Abstract: In a calculation for estimating axis error in a permanent magnet motor, a d-axis commanded voltage value is added to the product of three signals, which are a q-axis detected current value or commanded current value, an inductance value, and an estimated speed value, and then the resulting value is divided by the product of a commanded speed value ?r* and induced voltage constant Ke* or an arctangent calculation is performed in the same way, instead of using a resistance setting.

Abstract: A control apparatus and a control method for an AC electric motor detect DC bus current plural times at predetermined intervals during first and second predetermined periods and multiply vectors having integrated values of detected values during respective periods as elements by an inverse matrix of a matrix having integrated values during respective periods of sine and cosine functions of output voltage phase of an inverter at the moment that detection is made as elements to thereby estimate reactive and active currents.

Abstract: It is attained by being provided with a motor constant calculation unit for calculating electric constants of a motor, and by correcting setting values of electric constants defined on one of the axes of two orthogonal axes, by a functional expression using a state variable defined on the same axis, and by correcting them by a functional expression using a state variable defined on the other axis.

Abstract: A sinusoidal signal is superimposed on a current command value of a q-axis (torque shaft) supplied from a host, and according to the resulting current command value, the output voltage of a power converter is controlled. For the calculation of the superimposed signal added to the current command value of the q-axis, with the use of the ripple component information of induced voltage coefficients of the d-axis and q-axis of the rotating coordinate system of a permanent magnet motor, the current command values of the d-axis and q-axis, an average value of induced voltage coefficients of the d-axis, and inductance values of the d-axis and q-axis, the sinusoidal superimposed signal is calculated and added to the above-described current command value of the q-axis.

Abstract: A torque ripple suppression control device for a permanent magnet motor includes a current command conversion unit that outputs a current command value, a position detector that detects a rotational position of the permanent magnet motor, a current detection unit that detects a current at the permanent magnet motor, an induced voltage coefficient setting unit that outputs an information signal related to an induced voltage coefficient for an induced voltage at the permanent magnet motor, a torque ripple suppression operation unit that outputs a current correction command value for the permanent magnet motor, a current control operation unit that outputs a voltage command value based upon addition results obtained by adding together the current command value and the current correction command value and the current detection value, and a power converter that outputs a voltage with which the permanent magnet motor is to be driven.

Abstract: A semiconductor power converter includes a power converter for converting direct current to three-phase alternating current or vice versa; a means for detecting a current in an alternating current side of the power converter; a means for providing a current reference in the alternating current side of the power converter; a current controller for calculating a voltage reference in the alternating current side of the power converter to match the current reference and a value of the detected current; and a pulse width modulation means for controlling the power converter through pulse width modulation based on the voltage reference, wherein the current reference is used in place of the value of the detected current for at least one phase current among three phase currents in the alternating current side.

Abstract: If magnitude relations between the output terminal voltage based on a DC negative terminal of the inverter and a threshold voltage that is a fixed value are compared, polarity thereof is changed at a predetermined rotor phase. The magnitude relation, for example, is detected by an inexpensive and simple apparatus such as a level shift circuit and a NOT circuit. The rotor phase of the permanent magnet synchronous motor is inferred on the basis of changes in the magnitude relation and if it is differentiated, a rotation speed is inferred. If the inferred values of the rotor phase and rotation speed are fed back to synchronous operation or vector control, the free-running permanent magnet synchronous motor is restarted.

Abstract: A controller and a constant measuring apparatus have a means for supplying a synthesized current, resulting from superimposing an AC current to a DC current, from an inverter and for changing the DC current component of the synthesized current continuously or discontinuously. Accordingly, the controller and constant measuring apparatus can measure inductances, which are electric constants of the AC motor, with high accuracy and can use the measured inductances for control.

Abstract: In a system in which current is detected in an inexpensive manner or in a system in which a position detector is omitted, the present invention provides a high-efficiency vector controller for a permanent magnet motor that can minimize current at the same torque even when there is setting error (R?R*) in resistance. Even when a current value commanded for the d-axis is set to zero, a virtual inductance value calculated from a detected q-axis current value is used for output voltage value calculation and phase error estimation calculation; so even if there is setting error (R?R*) in resistance, current can be minimized at the same torque and thereby the present invention can provide a high-efficiency vector controller for a permanent magnet motor.

