Abstract: The purpose of the present invention is to provide a speed detection method for maintaining a fine time axis resolution and a power conversion device that uses the method. This power conversion device comprises an inverter for converting DC voltage into AC voltage and supplying the same to a motor, a motor speed calculation unit for calculating the speed of the motor from output pulses obtained from an encoder connected to the motor, and a control unit for receiving the motor speed from the motor speed calculation unit and controlling the inverter. In the power conversion device, the motor speed calculation unit measures the duty cycle of the output pulses, calculates the speed using the half cycles of the output pulses if the duty cycle is within a prescribed range from 50%, and calculates the speed using the full cycles of the output pulses if the duty ratio is outside of the prescribed range from 50%.

Abstract: A system includes a power distribution bus configured to distribute power from an electrical power source. The system also includes a plurality of electrical loads configured to receive portions of the power from the electrical power source. The system further includes a doubly-fed induction machine (DFIM) configured to reduce transmission impedance on the power distribution bus in response to a change in real or reactive power at one or more of the electrical loads, and reduce low frequency power oscillations at the source.

Abstract: Disclosed is a method and apparatus for real-time estimation of full parameters of a permanent magnet synchronous motor. According to this method and apparatus, it is possible to estimate in real time all four parameters of a permanent magnet synchronous motor without additional signal injection. In addition to the state equation, the “stator current ripple model” is additionally used to fundamentally solve the rank deficiency problem in the state equation without injecting additional signals. All four parameters of a permanent magnet synchronous motor can be estimated in real time.

Abstract: An electronic appliance such as a low harmonic drive, an active rectifier, a grid converter or any active front end or grid converter with an LCL filter. The converter is a two-level, a three-level or a multilevel inverter. The electronic appliance includes an LCL filter on a grid side of the electronic appliance and an active front end rectifier provided on a load side of the electronic appliance. The LCL filter includes grid side inductors and an active front end rectifier is connected to the LCL filter. A method for damping a corresponding electronic appliance is also disclosed.

Abstract: In an embodiment of the present disclosure, a heating, ventilation, air conditioning, and refrigeration (HVAC&R) system includes a refrigerant loop and a compressor disposed along the refrigerant loop. The compressor is configured to circulate refrigerant through the refrigerant loop. The HVAC&R system also includes a motor configured to drive the compressor and a variable speed drive (VSD) configured to supply power to the motor. The VSD further includes a first power pod configured to supply a first power to the motor and a second power pod configured to supply a second power to the motor.

Abstract: A battery module that includes a battery and a bidirectional DC-DC converter including a switching element that is arranged at a position where heat generated by the switching element is transmitted to the battery. The bidirectional DC-DC converter operates in a discharge mode in which DC power supplied from the battery is converted and supplied to an input/output unit, and in a charge mode in which DC power supplied from the input/output unit is converted and supplied to the battery. Moreover, a control unit forces the bidirectional DC-DC converter to operate in the discharge mode and to increase a switching frequency of the switching element in comparison with a switching frequency in normal driving, when a temperature in a periphery of the battery needs to be increased.

Abstract: The present invention provides a method and system for controlling the temperature of an electric motor by adjusting the electric losses in the motor. In an embodiment, the required load on the motor is determined and a first motor voltage is provided to meet the required load. A predetermined temperature set point for the motor is compared against the temperature of the motor and based on the temperature of the motor and the predetermined temperature set point, a secondary motor voltage is determined. The motor voltage may then be adjusted based on the calculated voltage and the motor load measurement adjusted based on the measured motor speed and actual motor voltage.

Abstract: Provided is a fuel cell system including: a fuel cell that supplies electricity to a load; a fuel cell converter that is connected between the fuel cell and the load and boosts a voltage output from the fuel cell; and a control unit that causes the fuel cell converter to perform a voltage boosting action and controls output electricity to the load. Upon detecting a voltage boosting disabling failure that is a failure in which the fuel cell converter is unable to perform the voltage boosting action and able to pass a current, the control unit stops the voltage boosting action of the fuel cell converter and passes a current through the fuel cell converter.

