134results about "Field acceleration method control" patented technology

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 system and method for controlling a permanent magnet motor are disclosed. Briefly described, one embodiment receives a torque command and a flux command; receives information corresponding to a direct current (DC) bus voltage and a motor speed; computationally determines feedforward direct-axis current information and feedforward quadrature-axis current information from a plurality of parameters associated with the permanent magnet motor; determines a current signal (i_dq*) based upon at least the requested torque command, the flux command, the DC bus voltage, the motor speed, the feedforward direct-axis current information, and the feedforward quadrature-axis current information; and controls a power inverter that converts DC power into alternating current (AC) power that is supplied to the permanent magnet motor, such that the permanent magnet motor is operated in accordance with the determined i_dq*.

A method and system for controlling motor torque provides improved responsiveness and reliability in motor control applications. The motor control system includes a power converter, a voltage detector for detecting the converter input voltage and a control circuit for controlling the converter. The control circuit includes a torque command limit value generator and a torque command limiter for limiting a torque command value. The system may also include a torque command coefficient generator for generating a coefficient corresponding to an input current of the power converter, and a multiplier for calculating a final torque command value for the motor by multiplying together the torque command value and the torque command coefficient. The torque command limit and coefficient values may be determined from the converter input voltage, calculated or detected converter input current and calculated input impedance between a power supply and the converter.

The invention relates to a method for the controlled application of a stator-current target value (I_Snom) and a torque target value (M_nom) for a polyphase machine (4) that is supplied by an electronic power converter. According to the invention: current components (I_Sdnom, I_Sqnom) in a co-ordinate system (d, q) with a fixed rotor flux or rotating magnetic pole are calculated in accordance with a torque target value and in asynchronous machines in accordance with a rotor-flux target value (Ψ_Rnom), a calculated rotor-flux actual value (Ψ<SB>R</SB>) or a rotating magnetic-pole flux; a stator-circuit frequency (ω<SB>S</SB>) is determined; a terminal-flux target value (Ψ_Knom) is calculated in accordance with the values (I_Snom, I_Sqnom, Ψ<SB>R</SB>, ω<SB>S</SB>) by means of the machine parameters (L, R<SB>S</SB>), said terminal-flux target value being subsequently projected onto a flux-course curve, selected from stored, off-line optimised flux-course curves. This permits the state of the stator current (I<SB>S</SB>) to be regulated in relation to the rotor flux (Ψ<SB>R</SB>) or rotating magnetic-pole flux by means of momentary values, facilitating a stationary and dynamic precise control of motor currents (I₁,I₂,I₃) and thus the torques (M) of a polyphase machine (4).

The invention discloses a one-phase open-circuit fault-tolerant direct thrust control method for a five-phase permanent magnet linear motor. Firstly, a Clark transform matrix and an inverse matrix thereof are derived based on fault-tolerant phase current. On the above basis, a stator flux linkage on alpha-beta is derived, a stator virtual flux linkage is defined according to the requirements of acircular stator flux linkage trajectory, and thus the voltage compensation on alpha-beta is derived. The stator actual voltage on the alpha-beta is derived by a modulation function of a voltage sourceinverter, and voltage is combined with voltage compensation and stator current, and a stator virtual flux linkage and thrust are observed by a stator flux observer and a thrust observer. Then statorvirtual target votlage is calculated according to given thrust, a given stator flux linkage amplitude and the observed stator virtual flux linkage and thrust. Finally, the stator actual voltage is calculated by the voltage and the voltage compensation, and the motor is controlled by the voltage by the voltage source inverter. According to the method, a thrust fluctuation caused by a motor failureis suppressed, and more importantly, the dynamic performance and steady state performance are consistent with that in a normal condition.

To minimize switching losses in a rotating electrical machine, exemplary embodiments of the present disclosure proposes an iterative control method which calculates optimal switching states in advance. A rotating electrical machine can be controlled on the basis of this iterative control method.

An open-loop and/or closed-loop control device for operating an asynchronous machine which is fed by a 3-phase power converter. The open-loop and/or closed-loop control structure has a stator flux controller and a pulse pattern generator for generating pulse signals based on mean values. An output of the stator flux controller is connected to an input of the pulse pattern generator, with the result that the pulse pattern generator can generate the pulse signals as a function of a manipulated variable which is generated by the stator flux controller. The stator flux controller is configured so as to generate the manipulated variable as a function of a desired value of the stator flux of the asynchronous machine and as a function of a desired value of the torque of the asynchronous machine. The stator flux controller has a dead-beat control response.

An electric drive is disclosed, in particular for a power tool, including a rotor, a stator, and a first coil arrangement, which is designed to drive the rotor by a first rotating field, and including a first motor control arrangement, which is designed to supply the first coil arrangement with electric current in order to generate a first rotating field. The stator has a second coil arrangement for generating a second rotating field. The second coil arrangement can be actuated and energized separately from the first coil arrangement so as to actuate the second coil arrangement in an arbitrary commutation sequence.

