53 results about "Flux vector" patented technology

In a driving control method for a synchronous reluctance motor, a novel vector control method is employed which does not need the salient pole position angle detector. More particularly, the present invention provides a vector control method which can accurately and efficiently estimate cosine and sine signals, being rotation signals for the vector rotators.A flux vector estimator 12a uses voltage and current information of a stator to estimate a stator flux vector by dividing it into an in-phase flux vector having the same direction as a current vector and a mirror-phase flux vector determined as a difference between the stator flux vector and the in-phase flux vector. A cosine and sine generator 12b uses the estimated in-phase and mirror-phase flux vectors to generate the cosine and sine values of an intermediate angle of the angles of such flux vectors and outputs a rotation signal of the vector rotators. Thus, vector control is established.

A method for sensorless estimation of rotor speed and position of a permanent magnet synchronous machine the method comprising the steps of calculating first stator flux vector estimate ({circumflex over (ψ)}d,i+j{circumflex over (ψ)}q,i) using the flux model and measured stator currents, calculating second stator flux vector estimate ({circumflex over (ψ)}d,u+j{circumflex over (ψ)}q,u) using the voltage model and measured stator voltages, comparing the directions of the first and second flux vectors to achieve a first error signal (Fε), using speed adaptation to achieve estimates for the rotor angular speed ({circumflex over (ω)}m) and angular position ({circumflex over (θ)}m) from the first error signal (Fε), injecting a known voltage signal (uc) to the stator voltage, detecting a current signal (iqc) from the stator current to form a second error (ε) signal, which is dependent on the estimation error of the rotor position, augmenting the voltage model by the second error signal (ε) to keep the first and second flux vector estimates aligned and so to correct the rotor angular speed ({circumflex over (ω)}m) and angular position ({circumflex over (θ)}m) estimates.

In a driving control method for a synchronous reluctance motor, a novel vector control method is employed which does not need the salient pole position angle detector. More particularly, the present invention provides a vector control method which can accurately and efficiently estimate cosine and sine signals, being rotation signals for the vector rotators. A flux vector estimator 12a uses voltage and current information of a stator to estimate a stator flux vector by dividing it into an in-phase flux vector having the same direction as a current vector and a mirror-phase flux vector determined as a difference between the stator flux vector and the in-phase flux vector. A cosine and sine generator 12b uses the estimated in-phase and mirror-phase flux vectors to generate the cosine and sine values of an intermediate angle of the angles of such flux vectors and outputs a rotation signal of the vector rotators. Thus, vector control is established.

A controller for a power converter detects a current output from the power converter, estimates a flux vector of the motor, and calculates a torque line in a physical model resulting from mathematizing a circuit equivalent to the motor, based on the estimated flux vector. The torque line indicates a line for obtaining a desired torque in a subsequent control period. The controller calculates a stator flux command value in accordance with a loss, calculates a voltage command value based on the torque line and the stator flux command value, and controls an output voltage.

A method for controlling a variable speed wind turbine generator is disclosed. The generator is connected to a power converter comprising switches. The generator comprises a stator and a set of terminals connected to the stator and to the switches of the power converter. The method comprises: determining a stator flux reference value corresponding to a generator power of a desired magnitude, determining an estimated stator flux value corresponding to an actual generator power, determining a difference between the determined stator flux reference value and the estimated stator flux value, and operating said switches in correspondence to the determined stator flux reference value and the estimated stator flux value to adapt at least one stator electrical quantity to obtain said desired generator power magnitude.

A method of assembling an electrical machine includes programming at least one processor with a stator flux vector estimation scheme. The electrical machine has a stator at least partially extending around a rotor. The electrical machine is electrically coupled to an electric power system. The electric power system transmits at least one phase of electric power to and from the electrical machine with at least partial power conversion. The stator flux vector estimation scheme is programmed to generate at least one stator back-electromagnetic force (back-EMF) signal and to generate at least one stator flux vector signal using the at least one stator back-EMF signal. The at least one stator flux vector signal at least partially represents an estimated rotor position. The method also includes coupling at least one output device in data communication with the at least one processor.

Systems, computer implemented methods, and program products to determine approximate static well pressures for one or more arbitrary shaped wells by estimating the drainage volume of the one or more wells, are provided. The drainage volume of the one or more wells, for example, can be estimated from the one or more computed fluid flow flux vectors, and the approximate static well pressures for the one or more wells can be subsequently calculated by taking the pore volume average of the dynamic grid block pressures within the drainage volume of the one or more wells. The one or more fluid flow flux vectors can be calculated at each iteration in a numerical reservoir simulator as a part of standard simulator computations, negating a need for additional, extraneous computations to calculate effective drainage volume of the one or more wells.

Systems, computer implemented methods, and program products to determine approximate static well pressures for one or more arbitrary shaped wells by estimating the drainage volume of the one or more wells, are provided. The drainage volume of the one or more wells, for example, can be estimated from the one or more computed fluid flow flux vectors, and the approximate static well pressures for the one or more wells can be subsequently calculated by taking the pore volume average of the dynamic grid block pressures within the drainage volume of the one or more wells. The one or more fluid flow flux vectors can be calculated at each iteration in a numerical reservoir simulator as a part of standard simulator computations, negating a need for additional, extraneous computations to calculate effective drainage volume of the one or more wells.

A controller for a power converter detects a current output from the power converter, estimates a flux vector of the motor, and calculates a torque line in a physical model resulting from mathematizing a circuit equivalent to the motor, based on the estimated flux vector. The torque line indicates a line for obtaining a desired torque in a subsequent control period. The controller calculates a stator flux command value in accordance with a loss, calculates a voltage command value based on the torque line and the stator flux command value, and controls an output voltage.

