Abstract: A switch includes a fixed contact, a movable contact, a motor to drive the movable contact via a drive mechanism that converts rotational motion into linear motion, and a drive controller to control driving of the motor. The drive controller controls a rotation speed of the motor such that during an opening operation of the switch, a moving speed of the movable contact in a part of an entire moving range of the movable contact is lower than a moving speed of the movable contact during a closing operation of the switch. The part of the entire moving range includes an interrupting point at which an arc current is extinguished.

Abstract: A device estimates the electromagnetic torque of a three-phase synchronous electric machine including permanent magnets. The device includes: a first flux estimator including two integrators of electromotive force for estimating the respective components of the flux in a fixed two-phase coordinate system tied to the stator, an estimator for estimating the torque from the respective estimated-flux components, a second flux estimator that uses currents expressed in a rotating two-phase coordinate system tied to the rotor, with an observer for determining variables that characterize magnetic uncertainties of the machine with a view to correcting the flux estimation of the second estimator, and a detector for generating a signal for resetting initial flux conditions of the two integrators based on the flux estimation delivered by the second estimator, when the discrepancy between the estimated torque and a setpoint torque is higher than a predefined threshold.

Abstract: Examples include a method for controlling a motor soft-starter for starting an electric motor on a three-phases electric network in order to compensate a misbalance between the windings of the electric motor due to a misbalance between the phases of the electric network.

Abstract: The invention relates to controlling an electric drive system, a control range for the switching frequency of a power converter in such a drive system being adaptable when the rotational frequency curve or the torque curve of the electrical machine is taken into account. In this way, psycho-acoustic irritations can be avoided.

Abstract: A method for controlling an electric machine, in particular a permanent magnet synchronous machine, having a first, in particular three-phase, winding system, which is controlled by a first converter, and having a second, in particular three-phase, winding system, which is controlled by a second converter. The first converter is operated with block commutation and the second converter is operated with pulse width modulation, in particular space vector modulation.

Abstract: A method for controlling an electric machine, in particular a permanent magnet synchronous machine, having a first, in particular three-phase, winding system, which is controlled by a first converter, and having a second, in particular three-phase, winding system, which is controlled by a second converter. The first converter is operated with block commutation and the second converter is operated with pulse width modulation, in particular space vector modulation.

Abstract: Described is a method of aligning a rotor of a polyphase synchronous motor having a permanent magnet rotor to a predetermined, selected, or specified rotor angle. The method comprises sensing or measuring the stator winding voltages/currents during synchronous operation of the motor. Based on the sensed or measured stator winding voltages/currents, a synchronously rotating reference frame vector voltage (Vq) in the q-axis is determined as a product of stator winding resistance (Rs) and stator winding current (iq) in the q-axis. Corresponding polyphase drive voltages for the synchronous motor for the predetermined, selected, or specified rotor angle (?) are determined from the synchronously rotating reference frame vector voltage (Vq). The polyphase drive voltages are applied to align the rotor on stopping at said predetermined, selected, or specified rotor angle (?). The polyphase drive voltages are applied by suitable PWM drive signals.

Abstract: A system for supplying AC driving voltages to a plurality of electric motors, wherein said plurality of electric motors comprise a main electric motor, one or more additional electric motors, and a variable voltage source associated with each phase of said main motor, wherein with each phase of each of said one or more additional electric motors a plurality of switches is associated, which are controllable for selectively acquiring a neutral switching state and at least one of a positive parallel switching state, and a positive serial switching state.

Abstract: A motor control device includes: a power converter to which a first motor and a second motor are connected in parallel, the power converter being configured to convert a direct-current voltage into an alternating-current voltage and supply the alternating-current voltage to the first motor and the second motor; a switching unit provided between the second motor and the power converter; a current detector configured to detect an electric current flowing through the first motor and the second motor; and a controller configured to control the power converter based on at least a current value detected by the current detector. The controller deactivates the power converter upon receiving from outside an abnormal step signal, attributed to the occurrence of an abnormality, that excludes a normal stop signal representing a stop command and switches the switching unit from an on state to an off state upon deactivation of the power converter.

Abstract: A machine learning (ML)-based phase current balancer for a multiphase power converter includes one or more inputs, one or more outputs, and an artificial neural network. The artificial neural network includes a plurality of artificial neurons and is trained to provide corrective phase current imbalance information at the one or more outputs for correcting phase current imbalance within the multiphase power converter, based on information available at the one or more inputs and indicative of individual phase currents of the multiphase power converter.

