154 results about "Phase inductance" patented technology

The invention discloses a method for initially positioning and starting a switched reluctance motor without a position sensor, and belongs to the technical field of control of the switched reluctance motor. The method comprises the following steps of: setting an inductance bottom threshold value LLow and an inductance top threshold value LHigh based on the basic characteristic that the inductance of the switched reluctance motor periodically changes with the position of a rotor; injecting short pulses into each phase winding and calculating inductance values according to a phase voltage equation; judging phases which can be currently switched on according to the relation among each phase inductance calculated value and LLow and LHigh and selecting estimated phases of an initial position angle at the same time; and establishing a phase inductance mathematical model to obtain angle information in the selected phases by using the relation between the inductance mathematical model and the inductance calculated values. Though the method, an initial switch-on phase selection signal can be accurately acquired and the initial position angle of the rotor can be calculated at the same time, so the switched reluctance motor can be started and initially positioned without the position sensor, an algorithm is simple and generality is high.

The invention discloses a method for estimating the rotor position of a switched reluctance motor without a position sensor, and belongs to the technical field of the control of the switched reluctance motors. In the method, based on the fundamental feature that an inductor of the switched reluctance motor is changed periodically with the rotor position, phase inductance reaches maximum at a position where a stator is aligned with a rotor, so the slope of the phase inductance is changed into negative from positive at the maximum position of the inductance, and slope zero-crossing points exist. In the method, by sampling each phase current and phase voltage in real time, each phase inductance value can be detected in real time, and simultaneously, the inductance slope can be calculated; the calculated inductance slope is subjected to zero balancing to obtain pulse signals of the slope zero-crossing points, so that a zero-crossing position, namely the position where a stator tooth pole is aligned with a rotor tooth pole can be detected; and the phase difference of the two adjacent maximum inductance positions is 45 degrees, so the difference of positions of the two slope zero-crossing points is 1/8 cycle, and the real-time rotate speed and rotor position information of the motor can be calculated according to the zero-crossing pulse signals. The method has the advantages of independent of parameters of a motor body, no need of measurement of motor characteristics such as static flux linkage and the like, simple algorithm and easy realization, so the method has strong generality compared with a non-position strategy.

The invention discloses a position-sensor-free control method suitable for four-quadrant operation of a switch reluctance motor, and belongs to a switch reluctance motor control method. The position-sensor-free control method comprises the following steps of constructing a simplified inductance model according to a fourier series expression of inductance of the switch reluctance motor; fitting a function relation in which an inductance model parameter is changed along with phase current by measuring inductances at three special positions of the switch reluctance motor at different phase currents on line, and constructing a non-linear inductance model of the switch reluctance motor; deriving an analysis formula for estimating a position of a rotor of the switch reluctance motor through phase inductance according to the non-linear inductance model; and when the motor runs, detecting the phase current and phase voltage in real time, estimating an excitation phase magnetic chain according to a voltage equation to obtain excitation phase inductance, calculating the current position of the rotor according to the estimation analysis formula by using the derived position of the rotor, and realizing sensor-free running control over the switch reluctance motor according to the estimated position of the rotor. The algorithm is simple, small in calculated amount, favorable for real-time implementation of a micro controller and higher in position estimation precision.

The methods and devices provided herein include methods and devices for controlling a permanent magnet motor. In one implementation, a method is provided that allows for the determination of the values of the phase back EMF voltage and of the phase inductances while the phases are powered with a PWM (Pulse Width Modulation) controlled current and/or voltage.

A multi-phase switching voltage regulator having asymmetric phase inductance includes a controller and a plurality of power stages each configured to deliver output current to a load through an inductor. At least one of the inductors has a higher open circuit inductance than the other inductors so that at least one of the power stages has a different output inductance compared to the other power stages. The controller is configured to control switching of the power stages so as to regulate an output voltage of the multi-phase switching voltage regulator, including allowing all of the power stages to provide current to the load through the respective inductors during a full power event at the load and preventing all of the power stages except for the at least one power stage having the higher open circuit inductance from providing current to the load during a low power event at the load.

The invention discloses a vacuum cleaner, a control method, device and system for a brushless DC motor, wherein the method comprises the following steps: offline obtaining a temperature-phase resistance meter and a temperature-phase inductance meter of the motor; in a low-speed operation phase of the motor, during the high-level time of each PWM control cycle, obtaining a conducting phase positive-side voltage, a conducting phase negative-side voltage, a non-conducting phase opposite potential voltage, a bus current instantaneous value and the current winding temperature, and obtaining phase current corresponding to any two moments; obtaining the phase current change rate of the motor according to any two moments and the corresponding phase current, and obtaining the phase resistance and phase inductance of the motor according to the current winding temperature, the temperature-phase resistance meter, and the temperature-phase inductance meter; obtaining a flux linkage value of the motor according to the aforementioned parameters, and judging whether the flux linkage value is greater than a commutation threshold; if yes, performing commutation. Thereby, the accurate commutation ofthe motor can be realized in the low speed operation phase of the motor, the motor can be prevented from being out of step, and the reliability is high.

