Abstract: Residual voltage measurements taken after removal of electric power to an electric motor are used to improve the functioning of an electric motor monitoring system. For example, an intelligent electronic device (IED) may acquire residual voltage measurements of a motor after disconnected electric power to the motor. The IED may determine a thermal condition of the motor based at least in part on the residual voltage measurement. The IED may prevent starting of the motor based at least in part on the thermal condition.

Abstract: A motor selection device is equipped with a speed calculation unit that calculates an average speed from a speed waveform of a motor that drives a predetermined driven object, the speed waveform being obtained when the driven object is made to perform a prescribed operation, a current calculation unit that calculates a root mean square current from a current waveform of the motor that drives the driven object, the current waveform being obtained when the driven object is made to perform the prescribed operation, a storage unit that stores a motor characteristic corresponding to a speed of a target motor serving as an object to be selected, and a determination unit that determines whether or not the prescribed operation by the target motor is possible, using the motor characteristic corresponding to the average speed, and the root mean square current.

Abstract: A motor drive system capable of suppressing heat generation during a low speed operation may include: an inverter including a plurality of switching elements to convert direct current power to alternating current power having a plurality of phases; a motor driven with the alternating current power converted in the inverter; and a controller determines an operating point of the motor on the basis of a torque command of the motor and generates a d-axis current command and a q-axis current command corresponding to the operating point. In particular, when each of the switching elements is overheated, the controller changes the d-axis current command and the q-axis current command by changing the operating point to a different operating point corresponding to a torque of the same magnitude as the torque command.

Abstract: A drive system for driving an AC electric machine includes an electric machine power converter that provides a primary current excitation vector having a magnitude and angle to drive the AC electric machine. A control system separate from or incorporated into the power converter causes the power converter to inject a carrier signal to the AC electric machine that is superimposed onto the current vector and that generates a carrier response signal that has sensitivity to magnetic alignment information of the AC electric machine at its operating point, the carrier response signal providing a measurable magnetic alignment signature of the AC electric machine. The control system causes the power converter to inject the carrier signal at an injection angle between a constant flux injection angle and a constant torque injection angle, to reduce noise and/or vibration of the AC electric machine caused by the injected carrier signal.

Abstract: A power conversion device is configured to output on/off signals for switching on and off respective semiconductor switching elements of an inverter configured to invert a DC voltage output from a DC power supply into three-phase AC voltages so that, out of a plurality of voltage vectors defined so as to correspond to patterns of the on/off signals, the second closest voltage vector and the third closest voltage vector in phase to a current vector that is based on currents supplied as a result of output of the three-phase AC voltages from the inverter are formed.

Abstract: A motor control method includes acquiring at least one measured torque angle and two estimated torque angles, obtaining all combinations of two torque angles that are combinable with respect to a set of the at least one measured torque angle and the two estimated torque angles and performing an arithmetic operation to determine an error for each combination, selecting a control mode of the motor from control modes including a sensor mode, a sensorless mode, and a shutdown mode, the selecting being performed by referring to a table representing a relationship between the control modes and reference patterns relating to the calculated error group, and controlling the motor in accordance with the selected control mode.

Abstract: Monitoring conditions of an electric motor using stator current and voltage signals from power supplied to the motor is disclosed herein. The stator voltage and current signals may be used to calculate instantaneous power values which may be used to calculate slip. The slip may be used to monitor for a locked rotor condition during startup of the motor. The slip value may be used to provide thermal protection to the electric motor.

Abstract: A motor control device includes a rectifier which converts AC power into DC power and outputs it to a DC link, an inverter which converts the DC power of the DC link into AC power for each motor and outputs it, an AC voltage detection unit which detects an AC voltage value on the AC input side of the rectifier, a state determination unit which determines that a voltage dropped state has been set when the AC voltage value is smaller than a certain specified voltage and that a normal state has been set when the AC voltage value is equal to or larger than the specified voltage, and an output control unit which controls each motor in accordance with the amount of voltage drop with respect to the specified voltage of the AC voltage value when the state determination unit determines that the voltage dropped state has been set.

Abstract: An electrical inverter may include a plurality of phase modules to provide a plurality of phase outputs. Two or more of the plurality of phase modules may share a common insulated-gate bipolar transistor.

