Abstract: A method for estimating the output flow rate provided by a pump in a system including the pump, an upstream pipe and a downstream pipe, by using pressure information coming from a first downstream pressure sensor placed on the downstream pipe at a first distance from the pump and a second downstream pressure sensor placed on the downstream pipe at a second distance from the pump for calculating the output flow rate.

Abstract: A cover box including two half-shells configured to accommodate at least part of an electrical connection, each half-shell including: a recess, opening into the interior volume; and latching means. The half-shells are able to be assembled together by cooperation of latching means of a first half-shell with the latching means of a second half-shell, the recess of the first half-shell facing the recess of the second half-shell when the half-shells are assembled together. The electrical connection includes a screw and a nut cooperating with the screw, the nut being able to be engaged in the recess of the first half-shell, a head of the screw being able to be engaged in the recess of the second half-shell.

Abstract: Examples include a method for detecting the evolution of the magnetic state of a permanent magnet rotor. The method includes, during a first and a second time interval, applying a respective direct current command signal to the motor to estimate a respective stator resistance value, and applying a respective alternative voltage command signal corresponding to a specific direct axis stator current value to the motor while measuring respective stator phase current values. The method also includes determining respective rotor flux parameters as a function of the measured respective stator phase current values and of the estimated respective stator resistance values. The method further includes comparing the respective rotor flux parameters. The first and second time intervals are separated by a time period which exceeds at least 100 times any one of a first or second interval length.

Abstract: A diagnostic process for a cabling of a three phase motor in a “delta-inside” configuration with a soft starter to a three phases power supply including, after cabling a soft starter with the thyristor outputs of the soft starter to the motor windings inputs, cabling the motor windings outputs to the main phases and powering the power supply or prior to startup of the motor, at least a test process including: measuring with voltage sensors, connected to the Mains inputs, voltage sensors connected to the motor outputs of the thyristors of the soft starter and observer functions within the soft starter the frequency, voltage and phase angle of the Mains and motor lines in order to compare such voltages and phases without triggering the thyristors; calculating the differential angle ?? between the motor electric rotation angle ?M and the Mains rotation angle ?A; comparing the calculated differential angle ?? with known differential angles corresponding to a correct cabling differential angle and faulty cablings

Abstract: A control process for a control system of a load system connected to an electric grid through the control system wherein the control process is configured to provide one or more adapted drive commands to the control system dependent on the grid frequency. The control system may include an inverter, a converter, a thyristor bridge or contactors and the load may be a motor. A control device for implementing the control process also is disclosed.

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: Examples include a method for controlling a variable speed drive of an electric motor. The variable speed drive is connected to a torque sensor for sensing a torque supplied by the electric motor. The method includes performing, by the electric motor, a predetermined torque sequence. The method also includes measuring, by the torque sensor, a measured torque sequence corresponding to the predetermined torque sequence, and comparing the predetermined torque sequence and the measured torque sequence. As a result of the comparison, one or more torque sensor transfer function parameters are determined.

Abstract: A method for determining mechanical degradation of parts of a centrifugal pump having a fluid inlet, an impeller, and a fluid outlet. The method includes calculating at least one of a wear-ring clearance effect and an impeller wear effect. The wear-ring clearance effect is calculated using measurements of an actual pump flow rate Qp and actual pump power Pwp, calculating an internal flow rate of the pump QpPwp, calculating the mechanical power PwQp that should be used if the pump worked as specified in a theoretical curve, and calculating a difference between a theoretical Head and an internal Head Hpth?HpPwp to obtain the loss of Head due to the wear-ring clearance.

Abstract: Examples include a method for controlling a variable speed drive driving a three-phase electric motor. The method includes measuring current signals in the windings of the electric motor, and determining a current parameter associated to the electric motor based on the current signals. The current parameter includes either a current offset of at least one winding of the electric motor in relation to a zero-current value, or a current misbalance between windings of the electric motor. The method further includes determining an amended control law of the electric motor for decreasing the determined current parameter, and applying pulse width modulation signals on insulated gate bipolar transistors of the inverter based on the amended control law.

Abstract: A method to estimate a remaining of useful life of a DC link capacitor of a converter through determination of a minimum value Clim of its capacitance C under which performances of the converter are considered as insufficient. The method includes implementing a real time model including a motor drive model and a capacitor model using decreasing capacitor values to calculate a forecasted minimum capacitance Clim sufficient for keeping at least one of DC voltage ripple, motor current ripple, speed ripple or torque ripple under a specified value. The method further includes calculating a time difference between a time Tactual, for which the capacitor has an estimated capacitance based on an ageing curve Ccurve, and a time Tlim for which the capacitor will have the forecasted minimum capacitance Clim, with the use of an ageing curve Ccurve of the capacitor and estimating the remaining useful life of the capacitor Tactual-Tlim.