A system (100) has a motor controller (102), an actuation circuit (104, 106, RSNS), and a sensorless, brushless DC motor (108). 2N voltage pulses are generated for 2N pairs of phases of motor (108). A current is sensed for each of the 2N pairs of phases, to determine a phase inductance from the sensed current for each of the 2N pairs of phases. The determined phase inductances are compared to a look-up table to determine the initial position of motor (109).

An embodiment of the invention discloses a high-voltage direct-current circuit harmonic impedance analysis equivalent model and a high-voltage direct-current circuit harmonic impedance frequency analysis method, aiming to solve the problems that a harmonic current path in a typical converter model is limited between a converter transformer and a valve bridge, stray capacitance to ground of converter transformer sleeves is ignored, and a large difference exists between a design result and an actual measurement result of the model based on a direct-current-side harmonic current theory. The high-voltage direct-current circuit harmonic impedance analysis equivalent model comprises a current converter adopting a three-pulse converter model, and the three-pulse converter model comprises a leakage current path and a converter bridge. The high-voltage direct-current circuit harmonic impedance analysis equivalent model is more accurate by taking the nature that harmonic waves are reflected by 3n times under the effect of commutation induction of the leakage current path and the converter bridge into consideration; the influences of an alternating-current system and an alternating-current filter on high-voltage direct-current circuit resonance characteristics are taken into account, so that an analysis process of the high-voltage direct-current circuit resonance characteristics is more accurate and rigorous, and results are more reliable.

In an embodiment, a power-supply controller includes switching circuitry and an adjuster circuit. The switching circuitry is configured to cause a charging current to flow until the charging current has a predetermined relationship to a threshold, and to cause a discharging current to flow to an output node that carries an output voltage after the charging current. And the adjuster circuit is configured to adjust the threshold such that a ripple voltage superimposed on the output voltage has an approximately constant magnitude. For example, a power supply may include such a power-supply controller to maintain the magnitude of the output ripple voltage within a particular range during a pulse-frequency-modulation (PFM) mode despite variations in one or more parameters such as input voltage, output voltage, filter capacitance, phase inductance, and charging-current-sense impedance, from their respective nominal values.

A controller (72) for a switched reluctance machine (20) implements a model of at least one active phase representing dynamic magnetic machine characteristics. The controller (72) determines machine control signals based on rotational position obtained by numerically solving the model with measured machine operating parameters. The model may be implemented as the sum of orthogonal functions relating active phase voltage and current with constants derived from phase inductance to obtain the rotor angle.

The invention discloses a rotor rotating speed/position detecting method of an aero-switch reluctance starting/power generator. Through coaxially mounting a switched reluctance motor of which the number of teeth is same with that of one selected from a stator and a rotor on the aero-switch reluctance starting/power generator as a position detector, namely a switched reluctance type position detector is coaxially mounted. The position detector realizes estimation for per-unit value of each phase of inductance, thereby acquiring a rotor position signal by means of a correspondence between a phase inductance and a rotor position angle, and supplying accurate and reliable position and rotating speed information for the aero-switch reluctance starting/power generator. The rotor rotating speed/position detecting method of the aero-switch reluctance starting/power generator is suitable for adverse operation environments of high-temperature operation environment, high-speed operation environment, smeary environment, etc. Furthermore the rotor rotating speed/position detecting method of the aero-switch reluctance starting/power generator has advantages of high detecting precision, high reliability, simple structure, high firmness, high stability and relatively low cost of a detecting system, high sensitivity and high efficiency in detecting an output response, and high suitability for position detection in high-temperature and high-speed operation of the aero-switch reluctance starting/power generator.

A staggered parallel-connection direct-current voltage reduction converter with a phase-by-phase coupled inductor of the invention comprises power switch tubes, a filtering capacitor and a coupled inductor possessing n windings. In the coupled inductance windings, a first phase inductance winding is coupled with a second phase inductance winding; the second phase inductance winding is coupled with a third phase inductance winding; an n-1th phase inductance winding is coupled with an nth phase inductance winding; the nth phase inductance winding is coupled with the first phase inductance winding; except the first phase inductance winding and the nth phase inductance winding, a mth phase inductance winding is only coupled with a m-1th phase inductance winding and a m+1th phase inductance winding and is not coupled with other windings; the first phase winding is only coupled with the second phase winding and the nth phase winding, and the nth phase winding is only coupled with the first phase winding and the n-1th phase winding. An array-type magnetic core is used to realize phase-by-phase coupling of n phase coupled inductance windings. Through designing an inductive coupling coefficient and controlling conduction time of a main switch tube, an output current ripple of the converter is reduced and dynamic response is increased.

