202 results about "Electromagnetic torque" patented technology

The invention relates to a non-inductive FOC open-loop to closed-loop switching method and device for an electronic water pump and a vehicle. The method comprises the steps that a rotor is pre-positioned; starting an open loop I-F; switching condition judgment; estimating the rotor speed based on an observer, calculating a normalization factor, and obtaining a mixed scale factor through cubic polynomial operation; acquiring an open-loop current instruction of a q axis and a closed-loop current instruction output by a closed-loop speed PI regulator; performing weighted synthesis on the two paths of current instructions according to the mixing scale factor to obtain a temporary target current instruction, and applying a change rate limit to obtain a final current instruction output in the current period; the original angle error of the observer estimation angle and the open-loop slope angle is calculated and normalized, the allowable adjustment step length and direction of the round are dynamically determined, and the angle correction amount of the round is generated and superposed to the open-loop slope angle to update the rotor angle reference value; and closed-loop switching is completed. According to the invention, the problems of electromagnetic torque impact and rotating speed fluctuation caused by instruction step change are solved.

The invention discloses a motor multi-parameter identification method based on sampling noise excitation and bias compensation, and the method comprises the steps: firstly obtaining the voltage and sampling current of a motor, and enabling the sampling current to comprise sampling noise; then constructing an information evaluation index, and adjusting a proportional parameter of a current controller to improve the identification information amount; then, shaft voltage feed-forward compensation is constructed to suppress electromagnetic torque pulsation; recursion is carried out by adopting a least square method based on the discrete linear parameterization model to obtain a parameter initial value and a covariance matrix; secondly, estimating offset-containing parameters on line, and calculating a sampling noise variance by using an estimated residual error; and finally, obtaining unbiased parameter estimation according to bias compensation iteration updating so as to output online estimation values of stator resistance, direct-axis inductance Ld, quadrature-axis inductance Lq and permanent magnet flux linkage.

The invention discloses a permanent magnet synchronous motor wide speed range model prediction control method and system based on a mean value reduction optimization algorithm, and belongs to the technical field of motor control. According to the method, a discrete mathematical model of the permanent magnet synchronous motor is established under a d-q rotating coordinate system, a q-axis current reference value is generated by an outer ring through a speed PI regulator, and a d-axis current reference value is calculated in combination with a maximum torque per ampere (MTPA) principle and a weak magnetic region voltage constraint; finite control set model prediction control is adopted in an inner ring, enumeration prediction is conducted on candidate voltage vectors of the three-phase voltage source type inverter, a cost function containing a d-axis current error, a q-axis current error and an electromagnetic torque error is constructed, an optimal voltage vector is selected, and a three-phase PWM signal is generated through space vector pulse width modulation to drive a motor. The system is provided with a mean value reduction optimization module, joint optimization is carried out on speed outer ring PI parameters and cost function weight coefficients in the off-line stage, the parameters are stored in a lookup table, and automatic setting of control parameters is achieved. The permanent magnet synchronous motor can improve the dynamic response performance of the rotating speed and the current in the base speed area and the weak magnetic area, reduce the total harmonic distortion of the stator current, improve the voltage utilization rate and the overall operation efficiency of the permanent magnet synchronous motor, and is suitable for occasions such as electric vehicle driving and high-performance servo systems.

The invention belongs to the technical field of ship electric propulsion, and particularly relates to a ship electric propulsion dual-mode control system with a multi-redundancy architecture, and the system comprises the steps: firstly, accurately obtaining the actual rotating speed and electromagnetic torque of a motor through a sensor group with redundancy configuration and two-out-of-three voting logic; secondly, calculating load disturbance intensity by utilizing time domain difference analysis, and calculating the deviation between the actual torque and the theoretical hydrodynamic torque in combination with a propeller characteristic coefficient, so as to generate a load anomaly index; generating a dynamic flexible factor with a damping characteristic based on the index by using a Sigmoid function and low-pass filtering logic; and finally, carrying out weighted fusion on output instructions of the rotating speed mode and the torque mode according to the factor. According to the method, normal acceleration and sea wave disturbance can be accurately distinguished, smooth seamless switching between a static water speed stabilization mode and a severe sea condition machine protection mode is achieved, and control oscillation and mechanical damage are effectively avoided.