Abstract: A temperature monitoring device for protecting the winding of an electronically commutated electric motor from being heated over a specified limit temperature TG regardless of the rotational speed includes a phase current detection device for detecting the phase current IWinding for the motor windings, an overcurrent switch-off device for switching off the electric motor if a maximum permissible phase current IShutdown is exceeded, and an overcurrent monitoring device, which is connected to the overcurrent switch-off device, in order to transmit to it a switch-off signal if the detected phase current IWinding exceeds the maximum permissible phase current IShutdown ascertained by a detection and computing device, wherein an algorithm in which the measured ambient temperature TU is incorporated is used when ascertaining the maximum permissible phase current IShutdown.

Abstract: A method and apparatus are provided for controlling a sensorless multi-phase permanent magnet (PM) motor by sensing induced motor terminal voltages from the PM motor while the rotor is spinning, generating an input voltage vector signal from the plurality of induced motor terminal voltages, projecting the input voltage vector signal to a transformed voltage vector signal which does not include DC-offset components by using a Clarke transformation without a zero component that is applied to the input voltage vector signal, and estimating an initial rotor position of the rotor from the transformed voltage vector signal, wherein said sensing, projecting, and estimating are performed while a power converter for the sensorless multi-phase PM motor is disabled.

Abstract: A drive control for a three-phase motor has an inverter with multiple switches for generating three-phase voltages on the windings of the three-phase motor, and a control device for controlling the switches of the inverter on the basis of pulse-width modulation. The control device is set up to control the switches in a switching period by using a switching pattern, wherein the switching pattern is composed of two active voltage space vectors and multiple null vectors, wherein the null vectors vary within the switching pattern.

Abstract: A method of controlling a motor that generates an output current from an input voltage command. The method receives, from the motor, the output current that includes a direct-axis portion and a quadrature-axis portion, the output current being received as feedback current. The method determines a compensated voltage command by applying, to the feedback current, first gain factors and an inverse of second gain factors. The first gain factors decouple the d-axis portion and the q-axis portion of the compensated voltage command. The inverse of the second gain factors allow the compensated voltage command to be filtered in a manner that preserves decoupling between the d-axis and q-axis. The method determines the input voltage command for the motor by applying the second gain factors to the compensated voltage command to cause the motor to generate the output current with reduced influence of variations of operating parameters of the motor.

Abstract: An inverter system and method for driving an alternating current induction motor connected to a fluid transfer pump, including PWM control of power switching devices and fast-acting shutdown circuitry to disable the power switching devices when unintended or unexpected conditions are detected. The inverter system further includes start/stop safety logic, fault current detection and a fast acting current limit circuit incorporating a programmable current limit, operational status and parameter monitoring and communication, visual signalization, locked rotor detection, and the ability to incorporate closed loop control and remote operation into systems while they are in service.

Abstract: A motor drive control device that drives and controls a motor by using a PWM inverter includes a dead time compensation portion that obtains a compensation amount to compensate for an error of an output voltage of the PWM inverter generated when a dead time to avoid simultaneous turning-on of respective switching elements mutually connected in series in the PWM inverter is prepared and outputs a voltage command obtained by taking the compensation amount into account to the PWM inverter. The dead time compensation portion obtains the compensation amount based on a magnitude of a current command vector indicating a vector of a current to be followed by a current flowing through the motor. The current command vector is a vector defined by a coordinate system in synchronism with a rotor of the motor or its equivalent coordinate system.

Abstract: An aspect of the disclosed invention calculates a value of an inductance of a synchronous motor whose characteristic is unclear while suppressing a failure of the synchronous motor. A motor driving device according to an embodiment of the disclosed invention comprises: a motor; an inverter for supplying an alternating voltage to the motor; a current meter for measuring an introduced current flowing through the motor on the basis of the alternating voltage; and a control unit for controlling the inverter to change the size of the alternating voltage in stages, and calculating an inductance of the motor on the basis of the introduced current measured by the current meter.

Abstract: In a permanent magnet synchronous motor drive system, phase currents can be used to calculate a current that produces no shaft torque and only motor losses and a current that only produces shaft torque. These currents can be controlled to be resupplied into the motor drive system to a desired amount on a continuous basis to maintain a DC energy storage device voltage at a desired safe level. The calculated currents are resupplied to the motor drive system such that voltage levels within the DC energy storage device that approach a voltage maximum limit are transferred to the motor in the form of current that is dissipated by the motor without losing efficiency and control of driving a load with the motor.