Abstract: An electric machine including a housing, and a stator mounted to the housing. The stator includes a plurality of laminations, a first end turn and a second end turn. A rotor shaft extends through the housing. A hybrid rotor module is coupled to the rotor shaft. The hybrid rotor module includes a clutch basket having a rotor carrier. The clutch basket houses one or more clutch assemblies. A rotor is mounted to the rotor carrier, and one or more openings are formed in the rotor carrier. The one or more openings direct coolant onto at least one of the stator, the first end turn, and the second end turn.

Abstract: A system and method for wirelessly providing power to independent movers traveling along a track includes a sliding transformer to transfer power between the track and each mover. The sliding transformer includes a primary winding extending along the track and a secondary winding mounted to each mover. Each of the primary and secondary windings may be formed of a single coil or multiple coils. The primary and secondary windings are generally aligned with each other and extend along the track and along the mover in the direction of travel with an air gap present between the windings. A power converter on the mover may regulate the power supplied to the mover to control an actuator or a sensor mounted on the mover or to activate drive coils mounted on the mover to interact with magnets mounted along the track and, thereby, control motion of each mover.

Abstract: An induction motor overheat monitoring method and device detects overheating of an induction motor from a detection value of a current sensor. A resistance calculation relationship data indicating a relationship between a resistance and a feature amount at the time of starting of the induction motor and a determination reference value for determining overheating are stored in advance. At each starting, a current of the induction motor is detected, a signal regarding a phase angle difference is calculated, and a feature amount of the motor is calculated from the signal regarding the phase angle difference. Further, a resistance of the induction motor is calculated by using the feature amount of the motor and the resistance calculation reference data stored in advance. Then, a temperature of the induction motor is calculated from the resistance of the induction motor, and it is determined if the motor is overheated.

Abstract: According to an aspect, there is provided a method for evaluating safety of a speed of a motor controlled by a frequency converter. The method includes, first, measuring first, second and third phase currents of three-phase electric power fed from the frequency converter to the motor and forming first, second and third current measurement pairs based thereon. Then, the speed of the motor is estimated separately based on each measurement pair to produce respective first, second and third estimates for the speed of the motor. A voting logic is applied to the first, second and third estimates for the speed of the motor. A voting logic is applied to the first, second and third estimates. An output of the voting logic is fed to a safety logic controlling at least one safety function of the frequency converter. The output of the voting logic includes an estimate for the speed of the motor and an indication whether or not said final estimate is valid according to the voting logic.

Abstract: A method, system, and apparatus for controlling and regulating operation of a permanent magnet rotary electric machine including a stator and a rotor includes determining a first reactive power term associated with the electric machine based upon voltage, and determining a second reactive power term associated with the electric machine based upon flux. A first motor temperature associated with the electric machine is determined based upon the first and second reactive power terms, and power output from the permanent magnet electric machine is controlled based upon the first motor temperature.

Abstract: A drive apparatus is provided for driving a multi-phase rotating electric machine. The rotating electric machine includes a plurality of winding groups for respective phases. The drive apparatus includes a first inverter connected with start terminals of the winding groups of the rotating electric machine, a second inverter connected with intermediate terminals of the winding groups, and an energization controller configured to selectively perform energization of the winding groups by the first inverter and energization of the winding groups by the second inverter. Each of the first and second inverters includes a plurality of switch pairs respectively corresponding to the winding groups and each consisting of an upper-arm switch and a lower-arm switch that are connected in series with each other. Moreover, each of the upper-arm and lower-arm switches of the first inverter is configured to have bidirectionally-conducting and bidirectionally-blocking functions.