This invention discloses a modeling method for a proxy model of a permanent magnet synchronous motor under eccentric conditions. First, a mathematical model of the eccentric motor proxy model is established, including the permanent magnet flux linkage and no-load back EMF, flux linkage model, voltage model, electromagnetic torque, and torque balance equations. Then, no-load back EMF, permanent magnet flux linkage, and dq-axis inductance data are obtained through finite element simulation, and harmonic fitting is performed on the permanent magnet flux linkage. Next, a multi-dimensional parameterized lookup table covering eccentricity type and degree, speed, torque, and rotor position angle is constructed. The lookup table and interpolation algorithm are integrated into the simulation platform to form a high-fidelity proxy model module that can be called in real time. Finally, the model accuracy is verified by comparison with finite element simulation and experimental data. This invention achieves high-precision and rapid mapping of the electromagnetic characteristics of eccentric motors, balancing modeling accuracy, efficiency, and versatility.

This invention relates to a cascaded fuzzy feedforward direct-drive speed control method and system based on LC filtering. The method includes: obtaining a speed error and error rate of change from a reference speed and a real-time measured speed; inputting the speed error and error rate of change into a Mamdani fuzzy inference engine to output a power setpoint coefficient; inputting the power setpoint coefficient and a normalized measured speed signal into a two-dimensional torque-current reference lookup table, performing bilinear interpolation calculation, and outputting an electromagnetic torque command; converting the electromagnetic torque command into a quadrature-axis command current, generating a PWM signal through current closed-loop regulation and SVPWM modulation, and driving a two-level voltage-type inverter; the output of the two-level voltage-type inverter drives a low-voltage permanent magnet synchronous motor through an LC sine wave filter with an RC damping branch. Compared with the prior art, this invention has advantages such as low computational load, improved dynamic response, and enhanced disturbance rejection.

This invention discloses a high-precision intelligent forming control method, device, equipment, and storage medium for all-electric metallurgical equipment, relating to the field of intelligent control technology for metallurgical forming equipment. The method includes: performing stage self-identification of the metallurgical forming process based on the operating signal of the direct-drive motor to obtain stage identification results; switching the corresponding control strategy based on the stage identification results; controlling the direct-drive motor according to the switched control strategy, and introducing a virtual response mechanism to adjust the dynamic characteristics of the control system during stage switching to obtain adjusted control parameters; determining the forming load based on the mapping relationship between the electromagnetic torque of the direct-drive motor and the forming load, generating control commands based on the forming load, and controlling the output of the direct-drive motor based on the control commands and adjusted control parameters to achieve closed-loop control of the forming force. This achieves high-precision force control and multi-axis synchronous coordination throughout the entire metallurgical forming process without relying on external force sensors.

The invention relates to the technical field of permanent magnet direct-drive fans, and discloses a permanent magnet direct-drive fan modeling method considering a mechanical system and related equipment. A mechanical system transfer function and a complete electrical system transfer function including a permanent magnet synchronous generator stator loop, a machine side converter, a grid side inverter and the like are established; a permanent magnet direct drive fan small signal admittance model is constructed, the defect that a previous model neglects a mechanical system or part of an electrical system is made up, the model can accurately reflect the influence of mechanical shafting dynamic characteristics on harmonic transmission of an electrical subsystem through electromagnetic torque disturbance, and the accuracy of the fan broadband admittance model is improved. A reliable basis is provided for broadband oscillation analysis of an offshore wind power plant grid-connected system, the new energy delivery capacity is improved, and safe and stable operation of a novel electric power system is guaranteed.