Abstract: A method for controlling a hydraulic pumping system that includes a centrifugal pump operating at a functional point. The method uses parameters of the centrifugal pump at the functional point and end-of-lines characteristics of the centrifugal pump to determine an updated Net Positive Suction Head Required, NPSHr, value.

Abstract: Examples include a method for determining a permanent magnet flux state of a rotor in a synchronous motor using a VSD. The method includes obtaining d-axis and q-axis inductance values of the motor, fixing a non-zero stator current magnitude and controlling a motor speed using a speed loop regulation in a stator current angle ? polar coordinate frame to reach a zero motor speed steady state corresponding to the fixed non-zero stator current magnitude, to the obtained d-axis and q-axis inductance values, and to a no-load situation. The method further includes recording coordinates of the reached steady state.

Abstract: Examples include a method for determining a static load torque at standstill applied to a salient pole synchronous motor. The method comprises fixing a first non-zero torque-producing current component and controlling motor speed using a speed loop regulation of a first regulated component to reach a first zero motor speed steady state corresponding to the fixed first non-zero current component, the motor being subjected to the specific static load torque. The method further comprises controlling motor speed using a speed loop regulation of a second regulated component to reach a second zero motor speed steady state corresponding to a fixed second non-zero torque-producing current component, the motor being subjected to the specific static load torque, the first non-zero current component and the second non-zero current component corresponding to different values. The load torque is estimated as a function of components of the first and second zero motor speed steady states.

Abstract: A harmonic filter including: a n-pulse transformer of a three-phase current, n being a multiple of 6; and n/6, or n/6-1, bridge rectifiers at the output of the n-pulse transformer.

Abstract: A method for determining a resonance frequency of a mechanical system including an electric motor coupled to a mechanical load. The method includes starting the motor by providing a supply voltage using a motor controller, and once the electric motor is running at a predefined target rotational speed, applying a first excitation signal comprising a voltage pulse superimposed to the supply voltage. The method further includes measuring a mechanical response of the mechanical system, using a measurement system coupled to the motor, and analyzing the measured response, to determine at least one resonance frequency of the mechanical system.

Abstract: Examples include a method for controlling a variable speed drive driving an electric motor. The variable speed drive is connected to an electric power source and comprises a passive DC-link and an inverter stage controlled by a first controller of the variable speed drive. The passive DC-link is connected to the inverter stage. The method comprises running the electric motor to reach a steady-state operating point, measuring a plurality of values of current or voltage of the passive DC-link, and computing, by a second controller, a frequency spectrum of the DC-link based on the plurality of values of current or voltage measured. The method further comprises detecting a specific resonance frequency by comparing amplitudes of the frequency spectrum to a predetermined pattern, and modifying filter parameters of a digital filter of the DC-link or control parameters of a control law of the electric motor based on the specific resonance frequency.

Abstract: A method for detecting a structural fault of an electric motor. The method includes: (i) acquiring a measurement signal of a physical parameter representative of the rotation of the electric motor, (ii) obtaining the high frequency component of the measurement signal, resulting in a corrected signal, (iii) applying a set of band-pass filters to the corrected signal resulting in a set of filtered corrected signals, (iv) determining a stator frequency and a rotor frequency, (v) computing a frequency signature vector, (vi) computing a temporal symptom vector from the frequency signature vector and the set of filtered corrected signals, and (vii) detecting a structural fault of the electric motor from the determined temporal symptom vector and from a classifier model.

Abstract: Examples include a method for controlling a synchronous motor using a variable speed drive. The motor includes a permanent magnet rotor generating a magnetic flux. The method includes applying a predefined electrical command signal to the motor and estimating a motor speed in response to the applying of the predefined electrical command signal. The method also includes reaching a desired estimated motor speed and, in response to reaching the desired estimated motor speed, estimating a parameter related to the magnetic flux of the permanent magnet rotor. The method further includes recording the estimated parameter.

Abstract: A variable speed drive includes an output terminal for delivering a drive voltage; a power inverter for generating the drive voltage; a drive controller for controlling the generation of the drive voltage; and a current sensor for providing a drive current intensity signal to the drive controller. The drive controller includes a PWM generator; a control law module; and a state variable estimator estimating a state variable of the controlled AC electric motor.

Abstract: A method for adapting a deceleration of a motor powered by a variable speed drive, the variable speed drive comprising a plurality of at least N low-voltage power cells linked in series, N being greater than or equal to 1, the method comprising the following operations during a period of deceleration of the motor: determination of at least one average motor voltage over a given period as a function of motor voltage values measured at the terminals of the motor over the given period; as a function of the determined average motor voltage, determination of an average rectified voltage value, wherein a rectified voltage corresponds to a voltage obtained at the output of a rectifier of each power cell; and adaptation of the deceleration of the electrical device as a function of the average rectified voltage value.