Abstract: The present disclosure relates to a motor driving apparatus and, more specifically, to a motor driving apparatus which allows a maximum torque operation by correcting an angle error occurring during quick acceleration of a motor in a sensorless system. The motor driving apparatus comprises: an inverter for driving a motor, using an alternating current voltage; and a control unit for outputting a PWM signal for controlling an operation of a switching element included in the inverter. Here, the control unit determines an inductance parameter used to calculate a speed command value for determining a duty ratio of a PWM signal, and determines whether the motor is being accelerated, on the basis of a current change measured from the inverter. When the motor is being accelerated, the control unit enables a maximum torque operation by reducing an angle error of a rotor through a correction of reducing a previously-determined inductance parameter.

Abstract: A system for controlling an electrical current flowing between a power source and a multi-phase electromagnetic machine includes a first lane, A, comprising a first plurality of phases capable of providing said current from said power source to said machine, and further comprises a second lane, B, comprising a second plurality of phases capable of providing said current to said machine. The system is configured to provide said current via said first lane, A, while no current is being provided via said second lane, B. Each of said first plurality of phases comprises at least one inverter switch positioned between said power source and said machine. The system further includes means for detecting a fault in one of the first plurality of inverter switches of lane A, and further comprises a first phase isolation means provided on said first lane, A.

Abstract: A device for estimating a rotation speed and/or a direction of rotation of an induction machine is presented. The device controls stator voltages (uu, uv, uw) of the induction machine so that a voltage space-vector constituted by the stator voltages has a fixed direction and a current space-vector constituted by stator currents (iu, iv, iw) of the induction machine has a pre-determined length or a predetermined d-component. The rotation speed and/or the direction of rotation is/are estimated based on a waveform of a q-component of the current space-vector, where the d-component of the current space-vector is parallel with the voltage space-vector and the q-component of the current space-vector is perpendicular to the voltage space-vector. The device is usable when the induction machine does not have enough magnetic flux for flux-based determination of the rotation speed and/or the direction of rotation.

Abstract: A method for commissioning a synchronous or asynchronous electric motor having a stator and a rotor in which electrical power is applied to the motor when the rotor is stationary. The electric power is applied in two stages. The first stage utilizes a DC power that ramps in voltage over the duration of the first test to produce a current response that is employed to determine at least a first motor parameter. The second stage uses relatively high frequency AC power to generate one or more current responses that are employed to determine second and third motor parameters. A related electric motor drive system is also provided.

Abstract: The purpose of the invention is a method for controlling a three-phase electrical machine from an inverter. Each sector of the complex representation of the space vector modulation being subdivided into three subsectors, comprising a central subsector centred on the active vector, a first lateral subsector associated with the first zero-sequence vector, and a second lateral subsector, opposite the first lateral subsector relative to the central subsector, associated with the second zero-sequence vector, it comprises a step of control of the voltage at the terminals of each phase of the electrical machine, measured relative to neutral, with the value defined by the control vector associated with the subsector in which the control vector is located.

Abstract: A motor system provided with one motor and two inverters includes a first inverter control unit which changes a frequency of a first carrier wave (first carrier frequency) used for producing a switching signal fora first inverter according to an operating point of the motor; and a second inverter control unit which changes a frequency of a second carrier wave (second carrier frequency) used for producing a switching signal for a second inverter according to an operating point of the motor. The first carrier frequency has a changing characteristic depending on the first inverter control unit and the second carrier frequency has a changing characteristic depending on the second inverter control unit, and the changing characteristics are different from each other to make the first carrier frequency and the second carrier frequency differ from each other at an identical operating point.

Abstract: A device for stabilizing a direct current (DC) distribution system includes a capacitor unit charged by a DC voltage supplied by a power supply stage of the distribution system. The device further includes an inverter that has three pair of switching elements. The device also includes a controller that controls a plurality of switches thereof to selectively enable an inverter circuit or a voltage stabilizing circuit of the DC distribution system. The device alleviates instability of DC voltage which may be generated in a transient period, or to drive a motor connected to the device.

