615results about "Observer control" patented technology

A rotary sensor that outputs two analog signals, such as one sine wave and one cosine wave and has multiple periods within one period of the electrical angle of a motor is employed. The motor is energized at each position for a specified length of time upon its startup by using multiple electrical angles corresponding to the multiple candidate absolute angles obtained from the rotary sensor signal as the initial position of the motor, and the electrical angle at which the motor acceleration becomes maximum is determined as the absolute angle. While the motor drive is in operation, on the other hand, the phase difference Δθ between the phase of the motor at the counter electromotive voltage and the control phase is directly computed from the parameters of the motor, sensed current, voltage command and angle speed so as to correct the shifted position. A high-efficiency motor drive unit with improved maintainability of rotary sensor and improved accuracy of sensing the magnet pole position of a permanent magnet synchronous motor that accelerates and decelerates very quickly in a wide range of speed is realized.

A motor drive circuit comprises positive and negative input terminals for connection of the motor circuit to a DC supply, a DC link filter connected between the input terminals: an electric motor having at least two phases, a plurality of motor drive sub-circuits, each connected to a respective phase of the electric motor and which each control the flow of current into or out of the respective phase of the motor that has been drawn from the supply through the DC link filter, and a switching means provided in the electrical path between the DC link filter and the electric motor drive sub-circuits, the switching means being movable between a closed position in which it connects the DC link filter to the motor drive sub-circuits, and an open position which isolates the DC link filter from the motor drive sub-circuits.

A motor driving apparatus includes an inverter circuit for converting an output voltage of a power supply into a three-phase AC and outputting the same to the brushless motor, a rotor position estimation unit for estimating a rotor position of the brushless motor, and an inverter control unit for controlling the inverter circuit so that the brushless motor is driven by a current based on the estimated rotor position. The inverter control unit determines an advance angle of the current supplied to the brushless motor with respect to the estimated rotor position so as to minimize a deviation between a command rpm and an actual rpm. Therefore, it is possible to perform stable weak field control for the brushless motor, independently from the input voltage of the inverter circuit, without using predetermined control variables such as table values.

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 method of controlling an electric machine that includes sequentially exciting and freewheeling a winding of the electric machine. The winding is excited in advance of zero-crossings of back emf in the winding by an advance angle, and the winding is freewheeled over a freewheel angle. The method then includes varying the advance angle and the freewheel angle in response to changes in the speed of the electric machine. Additionally, a control system for an electric machine, and a product incorporating the control system and electric machine.

A system and method for detecting input phase loss in an adjustable speed drive (ASD) includes an input unit to detect operating data from the ASD. The operating data includes a DC link current of the ASD. The system also includes a state observer that is adapted to receive the operating data from the input unit and extract a DC link capacitor current of the ASD using the DC link current. The system also includes a controller programmed to compare the extracted DC link capacitor current to a predetermined fault range and generate a fault indication of an input phase loss if the extracted DC link capacitor current is within the predefined fault range. The controller is also programmed to calculate an estimated lifespan of the DC link capacitor based on the extracted DC link capacitor current.

A method for controlling regenerative braking of a vehicle includes: initiating the regenerative braking; detecting an amount of slip of a wheel during the regenerative braking; if the amount of slip is increasing, reducing a regenerative braking torque; and if the amount of slip is greater than a set value, actuating an antilock brake system and reducing the regenerative braking torque or a hydraulic braking torque continuously until the vehicle is stopped. Alternatively, if the amount of slip is increasing, the regenerative braking torque is not reduced.

A method of controlling an electric machine that includes sequentially exciting and freewheeling a winding of the electric machine. The winding is excited in advance of zero-crossings of back emf in the winding by an advance angle, and the winding is freewheeled over a freewheel angle. The method then includes varying the advance angle and the freewheel angle in response to changes in the voltage used to excite the winding. Additionally, a control system for an electric machine, and a product incorporating the control system and electric machine.

A control system for a multiphase permanent magnet motor having a controller for producing a control signal to energize each phase winding. The controller includes a current value calculator for determining a value of phase current advanced in phase with respect to back-EMF by a phase advance angle, and a phase advance optimization circuit for producing a value of the phase advance angle optimized so as to maximize output torque of the motor and mimimize the phase current. The phase advance optimization circuit determines the phase advance angle optimized for each phase of the motor.