The invention discloses a fault detection method and apparatus of a brushless direct current motor. The fault detection method includes the following steps of controlling the upper bridge arm switch of any one phase of the three-phase stator winding to be on and controlling an inverter to drive the lower bridge arm switches of the other two phases of the three-phase stator winding to on when the fault testing instruction is received; acquiring the bus voltage value of the brushless direct current motor and the steady-state current value of any one of the other two phases of the three-phase stator winding; calculating the phase resistance of the three-phase stator winding of the brushless direct current motor according to the bus voltage value and the steady-state current value; acquiring the phase inductance according to the phase resistance and steady-state current drop time; and determining the stator of the brushless direct current motor to be not matched and outputting the corresponding alarm signals when the phase resistance and the phase inductance of the three-phase stator winding. The fault that the stator winding of the brushless direct current motor does not match with the brushless direct current motor can be detected during the general assembly test.

The invention discloses a switched reluctance motor variable winding driving system and an online soft switching method, and belongs to the field of online soft switching. The system comprises a controller, a driving module, a power converter and a variable winding module, the variable winding module provided by the invention can change the connection mode of each coil in the phase winding of theswitched reluctance motor on line. According to the invention, a switched reluctance motor driving topological structure with online winding series-parallel connection switching capability is combinedwith an online soft switching method; through the variable winding module, the connection mode of the phase windings of the switched reluctance motor is changed on line, so that the control of the phase inductance value is realized, and the optimization of the torque performance of the motor at a low speed and the performance improvement of the motor at a high rotating speed are effectively realized; on-line series-parallel connection switching and fault winding removal of a winding coil are carried out by utilizing an interval with zero phase current of the switched reluctance motor, so thaton-line soft switching is realized, and the speed adjustment range and the motor fault tolerance capability are expanded.

In an embodiment, a power-supply controller includes switching circuitry and an adjuster circuit. The switching circuitry is configured to cause a charging current to flow until the charging current has a predetermined relationship to a threshold, and to cause a discharging current to flow to an output node that carries an output voltage after the charging current. And the adjuster circuit is configured to adjust the threshold such that a ripple voltage superimposed on the output voltage has an approximately constant magnitude. For example, a power supply may include such a power-supply controller to maintain the magnitude of the output ripple voltage within a particular range during a pulse-frequency-modulation (PFM) mode despite variations in one or more parameters such as input voltage, output voltage, filter capacitance, phase inductance, and charging-current-sense impedance, from their respective nominal values.

The utility model discloses a switch reluctance motor rotor-less position sensor control method. According to the method, one main switch in a power converter is opened, a phase winding of the switch reluctance motor is excited by positive voltage, a current of the phase winding increases firstly till the current of the phase winding reaches to a peak value, then the current of the phase winding decreases to a valley value position, the current of the phase winding continuously increases again, the valley value position of the current of the phase winding is a largest-phase-inductance initial end rotor position, the largest-phase-inductance initial end rotor position is acquired and is directly taken as a switch-off position of the main switch of the switch reluctance motor power converter, and the main switch of the power converter is switched off. The method does not need to have a rotor position sensor and does not need to store motor linkage data, and the method further has advantages of strong timeliness, dynamic response performance, good stability and relatively strong practicality and versatility.

A multiphase magnetic integration coupling inductor comprises a U-type iron core, a T-type iron core and coils; the magnetic pillars of the T-type iron core are positioned between magnetic pillars of the U-type iron core; an air gap group is formed between the magnetic yoke of the T-type iron core and each magnetic pillar of the U-type iron core; another air gap group is formed between the magnetic yoke of the U-type iron core and each magnetic pillar of the T-type iron core; each magnetic pillar of the U-type iron core are winded by the coil. The advantages are that the multiphase magnetic integration coupling inductor is applied to coupling integration of each phase inductor in an interleaving switch power supply, thus improving symmetry level of each phase inductance parameters, simplifying iron core coupling structure, reducing coil length, saving copper material, reducing coil copper loss, reducing power supply output current and voltage ripples, reducing power supply output filter capacitance, and improving power supply efficiency and dynamic response speed .

A multi-phase transformer provided by the invention comprises a shell and an inductance transformation unit, the inductance transformation unit comprises a magnet assembly, a primary coil, a secondarycoil and an inductance coil; at least three placing spaces are formed in the shell, a blocking wall of the shell is blocked between two adjacent placing spaces, and an inductance transformation unitis arranged in each placing space; a first coil placement position and a second coil placement position are formed in the magnet assembly, the inductance coil is arranged in the first coil placement position, the primary coil and the secondary coil are arranged in the second coil placement position, and the inductance coil is connected with the primary coil in series. The shielding effect among the multi-phase inductance transformation units is ensured by the independent placement space; the primary coil and the secondary coil are concentrically arranged to reduce the volume of the magnet assembly, thereby reducing the volume of the multi-phase transformer; one-time resin encapsulation can be carried out in the shell, the heat dissipation performance of the product is guaranteed, the production efficiency is improved, only one-time positioning installation is needed when the multi-phase transformer is installed on a circuit, the installation difficulty is reduced, and the efficiency isimproved.