2615results about "Motor parameters estimation/adaptation" patented technology

A variable-flux motor drive system including a permanent-magnet motor including a permanent magnet, an inverter to drive the permanent-magnet motor, and a magnetize device to pass a magnetizing current for controlling flux of the permanent magnet. The permanent magnet is a variable magnet whose flux density is variable depending on a magnetizing current from the inverter. The magnetize device passes a magnetizing current that is over a magnetization saturation zone of magnetic material of the variable magnet. This system improves a flux repeatability of the variable magnet and a torque accuracy.

A temperature estimation controller and methods are provided for controlling a torque command to prevent overheating of one or more of a plurality of phases of a permanent magnet motor. The temperature estimation controller includes a low speed temperature estimation module, a transition module and a temperature dependent torque command derater block. The low speed temperature estimation module determines a stator temperature of each of a plurality of phases of the permanent magnet motor in response to first thermal impedances measured for each of the plurality of phases with respect to a thermal neutral. The transition module is coupled to the low speed temperature estimation module and outputs the stator temperature of each of a plurality of phases of the permanent magnet motor as determined by the low speed temperature estimation module when a detected speed of the permanent magnet motor is less than a first predetermined speed. The temperature dependent torque command derater block is coupled to the transition module and derates the torque command in response to the stator temperature of one or more of the plurality of phases.

A synchronous motor drive system in accordance with the present invention detects a DC current of an inverter which drives a synchronous motor, and based on the magnitude of the current, estimates torque current components that flow through the motor, and then based on the estimated value, determines the voltage which is applied to the motor, and finally estimates and computes the magnetic pole axis located inside the motor using the estimated value of the torque current.

A constant detecting apparatus 15 comprising a detecting unit 26 and a calculating unit 27. The detecting unit 26 is structured comprising a rotation sensor 41, a torque sensor 42, a position sensor 43, a rotor temperature sensor 44, a winding temperature sensor 45, a phase voltage detector 46, and phase current detectors 47 and 47. The calculating unit 27 calculates the induced voltage constant Ke that changes depending on the motor temperature Tmag while the motor 11 is being driven based on each of the detected signals from the detecting unit 26, and at the same time, the d axis current Id and the q axis current Iq are calculated after elimination of the iron loss, and the d axis inductance Ld and the q axis inductance Lq in the actual operating state of the motor 11 are calculated.

The invention discloses an automatic regulating apparatus for controller parameters of a servo driver of a motor and a method thereof. The apparatus comprises an inertia identifier, a parameter initial regulator, a parameter checker, a parameter optimizer, a parameter saving and displaying device, a speed controller, a position controller, a torque controller, a PWM (Pulse-Width Modulation) generator and a coded disc. In the invention, the servo driver of an alternating current permanent magnet motor automatically configures the parameters of the position controller and the speed controller according to different rotary inertias of mechanic load, checks and further optimizes the automatically configured parameters through the parameter checker and the parameter optimizer so that the position response and the speed response of the servo driver are relatively optimal. The servo driver of the alternating current permanent magnet synchronous motor automatically regulates the control parameters according to work occasions and achieves ideal control effect. The whole process is manual participation free and completed fully by the servo motor of the alternating current permanent magnet synchronous motor.

A control apparatus for a brushless DC motor that rotatably drives the brushless DC motor including a rotor having a permanent magnet, and a stator having stator windings of a plurality of phases that generate a rotating magnetic field for rotating the rotor, by a current passage switching device constituted by a plurality of switching elements and performing successive commutation of current to the stator windings. The control apparatus includes: an angular error calculation device for calculating a sine value and a cosine value of an angular difference between an estimated rotation angle with respect to the rotation angle of the rotor and an actual rotation angle, based on a line voltage that is a difference between phase voltages of the plurality of phases on an input side of the stator winding and phase currents of the plurality of phases; and an observer for calculating the rotation angle of the rotor based on the sine value and the cosine value of the angular difference.