Abstract: A method for operating an inverter and an inverter configured to convert DC power supplied from a DC power source into AC power supplied to an AC network by applying operational parameter limits which define limits for allowed operating points of the inverter, collect, during the converting, data of operational conditions related to the inverter, determine on the basis of the collected data whether the set operational parameter limits can be optimized with regard to one or more optimization criteria, and in response to determining that the set operational parameter limits can be optimized, adapt one or more of the set operational parameter limits applied in the converting on the basis of the collected data.

Abstract: A motor driving apparatus drives an electric blower including a single-phase PM motor. The motor driving apparatus includes: a single-phase inverter that applies an alternating-current voltage to the single-phase PM motor; a rotor position detecting unit that outputs, to an inverter control unit, a position detecting signal corresponding to a rotational position of a rotor of the single-phase PM motor; a motor current detecting unit that outputs, to the inverter control unit, a signal corresponding to a motor current flowing to the single-phase PM motor; and the inverter control unit that outputs a driving signal to corresponding switching elements of the single-phase inverter on the basis of the position detecting signal and the motor current. The single-phase inverter performs control to increase or decrease effective electric power supplied to the single-phase PM motor. The air blower changes an air volume by the increase or decrease in effective electric power.

Abstract: Various embodiments are described herein for methods and systems for controlling a switched reluctance machine (SRM) having an axially extending rotor mounted to a shaft, an axially extending stator disposed coaxially and concentrically with the rotor, the rotor and stator having a plurality of salient poles, the stator poles protruding radially towards the rotor poles, and a plurality of electrical coils wound about the stator poles including a plurality of separate phase coils defining a plurality of phases of the SRM. In one example embodiment, the method comprises providing a control system operatively coupled to a current controller of the SRM, where the control system is configured to generate a unique set of current reference profiles based on an objective function and at least one constraint function and operating the SRM based on the unique set of current profiles generated by the control system.

Abstract: A method for controlling a drive having at least one converter, at least one motor and an assigned drive control, wherein a failsafe CPU is operated separately from the drive control and only processes safety-relevant information, where a number of safety functions are implemented by the failsafe CPU such that the safety-relevant functions of the drive are implemented in a simple and reliable manner.

Abstract: A method for identifying a resistance value (Rr) of the rotor of an electric induction motor (M), including determining a reference voltage (urefS) on the basis of a chosen value ({circumflex over (R)}r) for the resistance of the rotor of the electric motor, applying a control voltage (uS) to the electric motor, the control voltage being determined on the basis of the reference voltage (urefS), acquiring the values of the currents (i1, i2, i3) measured in the three phases of the electric motor, so as to deduce a stator current (iS) of the electric motor therefrom, comparing the obtained stator current (iS) with a predetermined value (irefS), correcting the value ({circumflex over (R)}r) used for the resistance (Rr) of the rotor and applying steps a) to d) until obtaining a stator current (iS) equal to the predetermined value.

Abstract: The present invention relates to a method for determining engine operation parameter values during and/or after a gear shift operation prior to performing said gear shift operation. The method comprises the steps of, prior to the gear shift operation: determining initial conditions comprising torque demand and engine speed and certain other engine operation parameter values; providing said initial conditions to an engine operation simulation model; providing a torque development course as well as an engine speed development course during the intended gear shift operation to said engine operation simulation model; and determining desired engine operation parameter values by means of said engine operation simulation model based upon the information thus provided to said engine operation simulation model.

Abstract: A power conversion topology and control method intended for use with a DC bus is disclosed, providing a means to prevent the flow of ground fault current while detecting a fault condition and optionally continuing to operate the DC bus. In one control configuration, a DC-DC power stage with an active current control loop drives differential current to zero, and a separate voltage control loop maintains the desired differential bus voltage. Absolute bus voltage with respect to ground is monitored in order to detect fault conditions. In another configuration, the absolute voltage of the bus with respect to ground is controlled and differential bus current is monitored to detect ground fault conditions.

Abstract: A method for controlling a drive having at least one converter, at least one motor and an assigned drive control, wherein a failsafe CPU is operated separately from the drive control and only processes safety-relevant information, where a number of safety functions are implemented by the failsafe CPU such that the safety-relevant functions of the drive are implemented in a simple and reliable manner.