The embodiment of the invention provides a motor torque monitoring method and device, equipment and a medium, and relates to the technical field of vehicles. The method comprises the following steps: in a first processing unit in a motor controller, obtaining a functional layer estimation torque through an electromagnetic torque algorithm based on a three-phase current signal; in a second processing unit in the motor controller, a safety layer estimation torque is obtained through a power torque algorithm based on the bus voltage signal and the bus current signal, and the first processing unit and the second processing unit are physically isolated; and determining the state of the torque based on the comparison of the estimated torque of the motor function layer and the estimated torque of the safety layer, and executing a corresponding system protection strategy based on the torque state. According to the method, the problem that the vehicle safety is affected due to the fact that torque monitoring is prone to misalignment when equipment abnormity or working condition abnormity occurs in motor torque monitoring in the related technology is effectively solved.

This invention relates to the field of servo control algorithm design for aircraft airborne pods, providing a method and system for calculating external disturbance reactance based on servo motor current feedback. The method acquires three-phase currents Ia, Ib, and Ic, and electrical angle θ, and obtains two-phase currents Id and Iq through Clarke and Park transforms, defining Iq as the external disturbance reactance estimate IQ. A setpoint r(t) and deviation e(t) = r(t) - IQ are established, and the PID controller output u(t) is calculated. u(t) is used as the q-axis control reference and written to the driver. In voltage control mode, it is mapped to Vq and Vd for inverse transformation and PWM modulation; in current control mode, it is mapped to the q-axis current reference Iqref and converted into corresponding voltage commands by the driver's current loop, driving the servo motor to generate electromagnetic torque to cancel out disturbance reactance. This invention eliminates the need for complex motor models and high-end inertial sensors, has low computational complexity, and can quickly and accurately estimate disturbances, ensuring stable control performance of the aircraft pod in complex flight environments.

The invention aims to solve the technical problems that a hemispherical resonator gyroscope in the prior art is difficult to adapt to a high-dynamic environment, cannot realize full-circumferential high-precision measurement and is insufficient in anti-interference capability, and provides a three-axis inertially stabilized platform system based on a full-angle mode hemispherical resonator gyroscope and a control method thereof. The system adopts a three-axis two-frame structure, and the method adopts a Y-axis stable control loop and an XZ double-axis stable control loop to realize three-axis stable control of the inertially stabilized platform; a stable control loop adopts a double-loop control mode of'a rate inner loop + a position outer loop ', angle change information sensed by a corresponding hemispherical resonator gyroscope is calculated by a correction network to generate a driving signal, a corresponding torque motor is driven to generate an electromagnetic torque for counteracting an interference torque, and the method can isolate the disturbance caused by the movement of a carrier; a six-position calibration method of a mixed mode is invented based on the stable control loop, and the method is characterized in that the gyroscope is stabilized at the optimal standing wave angle position during stable acquisition, so that the optimal measurement precision of the gyroscope is exerted.

The invention discloses a motor control method, a washing machine, a storage medium and a computer program product, relates to the technical field of washing machine control, is applied to the washing machine, and the washing machine at least comprises a washing machine roller and a motor. Obtaining the eccentricity amplitude and eccentric phase information of an eccentric load in the drum of the washing machine based on the motor rotating speed signal; and generating a target torque instruction based on the eccentricity amplitude and the eccentric phase information, and controlling a motor of the washing machine to generate an electromagnetic torque confronting the eccentric load based on the target torque instruction. The technical problem that an existing roller washing machine is low in operation efficiency under the dewatering working condition is solved.