Abstract: A power conversion device includes a first inverter connected to a first end of a winding of each phase of a motor, a second inverter connected to a second end of the winding of each phase, and first and second switching circuits. The power conversion device further includes a normal state operation mode in which power conversion is performed by using a first neutral point of the winding of each phase in the second inverter and the first inverter and an abnormal state operation mode in which the power conversion is performed by using a second neutral point of the winding of each phase in the first inverter and the second inverter. An operation mode of the power conversion is switched from the normal state operation mode to the abnormal state operation mode when at least one switch in the first inverter fails.

Abstract: An isolated DC/DC converter includes: DC/AC converter; an isolation transformer; a rectifier circuit; and a control unit. The control unit includes a DC input power calculation unit that calculates a DC input power of the DC/AC converter; a first adjustment unit that calculates a DC input power command value such that a DC output voltage detection value follows a DC output voltage command value; an input power limit unit that limits an upper limit value of the DC input power command value to a predetermined value and output the DC input power command value; a second adjustment unit that calculates a DC output power command value such that a DC input power calculation value follows the DC input power command value; and a drive pulse generation unit that generates drive pulses for semiconductor switching device based on the DC output power command value.

Abstract: An actual rotation speed of the asynchronous motor is detected according to the given rotation speed thereof. A given voltage of the asynchronous motor is obtained according to a vector control algorithm and a PI-IP control algorithm and is used as a reference output voltage of the BBMC. A duty cycle of a power switch tube in the BBMC is obtained according to a finite-time control algorithm by taking capacitor voltages and inductor currents in the BBMC as control variables of the speed regulation system. The conducting time of the power switch tube in the BBMC is controlled according to the duty cycle and an output control signal of a corresponding switching cycle, so that an output voltage consistent with its reference output voltage is obtained at an output end of the BBMC, so that the actual rotation speed of the asynchronous motor accurately tracks the given speed.

Abstract: An inverter system for a vehicle includes: an energy storage device configured to store electrical energy, a first inverter including a plurality of first switching elements and configured to convert the electrical energy stored in the energy storage device into alternating-current (AC) electric power, a second inverter including a plurality of second switching elements different from the plurality of first switching elements, a motor configured to be driven by receiving the AC power converted by the first inverter and the second inverter, current sensors disposed between the first inverter and the motor and the second inverters and the motor, respectively, and configured to detect a current input to the motor, and a controller configured to generate a pulse width modulation (PWM) signal for controlling driving of the motor.

Abstract: A method of automatically identifying an anomalous condition of an induction motor by normalizing the voltage measured across its terminals relative to the power flow to the motor or the motor's impedance. The starting and/or run current and associated voltage of the motor is measured, and a voltage variation between the measured voltage and the motor's rated voltage is determined. The power flow or impedance at the voltage variation is calculated to determine an expected power flow or impedance at the measured voltage variation. The actual power flow or impedance is compared against a nominal or expected power flow or impedance or a statistical comparison is carried out on a historical set of power flow or impedance values within an expected range at the voltage variation. When the measured values deviate from the expected ones, an alarm is triggered to indicate a potential anomaly with the motor or external thereto.

Abstract: A method for operating a self-propelled cleaning device, in particular a vacuuming and/or wiping robot, the cleaning device traveling in one or more rooms on the basis of a stored room map and, if necessary, carrying out cleaning jobs. The cleaning device furthermore receives information from a fire sensor, in particular initiates an emergency call in the event of a fire alarm. In order to devise a method which offers active help to individuals present in the rooms, the cleaning device, in the event of a fire alarm, outputs an acoustic and/or optical signal and moves toward an emergency exit or toward a safe location starting from its current location.

Abstract: A method for conducting testing of an electric motor to obtain performance curves, including locked rotor data, is provided.

