972results about "Motor control for motor oscillations damping" patented technology

A motor control device capable of suitably inhibiting the pulsating torque of an alternating-current motor is provided. The motor control device comprises an axis error inference machine (30) which infers an axis error based on a current value of an inverter, detected by a current sensor (2); a Fourier rectification machine (316a) which extracts an axis error vector from the time-base changes of the axis error; an integral control machine (316b) additionally provided with a circular amplitude limiter, which is used to calculate a correction current vector for offsetting the pulsating torque, wherein a circle with a set amplitude limiting value serving as the radius is used as the base for limiting the movement of the correction current vector, and the integral control machine (316b) additionally provided with the circular amplitude limiter performs the circular amplitude limiting for limiting the movement of the correction current vector so as to enable the deflection angle of the correction current vector to be close to the deflection angle of the axis error vector.

In an operation range of an actuator subjected to quick acceleration and deceleration, a motor drive apparatus, an electric actuator and an electric power steering apparatus capable of continuous torque control up to the high drive speed and high torque area. A controller comprises a voltage saturation detecting means for detecting the voltage saturation of the output voltage of an inverter circuit, based on the battery voltage, and a waveform controller that converts the drive waveform of the inverter circuit into the waveform created by superimposing harmonics of high odd-numbered order on a sinusoidal wave as a fundamental wave of the modulated wave modulated by a PWN carrier wave; and continuously changes the ratio of superimposing the high-order harmonics in response to the voltage saturation detected by a voltage saturation detecting means. This arrangement allows the controller to continuously change the drive waveform of the inverter circuit.

A vehicle includes a motor for driving wheels WH, an inverter to drive the motor, and a control device to perform PWM control of the inverter. The control device performs synchronous PWM control in a case where an electric current supplied to the motor by the inverter or torque generated in the motor is larger than a threshold value; and performs the synchronous PWM control or non-synchronous PWM control in a case where the electric current or the torque is smaller than the threshold value and sets carrier frequency or a pulse number of the PWM control to be higher than the case where the electric current or the torque is larger than the threshold value. Thereby, it is possible to provide a vehicle of achieving reduction of noise, reduction of cost and improvement of fuel consumption in a balanced manner.

A control device for an electric power steering apparatus includes a control unit which controls a motor giving steering assist force to a steering system according to a current command value computed based on steering toque and vehicle speed in a vector control manner and an advance angle map for compensating for a phase lag occurring in a motor current relative to the current command value. Advance angle compensation is made for the current command value based on the advance angle map.

Disclosed herein is a method for controlling an electric power steering system, wherein a motor is controlled by vector control and driven by a current command value calculated on the basis of a parameter such as a steering torque to provide a steering assist power to a vehicle steering system, and further wherein the current command value is limited on the basis of desired output characteristics and a desired angular speed during a field-weakening control and a non-field-weakening control of the vector control.

A control unit of an electric power converter, which is used in a three-phase motor having two winding wire systems, performs for a first duty instruction signal regarding a voltage applied to a first winding wire group a flatbed two-phase modulation process, and performs for a second duty instruction signal regarding a voltage applied to a second winding wire group a flattop two-phase modulation process. By phase-shifting the second duty instruction signal by 30° from the first duty instruction signal, a timing of maximum value of the first duty instruction signal is shifted from a timing of minimum value of the second duty instruction signal. Even when the maximum value is greater than a center output value and the minimum value is smaller than the center output value, overlapping of capacitor discharge is avoided, thereby reducing a ripple electric current.

Provided are a motor controller for suppressing a torque pulsation with a simple configuration and obtaining a sufficient output torque in the case of an open-type fault occurring in any one of windings of a motor and inverters, and an electric power steering device using the motor controller. In the motor controller for controlling a current supplied from and a voltage applied from a power source with respect to the motor including winding sets of a plurality of systems, when a fault determination unit (31) determines the occurrence of the open-type fault, the supply of the currents to the windings of one of the systems in which the fault has occurred is stopped by control performed on switching elements included in the inverter of the faulty system, whereas the supply of the currents to the windings of the normal system in which the fault has not occurred is continued.