This invention discloses a maximum power point tracking (MPPT) control system and method for a pump-driven turbine power generation system. It calculates output power by acquiring DC-side voltage and current, and also acquires rotational speed. Within each MPPT cycle, the operating state is identified by the power-speed slope feature G: when operating conditions change rapidly, the weight of the disturbance observation branch is increased; when approaching the maximum power point, the weight of the adaptive scale fuzzy logic control branch is enhanced. The two branches achieve branch current fusion according to the weights constructed using (|G|), outputting the q-axis stator current increment. A dq current closed loop is used to output a PWM drive signal to control the machine-side converter, adjusting the electromagnetic torque of the permanent magnet synchronous generator, thereby achieving efficient MPPT under time-varying head / flow conditions. This invention relies only on measurable power and speed signals, requiring no precise hydraulic model or data-intensive training, resulting in low computational load, ease of embedded implementation, improved energy recovery efficiency, and suppression of power fluctuations and torque pulsations.

The application discloses a kind of model construction method and device of wind power generation system, the method wind power generation system, at least including wind turbine and permanent magnet synchronous generator, the method includes: the mechanical characteristics of wind turbine is modeled according to momentum theory data to obtain wind turbine model;Maximum power output point of wind turbine is tracked by analyzing wind turbine model and using hill climbing search method;Ideal conditions met by permanent magnet synchronous generator are obtained;Under ideal conditions, three-phase voltage equation under natural coordinate system, flux linkage equation under natural coordinate system, electromagnetic torque equation of motor, mechanical motion equation of permanent magnet synchronous generator are established to obtain permanent magnet synchronous motor model.The application can reduce the loss generated by mechanical rotation in power generation process, so that the power generation efficiency of system is higher.

The application discloses a permanent magnet synchronous motor MTPA control method based on double virtual direct current signal injection, and particularly relates to a motor control method, in particular to a control method of a permanent magnet synchronous motor under a high-speed low-carrier ratio working condition. β A pair of virtual direct current signals with the same amplitude and opposite polarity are injected into a current vector angle, an electromagnetic torque containing the pair of signals is Taylor expanded, subtraction operation is performed on the two to obtain an approximate value of a first-order partial derivative of the torque to the current vector angle, the approximate value is input into an integral regulator, and when the input is controlled to be 0, an optimal current vector angle can be obtained β mtpa , and MTPA control is realized. In order to simultaneously improve dynamic performance and steady-state performance of the control, the method selects virtual direct current signals with different amplitudes to be injected under different working conditions, so that the motor can quickly approach an optimal current vector angle working state, and fluctuation of the current vector angle under a stable state is reduced.

The application belongs to the technical field of electric machines, and discloses a magnetic suspension fan variable frequency driving device and a harmonic suppression method; the method comprises the following steps: judging a transient operation process and activating a phase compensation mechanism by monitoring the state of the electric machine in real time, extracting harmonic components in real time and updating a weight vector to obtain harmonic currents of different orders; meanwhile, a phase compensation amount is dynamically obtained based on a pre-built control loop phase lag atlas, an anti-phase harmonic voltage is calculated in combination with the harmonic currents and the compensation phase, and the variable frequency device is injected through a space vector pulse width modulation method to realize accurate harmonic cancellation; torque safety monitoring is also independently operated in parallel in the whole process, the electromagnetic torque and its change rate are detected in real time to perform safety logic determination, and a protection action is triggered when the limit is exceeded; the application can realize accurate cancellation of anti-phase harmonics and actual interference harmonics in the transient process, significantly reduce the instantaneous impact of the electromagnetic torque, and effectively improve the operation stability and reliability of the magnetic suspension fan variable frequency driving system under transient working conditions.

