375 results about "Flux weakening" patented technology

The invention discloses a permanent magnet synchronous motor driving system capable of switching a winding. According to the permanent magnet synchronous motor driving system, a winding switch conversion device with a simple structure is utilized to realize automatic reconstruction of the winding. Meanwhile, operation switching of the low-speed and high-speed windings is realized with combination of double-inverter coordination control and flux weakening control so that range of operation rotating speed of the driving system is substantially widened, and operation efficiency and fault tolerance performance of the system are enhanced. In the low-speed state, single-inverter double-winding operation is performed; in the intermediate-speed state, double-inverter double-winding operation is performed; and in the high-speed state, firstly permanent magnet synchronous motor terminal voltage is limited by utilizing the flux weakening control mode, then the winding is switched and single-inverter single-winding operation is performed. A double-inverter circuit is adopted so that working modes of the system are flexible and various, i.e. both single-inverter operation and double-inverter operation can be realized, and thus the system has certain fault tolerance capability.

A control system for an electric machine includes a flux weakening module, which includes a voltage magnitude calculator that receives d-axis and q-axis command voltages and that generates a voltage magnitude. An error circuit compares the voltage magnitude to a reference voltage and generates an error signal. A controller receives the error signal and generates a feedback flux correction signal. A limiter limits the feedback flux correction signal to a predetermined flux value and generates a limited feedback flux correction signal. A feedforward stator flux generating circuit generates a feedforward stator flux signal. A summing circuit sums the feedforward stator flux signal and the limited feedback flux correction signal to generate a final stator flux command.

Systems and methods are disclosed to improve torque linearity of an electric machine when operating in a field-weakening region. The systems and methods adjust the q-axis and the d-axis components of the stator current commands of the electric machine using a flux weakening control loop and a torque linearity control loop such that torque linearity is maintained when the machine operates in a field weakening region of operation.

A control system and method for an electric machine includes a first calculation module that receives a modified torque command and a calculated stator flux command and that generates first and second current commands and first and second voltage commands. A voltage magnitude calculation module generates a voltage magnitude based the first and second voltage commands. A reference voltage calculator module generates a reference voltage based on a DC link voltage, an angular stator velocity and the first and second current commands. A flux weakening module generates the calculated flux command based on the angular stator velocity, the reference voltage and the voltage magnitude.

The invention aims at providing a flux-weakening control system based on a permanent magnet synchronous motor and a control method therefor. The control system comprises a torque input module, a torque-current table look-up module, a vector control and decoupling module, a space vector pulse width modulation and inverter module and the permanent magnet synchronous motor which are sequentially connected with each other; in addition, the permanent magnet synchronous motor also feedbacks current signals into the vector control and decoupling module; the system also includes a flux-weakening control module which is used for receiving straight-axis reference voltage and quadrature-axis reference voltage that are output by the vector control and decoupling module, and outputting straight-axis demagnetized current component into a straight-axis current input circuit of the vector control and decoupling module. The system can effectively avoid the error of a motor controller caused by saturation of an inverter, so as to provide larger surplus capacity for the inverter and lead the inverter to be far away from a saturation area, thus realizing the flux-weakening control for the permanent magnet synchronous motor which is in high speed running, and greatly enlarging the range of speed regulation when the motor runs at high speed.

A closed-loop permanent magnet motor control method and system optimally partitions torque and flux-weakening currents to produce a desired torque without exceeding the capability of the DC source. A maximum limit for allowable torque current and a minimum threshold for the maximum torque current are determined, and the flux current is varied based at least in part on whether the maximum torque current limit is above or below the minimum threshold while operating in a flux-weakening region to compensate for the variability of the DC source voltage.

The invention discloses a frequency conversion driving control system and method based on an electrolysis-free capacitive inverter. The method comprises the following steps: detecting system input voltage current, bus voltage, motor phase current and rotating speed; carrying out Clark and Park conversion on three-phase current to obtain d and q axis current; carrying out error adjustment on a given rotating speed and an actual rotating speed; calculating q axis given current according to input voltage current, speed ring output and capacitance; calculating d axis given current according to voltage; calculating d and q axis error current and carrying out PI adjustment to obtain d and q axis actual voltage; limiting amplitude of actual voltage to obtain d and q axis calculated voltage; carrying out error adjustment on the actual voltage and the calculated voltage and taking the result as current ring feedback; carrying out Park inverse conversion on the d and q axis calculated voltage to obtain alpha and beta axis voltage; and modulating the inverter to control a motor. By the frequency conversion driving control system and method based on the electrolysis-free capacitive inverter, the motor can run at high speed in a flux weakening region, a network side high power factor is obtained, a control structure is simplified, and the reliability of the system is improved.