A motor magnetic-pole-position estimating apparatus includes a command voltage output device and a current detector. A model-current calculator is configured to calculate a model current corresponding to a voltage equation for a predetermined model of a motor based on a command voltage and an actual current. A current-difference calculator is configured to calculate a current difference between the model current and the actual current. Each of first and second magnetic-pole-position-difference calculators is configured to calculate a magnetic-pole-position difference between an actual magnetic-pole position of the motor and an estimated or designated magnetic-pole position based on the current difference depending on whether or not a rotation speed of the motor is lower than a predetermined value. A magnetic-pole-position calculation device is configured to calculate the magnetic-pole position of the motor based on the magnetic-pole-position difference calculated by the first or second magnetic-pole-position-difference calculator.

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.

The invention discloses a permanent synchronization motor torque control method based on a sliding mode flux linkage observer. Direct torque control is performed on a permanent synchronization motor through a 3/2 coordinate conversion module, the sliding mode flux linkage observer, an electromagnetic torque calculation module, a rotating speed PI adjustor, a torque PI adjustor, a flux linkage self-adaptation module, an expected voltage calculation module, an SVPWM module and an inverter. The sliding mode flux linkage observer is adopted for estimating the size, phase and rotator speed of stator flux linkage, and set torque is processed through the flux linkage self-adaptation module to obtain a set value of the stator flux linkage. Expected voltage calculation is performed on size and phase estimation values and the set value of the stator flux linkage and the output quantity of the torque PI adjustor, so that two-phase alternating-current voltage reference values on a two-phase static coordinate system are obtained, and then through SVPWM conversion, a switching signal is obtained to drive the voltage source inverter to achieve direct torque control over the permanent synchronization motor.

Let the rotating axis whose direction coincides with the direction of the current vector that achieves maximum torque control be called the qm-axis, and the rotating axis perpendicular to the qm-axis be called the dm-axis. A motor control device switches its operation between low-speed sensorless control and high-speed sensorless control according to the rotation speed of the rotor. In low-speed sensorless control, the magnetic salient pole of the motor is exploited, and the d-q axes are estimated by, for example, injection of a high-frequency rotating voltage. In high-speed sensorless control, the dm-qm axes are estimated based on, for example, the induction voltage produced by the rotation of the rotor. During high-speed sensorless control, the γ(dm)-axis current is kept at zero irrespective of the δ(qm)-axis current.

A method of controlling a permanent-magnet motor that includes sequentially exciting and freewheeling a winding of the motor. The method includes varying the angle over which the winding is freewheeled in response to changes in speed of the motor. Additionally, a control system for a permanent-magnet motor, and a product incorporating the control system and motor.

A magnetic pole position in a synchronous motor having salient poles is estimated from an instructed voltage applied to the motor, a current generated from the instructed voltage and parameters. To estimate the position substantially matching with a true magnetic pole position, a phase matching voltage having a phase matching with the estimated magnetic pole position previously obtained is applied to the motor. The phase matching voltage has a harmonic frequency higher than that of the instructed voltage. A phase matching current generated from the phase matching voltage is detected from the motor. A value of at least one of the parameters is corrected such that a difference in phase between the phase matching voltage and the phase matching current substantially becomes zero. An estimated magnetic pole position is calculated from the instructed voltage, the generated current and the parameter having the corrected value.

An electric system that includes a single-phase permanent-magnet electric machine and a control system for driving the electric machine under load at speeds in excess of 60 krpm. Additionally, a product that includes the electric system.

An SEA architecture for controlling the torque applied by an SEA that has particular application for controlling the position of a robot link. The SEA architecture includes a motor coupled to one end of an elastic spring and a load coupled to an opposite end of the elastic spring, where the motor drives the load through the spring. The orientation of the shaft of the motor and the load are measured by position sensors. Position signals from the position sensors are sent to an embedded processor that determines the orientation of the load relative to the motor shaft to determine the torque on the spring. The embedded processor receives reference torque signals from a remote controller, and the embedded processor operates a high-speed servo loop about the desired joint torque. The remote controller determines the desired joint torque based on higher order objectives by their impedance or positioning objectives.

A synchronous machine control apparatus is characterized by including a magnet condition estimation unit (7, 7a) that estimates the temperature or the magnetic flux of a permanent magnet that forms the magnetic field of a synchronous machine (1), and is characterized in that the magnet condition estimation unit (7, 7a) coordinate-converts an armature current into currents on the γ-δ axis consisting of the γ axis and the δ axis that is perpendicular to the γ axis, based on the rotor position and the estimated γ axis, and estimates the temperature or the magnetic flux of the permanent magnet, based on the control command for the synchronous machine (1) and the γ-δ axis currents.