Abstract: A method for regulating operation of an induction motor having a rotor includes calculating a rotor flux angle error value, via a flux observer of a controller, using estimated d-axis and q-axis flux values of the rotor, estimating rotor position using a position observer of the controller, and calculating slip position of the rotor using d-axis and q-axis stator currents. The method also includes estimating a rotor flux angle as a function of slip position and estimated rotor position, calculating a corrected rotor flux angle by selectively adding the rotor flux angle error value to the estimated rotor flux angle, and controlling output torque of the motor using the corrected rotor flux angle. A logic switch may be used to selectively add the rotor flux angle.

Abstract: A control device repeats learning of: calculating an allowable condition for speed variations during a processing operation based on an allowable condition for processing error; setting an operating speed change rate used to increase or reduce an operating speed of a robot mechanism unit using a calculated allowable condition for speed variations; and, while increasing or reducing the operating speed change rate over a plurality of repetitions within a range not exceeding a maximum value of the operating speed change rate and within a range of an allowable condition for vibrations occurring in a control target, calculates a new correction amount based on an amount of difference between a position of the control target detected based on a sensor and a target position, and a previously-calculated correction amount.

Abstract: A power electronics unit for driving an electric machine excited by permanent magnets and including a rotor and a stator having at least one stator winding, comprising at least one power switch designed to drive the stator winding, and an overvoltage protection device to protect the power switch from overvoltage. The overvoltage protection device comprises a phase voltage detecting device associated with the power switch as well as a short-circuit switching circuit which, when a predetermined phase voltage threshold value of the phase voltage detected by the phase voltage detection device is reached or exceeded, is adapted to be activated for short-circuiting the stator winding associated with the power switch. The short-circuit switching circuit comprises the power switch designed to drive the stator winding.

Abstract: This invention provides a frequency converter and bypass frequency conversion control system, and its switching control method, belonging to the technical field of motor drive control. The frequency converter of this invention accesses a network voltage signal with a corresponding first frequency and first phase, wherein the frequency converter is configured to be able to operate in tracking and synchronization mode, and in tracking and synchronization mode, the frequency converter tracks the first frequency and first phase of the network voltage signal in order to basically synchronize the second frequency and second phase of its output voltage signal with the first frequency and corresponding first phase of the network voltage signal. The frequency converter of this invention achieves simple, low cost, fast synchronization with good synchronism.

Abstract: An air conditioner includes a controller that controls an inverter on the basis of an instruction received by a receiver. The controller includes: a rotational speed acquisition unit that acquires a specific rotational speed corresponding to a combination of an air volume and an air speed; a correction value acquisition unit that acquires a specific correction value by determining an operation mode, presence or absence of a power saving mode, and presence or absence of a sleeping mode; and a selection unit that selects three-phase operation when the specific rotational speed is lower than a threshold calculated by adding the specific correction value to a fixed value, or selects two-phase operation when the specific rotational speed is higher than or equal to the threshold.

Abstract: A machine learning device of a controller observes data on a movement speed of each motor of a robot and an adjustment amount of the movement speed, a target speed of a tip end of the robot, and a movement path proximate to the tip end of the robot, as state variables expressing a current state of an environment, and acquires determination data indicating an appropriateness determination result of the movement speed of the tip end of the robot. Then, the machine learning device learns the target speed data, the movement speed data, and the movement path data in association with the adjustment amount of the movement speed of each of the motors of the robot by using the observed state variables and the acquired determination data.

Abstract: API duty calculation unit of a microcomputer that performs control at a predetermined control period calculates a duty ratio of a voltage applied to a coil of a motor from a target rotation speed and an actual rotation speed calculated by a number-of-rotation information unit. The PI duty calculation unit generates a rectangular wave signal having a period according to one frequency selected from plural predetermined frequencies together with the start of one control period and indicating the calculated duty ratio, and outputs the rectangular wave signal to a PWM duty calculation unit. The PWM duty calculation unit generates a PWM signal for controlling an inverter circuit based on the rectangular wave signal output by the PI duty calculation unit and position information of a rotor of the motor calculated by an electrical angle position information unit.

