from the plurality of DC sources based on a plurality of priorities, a plurality of feedback signals and a plurality of system parameters.

Abstract: A drive system for a grid blower of a vehicle is provided. The system includes: an electrical bus, a grid of resistive elements connected to the electrical bus, the grid of resistive elements configured to thermally dissipate electrical power generated from braking of the vehicle, the electrical power being transmitted on the electrical bus to the grid of resistive elements, an electrical power modulation device configured to modify electrical power received from at least one of the electrical bus and the grid of resistive elements, and a grid blower motor coupled to an output of the electrical power modulation device, wherein a speed of the grid blower motor varies based on the electrical power that has been modified by the electrical power modulation device.

Abstract: A renewable energy source is converted into a desired DC voltage that is delivered to a DC motor controller of a permanent magnet motor. A micro controller monitors the amount of supplied renewable DC having the desired DC voltage, which is delivered to each phase of the motor by turning on FET switches on demand. If the renewable DC available at a given instant is not adequate to power a particular phase of the motor, then the micro controller turns on backup FET switches that are part of an independent drive circuit that is in parallel with drive circuits of the renewable DC power circuit, to deliver to the motor line DC, which is produced from an AC supply that has gone through an AC to DC converter. Once charged, the renewable DC power will power the next available phase of the motor.

Abstract: Method and device for operating an asynchronous motor having increased efficiency. According to the invention, ranges for a motor size of the asynchronous motor are specified. In addition, a value of the motor size is calculated depending on at least one measurement value of a measurement parameter during the operation of the asynchronous motor, wherein the respective calculated value of the motor size is allocated to one of the ranges. Furthermore, a control parameter is changed depending on the range to which the calculated motor parameter is allocated to provide an optimised control parameter such that the control parameter is changed beginning from a starting value specified for the respective range of the motor size until a predetermined criterion for a specific motor size is reached. Furthermore, the optimised control parameter is stored as a support point of a continuous optimal characteristic curve for the control parameter depending on the range to which the calculated motor size is allocated.

Abstract: For each phase of a controller, semiconductor switches comprise a high side switch and a low side switch. A direct current voltage bus provides electrical energy to the semiconductor switches. A measuring circuit is adapted to measure the collector-emitter voltage or drain-source voltage for each semiconductor switch of the controller. A data processor determines that a short circuit in a particular semiconductor switch is present if the measured collector-emitter voltage or measured source-drain voltage for the particular semiconductor switch is lower than a minimum threshold and if an observed current associated with the particular semiconductor switch has an opposite polarity from a normal operational polarity. A driver simultaneously activates counterpart switches of like direct current input polarity that are coupled to other phase windings of the electric motor, other than the particular semiconductor switch, to protect the electric motor from potential damage associated with asymmetric current flow.

Abstract: A method for controlling a specific electric machine includes receiving with a controller a back electromotive force (BEMF) coefficient for the specific electric machine. The controller is configured to control operation of an inverter coupled to the electric machine where the inverter is configured to provide or receive multi-phase electricity to or from the electric machine in motor mode or generator mode, respectively. The method further includes receiving with the controller an input related to a selected torque to be applied by or a selected power to be removed from the electric machine. The method further includes determining a first electrical parameter the inverter is to apply to in motor mode or a second electrical parameter the inverter is to convert power to in generator mode using the BEMF coefficient, and applying the first electrical parameter to the electric machine or converting the received power to the second electrical parameter.

Abstract: The invention relates to a switch cabinet arrangement of a device for generating electrical energy, wherein the switch cabinet arrangement comprises at least two separate power switch cabinets. The technical object of achieving an optimum scalability of devices for generating electrical energy with at the same time a simple installation and maintenance of the power switch cabinets despite a small available installation space, is achieved according to the invention in that the power switch cabinets respectively comprise a machine connection, a power module, a mains connection and a decentralised control unit, wherein the power module comprises a machine converter, a mains converter, a direct voltage intermediate circuit and a chopper, and wherein the power switch cabinets are electrically connected in parallel to one another via the machine connection and the mains connection.