The present invention discloses a hybrid excitation motor. The comprises a stator and a rotor which are coaxially sleeved with each other; grooves are formed in the inner wall of the stator which sleeves the rotor or the rotor which sleeves the stator along the circumferential direction of the inner wall; grooves are formed in the outer surface of the rotor which is sleeved with the stator or the stator which is sleeved with the rotor; a direct-current excitation winding and an alternating-current armature winding are arranged in the stator grooves; each stator tooth is provided with protrusions which protrude out from the corresponding groove and are located at side surfaces of two sides of the groove; each protrusion is provided with a permanent magnet; the polarities of the two permanent magnets arranged at the two side surfaces of each stator tooth are the same; and the polarities of the permanent magnets of two adjacent teeth are opposite. When the motor of the invention operates at a low speed, current in the direct-current winding is positive, a total excitation magnetic field can be enhanced, and the overload capacity of the motor can be improved; and when the motor operates at a high speed, the current in the direct-current winding is negative, the total magnetic field can be weakened, and the flux weakening ability of the motor can be improved. The excitation motor of the invention has the advantages of low risk of irreversible demagnetization of the permanent magnets, small magnetic resistance of excitation magnetic fields, strong flux adjustment ability of the excitation windings and reliable and stable operation. According to the motor of the invention, slip rings and electric brushes are not needed, and therefore, problems such as the problem of sparks can be avoided.

The invention discloses a surface-mounted permanent magnet synchronous generator flux weakening control method, belonging to the PMSM control technical field. The method employs a current regulator to provide a direct-axis voltage when a motor rotating speed is higher than a base speed, thereby allowing a motor to move along the intersection between a voltage horicycle and a constant torque curve. The method allows a current locus to meet a torque curve, and meanwhile to meet voltage and current restriction; an output direct current voltage can rapidly recover stability after short fluctuation, and possesses sound dynamic response.

The invention discloses a novel electric vehicle drive system of integrating charger functions. A motor driver and a charger share a power electronic conversion circuit between energy storage units, and also share a motor winding inductor, so that an electric vehicle motor driver and an on-board charger are organically integrated into a whole; and the limitation of an electric vehicle on the space weight is avoided. Double three-phase motors meet the low-voltage and high-current design requirements of electric vehicle motors, have relatively small torque ripples, meet the comfortable and smooth operating requirements of the electric vehicle, have relatively good fault tolerant capability and meet the high-reliability operating requirements of the electric vehicle. Permanent magnets NdFeB and AlNiCo are organically compounded on a rotor, so that the novel electric vehicle drive system has the advantage that the magnetic field of the permanent magnet AlNiCo is easy to adjust; the characteristic of high energy density of the permanent magnet NdFeB is reserved; the large starting torque and flux-weakening speed expansion operating requirements of the electric vehicle are met; the double three-phase windings can provide a torque current and a magnetization current respectively; and the magnetization efficiency is relatively high.

The invention discloses an open winding permanent magnet synchronous motor series compensation vector control system which is composed of a direct-current power source, a main converter powered by the direct-current power source, an open winding permanent magnet synchronous motor, a compensation converter powered by a power supply capacitor, voltage sensors arranged at the two ends of the power supply capacitor, a current sensor arranged on the stator side of the open winding permanent magnet synchronous motor, a speed sensor arranged on a rotation shaft of the open winding permanent magnet synchronous motor, and a controller controlling the main converter and the compensation converter. According to the open winding permanent magnet synchronous motor series compensation vector control system, the compensation converter which is arranged at the stator tail end of the open winding permanent magnet synchronous motor and powered by the power supply capacitor is controlled to equivalently change stator winding impedance, so that the power factor of the main converter approaches to or reaches 1; through cooperation control over the main converter and the compensation converter, distribution of active power and reactive power is changed, performance of the motor is improved, a flux weakening control area of the permanent magnet synchronous motor is expanded, and the operation range is widened.

The invention relates to the technology of a motor, solves problems that rotating speed of the motor cannot be effectively increased due to the limit of output voltage of an inverter and the fact that a control voltage space vector of the motor surpasses a voltage limit circle or an operation current space vector of the motor surpasses a current limit circle when an existing permanent magnet synchronous motor works at a higher frequency, and provides a flux-weakening control method for a variable frequency controller of the permanent magnet synchronous motor. The technical scheme can be summarized as the follows: a system samples DC bus voltage Vedc, and control voltage (img file='DDA0000579050440000011.TIF' wi='168' he='64') and (img file='DDA0000579050440000012.TIF' wi='94' he='72') are respectively obtained via calculation, wherein (img file='DDA0000579050440000013.TIF' wi='64' he='72') is a d-axis voltage instruction value, (img file='DDA0000579050440000014.TIF' wi='56' he='77') is a q-axis voltage instruction value, and (img file='DDA0000579050440000015.TIF' wi='64' he='72') is working voltage of the motor. Then modulation degree (img file='DDA0000579050440000016.TIF' wi='96' he='64') is calculated, and a preset flux-weakening control depth coefficient (img file='DDA0000579050440000017.TIF' wi='88' he='64') is systematically acquired. Besides, the d-axis current instruction value and the q-axis current instruction value are adjusted in real time according to comparison of (img file='DDA0000579050440000018.TIF' wi='74' he='64') and (img file='DDA0000579050440000019.TIF' wi='64' he='64'). The beneficial effects of the flux-weakening control method are that control is stable and thus the method is suitable for the permanent magnet synchronous motor.