Abstract: In a driving system for an inverter that uses a diode rectifying circuit to convert a single-phase or three-phase AC voltage to a desired DC voltage and drives a permanent magnet motor, a DC-voltage pulsating frequency is estimated from a pulsating frequency setting calculated from the power supply frequency of an AC voltage and the detected current values of the inverter, and the resulting estimated pulsating frequency value and detected current values are used to correct the output voltage of the inverter.

Abstract: When output voltage V1 of an electric power converter reaches a prescribed voltage V1*ref, a difference between V1 and V1*ref is integrated to correct a commanded torque to ?o* (?*=?o*+??).

Abstract: A motor control apparatus which controls an output voltage reference for an inverter driving a permanent magnet synchronous motor based on d-axis and q-axis current references, d-axis and q-axis current detected values, and a computed frequency value. When a torque reference specifying torque greater than maximum torque that the motor can output is input, a limit value for a phase angle that is a deviation between a rotation phase reference of control and a rotation phase value of the motor is varied depending on a quantity of the predetermined state.

Abstract: The invention relates to a speed control method of a magnetic motor and is capable of providing a speed controller of the magnetic motor realizing highly stable, highly efficient and highly responsive control characteristics even around critical torque of the motor. When an excessive torque command value (or a q-axis commanded current value) greater than a torque maximum value (or a q-axis current) that can be outputted by the motor is required, an input of speed control is limited so that the q-axis commanded current value does not increase up to a limit value.

Abstract: Current command values are used instead of detected current values to estimate axis error by calculation. An axis error command value is generated according to a speed command value, and a difference between the generated axis error command value and the estimated axis error value is used to control an estimated frequency value.

Abstract: A motor control system includes a power converter, a vector controller for controlling the power converter, an axial error estimating operation for estimating an axial error which is a deviation between the phase estimation value and phase value of the motor, and a rotational speed estimating computing unit 5 for performing control so as to equalize the estimation value to a command of the axial error, a motor constant identification computing unit. The motor constant identification computing unit identifies a motor constant with a q-axis voltage component and a rotational speed identified value or a rotational speed command to reflect the identified motor constant in the vector controller.

Abstract: A motor controller capable of suppressing a large speed change generated at the time of changeover from a synchronous operation mode to a position feedback operation mode and implementing even acceleration characteristics regardless of the load torque by estimating a torque of a permanent magnet motor in the synchronous operation mode for driving the permanent magnet motor and setting an initial value of a current command value in a position sensor-less operation mode on the basis of information of the torque estimated value.

Abstract: An apparatus for controlling the drive of an electric motor, having a current detector for detecting the current through an externally connected electric motor; a controller for generating a control signal to control the electric motor on the basis of the current detected by the current detector and the speed command for specifying the rotational speed of the electric motor; wherein the apparatus includes a load estimator for estimating the mechanical load condition associated with the electric motor on the basis of the current detected by the current detector and the speed command, and the controller controls the electric motor current on the basis of the detected current, the speed command and the estimated load condition.

Abstract: A vector control apparatus for a permanent magnet motor operated in the region of weak magnet field, wherein when the output voltages of the power converter saturate, the phase error command value represented by the difference between the angular position of the reference axis for control and the angular position of the motor magnetic flux axis is generated on the basis of the difference between the q-axis current command value and the detected value of the q-axis current, and the command values for the output voltages of the power converter are corrected by using the phase error command value, whereby a highly responsive torque control with high precision can be achieved.

Abstract: In a calculation for estimating axis error in a permanent magnet motor, a d-axis commanded voltage value is added to the product of three signals, which are a q-axis detected current value or commanded current value, an inductance value, and an estimated speed value, and then the resulting value is divided by the product of a commanded speed value ?r* and induced voltage constant Ke* or an arctangent calculation is performed in the same way, instead of using a resistance setting.

Abstract: It is attained by being provided with a motor constant calculation unit for calculating electric constants of a motor, and by correcting setting values of electric constants defined on one of the axes of two orthogonal axes, by a functional expression using a state variable defined on the same axis, and by correcting them by a functional expression using a state variable defined on the other axis.