A method of assembling an electrical machine includes programming at least one processor with a stator flux vector estimation scheme. The electrical machine has a stator at least partially extending around a rotor. The electrical machine is electrically coupled to an electric power system. The electric power system transmits at least one phase of electric power to and from the electrical machine with at least partial power conversion. The stator flux vector estimation scheme is programmed to generate at least one stator back-electromagnetic force (back-EMF) signal and to generate at least one stator flux vector signal using the at least one stator back-EMF signal. The at least one stator flux vector signal at least partially represents an estimated rotor position. The method also includes coupling at least one output device in data communication with the at least one processor.

A position sensorless control methodology for electrical machines using high frequency flux vector signal injection in the estimated rotor flux rotational reference frame is provided. In one aspect, the estimated position error function is derived directly from the stator flux equation without any simplification. The method is applicable for electrical generator motoring mode operation from standstill and power generation mode operation.

A method for controlling a variable speed wind turbine generator is disclosed. The generator is connected to a power converter comprising switches. The generator comprises a stator and a set of terminals connected to the stator and to the switches of the power converter. The method comprises: determining a stator flux reference value corresponding to a generator power of a desired magnitude, determining an estimated stator flux value corresponding to an actual generator power, determining a difference between the determined stator flux reference value and the estimated stator flux value, and operating said switches in correspondence to the determined stator flux reference value and the estimated stator flux value to adapt at least one stator electrical quantity to obtain said desired generator power magnitude.

A charge transfer system includes an on-board vehicle motor system and a plug in supply. The on-board vehicle motor system includes a first motor including a plurality of stator windings, a second motor including a plurality of stator windings, a first inverter having a plurality of switch legs, a second inverter having a plurality of switch legs, a controller, and an on-board power supply. The plug-in supply is connected between at least one switch leg of the first inverter and at least one switch leg of the second inverter. The controller modulates the switch legs of the first and second inverters such that electric current flows through at least one stator winding of the first or second motor to charge the on-board power supply. The current flow can also alternate in phase with plug-in supply polarity to produce a stable stator flux vector angle preventing motor rotation during charge transfer.

Systems, computer implemented methods, and program products to determine approximate static well pressures for one or more arbitrary shaped wells (119) by estimating the drainage volume (111) of the one or more wells (119), are provided. The drainage volume (111) of the one or more wells (119), for example, can be estimated from the one or more computed fluid flow flux vectors (107), and the approximate static well pressures for the one or more wells (119) can be subsequently calculated by taking the pore volume average of the dynamic grid block pressures within the drainage volume (111) of the one or more wells (119).; The one or more fluid flow flux vectors (107) can be calculated at each iteration in a numerical reservoir simulator as a part of standard simulator computations, negating a need for additional, extraneous computations to calculate effective drainage volume (111) of the one or more wells (119).

A position sensorless control methodology for electrical machines using high frequency flux vector signal injection in the estimated rotor flux rotational reference frame is provided. In one aspect, the estimated position error function is derived directly from the stator flux equation without any simplification. The method is applicable for electrical generator motoring mode operation from standstill and power generation mode operation.

A method for operating a converter circuit is specified with the converter circuit having a converter unit with a multiplicity of controllable power semiconductor switches and having an energy storage circuit formed by two series-connected capacitors, in which the controllable power semiconductor switches are controlled by means of a control signal formed from a hysteresis signal vector (x), and the hysteresis signal vector (x) is formed from a difference-phase connection current vector (Δifi,i) by means of a hysteresis regulator, and the difference-phase connection current vector (Δifi,i) is formed from the subtraction of a phase connection current vector (ifi,i) from a reference phase connection current vector (ifi,i,ref), with the reference phase connection current vector (ifi,i,ref) being formed from a difference power value (Pdiff), a difference wattless-component value (Qdiff) and a phase flux vector (ψg,αβ). In order to very largely stabilize the switching frequency of the controllable power semiconductor switches, a current correction value (i0) is additionally subtracted in order to form the difference-phase connection current vector (Δifi,i), with the current correction value (i0) being formed by integration of a phase connection voltage mean value (uinv,A), and the phase connection voltage mean value (uinv,A) being formed by determining the arithmetic mean value of the phase connection voltages (uinv,iM) with the reference point of the connection point of the capacitors in the energy storage circuit. A device is also specified, by means of which the method can be carried out in a particularly simple manner.

The invention relates to a low-speed gearbox and double-fed wind turbine optimization design method based on direct-current transmission, and belongs to the field of wind power. According to the method, a double-fed wind power generation system topology structure is adopted to conduct optimization design and control over a double-fed wind turbine comprising a gearbox, a double-fed induction generator (DFIG) and a direct-current transformer. The method comprises the steps that the ratio of the stator current, before optimization, of the DFIG to the stator current, after optimization, of the DFIG, the ratio of the rotor current, before optimization, of the DFIG to the rotor current, after optimization, of the DFIG, the ratio of the total current before optimization to the total current after optimization and the ratio of the total current, before optimization, of the direct-current transformer to the total current, after optimization, of the direct-current transformer are solved by adopting a stator flux vector directional control strategy; the total cost C<s2> of the double-fed wind turbine after optimization is solved; wind turbine optimization design parameters are solved; and a C<s2>-lambda curve is drawn according to a C<s2> formula, a minimum value of C<s2> and an optimum value of lambda are solved, and then the gearbox speed increasing ratio after optimization and the stator current, the rotor current, the synchronous revolving speed and the stator rated frequency of the DFIG are obtained, wherein lambda represents the ratio of the gearbox speed increasing ratio before optimization to the gearbox speed increasing ratio after optimization. According to the method, the gearbox speed increasing ratio is decreased, the failure rate can be decreased, the cost can be reduced, and the system operation reliability can be improved.