Abstract: A method includes controlling a first power output to an electric machine during a transient event. Controlling the first power output includes measuring values of the first power output provided to the electric machine during the transient event, receiving an estimated speed input of the electric machine, determining adjustment commands to compensate the first power output for the transient event of the electric machine, generating switch commands for gate drives of a variable frequency drive (VFD) based at least in part on the adjustment commands, and modifying the first power output during the transient event based on the switch commands.

Abstract: A motor control apparatus includes a rectifier which converts AC of a power source to DC, an inverter which converts DC to AC for a motor, a voltage amplitude calculation unit which calculates a power source voltage amplitude value, a power failure recovery detection unit which determines whether or not the AC input side has transitioned to a power failure state or a power recovery state on the basis of the power source voltage amplitude value, a protection operation command unit which outputs a protection operation command when a reference time has elapsed from a time point at which the AC input side transitioned to the power failure state, a time measurement unit which measures an elapsed time from when the AC input side transitioned to the power recovery state, and a condition change unit which changes the power failure reference voltage value and/or the reference time.

Abstract: An apparatus for restarting a medium voltage inverter is disclosed, wherein the medium voltage inverter can be restarted by estimating a rotor speed when an input power returns from an instantaneous defective state to a normal state, whereby a time to restart the medium voltage inverter can be reduced by a simple configuration to dispense with the need to wait until the rotor speed reaches zero speed.

Abstract: A vehicle includes one or more inverter-fed electric machines such as permanent magnet synchronous motors. In response to a torque request, a controller issues commands to an inverter calculated to cause the motor to produce the requested torque at the current temperature. A method adjusts the direct component of the winding current such that the requested torque is delivered efficiently. For a given rotor speed, bus voltage, and torque, the direct component increases as the temperature increases.

Abstract: A system can include an interface to receive sensed data and economic data; a production control framework that includes a module for modeling motor efficiency of an electric submersible pump, a module for modeling gas composition of a fluid being pumped by an electric submersible pump, a module for modeling solid dynamics in a fluid being pumped by an electric submersible pump, a module to update one or more of the modules for modeling in response to receipt of data via the interface; and an interface to output control commands to a controller for an electric submersible pump based at least in part on data received by the interface and analyzed by the production control framework. Various other apparatuses, systems, methods, etc., are also disclosed.

Abstract: A variable speed drive (VSD) can be used to vary the voltage-to-frequency ratio (V/f) supplied to a compressor motor of a heating, ventilation, air conditioning or refrigeration (HVAC&R) system to compensate for varying conditions in the HVAC&R system.

Abstract: Some embodiments of the inventive subject matter provide an apparatus for driving a shunt trip actuator for a circuit breaker or other switch. The apparatus includes an energy storage device and an accumulator circuit configured to store energy in the energy storage device responsive to a shunt trip control signal. The apparatus further includes a detector circuit configured to generate a detection signal responsive to a state of the energy storage device meeting a predetermined criterion and a driver circuit configured to drive the shunt trip actuator using the energy stored in the energy storage device responsive to the detection signal.

Abstract: A work machine prevents a fault in a swing electric motor if an uneven coil temperature increase occurs in the swing electric motor during swing press and related operations. An electricity storage device is connected to the electric motor. An inverter drives the electric motor and a swing control lever issues a command to drive the swing structure. A rotational speed detecting device detects swing speed of the swing structure and a controller controls torque of the electric motor. The controller reads the swing speed of the swing structure detected by the rotational speed detecting device to control such that, when the swing speed is zero, the torque of the electric motor is smaller than a maximum torque value and, when the swing speed is a first rotational speed higher than zero, the torque of the electric motor is the maximum torque value.

Abstract: A method of performing space vector modulation for PWM control for creating AC waveforms includes generating and sampling a reference signal to generate reference samples and performing a reference vector approximation to synthesize a reference vector associated with at least one of the reference samples. The reference vector approximation employs active vectors, one or more zero vectors, and one or more pseudo zero vectors in the formation thereof. Another method of performing space vector modulation (SVM) includes generating a reference signal and sampling the reference signal at a sampling frequency to generate a plurality of reference samples. The method also includes performing a reference vector approximation to synthesize a reference vector associated with at least one of the reference samples, wherein the reference vector approximation has a first portion that employs two adjacent active vectors and a remaining portion that employs two non-adjacent active vectors in the formation thereof.