Abstract: A survey voltage transmitter includes a diode, a resistor, a first connection wire connected to a hot wire of AC power at a place, a second connection wire connected to a neutral wire of the AC power, a switching unit for turning on/off a circuit connected between the hot wire and the neutral wire to control a current flow through the diode and the resistor connected in series, a switching control unit for controlling a switch time of the circuit by providing a time control signal to the switching unit to turn on the circuit at a predetermined phase angle of the AC power and turn off the circuit before a half wave extinction phase angle of the AC power, and a coding unit for controlling the switching control unit to generate the current flow or not and for generating a series of logic values corresponding to the current flow.

Abstract: An apparatus and a method for testing a stator core of a generator are presented. The apparatus includes a power supply. The power supply provides an excitation current having a base frequency. A frequency convertor is connected to the power supply. The frequency convertor converts the base frequency of the excitation current to an excitation frequency that is greater than the base frequency. An excitation cable connects the frequency convertor to a rotor at two axial ends. The rotor is excited by the excitation current with the excitation frequency as a single excitation winding for simulating an operation state of the generator causing hot spots on the stator core without overheating the rotor.

Abstract: A synchronization control system includes: a first slave station; a second slave station; and a master station, wherein the master station includes: a first command data generating unit that generates the first command data; a feedback data filter that extracts and outputs a frequency component in a first frequency domain from feedback data; a command data filter that extracts and outputs a frequency component in a second frequency domain higher than the first frequency domain from the first command data; an adding unit that adds data output from the feedback data filter and data output from the command data filter, and outputs addition data that is a result of the addition; and a second command data generating unit that generates the second command data on the basis of the addition data.

Abstract: The invention relates to an electromechanical assembly comprising: an alternator with a wound rotor; a regulator acting on the excitation of the alternator; a rectifier at the outlet of the alternator, supplying a rectified voltage to a continuous bus; and a booster circuit connected by means of a filter to the outlet of the alternator and supplying a voltage to the continuous bus.

Abstract: A method for checking an operation of an electric machine, which has three phases. For pulses of a first electric variable of the three phases, a pulse width modulation is carried out. Depending in each case on a positioning of electromechanical components of the electric machine with respect to one another, the first electric variable has a pulse with a longest pulse width for a first of the three phases, a pulse with an intermediate pulse width for a second of the three phases, and a pulse with a shortest pulse width for a third of the three phases. A cycle of the pulse width modulation is delimited by two points in time.

Abstract: A controller of a hybrid vehicle includes: a control unit configured to activate a starter device for starting any one of a drive motor and an engine by stepping up electric power from a battery by a voltage transformer. The control unit includes a limitation part that limits passing power of the voltage transformer when the temperature of the voltage transformer rises, and a calculation part that obtains a maximum electric power that can be supplied to the drive motor when the starter device is activated, by subtracting a consumed power of the starter device from limited power during limitation of passing power by the limitation part. The control unit activates the starter device and starts the engine, when required power of the drive motor reaches the maximum electric power calculated by the calculation part during limitation of passing power by the limitation part.

Abstract: A measuring system, during a measurement process thereof, uses a phase-locked loop mechanism of a stator phase voltage and a stator phase current of a three-phase AC motor to effectively remove harmonics and to sense and obtain the amplitude effective values of the phase voltage and the phase current of the three-phase AC motor and the phase difference between the phase voltage and phase current. Therefore, the measuring apparatus is capable of quickly and accurately calculating the input power of the motor without having to measure the parameters of the motor.

Abstract: A power switching control apparatus includes a current measurement unit that measures the current of a main circuit; a current estimation unit that detects a fault current on the basis of a current measurement value and estimates a future current waveform on the basis of a current waveform measured in a given duration after the detection; a target opening time determination unit that uses a current zero point obtained from the estimated current waveform, a predicted opening time, and a given minimum arc duration so as to determine a time by subtracting a sum of the opening time and the minimum arc duration from the current zero point as the target opening time; and an opening control unit that waits until the nearest one of the target opening times is reached and transmits an interruption control signal when the target opening time is reached.