Abstract: A power converting device includes power conversion circuitry connected to a power system, voltage amplitude determination circuitry that determines a voltage amplitude of the power system, and control circuitry that controls an output current from the power conversion circuitry to the power system based on an oscillation component of the voltage amplitude determined by the voltage amplitude determination circuitry.

Abstract: A data center power system includes an electrical power conductor that includes a live conductor surface and is configured to carry direct current (DC) power from a power source through a human-occupiable workspace of a data center; a grounded conductor positioned in the human-occupiable workspace apart from the electrical power conductor; a first electrical connector configured to mount to a data center rack that supports a plurality of electronic devices, the first electrical connector moveable to electrically contact the live conductor surface of the electrical power conductor; and a second electrical conductor positioned on the rack and configured to electrically contact the grounded conductor.

Abstract: A current detecting device includes: a drive signal generating unit configured to generate a control signal based on a control voltage value indicating drive force to be applied to a target; a current detecting unit configured to detect a current value output based on the control signal generated by the drive signal generating unit; and a correction unit configured to correct the current value detected by the current detecting unit, based on at least a magnitude of the control voltage value.

Abstract: The invention relates to a method of monitoring an electromechanical actuator system, the method comprising the steps of estimating the voltage drop in the power supply to the motor associated with defects of the inverter by means of a Kalman filter, estimating (300) at least the electromagnetic torque coefficient of the motor by taking account of the estimated voltage drop, and calculating (400) the electromagnetic torque of the motor from the electromagnetic torque coefficient of the motor.

Abstract: A method for monitoring a compressor includes measuring a power factor of a motor of a compressor. The method includes selectively detecting an occurrence of a fault event of an electrical grid based on the power factor. The method includes, in response to detecting that the fault event has occurred, switching the compressor from a first state to a second state. The compressor consumes less power in the second state than in the first state. The method includes identifying an apparent conclusion of the fault event. The method includes, in response to the apparent conclusion of the fault event, waiting for a first delay period before switching the motor of the compressor back to the first state.

Abstract: An algorithm for identifying a motor type of a multi-phase (typically 3-phase) motor is described. The algorithm applies a series of active voltage vector pulses to the phases of the motor and measures the current rise-time for each applied voltage vector. The motor type is determined on the basis of the measured current rise-times.

Abstract: A method according to an exemplary aspect of the present disclosure includes, among other things, controlling a vehicle using an estimated torque of an electric machine, the estimated torque based on one or more parameters associated with the electric machine that are independent from measured current feedback.

Abstract: A controller for an induction motor includes a proportional gain setter that sets a magnitude of a proportional gain of a current regulator, and the proportional gain setter sets the magnitude of the proportional gain based on the leakage inductance in response to the primary current.

Abstract: A method includes determining an initial voltage level and duration for an input voltage of a gate of each of multiple transistor devices. Each transistor device receives a power input and controls a current passing through the transistor device. The method also includes controlling the input voltage of the gate of each transistor device according to the initial voltage level and duration. The method further includes receiving real-time feedback including at least one of a present value of the current passing through each transistor device, a present voltage of the power input, and a present value of a capacitor voltage. The method also includes determining, based on the feedback, a subsequent voltage level and duration for the gate of each transistor device. In addition, the method includes controlling the input voltage of the gate of each transistor device according to the determined subsequent voltage level and duration.

Abstract: One exemplary embodiment of the present invention is a motor control device configured to control rotation of a motor based on a drive signal input from an input terminal wherein the motor control device extracts two or more pieces of information of first drive information indicating a drive state or a drive stop state of the motor, second drive information indicating a rotation direction of the motor, third drive information indicating whether the motor is in a forced stop state, and fourth drive information indicating a rotational speed of the motor from at least one of a duty ratio, a voltage, and a frequency in the single drive signal, and controls the motor.