Abstract: A system for controlling an electric motor is disclosed herein. In particular, the system receives a user input indicative of a desired performance parameter for the electric motor. Based on the desired performance parameter, the system determines a control parameter that defines an operational range. The system then adjusts the electric motor according to the control parameter so that the electric motor generates constant output power over the operational range.

Abstract: A with a converter controlled drive includes a rotor, a drive having a variable rotational frequency a working machine and a frequency converter. The drive and the working machine are connected to one another such that a torque is transmitted. The frequency converter is electrically connected to the drive and converts input frequencies to output frequencies. The output frequencies are grouped into a plurality of concentration ranges based upon a rotational speed of the machine. Each concentration range defines a blocking range. The machine has an operating rotational speed range which lies outside the blocking ranges.

Abstract: A control device for an AC rotating machine includes a voltage command calculation means (1) that calculates voltage commands on rotation two axes and a voltage applying means (2) that applies a voltage to an AC rotating machine (3), based on voltage commands on the rotation two axes outputted by the voltage command calculation means (1); the voltage command calculation means (1) calculates first-axis and second-axis voltage commands on the rotation two axes and reduces the limit value of the second-axis voltage command in proportion to the squared first-axis voltage command.

Abstract: A motor control apparatus includes a voltage regulator to execute a voltage increase mode to increase a voltage applied to an induction motor from a lower limit of a first range over time. A frequency regulator executes a frequency decrease mode to decrease a frequency of the voltage from an upper limit of a second range over time. The frequency regulator limits decrease of the frequency when a bus voltage of a bus exceeds a first threshold in the frequency decrease mode. The bus supplies DC power to an inverter to drive the motor. A mode changer alternatively changes the voltage increase mode and the frequency decrease mode to control the motor to change from a free running state to a state in which the voltage and the frequency satisfy a relationship. The determinator determines whether the voltage and the frequency satisfy the relationship.

Abstract: A motor control apparatus includes a voltage regulator to execute a voltage increase mode to increase a voltage applied to an induction motor from a lower limit of a first range over time. A frequency regulator executes a frequency decrease mode to decrease a frequency of the voltage from an upper limit of a second range over time. When a current through the motor exceeds a first threshold in the voltage increase mode, a mode changer changes the mode to the frequency decrease mode. When the current through the motor becomes smaller than a second threshold in the frequency decrease mode, the mode changer changes the mode to the voltage increase mode to control the motor to change from a free running state to a state in which the voltage and the frequency satisfy a relationship. A determinator determines whether the voltage and the frequency satisfy the relationship.

Abstract: Methods, systems and apparatus are provided for generating voltage commands used to control operation of a permanent magnet machine. For example, a control system is provided that generates voltage command signals for controlling a permanent magnet machine during a transition from an initial operating condition to a final operating condition. The control system includes a processor configured to execute software instructions, and a memory configured to store software instructions accessible by the processor. The software instructions comprise a voltage command generator module. Based on an electrical angular frequency of the permanent magnet machine, and synchronous reference frame current signals, the voltage command generator module is configured to generate ramped voltage command signals that each change linearly in accordance with a slope during a transition period that is set to a rise time.

Abstract: A control device performs voltage conversion control on a voltage conversion circuit between a power supply and motor control circuits which control a plurality of motors. The control device includes sampling units for sampling a DC voltage after voltage conversion, target voltage setting units for setting target voltages VHT1 and VHT2 of the plurality of motors, selection unit for selecting a target voltage VHT to be converted by the voltage conversion circuit from a plurality of target voltages VHT1 and VHT2, generating unit for generating a sampling timing TS on the basis of a gate signal GS1 or GS2 of one of the motors with the target voltage which has not been selected, and control unit for performing the voltage conversion control using the DC voltage sampled by the sampling units at the sampling timing TS in response to each sampling timing request DS in the voltage conversion control.

Abstract: A novel multiple induction electric motor system that separately produces synchronized variable frequency alternating current control signals and using multiple induction electric motors, produces synchronized rotating magnetic fields responsive to the control signals, induces magnetic fields around a conductor in inductive rotors responsive to the rotating magnetic fields and applies rotational forces between the rotating magnetic fields and the induced magnetic fields to a common shaft of the multiple motors. The common shaft sums the rotational forces and transmits the rotational forces to a drive wheel. Such a system can be implemented using two, three or more synchronized induction electric motors, and respective elements thereof, wherein the stator and rotor laminations can be arranged, stacked and/or otherwise configured such that the multiple induction electric motors operate at lower temperatures and at higher efficiencies.