The application discloses a permanent magnet synchronous motor rotating speed control method, related devices and a permanent magnet synchronous motor, relates to the motor control field, and utilizes a dynamic estimation model of fusion of rotor position information, rotating speed information and total load disturbance of the permanent magnet synchronous motor to process the rotor position of the permanent magnet synchronous motor, namely, the rotating speed estimation value of the permanent magnet synchronous motor and the estimation value of the total load disturbance can be obtained. On the basis, the electromagnetic torque value of the permanent magnet synchronous motor is obtained by inputting the rotating speed request value at the current moment, the rotating speed estimation value and the estimation value of the total load disturbance obtained above into the rotating speed loop control model. The rotating speed estimation value and the total load disturbance estimation value of the permanent magnet synchronous motor are more accurate and reliable by only utilizing the rotor position of the permanent magnet synchronous motor, and then the rotating speed estimation value and the total load disturbance estimation value are processed, namely, the electromagnetic torque can be obtained. While reducing the artificial workload, precise control is realized.

This invention discloses a method and system for evaluating the heat dissipation performance of a motor based on temperature rise curve fitting, relating to the field of motor thermal health management technology. The method includes: monitoring the casing temperature and ambient temperature and calculating the temperature rise sequence; collecting current, speed, and cooling characteristic parameters to determine the evaluation period; generating a detection sequence within the evaluation period and injecting current under electromagnetic torque disturbance constraints to obtain a detection thermal input sequence; simultaneously demodulating the detection thermal input sequence and the temperature rise sequence to obtain thermal frequency response estimation and coherence, thereby selecting effective frequency bands and reconstructing a standardized temperature rise curve; fitting the standardized temperature rise curve to obtain thermal impedance parameters and calculating cooling sensitivity under two cooling levels, decomposing convection link parameters and heat conduction link parameters; calculating the heat dissipation deviation and making multi-level judgments, outputting a pre-diagnostic level. By using constrained injection, identifiable thermal excitation is achieved, improving the observability of the evaluation without significantly affecting the output.

This invention discloses a speed and torque control method and system for a permanent magnet synchronous motor. The system includes a voltage frequency domain information calculation module, a third harmonic generation module, a current generation module, a motor transfer function module, and a load torque adaptive control module. It calculates and outputs the fundamental voltage amplitude and frequency based on the motor's mathematical model; outputs the third harmonic amplitude through adjustable coefficients; outputs the dq-axis current, electromagnetic torque, and motor speed using the SHEPWM mathematical model; adjusts the load torque by regulating parameters, outputting an adaptive load torque based on speed feedback; and adjusts the motor speed output by the motor transfer function module according to the adaptive load torque. This invention significantly improves the maximum output torque of the permanent magnet synchronous motor; achieves stable speed control without complex parameter tuning, reducing the difficulty of implementing the control system; and effectively suppresses speed fluctuations introduced by the third harmonic, achieving synergistic optimization between torque enhancement and speed stability.

The invention relates to the field of energy storage, in particular to a virtual torque feedforward-based double-fed gravity energy storage system cooperative control method and system, and the method comprises the steps: obtaining a basic electromagnetic torque reference value based on a proportional integral controller according to the real-time rotor speed of a DFIG; obtaining an electromagnetic torque standard value by using the basic electromagnetic torque reference value and a corresponding mechanical torque ideal value; reactive power feed-forward calculation is performed by using the electromagnetic torque standard value to obtain a cooperative control result of the double-fed gravity energy storage system, predictive compensation of instructions is realized by optimizing a control algorithm, the burden of a feedback controller is significantly reduced, and the dependence of the system on high feedback gain is reduced, so that overshoot or oscillation is effectively weakened, and the cooperative control effect of the double-fed gravity energy storage system is improved. The dynamic response capability of the system is optimized, rotating speed fluctuation caused by heavy object switching can be effectively inhibited, and meanwhile reactive power fed into a power grid is compensated to be stabilized at a designed reference value instruction.