Abstract: An AC rotary machine control apparatus is provided with: predriver ICs for giving drive signals to the gates of power converting switching elements bridge-connected to the respective phases of an AC rotary machine; predriver IC output cutting-off switching elements for operating on the basis of a cut-off signal from a calculation processing device having detected an abnormality state of the predriver ICs, and cutting off drive signals given from the predriver ICs to the gates of the power converting switching elements; and a gate driver circuit for becoming conductive on the basis of a signal from the calculation processing device and giving drive signals from a power source circuit to all the gates of the lower arm elements of the power converting switching elements, when drive signals from the predriver Ics are being cut off by the predriver IC output cutting-off switching elements.

Abstract: The present invention is to adjust the relevant parameters at the variable load factor of the motor of the electric vehicle and the arbitrary rotational speed through the optimization algorithm and to operate with high efficiency over the whole range. In order to optimize the efficiency of the motor for the electric vehicle, the optimization control device 20 obtains the operating load factor in real time with the algorithm 9 for calculating the load factor, the rotation speed ? is obtained by ? detection 6, the power factor PF is acquired by the PF calculation 4, and the torque current component Iq and the magnetic field current component Id are acquired by the Id and Iq conversion algorithm 5, respectively.

Abstract: A capacitor is connected between the direct current voltage terminals. Switched terminals of a first switch and a second switch are coupled in series, between the direct current voltage terminals. An electric machine or generator has one or more windings and a first phase output terminal associated with the switched terminals. A first set of blocking diodes are cascaded in series and second set of blocking diodes are cascaded in series. A first voltage supply provides a first output voltage level and a second output level switchable to the first control terminal, where the first output level is distinct from the second output level. A second voltage supply provides the first output voltage level and the second output level switchable to the second control terminal.

Abstract: A current detection circuit includes a first resistor and a second resistor identical in current path and equal in resistance value, a first and second signal transmission units which transmit respectively a signal representing the potential of the first resistor, a third and fourth signal transmission units which transmit respectively a signal representing the potential of the second resistor, a first difference operation unit which calculates the difference between the respective signals from the first and second signal transmission units, a second difference operation unit which calculates the difference between the respective signals from the third and fourth signal transmission units, and a summing unit which sums the signals output from the first and second difference operation units. The first signal transmission unit and the fourth signal transmission unit, and the second signal transmission unit and the third signal transmission unit are disposed in proximity to each other.

Abstract: A power conversion topology and control method intended for use with a DC bus is disclosed, providing a means to prevent the flow of ground fault current while detecting a fault condition and optionally continuing to operate the DC bus. In one control configuration, a DC-DC power stage with an active current control loop drives differential current to zero, and a separate voltage control loop maintains the desired differential bus voltage. Absolute bus voltage with respect to ground is monitored in order to detect fault conditions. In another configuration, the absolute voltage of the bus with respect to ground is controlled and differential bus current is monitored to detect ground fault conditions.

Abstract: A method for estimating a motor parameter in a load commutated inverter arrangement, including the steps of: measuring a motor side ac-voltage; detecting commutation interval information of the measured motor side ac-voltage; estimating a motor parameter based on the detected commutation interval information; and indicating when the estimated motor parameter deviates from a monitoring parameter thereof.

Abstract: The present invention discloses a motor efficiency analysis method for motor inverter. The method can be performed via a real-time motor operation efficiency display device. Based on the measured primary current signal and the voltage provided by the driving device, the device can estimate related data, such as the real-time efficiency, rotational speed, torque and stator resistance, by means of several algorithms. Besides, the device is designed to be applied to most motors; therefore, users can manage the efficiency of all motors of the factory without the need to stop the machines or the manufacturing process.

Abstract: A method for simulating a field-oriented stator voltage of a stator of an asynchronous machine required in the steady state during operation using a model, wherein the asynchronous machine is operated without a rotary encoder, in a field-oriented manner and with a graduated voltage, includes providing a field-oriented detected stator voltage. The method further includes providing a field-oriented detected stator current. The method further includes simulating the field-oriented stator voltage required in the steady state during operation on the basis of the field-oriented detected stator voltage and the field-oriented detected stator current.

Abstract: The present disclosure describes a method and arrangement for damping a resonant component of a common-mode current of a multi-phase power converter comprising an output filter with a virtual ground connection to the power converter. In the method and arrangement, the common-mode current is determined, a feedback signal is formed on the basis of the common-mode current, and the feedback signal is injected into a common mode current reference in order to dampen the resonance frequency component. A delay is added to the feedback signal so that the feedback signal has a sufficient phase margin with respect to a subsequent cycle of the resonance frequency component of the common-mode current.