Abstract: A control apparatus in a motor drive system includes a magnet temperature acquiring device and a step-up ratio determining device. The magnet temperature acquiring device is configured to estimate or detect a temperature of a permanent magnet provided in a rotor or a stator of a motor of the motor drive system. The motor drive system includes a power supplying device to output direct current voltage, and a voltage step-up device to increase, at a certain step-up ratio, the direct current voltage which is output from the power supplying device. The step-up ratio determining device is configured to determine the certain step-up ratio in accordance with the temperature of the permanent magnet estimated or detected by the magnet temperature acquiring device.

Abstract: A traction motor system calculates motor flux by generating a real time effective resistance of a resistance grid calculated from motor torque and measured voltage on a DC link. Calculating effective resistance avoids solely relying on DC link voltage, which can be influenced by conditions such as wheel slip and drop out of one or more resistance grids. The effective resistance calculation is based on nominal motor values using known power levels and conditions. From these nominal values and the effective resistance, various scaling factors based on actual motor power can be generated and used to adjust a nominal flux reference to more accurately reflect actual motor flux. The scaling factors include power and torque scaling factors and a resistance scaling factor that is active during conditions such as wheel slip.

Abstract: The invention relates to an asynchronous motor unit including a frequency converter for regulating the asynchronous motor. The frequency converter comprises an input-side, uncontrolled bridge rectifier, a DC voltage intermediate circuit and an output-side inverter. According to the invention, the DC voltage intermediate circuit furthermore comprises a DC-to-DC converter with galvanic isolation, with the result that electrical isolation between the bridge rectifier and the inverter is produced.

Abstract: A power-saving driving device is provided for a same load pattern device 23 that is driven by a motor 21 receiving electric power from an inverter 19 and repeatedly operated in a same load pattern. The power-saving driving device includes: an electric power amount calculator 81 that calculates an electric power amount W received by the inverter in the same load pattern; and a parameter selection and command device 83 that makes a parameter of the inverter change to a plurality of values, compares the received electric power amounts corresponding to the values of the parameter, selects the parameter value minimizing the received electric power amount and issues the selected value as a command to the inverter.

Abstract: Systems and methods for driving a motor are provided. One implementation of a drive system comprises a user interface, a variable speed drive, and a controller. The user interface enables a user to select an operating frequency set point and an operating voltage set point. The operating frequency set point is selected from a range of frequency set points and the operating voltage set point is selected from a range of voltage set points. The variable speed drive is configured to drive a motor at the selected operating frequency set point and selected operating voltage set point. The controller is configured to receive input from the user interface and control the operating frequency and operating voltage of the variable speed drive.

Abstract: Methods, system and apparatus are provided for controlling third harmonic voltages when operating a multi-phase machine in an overmodulation region. The multi-phase machine can be, for example, a five-phase machine in a vector controlled motor drive system that includes a five-phase PWM controlled inverter module that drives the five-phase machine. Techniques for overmodulating a reference voltage vector are provided. For example, when the reference voltage vector is determined to be within the overmodulation region, an angle of the reference voltage vector can be modified to generate a reference voltage overmodulation control angle, and a magnitude of the reference voltage vector can be modified, based on the reference voltage overmodulation control angle, to generate a modified magnitude of the reference voltage vector.

Abstract: A control circuit for a blender provides low-cost power conditioning through the use of a high resistance which provides temporary power for operation of low-voltage logic circuitry and low-voltage switches for a time sufficient to switch the motor on, and a lower resistance which provides sufficient power for maintaining the motor on state indefinitely as instructed by the low-voltage logic circuitry. Low average power dissipation is provided by powering the low-voltage logic circuitry and low-voltage switches using the high resistance in a standby mode and switching in the lower resistance only when the motor is activated.

Abstract: A system and method for determining rotor speed of an AC induction machine is disclosed. The system is programmed to estimate a rotor speed of the induction machine according to a linear speed estimation algorithm and based on name plate information (NPI) of the induction machine and parameters of the AC induction machine during operation thereof. The rotor speed estimation system is also programmed to estimate a rotor speed of the AC induction machine according to a frequency-domain signal processing algorithm and determine if the rotor speed estimated thereby is valid. If the rotor speed estimated by the frequency-domain signal processing algorithm is valid, then a tuned rotor speed of the AC induction machine is estimated according to the linear speed estimation algorithm and based, in part, on the rotor speed estimated by the frequency-domain signal processing algorithm.