The invention relates to the technical field of wind turbine generator control, in particular to a wind turbine generator self-adaptive control method based on maximum power point tracking. The method comprises the steps of determining a pneumatic torque observation value of a wind wheel according to a filtering rotating speed and an electromagnetic torque; the torque overload rate is determined according to the difference between the observed value of the pneumatic torque and the theoretical optimal torque; determining a kinetic energy sensitivity coefficient according to the filtering rotation speed and the rated rotation speed; generating a comprehensive unloading index for triggering torque adjustment according to the torque overload rate and the kinetic energy sensitivity coefficient; according to the comprehensive unloading index, unloading processing and safe amplitude limiting are carried out on the theoretical optimal torque, and a generator torque set value is obtained; generating a torque adjusting instruction of the wind turbine generator according to the torque set value of the generator; wherein in the adjusting process, the torque adjusting instruction indicates that the maximum change rate allowed by torque decrease is larger than the maximum change rate allowed by torque increase, and therefore the adaptive capacity of the unit to the complex wind speed working condition is improved.

- Method and system for estimating the electromagnetic torque of a synchronous machine. - The method comprises a measurement step (E1) of the rotor voltage and the stator and rotor currents, a determination step (E2) of a flux-current model of the machine in which the dynamic magnetic uncertainties have a non-zero constant second derivative, a determination step (E3) of a polytopic linear variable-parameter system from the flux-current model, a determination step (E4) of a state observer for the linear variable-parameter system, an estimation step (E5) of the state variables by the state observer, and an estimation step (E6) of the electromagnetic torque from the estimated state variables. Figure for the abstract: Fig. 1

The invention discloses a new energy automobile electric driving method and an electric driving device structure. A multi-phase alternating current output end of an MCU motor control unit is connected to a circuit structure formed by connecting stator windings of EM driving motors in series in a split-phase mode, and a common-mode rotating magnetic field is generated; all the rotors generate electromagnetic torque output and mutual coupling effects through the split-phase series circuit structure and the common-mode rotating magnetic field, and native self-coupling and driving are achieved. The problems of poor adaptive capacity, complex software and hardware structure, poor reliability, high cost and the like of a scheme for forcibly controlling the rotating speed of each EM driving motor in the distributed electric driving system by depending on an external software algorithm in the prior art are solved.

The application provides an electromagnetic rotary energy harvesting device and method based on a double-layer Halbach array, which comprises coaxially arranged rotor and stator assemblies, the rotor assembly is fixed to the shaft end of a rotating machine and rotates synchronously with the shaft end of the rotating machine, the coils of the annular coil assembly are symmetrically distributed according to a three-phase winding and are connected in Y shape, the magnet housing of the stator assembly is provided with magnets and counterweights, the magnets comprise inner and outer ring magnets, the double-layer concentric cylindrical Halbach array is formed by the inner and outer ring magnets, the inner and outer ring magnets are arranged in the coil assembly and are magnetized in a radially staggered manner, the counterweights balance the electromagnetic torque by gravity torque, and the relative rotation of the rotor and stator assemblies is ensured. The double-layer Halbach array is used to concentrate the magnetism of the magnets to the middle annular air gap area, the kinetic energy-electric energy conversion is realized by combining electromagnetic induction, the magnetic stabilization and voltage stabilization are realized by adjusting the arrangement angle of the magnets, and the relative movement of the magnets and the coils is realized without additional fixation of the magnets of the stator assembly by relying on the single pendulum structure of the counterweights.

The invention discloses a liquid cooling centrifugal pump device of an integrated printed permanent magnet synchronous motor, and belongs to the technical field of centrifugal pumps. The liquid cooling centrifugal pump device of the integrated printed permanent magnet synchronous motor comprises a pump base and an upper cover, the pump base and the upper cover are sealed to form a storage cavity, an inlet flow channel is formed in the upper cover, an outlet flow channel is formed in one side of the pump base, and the inlet flow channel, the storage cavity and the outlet flow channel form a complete fluid flow channel; an impeller, a motor rotor and a motor stator are coaxially arranged in the storage cavity from top to bottom, back iron is fixedly connected to the bottom of the impeller, a fixing frame is fixedly connected to the bottom of the back iron, a permanent magnet is embedded in the fixing frame, a connecting shaft is vertically and rotatably connected in the storage cavity, and the impeller, the back iron and the fixing frame fixedly sleeve the connecting shaft; when an external controller applies three-phase alternating current, the permanent magnet is directly driven to rotate, electromagnetic torque does not need a mechanical transmission chain, and the problems of large size, low efficiency and poor reliability in the prior art are solved.