A control device has a unit for selecting each of controlled voltages outputted from an inverter to a generator, a unit for judging a polarity of a current flowing through the generator, a unit for predicting a current of the generator from each selected voltage to be outputted from the inverter in the succeeding period, while performing the prediction based on the current polarity each time the selected voltage differs from the voltage already outputted from the inverter in the present period, a unit for determining one voltage corresponding to one predicted current nearest to an instructed current among the predicted currents, and a unit for controlling the generator by controlling the inverter to change the voltage already outputted from the inverter to the determined voltage and to apply the determined voltage to the generator in the succeeding period.

A system and method for determining the stator winding resistance of AC motors is provided. The system includes an AC motor drive having an input connectable to an AC source and an output connectable to an input terminal of an AC motor, a pulse width modulation (PWM) converter having switches therein to control current flow and terminal voltages in the AC motor, and a control system connected to the PWM converter. The control system generates a command signal to cause the PWM converter to control an output of the AC motor drive corresponding to an input to the AC motor, selectively generates a modified command signal to cause the PWM converter to inject a DC signal into the output of the AC motor drive, and determines a stator winding resistance of the AC motor based on the DC signal of at least one of the voltage and current.

There is provided a controller for a motor capable of changing the phase difference between two rotors that can prevent demagnetization of permanent magnets or the rotors. The motor has two rotors each having a permanent magnet and phase difference changing driving means for changing the phase difference between the rotors. The controller has a demagnetization determining means for determining whether or not demagnetization of the permanent magnets of the rotors occurs during operation of the motor, and rotor phase difference controlling means for controlling the phase difference changing driving means to change the phase difference between the rotors from a current phase difference to a phase difference that results in a higher strength of a composite field of the permanent magnets if the result of determination by the demagnetization determining means is positive.

A system and method for measuring and controlling stator winding temperature in an AC motor while idling is disclosed. The system includes a circuit having an input connectable to an AC source and an output connectable to an input terminal of a multi-phase AC motor. The circuit further includes a plurality of switching devices to control current flow and terminal voltages in the multi-phase AC motor and a controller connected to the circuit. The controller is configured to activate the plurality of switching devices to create a DC signal in an output of the motor control device corresponding to an input to the multi-phase AC motor, determine or estimate a stator winding resistance of the multi-phase AC motor based on the DC signal, and estimate a stator temperature from the stator winding resistance. Temperature can then be controlled and regulated by DC injection into the stator windings.

A method and system for estimating a temperature of an electric machine comprising obtaining a temperature value responsive to a temperature signal from a temperature sensor, the temperature sensor is operatively connected to and transmitting the temperature signal corresponding to a measured temperature to a controller. The controller executes a temperature estimation process; and is operatively connected to a switching device, where the switching device is operatively connected between the electric machine and a power source, the switching device being responsive to the controller. Also disclosed is a storage medium encoded with a machine-readable computer program code for estimating an operating temperature of an electric machine. The storage medium includes instructions for causing controller to implement method for estimating an operating temperature of an electric machine as described above. Additionally disclosed is a computer data signal embodied in a carrier wave for estimating an operating temperature of an electric machine. The computer data signal comprising code configured to cause a controller to implement a method for estimating an operating temperature of an electric machine as described above.

An apparatus and method for determining a condition of an electric machine. Search coils are wound around stator teeth and the induced voltage is used to decouple stator and rotor fluxes. The decoupled fluxes allow for machine condition monitoring and fault diagnosis.

A method and system for estimating a parameter of an electric machine, including a controller and a switching device, the controller executes a parameter estimation process, which is responsive to at least one of: a current value and a torque command and the resultant of the parameter estimation process representing an estimated parameter of the electric machine. The parameter estimation includes a method for estimating a temperature of the electric machine comprising: a temperature sensor operatively connected to and transmitting a temperature signal corresponding to a measured temperature to a controller, which executes a temperature estimation process responsive to a temperature signal from a temperature sensor.

