Patent classifications
H02P21/0003
PREDICTIVE CONTROL METHOD OF CURRENT INCREMENT FOR PERMANENT MAGNET SYNCHRONOUS MOTOR UNDER HIGH-SPEED OPERATION
The present disclosure provides a predictive control method of current increment for a permanent magnet synchronous motor includes: substituting a mathematical expression of a stator voltage during one control period into a continuous time domain current model to obtain a discrete current prediction model and a predicted current at the next time point; obtaining a predicted current increment from a current increment prediction model by subtracting a predictive current at a present time point from a predictive current at a next time point; establishing a cost function according to a preset reference current increment and the predicted current increment; obtaining an optimal voltage increment by minimizing the cost function; superposing the optimal voltage increment on a stator voltage of a present control period to obtain an optimal stator voltage of a next control period for controlling control the permanent magnet synchronous motor.
CURRENT REGULATORS FOR DUAL WOUND SYNCHRONOUS MOTOR DRIVES
A method of controlling a dual wound synchronous machine (DWSM) includes: determining virtual current commands based on a current command associated with each of two winding sets of the DWSM; determining virtual half-motor currents by applying a mathematical transformation on measured output currents; determining half-motor difference currents based on differences between the corresponding virtual current command and the virtual half-motor current; calculating forward path voltage commands based on the corresponding difference currents and using first and second gain factors; determining feedback voltage commands by applying third and fourth gain factors to the virtual half-motor currents; determining virtual final voltage commands based on the corresponding forward path and feedback voltage commands; determining final voltage commands by applying a second mathematical transformation to the virtual final voltage commands; commanding, based on the final voltage commands, inverters to apply corresponding voltages to the two winding sets and thereby generating the output currents.
MTPA based method for parameterless and position-sensorless control of a permanent magnet synchronous motor
A parameterless and position-sensorless MTPA control of a permanent magnet synchronous motor including: using three rotating reference frames having different observation angles to parse the current vector; using a target current value and a preset current-rotor angle y that is between the current vector and the q.sub.r-axis of the (d.sub.r, q.sub.r) rotor reference frame to obtain the angles between the current vector, the voltage vector, and the rotor position; obtaining the target voltage value and the target voltage angle by using the obtained angles to obtain the target phase voltage values for regulation. The method is simple in controlling the motor, improves the control efficiency and reliability, and improves the control accuracy.
POWER CONVERSION APPARATUS
A modulation processing unit performs a down-shift process or an up-shift process. In the down-shift process, a neutral-point voltage is shifted towards a low voltage side such that a smallest phase voltage command value is a lower fixed value that is a first lower limit value or a second lower limit value. In the up-shift process, the neutral-point voltage is shifted towards a high voltage side such that a largest phase voltage command value is an upper fixed value that is a first upper limit value or a second upper limit value. The modulation processing unit selects either of a first fixed value, being the first lower limit value or the first upper limit value, and a second fixed value, being the second lower limit value or the second upper limit value, based on a difference between the phase voltage command values in the down-shift process or the up-shift process.
Controller and control method for rotary electric machine
A control unit applied to a motor that includes a rotor having a field winding and a rotor having armature winding groups to control a field current passed through the field winding. Each of the armature winding groups is applied with a prescribed voltage. The field current is controlled so as to be a minimum field current value If_min with which a deviation between an amplitude of an induced voltage generated in the armature winding groups by rotation of the rotor, and an amplitude of the voltage applied to the armature winding groups becomes equal to or smaller than a prescribed value.
PREDICTIVE DEADBEAT CONTROL OF MOTOR PHASE CURRENTS WITH MODEL MISMATCH COMPENSATION AND ADJUSTABLE CONTROL DYNAMICS
The invention relates to a motor control device for controlling a motor current, with a predictive deadbeat control unit configured to, based on a motor current error input signal, use a model predictive control scheme for providing an output signal for controlling the motor current according to a deadbeat control scheme, where the deadbeat control scheme is characterized by minimizing the motor current error input signal within a preset time period; an interface unit configured to allow adjusting the preset time period by a user input; and an integrator unit configured to, based on the motor current error input signal, provide an integrator output that is added to the output signal for controlling the motor current with controlling a motor current, with the advantages of a predictive deadbeat control scheme while avoiding the problems present in the conventional predictive deadbeat approaches. The invention also relates to a corresponding method.
Method of operating a synchronous motor in a flux weakening mode and a controller therefor
Described is a method of controlling operation of a synchronous motor. The method comprises, during constant power/speed motor operation, determining a value of a stator voltage (v.sub.s.sup.2) for an orthogonal rotating reference frame of the motor. Comparing the value of the determined stator voltage (v.sub.s.sup.2) to a threshold voltage (v.sub.s.sup.2.sub._max1), said threshold voltage (v.sub.s.sup.2.sub._max1) having a value between that of a maximum stator voltage (v.sub.s.sup.2.sub._max0) for a basic speed mode of operation of the motor and that of a maximum stator voltage (v.sub.s.sup.2.sub._max2) of the motor closed loop controller. If the determined value of the stator voltage (v.sub.s.sup.2) is greater than or equal to the value of the threshold voltage (v.sub.s.sup.2.sub._max1), then controlling operation of the motor in a flux weakening mode of operation until a value of a current component (i.sub.d−Δi.sub.d) in a d-axis reaches a maximum negative value (−i.sub.dmax), or until the value of the stator voltage (v.sub.s.sup.2) is less than the value of the threshold voltage (v.sub.s.sup.2.sub._max1).
Synchronous reluctance motor having radial-direction widths slit configuration on a q-axis for improved power factor
The rotation of the synchronous reluctance motor is controlled through energization of the winding with current of a phase having a ratio k between the total sum of radial-direction widths of the slits on the q-axis and a magnetic gap length, and having a lead angle β from the d-axis. Among the core layers, the radial-direction width, on the q-axis, of the core layer that lies at a position closest in the circumferential direction to a point P at which there intersect the outer periphery of the rotor and the straight line passing through the rotor center and drawn at an angle ψ=arctan(tan β/(1+0.2k)) from the d-axis, is larger than the radial-direction width of other core layers on the q-axis.
CONTROL APPARATUS FOR ROTATING ELECTRIC MACHINE
In a control apparatus for a rotating electric machine, a phase feedback gain is set such that first and second conditions are met. The first condition is that gain margin and phase margin in frequency characteristics of a first loop transfer function are ensured. The second condition is that a gain intersection angular frequency in frequency characteristics of the first loop transfer function is lower than respective resonance angular frequency in frequency characteristics of first and second transfer functions. An amplitude feedback gain is set such that third and fourth conditions are met. The third condition is that gain margin and phase margin in frequency characteristics of a second loop transfer function are ensured. The fourth condition is that a gain intersection angular frequency in frequency characteristics of a second loop transfer function is lower than respective resonance angular frequency in frequency characteristics of third and fourth transfer functions.
FRACTIONAL-ORDER PROPORTIONAL-RESONANT CONTROLLER
A closed-loop system may include a plant (an electric machine requiring control) and a fractional-order proportional-resonant controller. The fractional-order proportional-resonant controller may have an order greater than zero and less than or equal to one. The order for the fractional-order proportional-resonant controller may be selected to yield a target amplitude and target slope for frequency response. The frequency response may be such that a steady-state error associated with a speed of the electric machine is inversely proportional to the target amplitude and less than a predetermined threshold. The order of the controller may be 0.9.