Abstract: A compressor monitoring system includes current and voltage monitors, current and voltage averaging modules, a control module, and a switch. The current monitor measures a current drawn by a motor of a compressor. The current averaging module generates first and second average current values based on the current measured by the current monitor. The voltage monitor measures a utility power voltage. The voltage averaging module generates first and second average voltage values based on the voltage measured by the voltage monitor. The control module selectively generates a fault signal when a first ratio is greater than a first predetermined threshold and a second ratio is less than a second predetermined threshold. The first ratio is based on the first and second average current values. The second ratio is based on the first and second average voltage values. The switch deactivates the motor when the fault signal is generated.

Abstract: Identification of electrical equivalent circuit parameters (15) of a three-phase asynchronous motor (09) without a shaft encoder. The method comprises—Assumption of a standstill position of the rotor (11);—Equidirectional test signal infeed U1?, U1? in ? and ? in the stator axis direction of the asynchronous motor (09);—Measuring of a measuring signal I1?, I1? of the ? and ? axial direction of the asynchronous motor (09); and—Identification of equivalent circuit parameters of the asynchronous motor (09) on the basis of the test signal voltages U1?, U1? and of the measuring signal currents I1?, I1?; whereby the test signal feed allows the rotor (11) to remain torque-free. Determination of equivalent circuit parameters (15) of an asynchronous motor (09) as well relates to a motor control device (35), whereby the identified equivalent circuit parameters (15) can be used for the determination, optimization and monitoring of a motor control and for control of electrical drives.

Abstract: A double fed induction generator (DFIG) system and controller are presented in which the rotor side converter is preloaded with one or more initial values for resuming regulated operation to counteract transients upon deactivation of the crowbar protection circuit to provide grid fault ride through.

Abstract: A novel multiple induction electric motor and vehicle that stores electrical power; provides a first and second direct current power input from the stored electrical power; separately produces first and second synchronized variable frequency alternating current control signal from the first and second direct current power inputs, respectively; produces first and second synchronized rotating magnetic fields responsive to the first and second variable frequency alternating current control signals, respectively; induces a first induced magnetic field around a conductor in a first inductive rotor responsive to the first rotating magnetic field; induces a second induced magnetic field around a conductor in a second inductive rotor responsive to the second rotating magnetic field; applies first and second rotational forces between the first and second rotating magnetic fields and the first and second induced magnetic fields to the shaft; and transmits the first and second rotational forces to a drive wheel.

Abstract: A motor driving control apparatus includes a motor driving unit which drives a motor and a driving control unit which supplies to the motor driving unit a command value for the motor driving unit to drive the motor. A power characteristic acquiring unit acquires a power characteristic of an AC power supply that supplies power to the motor. A control parameter determining unit determines based on a voltage characteristic of the AC power supply whether, during driving of the motor, the voltage of the AC power supply drops to a level that adversely affects the driving of the motor, and if positive, the control parameter determining unit sets a control parameter so that the voltage of the AC power supply does not drop below that level and supplies the control parameter to the driving control unit in order for the driving control unit to determine the command value.

Abstract: A data processor establishes a first range of rotational speeds of a rotor of the motor from a first lower limit to a first higher limit and a second range of rotational speeds from a second lower limit to a second higher limit. A hysteresis band or a rotational range of speeds is established such that during operation in the first range the first higher limit is adjusted (e.g., raised by a first amount to be greater than the second lower limit). A sensor detects or measures a rotational speed of a rotor of the motor. The data processor determines whether the measured rotational speed falls within the first range or the second range, as adjusted by the hysteresis band, to identify a selected speed range. A switching frequency of a pulse-width modulation signal is varied in accordance with the selected speed range.

Abstract: An inverter comprises output switches for generating motor phase currents for application to an electrical motor based on a commanded torque. A current sensor is arranged for detecting motor phase currents applied to the electrical motor by an inverter. A voltage sensor is configured for measuring voltages applied to the electrical motor by the inverter. An output port is capable of outputting output signals of the detected motor phase currents and measured voltages for processing by a vehicle controller. The output signals are suitable for input to a vehicle controller for determining whether or not to generate an override control signal. An input port is configured for receiving the override control signal from the vehicle controller. The input port is coupled to an override input module for switching off a supply of electrical energy to the electric motor.