The invention relates to a reverse flux-weakening control type intelligent permanent magnet contactor with no position sensor, which mainly comprises a microprocessor, a rectifier and filter circuit, a control voltage detection module, switch control circuits, power switches, a coil voltage/current detection circuit, a switch power supply circuit, a standby power supply control module and the like. A first switch control circuit drives a power switch Q1 to be conducted with a power switch Q3 to realize the forward flux increasing of a coil; and a second switch control circuit drives a power switch Q2 to be conducted with a power switch Q4 to realize the reverse flux weakening of the coil. The voltage and current signals of the coil are detected in real time to estimate the real-time displacement signals of a movable iron core during the closing of the contactor to realize a detection method without using a position sensor. Through the feedback of the displacement signals of the movable iron core, by adopting the reverse flux-weakening control strategy, the detection-feedback-regulation-control intelligent closed loop operation is realized in the closing process of the contactor, the dynamic attractive force and the counter force of the permanent magnet contactor are in good matching, the primary bounce and the secondary bounce of the contact are reduced, and the electrical service life and mechanical service life of the contactor are improved.

The invention relates to a double-layer V-shaped built-in permanent magnet motor rotor for an electric automobile. Multiple groups of permanent magnet slots which are radially arranged in an inner layer and an outer layer are uniformly arranged on the iron core of the rotor at intervals along the circumferential direction; one or more V-shaped magnetized stripy magnetic steel is embedded in each permanent magnet slot. By virtue of the optimization of structures such as the angle of polar arc of inner-layer V-shaped magnetic steel, the included angle of outer-layer V-shaped magnetic steel, the width proportion of the inner-layer magnetic steel to the outer-layer V-shaped magnetic steel and the included angle of the outer-layer forcipated permanent magnet slot and the outer-layer magnetic steel, the air-gap flux density waveform is more approximate to the sinusoidal distribution, the harmonic component is reduced, the air-gap field waveform of the motor is improved, the fundamental wave frequency of spline torque fluctuation is improved, the spline fundamental wave and the ultraharmonics torque amplitude value are reduced, the torque fluctuation caused by splines is reduced, and the synthesis torque fluctuation of the motor is greatly reduced; and meanwhile, the reluctance torque is obviously increased, the salient pole rate and flux weakening speed expanding capability of the motor are improved, a constant-power speed range wider than that of a surface-mounted permanent magnet motor can be obtained, and the driving requirement of electric and hybrid automobiles can be met.

The invention discloses a hybrid excitation synchronous motor efficiency optimized control method. In the condition that motor output torque and rotation speed are satisfied, d shaft, q shaft and excitation winding current are controlled, thus iron consumption and copper consumption of a hybrid excitation synchronous motor are minimal, the optimized efficiency of the hybrid excitation synchronous motor is achieved, and the motor efficiency is raised. When the motor runs in a low speed area, according to the size of a load, and through the d shaft, q shaft and excitation winding current coordinated control, the sum of iron consumption and copper consumption is minimal. When the motor runs in a high speed area, by using d shaft current and excitation winding current common flux weakening, through the d shaft, q shaft and excitation winding current coordinated control, the iron consumption and copper consumption of the motor are minimal, and the optimal efficiency of a hybrid excitation synchronous motor is achieved. According to the hybrid excitation synchronous motor efficiency optimized control method, the motor loss is reduced, the efficiency of energy use is raised, and the energy saving effect is achieved.