Abstract: A circuit and method for converting an input AC voltage of a source to an output AC voltage of a destination is disclosed. The circuit may include a main switch cell coupled to the source, a freewheeling switch cell coupled to the main switch cell, a first inductor coupled to the main switch cell, the freewheeling switch and the destination, and a second inductor coupled to the first inductor, the main switch cell, the freewheeling switch and the destination. The circuit may also include a plurality of current paths when at least one of the main switch cell and/or the freewheeling switch cell is on. In some implementations, the main switch cell and the freewheeling switch cell are controlled using a switching method.

Abstract: The invention relates to a method for determining a rotor position of a rotatory, multi-phase, electronically commutated electric machine (1). Said electric machine (1) comprises several phase windings (4) which can be supplied with current by means of phase connectors. Said method consists of the following steps: phase currents and phase connections are identified on phase connections of the electric machine (1); the induced currents on the phase connections of the electric machine (1) are determined from the identified phase currents and phase flows; the identified current indicator of the induced current is provided with respect to a Cartesian coordination system which is fixed to a stator by the induced currents; the position of the rotor is identified as a space indicator angle of the current indicator of the induced current provided with respect to the Cartesian coordination system which is fixed to the stator.

Abstract: A system and method for dynamically optimizing flux levels in electric motors based on estimated torque. Motor parameters and motor equations are used to estimate operating characteristics and to set current and voltage limits which define an optimal flux operating range for a given speed and torque of the motor. A slope of a linear flux gain is determined within the defined operating range at different speeds of the motor. The determined slopes for the different speeds are saved in a memory element. A control element determines and achieves an optimal flux level for the motor by accessing the table to identify a specific slope which corresponds to an actual speed of the motor, multiplying the slope by the estimated torque and adding an offset value to determine a phase current component value associated with the optimal flux level, and applying the determined phase current component value to the motor.

Abstract: Angular speed of a rotor of an induction motor without an encoder for rotor position and speed sensing is controlled by first sensing stator currents and voltages of the induction motor. A dynamic gain estimator is designed by applying a state transformation to a model of the induction motor. A states of the induction motor is estimated by applying the dynamic gain estimator to the currents and the voltages, and then the state is used to control the angular speed of the rotor of the induction motor.

Abstract: The present invention concerns a method of detecting electric variables of a three-phase AC network having a first, a second and a third phase, including the steps of measuring a respective voltage value of the first, second and third phases in relation to a neutral conductor at a first moment in time, transforming the three voltage values of the first moment in time into polar co-ordinates with a voltage amplitude and a phase angle, repeating measurement and transformation for at least one further moment in time, and determining the currently prevailing frequency, voltage amplitude and/or phase angle of at least one of the phases from the voltage values transformed into polar co-ordinates.

Abstract: Representative implementations of devices and techniques provide optimized control of a three-phase AC motor. A field oriented control (FOC) arrangement uses optimization components and techniques to improve power efficiency of the motor, with fast control response over a full range of motor speeds.

Abstract: A computer-implemented method for estimating a rotor speed of an alternating current (AC) machine is provided. The method includes determining a stator flux signal based on signals of voltage and current inputs to the AC machine, and determining a rotor flux signal of the AC machine based on the determined stator flux signal. The method includes determining an electrical angle signal based on the determined rotor flux signal, and deriving an electrical frequency signal from the determined electrical angle signal. Subsequently, the method includes sampling the derived electrical frequency signal at a predetermined sampling rate, and storing a predetermined number of sample values. The method further includes evaluating a median value of the predetermined set of electrical frequency sample values, determining a slip frequency value of the AC machine, and determining the rotor speed of the AC machine by subtracting the slip frequency value from the electrical frequency median value.