Abstract: An insulation inspection device for motors includes an inverter for driving a motor, a partial discharge detecting unit for determining soundness of the motor, and a control circuit for controlling the inverter. The control circuit adjusts a switching interval of a voltage pulse of the inverter so as to be equal to a pulse round-trip propagation time between the inverter and the motor, thereby generating surge voltage higher than driving voltage for the motor, between the motor and ground, and adjusts a switching time for each phase of the inverter, thereby generating surge voltage higher than driving voltage for the motor, between phases, thus performing insulation inspection.

Abstract: A PFC switching power conversion circuit providing low THD, including: a bridge rectifier for providing an input voltage according to an AC voltage; an electromagnetic interference filtering circuit for providing a line voltage according to the input voltage; a switching power converter for converting the line voltage to an output voltage or current under a control of a driving voltage, the driving voltage causing a switching current to flow through a main inductor; and a controller for receiving and processing at least one feedback signal from the switching power converter to generate the driving voltage in a constant on-time manner, the controller including an off-time detector and a timer, the off-time detector being used to detect decreasing periods of the switching current to determine respective off-time periods, and the timer being used to set a minimum limit on the respective off-time periods.

Abstract: Techniques are presented for more efficient three-phase inverter control for electrified vehicles (EVs). The techniques can be executed by a controller of an EV that includes one or more processors. Specifically, the techniques include closed-loop discontinuous pulse-width modulation (DPWM) control of a three-phase inverter based on electric motor current feedback. The three-phase inverter control techniques can be further based on electric motor/rotor position feedback. Based on the feedback, the techniques can select one of a plurality of zero-voltage vectors in real-time. The selected zero-voltage vector can be used when generating duty cycles for switching of the three-phase inverter, which can result in decreased switching losses and increased efficiency of the three-phase inverter.

Abstract: The present application discloses a method and an apparatus for measuring a rotor resistance of an induction motor, which method comprises: injecting a first voltage step signal into a test phase of the induction motor when the induction motor is at standstill; measuring and recording a current value I0+ at an initial moment of the first voltage step signal; and calculating the rotor resistance Rr of the induction motor based on a first current value Is1, a second current value Is2 and the current value I0+ at the initial moment, the first current value Is1 being equal to a steady-state current value corresponding to a voltage value before a step of the first voltage step signal, and the second current value Is2 being equal to a steady-state current value corresponding to a voltage value after the step of the first voltage step signal.

Abstract: An apparatus for minimizing an influence of a temperature change may include a motor, a temperature sensor for sensing a temperature of the motor to create the temperature information, a command compensation unit compensating a torque command or a magnetic flux demand according to the information on the sensed temperature to create a compensation torque command value or a compensation magnetic flux command value, and an inverter for driving the motor according to a D-axis voltage command value and a Q-axis voltage command value are created according to a D-axis current command value and a Q-axis current command value which are matched with the compensation torque command value or the compensation magnetic flux command value.

Abstract: A method and a control device for identifying the angle and polarity of the rotor of a permanent magnet synchronous motor (PMSM), the motor including a stator, including windings and a rotor including at least two permanent magnets. The method includes the steps of determining the rotor d-axis direction by supplying a stator voltage vector pulses to the motor terminals at at least two different stator angles, measuring the phase current at each angle, and determining rotor d-axis position based on motor inductance value in each stator angles calculated from the measured values and determining the rotor d-axis polarity by supplying a current vector to the motor terminals at the q-axis direction, and determining the magnet polarity by observing the direction of the rotor rotation during the test pulses.

Abstract: A controller for switching an inverter includes a current detecting unit, an overcurrent level determining unit which determines an overcurrent level for stopping the inverter in accordance with a value corresponding to the number of revolutions of a motor, a current comparing unit which compares a detected output current value of the inverter with the overcurrent level, and a gate signal generating unit which generates a signal for turning off all semiconductor switching devices of the inverter when the current comparing unit makes a determination that the detected output current value has reached the overcurrent level. The overcurrent level is lowered as the number of revolutions of the motor increases.