An electric power steering apparatus includes: a rotation speed detecting unit which detects a rotation speed of the electric motor; a compensation current determining unit which determines an instruction value of a compensation current to flow through the electric motor to suppress torque ripples due to distortion of an induced electromotive force waveform of the electric motor in accordance with a load correspondence quantity as a physical quantity corresponding to a load of the electric motor and the rotation speed detected by the rotation speed detecting unit; a correcting unit which corrects the current target value on the basis of the compensation current instruction value; and a control unit which performs a feedback control on the electric motor so that a current having the current target value as corrected by the correcting unit flows through the electric motor.

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 control for an electric motor is utilized to avoid operation in or near the resonance frequencies for the electric motor and its associated system components. The resonance frequencies can be identified experimentally at the design stage, or during operation of a component and electric motor. During start-up, shutdown or frequency adjustment, the control drives the speed through the resonance frequency zones more rapidly, and also avoids operation in or near those resonance frequencies during steady state operation. In disclosed embodiments, the electric motors are associated with fans, pumps and compressors in a refrigerant system.

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 object of the present invention is to provide a motor control apparatus having excellent harmonic current control performance, that can simplify circuit configuration and circuit processing while, at the same time, achieving improved control accuracy. To achieve this object, detected motor currents are converted by coordinate converters 19 and 20 into an nth-order dq-axis signal and an mth-order dq-axis signal, and their DC components are extracted by low-pass filters 22 and 23; then, the differences of the DC components relative to respective command values are converted back into three-phase AC signals to control the motor currents.

A motor control apparatus comprises a fundamental wave current control system that controls a fundamental wave component of a motor current in an orthogonal coordinate system which rotates in synchronization with a rotation of a 3-phase AC motor, a higher harmonic current control system that controls a higher harmonic component contained in the motor current in an orthogonal coordinate system rotating with a frequency which is an integral multiple of the frequency of the fundamental wave component of the motor current, a voltage command value generating device that generates 3-phase AC voltage command values by adding an output from the fundamental wave current control system and an output from the higher harmonic current control system, a power conversion device that converts a DC source voltage to a 3-phase AC voltage corresponding to the 3-phase AC voltage command values and outputs the 3-phase AC voltage to the 3-phase AC motor, a voltage saturation detection device which detects that an output voltage from the power conversion device is in a saturated state and a gain adjustment device that reduces a current control gain for the higher harmonic current control system if the voltage saturation detection device detects that an output voltage is in a saturated state.

A synchronous motor controlling apparatus which can be applied to the carrier synchronized position estimating method as well and have protection-related functions such as detection of inverted magnetic pole position of a motor in a simple method, and an electric motor using the synchronous motor control apparatus. A controller controls a voltage applied to an AC motor with a PWM signal. A magnetic pole position detector of the controller detects a current of the AC motor to estimate a pole position of the AC motor. A fault detector detects a fault in the estimated magnetic position of the AC motor.

A periodic disturbance observer determines real part Î_An and imaginary part Î_Bn of an estimated current including a periodic disturbance, from value of identification identifying a system transfer function of an nth order torque ripple frequency component from a command torque to a detected torque value, with a one-dimensional complex vector having a real part P̂_An and an imaginary part P̂_Bn, a cosine coefficient T_An, a sine coefficient T_Bn, and the real part P̂_An and imaginary part P̂_Bn of the system transfer function; subtracts command compensating current I_An* and I_Bn* obtained through pulsation extracting filter G_F, respectively, from the real part Î_An and imaginary part Î_Bn of the estimated current, and thereby determines estimated periodic disturbance current real part dÎ_An and imaginary part dÎ_Bn to cancel the periodic disturbance current.