A motor control device which controls a motor for driving a blower unit, comprises: a target motor output calculating section which calculates a target motor output which causes an air flow of air supplied from the blower unit to coincide with a target air flow; and an operation command generating section which obtains the motor output of the motor, and generates a command for controlling a physical amount of the motor such that the motor output coincides with the target motor output based on a result of comparison between the motor output and the target motor output; and the target motor output calculating section is configured to calculate the target motor output as a product of a polynomial of variables derived by dividing the target air flow by the motor speed, and a cube of the motor speed.

The invention relates to the wide speed regulation range and low torque ripple suppression method of a brushless direct current motor. A rotating-speed and torque double-closed-loop control mode is adopted. At a non-commutation moment, torque control is performed. At a commutation moment, overlapping commutation is performed and a current prediction module is added to carry out duty ratio calculation. When a Hall position signal jump sign commutation begins, a turn-off phase current decreases to zero and sign commutation is ended. At this time, an overlapping commutation method is adopted; andin order to reflect the current of a non-commutation phase on a direct current bus during a delayed turn-off period, the measure of using turn-off phase and non-commutation phase synchronization PWMmodulation to open phase constant open is adopted during a commutation period. Simultaneously, a non-commutation phase current value and a motor rotation speed at a current moment which is a k momentare sampled, according to the operation state of the motor at the current moment which is the k moment, a three-phase winding opposite electromotive force is acquired, a current prediction control module is used to calculate a prediction control law D so as to control inversion circuit output, and the torque ripple suppression of the brushless direct current motor under a wide speed regulation range is realized.

The invention discloses a medium-voltage frequency conversion system used for shale gas extraction. The medium-voltage frequency conversion system comprises an electric control chamber, an ABB medium-voltage frequency conversion system, a motor system, a programmable logic controller (PLC) control system, a fracturing pump, a user operating system and a remote monitoring system. The motor system comprises an alternate current frequency conversion motor, a soft starter, a sensor and a cooling system. The soft starter, the sensor and the cooling system are respectively connected with the alternate current frequency conversion motor. Voltage output of the electric control chamber is connected with the ABB medium-voltage frequency conversion system, output of the medium-voltage frequency conversion system is connected with the alternate current frequency conversion motor, the alternate current frequency conversion motor directly drives the fracturing pump, data output of the sensor is connected with the PLC control system, and the PLC control system is also respectively connected with the ABB medium-voltage frequency conversion system, the soft starter and the user operating system. According to the medium-voltage frequency conversion system, the motor directly drives the fracturing pump to replace a traditional mechanical transmission line, work efficiency of a unit is improved, the size and the weight of the unit are reduced, and manufacturing cost is reduced.

A model prediction-direct torque control method for a permanent magnet synchronous motor belongs to the technical field of control. The object of the invention is to complete the accurate estimation of torque and flux linkage in a system by using a reduced-order observer, and then to design the model prediction-direct torque control method for a permanent magnet synchronous motor of a hub motor drive system controller through a model prediction control algorithm. The steps include: selecting motor torque and flux linkage as state variables, selecting an objective function enabling the minimumerror between a predicted value and an expected value of torque and flux linkage, and obtaining three-phase voltage for controlling the motor to finish control over the PMSM. The model prediction control algorithm applied by the invention can effectively deal with the multi-input multi-output and multi-constraint optimization control problems, replaces a hysteresis loop comparator and a switch selection module of conventional direct torque control, avoids the upper and lower limit pulsation of the hysteresis loop and unnecessary switching losses, and effectively suppresses the torque pulsationof the drive motor.

The invention discloses an intelligent reconstruction flexible motor driven controller which comprises a digital signal processing module, a CPLD module, an intelligent power module, a sensor module and a host computer. The invention is characterized in that: output current of the digital signal processing module outputs a PWM wave through the CPLD module; output of the CPLD module is connected with the intelligent power module through base electrode driving; the sensor module acquires feedback current, load torque and moment of inertia of a target motor and outputs the feedback current, the load torque and the moment of inertia to the digital signal processing module; the digital signal processing module is connected with the host computer through a communication line; the host computer receives the feedback current, the load torque and the moment of inertia of the digital signal processing module, employs a flexible control method, and sends a corresponding control strategy to the digital signal processing module. According to a driver, the corresponding control strategy is adjusted according to the change of load, and control precision and system stability are raised.

A vehicle includes one or more inverter-fed electric machines such as permanent magnet synchronous motors. In response to a torque request, a controller issues commands to an inverter calculated to cause the motor to produce the requested torque. A method of operating the inverter may determine the commands based on the ratio of rotor speed to inverter input voltage, reducing the approximation error associated with multi-dimensional lookup tables. When the speed and voltage vary while maintaining a constant ratio and constant torque request, the issued commands produce a winding current in the electrical machine with constant direct and quadrature components.

A motor control device (10) includes: a power conversion unit (40) having a rectification circuit (20) for rectifying AC voltage from an AC power supply (31), a capacitor circuit (22) for receiving an output from the rectification circuit (20) and outputting a pulsating rectified voltage from both ends of the capacitor (13), and an inverter circuit (25) for receiving the rectified voltage and outputting AC current to a motor (30); and a motor control unit (41) for controlling the inverter circuit (25) so as to control the motor (30). The motor control unit (41) performs torque control operation to vary the output torque of the motor (30) inaccordance with the load torque of the motor (30).