Abstract: A pump control device for a pump device having a DC brushless motor as a drive source and a flow rate of the pump device is increased and decreased depending on a corresponding increase and decrease of a rotational speed of the DC brushless motor is structured so that, when the rotational speed of the DC brushless motor is higher than a predetermined speed, the DC brushless motor is controlled in an open loop control and, when the rotational speed of the DC brushless motor is lower than the predetermined speed, the DC brushless motor is controlled in a closed loop control on the basis of a measurement result of an actual rotating speed which is an actual rotational speed of the DC brushless motor.

Abstract: Systems and methods for measuring cogging torque. An example method includes causing an electric motor to rotate in a positive direction, and for given multiple encoder positions of an encoder, determining a first respective motor winding current applied to the electric motor at the given encoder position. Additionally, the method includes causing the electric motor to rotate in a negative direction, and for the given multiple encoder positions, determining a second respective motor winding current applied to the electric motor at the given encoder position. Further, the method includes, for the given multiple encoder positions, determining a respective cogging torque based on a difference between the first and second respective winding currents. And the method includes storing a cogging torque profile for the electric motor in a database based on the determined respective cogging torque for the given multiple encoder positions.

Abstract: An applied-voltage electrical angle setting method for a synchronous motor includes detecting applied voltage and current of the synchronous motor M, calculating current peak value Ip based on the detected values while calculating present applied voltage phase ?, calculating target current phase ?targ based on the current peak value Ip followed by calculating target applied voltage phase ?targ corresponding to the target current phase in a target value setting unit 20, and calculating new applied voltage electrical angle instruction value ?vtarg, based on change angle ??v obtained by correcting a difference between the present applied voltage phase ? and the target applied voltage phase ?targ by response time constant L/R of the synchronous motor, rotational speed ? calculated based on the applied voltage and the current, and the previous applied voltage electrical angle instruction value ?vtarg, in a voltage electrical angle instruction value setting unit 10.

Abstract: A pulse width modulated (PWM) trapezoidal commutation drive to a brushless direct current (BLDC) motor is sine modified so that the applied drive voltage substantially matches the induced voltage generated in the BLDC motor. The values of the cosine of the angles between ?30 degrees and +30 degrees are used to modify the duty cycle of the PWM drive signal dependent upon the rotor angular positions determined from the times between the zero crossing BEMF voltages measured at the unconnected motor terminals.

Abstract: A control device includes a PWM control unit that executes PWM control over an alternating-current motor mounted on a vehicle. The PWM control unit includes an alarm sound generation processing unit and a slip determination unit. The slip determination unit determines whether a drive wheel coupled to the alternating-current motor is slipping on the basis. of a d-axis current (Id), a q-axis current (Iq), a d-axis voltage command value (Vd) and a q-axis voltage command value (Vq) of the alternating-current motor. When the drive wheel is not slipping, the alarm sound generation processing unit generates an alarm sound from the alternating-current motor by adding a variation value (?V) to the d-axis voltage command value (Vd) at a predetermined interval. When the drive wheel is slipping, the alarm sound generation processing unit temporarily stops adding the variation value (?V) to the d-axis voltage command value (Vd).

Abstract: A frequency converter includes a housing, a frequency conversion component installed in the housing, a controller that controls the frequency conversion component, and a user interface that transmits control commands from a user to the controller. The controller of the frequency converter are provided with a load examination function that examines whether a load is connected to an output of the frequency conversion component, the controller raising an output frequency of the frequency conversion component to a desired value in response to a load connected to the frequency conversion component and detected by the load examination function.

Abstract: In a rotating electrical machine, a conductive foil or conductive rubber is applied to the surface of insulation layer of a conductor series connection area or to the surface of insulation layer of a turn conductor of coils of rotating electrical machine winding, waveforms of grounding voltages of the individual turn conductor portions are measured through the medium of an electrostatic capacitance of the insulation layer of coil conductor series connection area or through the medium of the insulation layer of coil turn conductor, and a partial discharge is measured while measuring a voltage developing in the coil or across a winding turn in the coil from a difference between the waveforms of grounding voltages.