A control device receives a power supply current from a current sensor and a reactor current from a current sensor and detects a maximum value and a minimum value from the reactor current and from the detected maximum and minimum values and the power supply current determines whether the reactor current traverses the zero point, and if so the control device generates and outputs a signal to an up converter which responds to the signal by stopping switching to perform an up or down converting operation.

In a case where a computing period of a torque ripple compensation section which computes current compensation values Δid and Δiq to be caused to flow into a motor in order to prevent occurrence of a torque ripple in the motor differs from a control period of a current control section which controls a feedback to the motor in such a way that current command values i*d and i*q additionally provided with the current compensation values Δid and Δiq flow into the motor, the microcomputer sets the current compensation values Δid and Δiq to zero when a rotor angular velocity ωre of the motor is equal to or greater than a first threshold value ω₁.

A first inverter and a second inverter supply two coil sets forming a three-phase motor with AC voltages, which are the same in amplitude but shifted by 30° in phase. Current detectors detect phase currents supplied from the inverters to the coil sets. Temperature estimation sections estimate temperatures of the inverters or the coil sets based on an integration value of the phase current detection values. A current command value limitation section limits upper limits of current command values of both coil sets based on the estimated temperatures Tm1 and Tm2. Thus, the inverters and the coils sets are protected from overheating without increasing torque ripple.

An electric power steering apparatus includes a steering torque detector, a brushless motor PWM-driven with a three-phase alternating motor current, a target current setting section for setting a d-axis target current value and a q-axis target current value, motor current detectors for detecting motor current values supplied to the brushless motor, a three-phase AC/d-q coordinate transformation circuit, a first deviation calculation circuit for calculating a deviation of a current value of a q-axis detection signal from the q-axis target current value, a second deviation calculation circuit for calculating a deviation of a direct current value a d-axis detection current signal from the d-axis target current, a motor control section for controlling driving of the brushless motor through a vector control process on the basis of deviation signals outputted from the first and second deviation calculation circuits, and an attenuation device provided in a feedback transmission path of the q-axis detection current signal for attenuating a high frequency noise mixed in the q-axis detection current signal.

Parameters “n”, “ad”, “pd”, “aq”, “pq” and the like of a motor parameter setting unit 4 are set so as to satisfy [Expression 23] and the like, a d-axis current command value “Idco” outputted from a d-axis current instructing unit 2 and a q-axis current command value “Iqco” outputted from q-axis current instructing unit 3 are corrected based on these parameters “n”, “ad”, “pd”, “aq” and “pq”, on a detection result of rotation angle detecting unit 11, and on the like, and a (6×n)f sine component, (6×n)f cosine component, (6×(n+1))f sine component and (6×(n+1))f cosine component of torque “T” shown in [Expression 22] are made zero. In such a way, 6×n and 6×(n+1) ripple components and the like, which are generated in a motor provided in elevator equipment or the like, are suppressed, and a torque ripple of the motor is reduced to a large extent.

The invention discloses a method, device and system for suppressing shaking of an electric automobile. The method, device and system are used for suppressing the shaking of the electric automobile andimproving the driving comfort level. The method includes the steps that a rotation speed signal of a motor is obtained; Fourier analysis is conducted on the rotation speed signal, and the frequency and the amplitude of an effective component, causing rotation speed shaking, in the rotation speed signal are obtained, wherein rotation speed shaking is shaking caused by the non-linear relationship between traction torque and the resistance moment of the electric automobile; according to the frequency and the amplitude of the effective component causing rotation speed shaking, a parameter for suppressing rotation speed shaking is obtained; according to the parameter for suppressing rotation speed shaking and the rotation speed signal, compensation torque is obtained through a differential inertial element and a band-pass filtering element; and the compensation torque and given torque are superposed so as to suppress the rotation speed shaking. Due to the fact that the shaking of the electric automobile is suppressed, mechanical resonance generated in the shaking process is reduced, and therefore hardware wear of the electric automobile is reduced.