The invention discloses a two-phase open-circuit fault-tolerant control strategy under a minimum copper loss constraint of a dual three-phase SynRM, and the strategy comprises the steps: respectively deducing the synthetic magnetomotive force of a residual winding, constructing a quadratic optimization model with linear constraint, and optimizing the current amplitude for the open-circuit faults of orthogonal and non-orthogonal two-phase windings, so as to enable the direction of the synthetic magnetomotive force to meet the requirements; establishing a static coordinate and a rotation transformation matrix after the fault, and performing orthogonality correction; a virtual voltage vector is synthesized based on weighted superposition of the original vectors, and a corresponding virtual voltage vector set is constructed for the two faults; and on the basis of the corrected transformation matrix and the virtual voltage vector set, constructing a voltage vector distribution diagram and a switch table in a fault state, dividing an alpha-beta subspace into 16 sectors, and selecting an optimal virtual voltage vector to realize accurate control of the flux linkage amplitude and the electromagnetic torque. Stable operation of the motor can be maintained, and the fault-tolerant capability and the operation reliability of the system are remarkably improved.

This invention discloses a method and apparatus for three-phase short-circuit transient modeling of a permanent magnet synchronous motor. The method includes: acquiring the parameter values ​​of the motor body, the initial values ​​of the synchronous motor during a short circuit, and the constraints; determining the dq-axis current value based on the motor body parameters, the initial values ​​during the short circuit, and the constraints; and establishing a three-phase short-circuit transient model based on the dq-axis current value. This invention establishes motor equations and electromagnetic torque equations based on the motor body parameters, and derives an analytical transient model of active short circuit by determining the initial conditions during a short circuit. This allows for the acquisition of the dq-axis current and torque at any given time, providing a precise data foundation for realizing active short circuits. Furthermore, the analytical model helps the controller set reasonable compensation and achieve precise adjustment.

The invention discloses a double-parallel brushless direct current motor drive axle system and a synchronous control method. The synchronous control method comprises the following steps: calculating electromagnetic torques of a front motor and a rear motor; a main motor is selected, a main motor rotor speed signal and an accelerator pedal opening signal are transmitted to a speed PI control unit, a main motor current signal is transmitted to a current PI control unit, and the system stability is determined according to the electromagnetic torque; the reference torque of the motor is calculated and sent to the current PI control unit; according to the current of the main motor and the reference torque of the motor, reference q-axis voltage is calculated and sent to an inverter, and three-phase alternating current is generated to complete driving of the front motor and the rear motor; and the front motor and the rear motor output corresponding torques and transmit the torques to the front drive axle, the rear drive axle and the wheels to complete vehicle driving. The stability of the vehicle under the uneven road can be effectively improved, and the weight, the size and the cost of the driving system are reduced.

An apparatus for estimating the electromagnetic torque of a three-phase synchronous motor including permanent magnets, comprising: a first flux estimator (10) including two electromotive force integrators (103) for estimating corresponding components of the flux in a fixed two-phase coordinate system associated with the stator; an estimator (20) for estimating the torque from the corresponding estimated flux components; a second flux estimator (40) using current expressed in a rotating two-phase reference system associated with the rotor, the second flux estimator having an observer for determining variables characterizing magnetic uncertainties of the motor in order to correct the flux estimation of the second estimator; and a detector (30) for generating a signal (RES) for resetting the initial flux conditions of the two integrators based on the flux estimation performed by the second estimator when the difference between the estimated torque and the setpoint torque is higher than a predefined threshold.