Axial error calculation unit is provided for estimating an axial error DELTAtheta between a d-q axis and a dc-qc axis by using Ld, Lq, Ke, Id*, Iq*, Idc and Iqc in a range of all rotational speeds except zero of a rotational speed command of a synchronous motor, Ld denoting an inductance on a magnetic pole axis d of the synchronous motor, Lq an inductance on a q axis orthogonal to the magnetic pole axis d, Ke a generated power constant of the motor, Id* a current command of the d axis, Iq* a current command on a q axis, Idc a detected current value on an assumed dc axis on control, and Iqc a detected current value on an assumed qc axis orthogonal to the assumed dc axis. Irrespective of presence of saliency, position sensorless control can be achieved in a wide range a low to high speed zone.

A drive motor control apparatus for a vehicle, wherein the vehicle has a motor and rotation detecting unit. In the apparatus, the first difference computing unit computes one of multiple first differences every time an actual detected angle of rotation of the motor becomes a corresponding representative angle during the one cycle. The first difference indicates an advancing amount of an estimated angle relative to the actual detected angle. The second difference computing unit computes multiple second differences based on the first differences of the one cycle. The second differences are adjusted in accordance with a degree of acceleration and deceleration of the motor. The adjusted second differences are used for correcting the actual detected angle of rotation of the motor.

In order to provide a driving device for a motor having a capability equivalent to conventional vector control type sensorless method by simplifying the controls structure to reduce number of parts to be adjusted, and to stabilize the control system, a driving device for a synchronous motor does not include a speed controller or a current controller, and calculates a voltage impressed on a motor on coordinate axes (dc/qc axes) based on a magnetic pole axis. For calculating a voltage command, command values such as a rotation speed command and a current command are used, and Iq* corresponding to a torque current command is calculated and provided based on a detected current value.

A technique for reconstructing phase currents based on measurements of a DC bus current. Non-observable regions of DC bus current samples to reconstruct phase currents are reduced in size by using two phase space vector modulation. The non-observable regions can be further reduced by omitting deadtime insertions for switch actuations when output current is higher than a given threshold. Voltage command vectors in non-observable areas can be constructed by two time averaged vectors one of which is constructed to obtain an observable DC bus current reflecting motor phase current. The additive vectors have the same combined time average value as that of the voltage command vector in order to preserve volt-seconds. Current samples may also be averaged to provide a more accurate reconstruction of phase current. Current samples are time delayed to avoid transients for more accurate readings. When three phase PWM inverter modulation results in inability to determine the motor phase current from the DC bus measurement, the technique includes dynamically switching to two phase PWM modulation to reduce the time interval when the motor phase current is not determinable through the DC bus current measurement.

When a rectangular wave voltage control mode is selected, a control apparatus estimates the output torque of an alternating-current motor based on the outputs of a current sensor and a rotation angle sensor, and executes torque feedback control by adjusting the phase of rectangular wave voltage based on the difference between the torque estimated value and a torque command value. The control apparatus executes a switching interruption that outputs a control command to a switching element of an inverter every 60 degrees of electrical angle, and executes an angle interruption that samples the phase currents of the alternating-current motor based on the output of the current sensor and converts those phase currents into a d-axis current and a q-axis current every predetermined electrical angle that is set beforehand. The control apparatus for the alternating-current motor then sets the predetermined electrical angle such that the number of angle interruptions between switching interruptions varies according to the rotation speed of the alternating-current motor.

An inductance parameter identification method of a synchronous motor and an implementation system thereof are provided. The method comprises: applying a three-phase balance high frequency voltage or current signal to the synchronous motor; sampling a feedback high frequency current or voltage of the synchronous motor; extracting positive sequence and negative sequence component amplitude of the feedback high frequency current or voltage which has the same frequency of the injecting voltage or current; and calculating to get d-axis inductance Ld and q-axis inductance Lq of the synchronous motor. Identification of the d-axis inductance and q-axis inductance of the synchronous motor can be implemented more accurately on a general inverter on the basis of non-increase of hardware cost. The method and system have the following advantages of implementing easily, not high demand for the motor feedback current sampling accuracy, and controlling easily for the frequency and amplitude of the high frequency voltage signal injected into the motor, and identifying to get the d-axis inductance and q-axis inductance of the motor directly no matter the motor shaft is in a free state, or in a hold tight stage, which do not affect accuracy of identification.