The invention provides a method and device for driving a compressor for a variable-frequency air conditioner. The method comprises the steps that when the compressor operates at a low speed, a torque compensation instruction value used for restraining vibration is acquired according to an actual rotating speed value of a motor in the single-rotor compressor; when the compressor operates at an intermediate speed, a q-axis voltage compensation instruction value and a d-axis voltage compensation instruction value reduce current fluctuation and are acquired according to an actual q-axis current value and an actual d-axis current value; when the compressor operates at a high speed, the step-up ratio of a power-factor adjustment circuit is automatically adjusted according to the d-axis current instruction value output through flux-weakening control; the step-up ratio is used by the power-factor adjustment circuit for increasing an output direct-current bus voltage value. According to the method and device for driving the compressor for the variable-frequency air conditioner, vibration generated when the motor operates at the low speed and current fluctuation generated when the motor operates at the intermediate speed can be reduced, the direct-current voltage can be automatically adjusted when the motor operates at the high speed, meanwhile, an optimal voltage is provided for a system, and accordingly overall efficiency of the system is improved.

The invention discloses a field weakening control method of an enhancement type permanent magnet synchronous motor. The field weakening control method is the method that current closed-loop control is carried out on an inner ring, voltage closed-loop field weakening control is carried out on an outer ring in a combined mode, in particular, the virtual voltage is used as voltage feedback, and voltage error feedforward control is increased, wherein a torque current command iqref and a first exciting current command idref1 which are used for the current closed-loop control are respectively obtained according to a current amplitude command isref, and controlled accordingly to the maximum torque current ratio at the speed lower than the base speed; a second exciting current command idref2 is obtained according to stator voltage closed-loop control, and the field weakening control over the second exciting current command idref2 is achieved at the speed higher than the base speed; dynamic responses of the field weakening control is improved by designing feedforward orientation angle delta theta control according a voltage error value delta u, the field weakening control accuracy is greatly improved, and the flux weakening area current dynamic response speed is greatly increased; control at the speed lower than the base speed and control at the speed higher than the base speed are organically fused, and a large-output torque and high-speed operation integrated control method is formed. The field weakening control method can be widely used for driving control of electric cars.

The invention relates to a mineral processing technology for low grade hematite ore. The technologies of grading, ore grinding and magnetic separation are additionally set before floatation, ferromagnetic fine fraction magnetic ore concentrate can be recycled in advance in a magnetic separation mode, monomer separation is further carried out at the upper part of a coarse fraction sieve in flux-weakening ore concentrate and ferromagnetic ore concentrate through additional technologies of sieving and regrinding, the ore is returned, recycled and reselected, and tail escaping is realized in advance; by adopting the two modes, the flotation pulp handling capacity and floatation reagent consumption can be greatly reduced, the production cost is reduced, the ore concentrate quality is stabilized, and the proportion of flotation tailings in comprehensive tailings is reduced, so that the grade of comprehensive tailings is reduced to 10%-11% from 11%-14%.

A lead-angle control device according to the present invention includes: a space voltage vector controller calculating effective vector application times necessary for obtaining output voltage vectors of an inverter from stationary-coordinate-system instruction voltage components; a lead-angle compensator comparing the sum of the effective vector application times with a sampling period, and generating lead-angle compensation values; a speed controller generating an instruction current for compensating an error caused by a difference between an instruction speed and a current speed; an instruction current generator which generates a rotating-coordinate-system instruction current component by extracting a lead-angle component at a point where maximum torque-per-ampere can be obtained from the magnitude of the instruction current and performing a mathematical calculation on the magnitude of the instruction current and a lead-angle component; and an instruction voltage generator generating a stationary-coordinate-system instruction voltage component from the rotating-coordinate-system instruction current component.

The invention discloses an automobile electric power steering (EPS) system. The EPS system comprises a motor winding temperature on-line estimation module and a control parameter self-adjusting function module, wherein the motor winding temperature on-line estimation module is used for acquiring the current and the environmental temperature of a motor and estimating the winding temperature and the winding resistance of the motor; and the control parameter self-adjusting function module is used for real-timely adjusting the flux weakening parameter, the d-axis PI control parameter and the q-axis PI control parameter in the motor control algorithm according to the estimated winding temperature and winding resistance of the motor, power assisting moment directive value of the motor, current of the motor, rotational speed of the motor and angle of the motor. The automobile EPS system can achieve on-line estimation of the winding temperature of the motor, realizes self-adjustment of the control parameter, and reduces the control torque fluctuation of the motor under different use conditions.

A radial gap brushless electric machine (30) having a stator (31) and a rotor (32) and a primary air gap (34) also has at least one stationary excitation coil (35a, 36a) separated from the rotor (32) by a secondary air gap (37a, 37b) so as to induce a secondary flux in the rotor (32) which controls a resultant flux in the main air gap (34). Permanent magnetic (PM) material (38) is disposed in spaces between the rotor poles (A-H) to inhibit the secondary flux from leaking from said pole portions (A-H) prior to reaching the main air gap (34). By selecting the direction of current in the stationary excitation coil (35a, 36a) both flux enhancement and flux weakening are provided for the main air gap (34). A method of non-diffused flux enhancement and flux weakening for the machine is also disclosed.